Fiat Kobelco Ex255t Service Manual.pdf 4w4q5h

EX255-EX285 Tier2 TECHNICAL MANUAL - OPERATIONAL PRINCIPLE TECHNICAL MANUAL- TROUBLESHOOTING WORKSHOP MANUAL EXCAVATOR WORKSHOP MANUAL ENGINE

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EXCAVATOR TECHNICAL MANUAL OPERATIONAL PRINCIPLE (Tier 2)

All information, illustrations and specifications in this manual are based on the latest product information available at the time of publication. The right is reserved to make changes at any time without notice.

FIAT KOBELCO CONSTRUCTION MACHINERY S.p.A. FORM No. 604.13.191 - Edition - July 2002

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ENGINEERING

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COPYRIGHT BY FIAT KOBELCO CONSTRUCTION MACHINERY S.p.A. Documentation Centre Strada di Settimo, 323 - S. MAURO T.SE ( TO ) ITALY

Reproduction of text or illustrations, in whole or in part, is strictly prohibited

Print No. 604.13.191 - VII - 2002 Printed by Satiz - Turin (Italy) Coordinamento Editoriale Satiz - Torino

EX255-EX285

IN-1

INTRODUCTION TO THE READER • This manual is written for an experienced technician to provide technical information needed to maintain and repair this machine. - Be sure to thoroughly read this manual for correct information concerning the service procedures.

- If you have any questions or comments, or if you found any errors regarding the contents of this manual, please : FIAT KOBELCO CONSTRUCTION MACHINERY S.p.A. Strada Settimo, 323 San Mauro Torinese (TO) 10099 ITALY PRODUCT Fax. ++39 011 6877357

ADDITIONAL REFERENCES • Please refer to the materials listed below in addition to this service manual: - Operation and Maintenance Instruction Manual - Parts Catalog

SERVICE MANUAL COMPOSITION • The complete service manual consists of three books: - Technical Manual - Operational Principle - Technical Manual - Troubleshooting - Workshop Manual

- The Workshop Manual includes information needed for maintenance and repair of the machine, tools and devices needed for maintenance and repair, maintenance standards, removal/installation and assembly/disassembly procedures.

- The Technical Manual-Operational Principle includes the technical information concerning the operation of main devices and systems.

• The Service Manual for EX255 and EX285 Excavators consists of the following book/print numbers:

- The Technical Manual -Troubleshooting includes the technical information needed for operational performance tests, and troubleshooting procedures.

BOOK

PRINT NUMBER

- Technical Manual - Operational Principle

604.13.191

- Technical Manual - Troubleshooting

604.13.196

- Workshop Manual

604.13.201

IN-2

EX255-EX285

INTRODUCTION PAGE NUMBER • Each page has a number, located on the external upper corner of the page. Each page number contains the following information: Example: T 1-2-3 Consecutive page number for each group Group number (if exist) Section number T : Technical Manual W : Workshop Manual

SYMBOLS In this manual, the following safety alert symbol and signal words are used to alert the reader to the potential for personal injury or machine damage.

This is the safety alert symbol. When you see this symbol, be alert to the potential for personal injury. Never fail to follow the safety instructions prescribed along with the safety alert symbol. The safety alert symbol is also used to draw attentio in to component/part weights. To avoid injury and damage, be sure to use appropriate lifting techniques and equipment when lifting heavy parts.

UNITS USED SI Units (International System of Units) are used in this manual. MKSA system units and English units are also indicated in parentheses just behinds SI units. Example: 24.5 MPa (250 kgf/cm2, 3560 psi) A table for conversion from SI units to other system units is shown below for reference purposes.

Quantity

To convert from (SI)

Into (Others)

Multiply by

Quantity


Into (Others)

Multiply by

Lenght

mm

in

0.03937

Pressure

MPa

kgf/cm2

10.197

mm

ft

0.003281

MPa

psi

145.0

L

US gal

0.2642

kW

CV-PS

1.360

L

US qt

1.057

kW

HP

1.341

m3

yd

1.308

Temperature

°C

°F

°C x 1.8 + 32

Velocity

Volume Mass

kg

lb

2.205

Force

N

kgf

0.10197

N

lbf

0.2248

N.m

kgf.m

0.10197

N.m

lbf.ft

0.7375

Torque

Power

Flow rate

km/h

mph

0.6214

min-1

rpm

1.0

L/min

US gpm

0.2642

mL/rev

Cc/rev

1.0

TECHNICAL MANUAL

EX255-EX285

OPERATIONAL PRINCIPLE

SECTION AND GROUP CONTENTS

Section 1 -

GENERAL

Group 1 Group 2

Specifications Component Layout

Section 2 -

SYSTEM

Group 1 Group 2 Group 3

Control System Hydraulic System Electrical System

Section 3 -

COMPONENT OPERATION

Group Group Group Group Group Group Group

Pump Device Swing Device Control Valve Pilot Valve Travel Device Other components (Upperstructure) Other components (Undercarriage)

1 2 3 4 5 6 7

SECTION 1

EX255-EX285

GENERAL

CONTENTS Group 1 -

Specification

EX255 Excavator Dimensions ............. T1-1-1 EX285 Excavator Dimensions ............. T1-1-3 EX255 Excavator performance ............ T1-1-5 - Engine Data ....................................... T1-1-5 - Engine Accessory .............................. T1-1-6 - Hydraulic Devices .............................. T1-1-6 - Electrical Equipment .......................... T1-1-7 EX285 Excavator performance ............ T1-1-8 - Engine Data ....................................... T1-1-8 - Engine Accessory .............................. T1-1-9 - Hydraulic Devices .............................. T1-1-9 - Electrical Equipment .......................... T1-1-10

Group 2 -

Component layout

Main Components ................................ T1-2-1 Electrical System (overall system) ................................... T1-2-2 Electrical System (cab) ........................ T1-2-3 Electrical System (monitor and switch s) ................. T1-2-5 Electrical System (batteries compartment) ....................... T1-2-6 Electrical System (fuses) ..................... T1-2-7 Pump and related parts ........................ T1-2-8 Other Components ............................... T1-2-9

EX255-EX285 EX255

T1-1-1

SPECIFICATIONS EX255 EXCAVATOR DIMENSIONS (Monoblock Version) E G

D/D'

H

F C

I

L M

A B

N

OM0253

VERSIONS

B

C

D

D’ (*)

3 463

4 260

1 090

2 950

2 937

10 170 1) 3 206 2 815

EX255 EL (mm) 3 845

4 642

1 090

2 950

2 937

10 170

EX255 LC

4 642

1 090

2 950

2 937

EX255

(mm)

3 845

E

F (**)

A

G

H

I

L

2 940

960

460

2 815

2 940

960

460

10 170 4) 3 204 2 815

2 940

960

460

2) 3 237 3) 2 991

(mm)

(*) Rear swing radius

(**) Arm: 1) 2158 mm, 2) 2480 mm, 3) 2950 mm, 4) 3600 mm

EX255

EX255 EL

EX255 LC

M-Track shoe width

(mm)

600

700

800

900

600

700

800

900

600

700

800

900

N-Maximum width

(mm)

2 990

3 090

3 190

3 290

2 990

3 090

3 190

3 290

3 190

3 290

3 390

3 490

24 500 24 750 25 000 25 250 25 000 25 300 25 600 25 900 25 100 25 400 25 700

26 000

Working weight Spec. Ground Press.

(kg) (bar)

0.54

0.47

0.41

0.36

0.51

0.44

0.39

0.35

0.51

0.44

0.39

0.35

DIGGING DATA

6 000 mm Boom

OM0254

Arm

mm

2 158

2 480 2 950

3 600

A

mm

9 650

9 865 10 277 10 903

A’

mm

9 462

9 681 10 100 10 737

B

mm

6 172

6 485 6 948

7 597

B’

mm

5 940

6 253 6 737

7 429

C

mm

9 551

9 460 9 635

9 988

D

mm

6 770

6 759 6 946

7 279

E

mm

3 789

3 952 3 865

3 892

T1-1-2

EX255-EX285 EX255

SPECIFICATIONS EX255 EXCAVATOR DIMENSIONS (Triple Articulation Version) G

E D/D'

F

H C

I

L M

A B

N OM0255

VERSIONS

B

C

D

D’ (*)

3 463

4 260

1 090

2 950

2 937

10 145 1) 3 083 2 815

EX255 EL (mm) 3 845

4 642

1 090

2 950

2 937

10 145

EX255 LC

4 642

1 090

2 950

2 937

EX255

(mm)

3 845

E

F (**)

A

G

H

I

L

2 940

960

460

2 815

2 940

960

460

10 145 4) 3 290 2 815

2 940

960

460

2) 3 137 3) 3 019

(mm)


(**) Arm: 1) 2 158 mm, 2) 2 480 mm, 3) 2 950 mm, 4) 3 600 mm

EX255 M-Track shoe width N-Maximum width Working weight Spec. Ground Press.

(mm) (mm) (kg) (bar)

EX255 EL

EX255 LC

600

700

800

900

600

700

800

900

600

700

800

900

2 990

3 090

3 190

3 290

2 990

3 090

3 190

3 290

3 190

3 290

3 390

3 490

25 100 25 350 25 600 25 850 25 600 25 900 26 200 26 500 25 700 26 000 26 300

26 600

0.56

0.48

0.43

0.38

0.52

0.45

0.40

0.34

0.52

0.45

0.40

0.34

3 600

DIGGING DATA

3 100 mm Boom

OM0256

Arm

mm

2 158

2 480

2 950

A

mm

9 756

9 993

10 420 11 058

A’

mm

9 570

9 812

10 246 10 895

B

mm

5 791

6 067

6 517

7 170

B’

mm

5 678

5 958

6 414

7 077

C

mm

11 099 11 237 11 379 12 128

D

mm

6 306

8 146

5 840

5 248

E

mm

2 868

2 896

2 568

2 808

EX255-EX285 EX285

T1-1-3

SPECIFICATIONS EX285 EXCAVATOR DIMENSIONS (Monoblock Version) E / E' G

D / D'

H

F C

I

L M

A B

N

VERSIONS

B

C

D

(mm) 3 706

4 574

1 208

2 937

EX285 LC (mm) 4 011

4 879

1 210

2 937

EX285

A


D’ (*)

E

E’ (***)

F (**)

OM0540

G

1) 3 531 2 950 10 293 10 282 2) 3 350 2 815 3) 3 166 2 950 10 293 10 282 4) 3 295 2 815

(**) Arm: 1) 2 120 mm, 2) 2 400 mm, 3) 3 100 mm, 4) 3 750 mm

H

I

L

3 028

1 012

525.5

3 028

1 012

525.5

(***) Arm: 2 120 mm

EX285

EX285 LC

M-Track shoe width

(mm)

600

700

800

900

600

700

800

900

N-Maximum width

(mm)

3 000

3 100

3 200

3 300

3 190

3 290

3 390

3 490

(kg)

26 700

27 066

27 432

27 800

27 442

27 830

28 220

28 608

(bar)

0.65

0.57

0.50

0.45

0.62

0.54

0.48

0.43


DIGGING DATA

6 200 mm Boom Arm

OM0254

mm 2 120

2 400

3100

3750

A

mm

9 834 10 062 10 705 11 299

A’

mm

9 620

9 864 10 519 11 124

B

mm

6 120

6 538

7 230

7 878

B’

mm

5 998

6 319

7 052

7 725

C

mm

9 802

9 638

9 978 10 242

D

mm

6 857

6 906

7 215

7 472

E

mm

4 269

4 307

4 146

4 124

T1-1-4

EX255-EX285 EX285

SPECIFICATIONS EX285 EXCAVATOR DIMENSIONS (Triple Articulation Version) G

E / E' D / D'

H

F C

I

L M

A B

N

VERSIONS

B

C

D

(mm) 3 706

4 574

1 208

2 937

EX285 LC (mm) 4 011

4 879

1 210

2 937

EX285

A


D’ (*)

E

E’ (***)

F (**)

G

1) 3 139 2 950 10 081 10 199 2) 3 166 2 815 3) 3 094 2 950 10 081 10 199 4) 3 376 2 815

(**) Arm: 1) 2100 mm, 2) 2400 mm, 3) 3100 mm, 4) 3750 mm

OM0255

H

I

L

3 028

1 012

525.5

3 028

1 012

525.5

(***) Arm: 2 120 mm

EX285

EX285 LC

M-Track shoe width

(mm)

600

700

800

900

600

700

800

900

N-Maximum width

(mm)

3 000

3 100

3 200

3 300

3 190

3 290

3 390

3 490

(kg) 27 400

27 766

28 132

28 498

28 140

28 506

28 872

29 238

0.58

0.52

0.46

0.69

0.60

0.53

0.48


(bar)

0.67

DIGGING DATA

3 200 mm Boom

OM0256

Arm

mm

2 120

2 400

3 100

3 750

A

mm

9 882 10 072 10 733 11 345

A’

mm

9 680

9 875 10 548 11 170

B

mm

5 784

6 014

6 699

7 335

B’

mm

5 671

5 905

6 600

7 244

C

mm 11 285 11 370 11 924 12 413

D

mm

8 175

8 264

8 813

9 302

E

mm

3 038

3 009

2 726

2 867

EX255-EX285 EX255

T1-1-5

SPECIFICATIONS EX255 EXCAVATOR PERFORMANCE GRADEABILITY .......................................................................................................... 35° (70%) in continuous TRAVEL SPEED ................................................................................................... 2.2 / 3.4 mph (3.5/5.4 km/h) - Slow ................................................................................................................... 0 to 2.2 mph (0 to 3.5 km/h) - Fast .................................................................................................................... 0 to 3.4 mph (0 to 5.4 km/h)

EX255 ENGINE DATA MAIN SPECIFICATIONS - Manufacturer ........................................................................................................................................ ISUZU - Model ................................................................................................................................. CC-6BG1 TRA-05 - Type .......................................................................... Diesel, 4 cycle, vertical, 6-cylinder inline, water-cooled, direct injection type turbocharged, with intercooler - Cyl. No.-bore x stroke .......................................................................... 6-105 mm x 125 mm (4.13 in x 4.92 in) - Piston displacement ............................................................................................................ 6494 cm3 (475 in3) - Rated output ........................................................................................ 118 kW/2000 min-1 (158 HP/2000 rpm) HP Mode: 125 kW/2100 min-1 (168 HP/2100 rpm) - Compression ratio .........................................................................................................................................18 - Dry weight ............................................................................................................................... 490 kg (1080 lb) - Firing order ....................................................................................................................................... 1-5-3-6-2-4 - Rotation direction .............................................................................................. Clockwise (view from fan side) COOLING SYSTEM - Cooling fan ............................................................................................. Dia. 670 mm, 6 blades, draw-in type - Fan pulley ratio .................................................................................................................... Engine rpm x 0.95 - Thermostat ....................................................... Cracking temp. : 82 °C (180 °F) (under atmospheric pressure) Full open (Stroke: 10 mm or larger) temp. : 95 °C (203 °F) - Water pump ........................................................................................................... Centrifugal type, belt driven LUBRICATION SYSTEM - Lubrication pump type ................................................................................................................... Gear pump - Oil filter .............................................................................. Full-flow paper element type with by function - Oil cooler ........................................................................................................................ Water-cooled, built-in STARTING SYSTEM Motor ............................................................................................ Magnetic pinion shift system, reduction type Voltage-Output .............................................................................................................................. 24 V - 4.5 kW PRE-HEAT SYSTEM - Heating method ............................................................................................................................... Glow plug ENGINE STOP SYSTEM - Stop method ....................................................................................................................................... Fuel cut ALTERNATOR - Type ........................................................................................................................... AC type (with regulator) - Voltage-Output .................................................................................................... 24 V - 50 A (Brush-less type) SUPERCHARGING SYSTEM - Type ............................................................................................................. Exhaust-gas-turbo type IHI RG6 FUEL SYSTEM - Injection pump model .....................................................................................................................Bosch type - Governor ..................................................................................................... Centrifugal all speed control RSV - Injection nozzle ....................................................................................................................... Multihole nozzle

T1-1-6

EX255-EX285 EX255

SPECIFICATIONS EX255 ENGINE ACCESSORY RADIATOR ASSEMBLY - Type ...................................................................... Radiator/Oil Cooler tandem type and intercooler assembly - Mass .......................................................................................................................................... 85 kg (187 lb) - Radiator Capacity ....................................................................................................................................... 8 L - Oil Cooler Capacity ................................................................................................................................. 6.3 L BATTERY - Capacity ........................................................................................................................................ 160 Ah x 2 - Voltage ............................................................................................................................................... 12V x 2

HYDRAULIC DEVICES EX255 MAIN PUMP - Model .......................................................................................................................................... HPV102FW - Type ............................................................... Variable displacement plunger pump: regulator attached type - Max. flow (theoretical value) ...................................................................................................... 194 L/min x 2 PILOT PUMP - Model ................................................................................................................................... HY/ZFS 11/16.8 - Type ....................................................................................................... Fixed displacement type gear pump - Max. flow (theoretical value) ........................................................................ 33.6 L/min; HP Mode: 35.3 L/min CONTROL VALVE - Model ......................................................................................................................................... KVMG-200H - Type ................................................................................................................... Pilot pressure operated type (4-spool + 5-spool) - Main relief pressure ................................................................ Normal: 34.3 MPa (350 kgf/cm2) @ 140 L/min Power Boost: 36.3 MPa (370 kgf/cm2) @ 140 L/min - Overload relief pressure ........................................................................ 37.3 MPa (380 kgf/cm2) @ 50 L/min (Boom raise / lower, Arm roll-in, Bucket roll-in) 39.2 MPa (400 kgf/cm2) @ 50 L/min (Arm roll-out, Bucket roll-out) SWING DEVICE - Type ....................................................................................................... Two-stage planetary reduction type SWING MOTOR - Model .............................................................................................................................................. M2X146B - Type ............................................................................. Swash-plate type, fixed-displacement plunger motor SWING BRAKE VALVE - Type ............................................................................................................. Non counter balance valve type - Relief pressure .................................................................................... 31.4 MPa (320 kgf/cm2) @ 140 L/min SWING PARKING BRAKE - Type ............................................................................................................. Multiple-wet-plate negative type - Cracking pressure for release ................................................................ 1.96 to 2.64 MPa (20 to 27 kgf/cm2) TRAVEL DEVICE - Type ..................................................................................................... Three-stage planetary reduction gear TRAVEL MOTOR - Model ............................................................................................................................................... HMV116 - Type ............................................................................. Bent-axis type, variable displacement plunger motor

EX255-EX285 EX255

T1-1-7

SPECIFICATIONS TRAVEL BRAKE VALVE - Type .................................................................................................................... Counter balance valve type - Relief pressure .......................................................................................................... 34.8 MPa (355 kgf/cm2) TRAVEL PARKING BRAKE - Type ............................................................................................................. Multiple-wet-plate negative type - Cracking pressure for release ............................................................ 0.95 to 1.02 MPa (9,7 to 10.4 kgf/cm2) CYLINDERS

Rod diameter

Boom

Arm

Bucket

Positioning (*)

90 mm

100 mm

85 mm

90 mm

Cylinder inner diameter

125 mm

135 mm

125 mm

145 mm

Stroke Fully retracted length

1350 mm

1610 mm

1075 mm

1205 mm

1950 mm

2235 mm

1665 mm

1799 mm

(*) Triple articulation version

FRONT ATTACHMENT PILOT VALVE - Model ................................................................................................................................. HVP04S-040-101 TRAVEL PILOT VALVE - Model ................................................................................................................................. HVP05D-040-101 SOLENOID VALVE UNIT - Functions ............................................................................................... SC: Arm regenerative control SD: Speed sensing control SG: Power boost control SI: Travel motor swash angle control OIL COOLER BY CHECK VALVE - Cracking pressure .......................................................................................... 392 KPa (4 kgf/cm2) at 5 L/min

EX255 ELECTRICAL EQUIPMENT BATTERY RELAY - Voltage - Current ........................................................................................................................ 24 V - 100 A GLOW RELAY - Voltage - Current .......................................................................................................................... 24 V - 30 A HORN - Specifications ........................................................................................................... 24 V - 1.5 A, 113 dB (A) LIGHT - Specifications ............................................................................................ Work lights: Halogen 24 V - 70 W Dome light: 24 V - 10 W AIR CONDITIONER - Refrigerant .............................................................................................................................................. 134 a - Temperature control .............................................................................................................. electronic control

EX285 EX255-EX285

T1-1-8

SPECIFICATIONS EX285 EXCAVATOR PERFORMANCE GRADEABILITY .......................................................................................................... 35° (70%) in continuous

TRAVEL SPEED ................................................................................................... 1.9 / 3.2 mph (3.0/5.1 km/h) - Slow ................................................................................................................... 0 to 1.9 mph (0 to 3.0 km/h) - Fast .................................................................................................................... 0 to 3.2 mph (0 to 5.1 km/h)

EX285 ENGINE DATA MAIN SPECIFICATIONS - Manufacturer ........................................................................................................................................ ISUZU - Model ................................................................................................................................. CC-6BG1 TRA-06 - Type .......................................................................... Diesel, 4 cycle, vertical, 6-cylinder inline, water-cooled, direct injection type turbocharged, with intercooler - Cyl. No.-bore x stroke .......................................................................... 6-105 mm x 125 mm (4.13 in x 4.92 in) - Piston displacement ............................................................................................................ 6494 cm3 (475 in3) - Rated output ........................................................................................ 125 kW/2050 min-1 (168 HP/2050 rpm) HP Mode: 132 kW/2150 min-1 (177 HP/2150 rpm) - Compression ratio .........................................................................................................................................18 - Dry weight ............................................................................................................................... 490 kg (1080 lb) - Firing order ....................................................................................................................................... 1-5-3-6-2-4 - Rotation direction .............................................................................................. Clockwise (view from fan side) COOLING SYSTEM - Cooling fan ............................................................................................. Dia. 670 mm, 6 blades, draw-in type - Fan pulley ratio ................................................................................................................... Engine rpm x 0.95 - Thermostat .................................................... Cracking temp. : 82 °C (180 °F) (under atmospheric pressure) Full open (Stroke: 10 mm or larger) temp. : 95 °C (203 °F) - Water pump ......................................................................................................... Centrifugal type, belt driven LUBRICATION SYSTEM - Lubrication pump type ................................................................................................................... Gear pump - Oil filter .............................................................................. Full-flow paper element type with by function - Oil cooler ........................................................................................................................ Water-cooled, built-in STARTING SYSTEM Motor ............................................................................................ Magnetic pinion shift system, reduction type Voltage-Output .............................................................................................................................. 24 V - 4.5 kW PRE-HEAT SYSTEM - Heating method ............................................................................................................................... Glow plug ENGINE STOP SYSTEM - Stop method ....................................................................................................................................... Fuel cut ALTERNATOR - Type ........................................................................................................................... AC type (with regulator) - Voltage-Output .................................................................................................... 24 V - 50 A (Brush-less type) SUPERCHARGING SYSTEM - Type ............................................................................................................. Exhaust-gas-turbo type IHI RG6 FUEL SYSTEM - Injection pump model .....................................................................................................................Bosch type - Governor ..................................................................................................... Centrifugal all speed control RSV - Injection nozzle ...................................................................................................................... Multihole nozzle

EX285 EX255-EX285

T1-1-9

SPECIFICATIONS EX285 ENGINE ACCESSORY RADIATOR ASSEMBLY - Type ...................................................................... Radiator/Oil Cooler tandem type and intercooler assembly - Weight ....................................................................................................................................... 85 kg (187 lb) - Radiator Capacity ....................................................................................................................................... 8 L - Oil Cooler Capacity ................................................................................................................................. 6.3 L BATTERY - Capacity ........................................................................................................................................ 160 Ah x 2 - Voltage .............................................................................................................................................. 12 V x 2

EX285 HYDRAULIC DEVICES MAIN PUMP - Model .......................................................................................................................................... HPV102FW - Type ............................................................... Variable displacement plunger pump: regulator attached type - Max. flow (Theoretical value) .................................................................................................... 209 L/min x 2 PILOT PUMP - Model ................................................................................................................................... HY/ZFS 11/16.8 - Type ....................................................................................................... Fixed displacement type gear pump - Max. flow (Theoretical value) ..................................................................... 34.4 L/min; HP Mode: 36.1 L/min CONTROL VALVE - Model ......................................................................................................................................... KVMG-200H - Type ................................................................................................................... Pilot pressure operated type (4-spool + 5-spool) - Main relief pressure ................................................................ Normal: 34.3 MPa (350 kgf/cm2) @ 140 L/min Power Boost: 36.3 MPa (370 kgf/cm2) @ 140 L/min - Overload relief pressure ........................................................................ 37.3 MPa (380 kgf/cm2) @ 50 L/min (Boom raise / lower, Arm roll-in, Bucket roll-in) 39.2 MPa (400 kgf/cm2) @ 50 L/min (Arm roll-out, Bucket roll-out) SWING DEVICE - Type ....................................................................................................... Two-stage planetary reduction type SWING MOTOR - Model ........................................................................................................................................ M2X210CHB - Type ............................................................................. Swash-plate type, fixed-displacement plunger motor SWING BRAKE VALVE - Type ............................................................................................................. Non counter balance valve type - Relief pressure ......................................................................... 27.7±0.3 MPa (282±3 kgf/cm2) @ 140 L/min SWING PARKING BRAKE - Type ............................................................................................................. Multiple-wet-plate negative type - Cracking pressure for release ................................................................ 2.25 to 2.84 MPa (23 to 29 kgf/cm2) TRAVEL DEVICE - Type ..................................................................................................... Three-stage planetary reduction gear TRAVEL MOTOR - Model ............................................................................................................................................... HMV145 - Type ............................................................................. Bent-axis type, variable displacement plunger motor

T1-1-10

EX255-EX285 EX285

SPECIFICATIONS TRAVEL BRAKE VALVE - Type .................................................................................................................... Counter balance valve type - Relief pressure .......................................................................................................... 34.8 MPa (355 kgf/cm2) TRAVEL PARKING BRAKE - Type ............................................................................................................. Multiple-wet-plate negative type - Cracking pressure for release ............................................................ 0.95 to 1.02 MPa (9.7 to 10.4 kgf/cm2) CYLINDERS

Rod diameter

Boom 90 mm

Arm 100 mm

Bucket 90 mm

Positioning (*) 90 mm

Cylinder inner diameter

135 mm

145 mm

135 mm

145 mm

Stroke

1340 mm

1555 mm

1070 mm

1205 mm

Fully retracted length

1920 mm

2155 mm

1660 mm

1799 mm


FRONT ATTACHMENT PILOT VALVE - Model ................................................................................................................................. HVP04S-040-101 TRAVEL PILOT VALVE - Model ................................................................................................................................. HVP05D-040-101 SOLENOID VALVE UNIT - Functions ............................................................................................... SC: Arm regenerative control SD: Speed sensing control SG: Power boost control SI: Travel motor swash angle control OIL COOLER BY CHECK VALVE - Cracking pressure .......................................................................................... 392 KPa (4 kgf/cm2) at 5 L/min

EX285 ELECTRICAL EQUIPMENT BATTERY RELAY - Voltage - Current ........................................................................................................................ 24 V - 100 A GLOW RELAY - Voltage - Current .......................................................................................................................... 24 V - 30 A HORN - Specifications ................................................................................................................. 24 V - 1.5 A, 113 dB LIGHT - Specifications ............................................................................................ Work lights: Dome light:

Halogen 24 V - 70 W 24 V - 10 W

AIR CONDITIONER - Refrigerant .............................................................................................................................................. 134 a - Temperature control ............................................................................................................. Electronic control

EX255-EX285

T1-2-1

COMPONENT LAYOUT MAIN COMPONENTS

SM5601

1 2 3 4 5 6 7 8 9 10 11

-

Bucket Cylinder Arm Cylinder Boom Cylinder Center t Swing Bearing Swing Device Fuel Tank Hydraulic Oil Tank Control Valve Pilot Filter, Pilot Relief Valve Pump Device

12 13 14 15 16 17 18 19 20 21

-

Engine Radiator Oil Cooler Intercooler Battery Travel Device Shockless Valve Pilot Shut-Off Valve Travel Pilot Valve Front/Swing Pilot Valve

T1-2-2

EX255-EX285

COMPONENT LAYOUT ELECTRICAL SYSTEM (overall system)

SM5402

1 2 3 4 5 6 7,8 9 10 11 12 13 14 15 16 17 18 -

Wiper Motor Monitor Relays, Relays box Windshield Horn Work Light Fuel Sensor with Low Fuel Level Switch Solenoid Valve Unit Pressure Switch (Travel) Hydraulic Oil Level Switch PC Pressure Sensor (Upper: 4-Spool Side) PC Pressure Sensor(Lower: 5-Spool Side) EC Motor EC Sensor Pump Delivery Pressure Sensor 1 Pump Delivery Pressure Sensor 2 N (Engine Speed) Sensor

19 20 21 22 23 24 25 26 27 28 29

-

30 31 32 33 -

Engine Oil Pressure Switch Coolant Temperature Switch (Engine Preheat Circuit) Engine Oil Level Switch (on oil pan) Overheat Switch Coolant Temperature Sensor Battery Relay Coolant Level Switch Battery Starter Relay Air Cleaner Restriction Switch Pressure Switch (Boom Raise), Pressure Sensor (Arm Roll-In) Pressure Switch (Front) Fuse Box MC (Main Controller) QOS Controller

EX255-EX285

T1-2-3

COMPONENT LAYOUT ELECTRICAL SYSTEM (cab)

SM5603

1 2 3 4 5 6 7 8 9 10 11 12

-

Relay box Air conditioner relays (if installed) Connection for cab light (ceiling) WWES connection for wiper cut-off microswitch Heater connection Air conditoner connection Loudspeakers connection Cab ground Main controller (MC) Q.O.S. controller Load momentum alarm buzzer provision Load momentum alarm relay provision (R1)

13 14 15 16 17 18 19 20 21 22 23 24

-

Breaker relay (R2) variant provision R.H. Rotation bucket relay (R3) variant provision L.H. Rotation bucket relay (R4) variant provision Cab light relay (R5) Rear cab light relay (R6) A, B, K junction connector C, D juncton connector E, F junction connector G, H junction connector Dr. EX. connector Engine learning switch Fuse box

T1-2-4

EX255-EX285


1

2

3

4

8

5

7

6

SM5604

1 2 3 4 5 6

-

Connectors for monitor and switch s Cigarette lighter Connectors to cab harness Connectors not used Windshield wiper controller (1) connector for breaker switch (2) connector for cab light switch (3) connector for bucket rotation (4) connector for load momentum alarm switch (5) connector for rear cab light

7 8

- Connector not used - Connector

EX255-EX285

T1-2-5

COMPONENT LAYOUT ELECTRICAL SYSTEM (monitor and switch s)

10 24

11

1

12

2

23

13

22

14

21 20

15 16 17

19 3 18

T157-07-02-001 SM0610

5 25 6 4

32 7 8

26

31

27

9

28

30

T157-01-01-009 SM0611

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

-

Monitor Switch Power Boost Switch Key Switch Cigar Lighter HP Mode Switch E Mode Switch Engine Control Dial Air Conditioner Warm Up Complete Indicator Fuel Gauge E Mode Indicator Auto-Idle Indicator Hydraulic Oil Level Indicator Preheat Indicator Air Filter Restriction Indicator

29

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

T157-01-01-018 SM0612

-

Fuel Level Indicator Overheat Indicator Alternator Indicator Engine Oil Pressure Indicator Engine Oil Level Indicator Coolant Level Indicator HP Mode Indicator Coolant Temperature Gauge Work Light Switch Wiper Switch Travel Mode Switch Work Mode Switch Buzzer Stop Switch Auto-Idle Switch Washer Switch Level Check Switch

T1-2-6

EX255-EX285

COMPONENT LAYOUT ELECTRICAL SYSTEM (batteries compartment)

1 8

2 7

3

6 4

5

1 2 3 4

-

Battery relay Fuse link (Box B - Fuse 3-60A) Fuse link (Box A - Fuse 1-40A, Fuse 2-40A) Connection box

SM5605

5 6 7 8

-

Safety relay Engine coolant level switch Ground t connector Glow relay

EX255-EX285

T1-2-7

COMPONENT LAYOUT ELECTRICAL SYSTEM (fuses) FUSES IN THE BOX Fuse No.

LABEL

PROTECTED CIRCUIT

Rating (A)

1

SW. BACK UP

Backup power source

5

2

ENGINE C/U

MC (Power Source)

10

3

E.C. MOTOR

EC Motor

10

4

AUXILIARY

Auxiliary Power supply

5

5

REAR CAB LIGHT

Rear cab light power supply

10

6

HAMMER

Breaker

10

7

ROTARY BUCKET

Bucket rotation

10

8

SOLENOID

Solenoid valve power supply

5

9

SW. BOX

Switches

5

10

HEATING SEAT

Heating seat

10

11

WIPER

Windshield wiper

10

12

HEATER

Heater

20

13

LIGHT

Light

15

14

CAB LIGHT

Cab light

15

15

RADIO

Radio

5

16

LIGHTER

Cigar light

15

17

HORN

Horn

10

18

GLOW RELAY

Glow relay power supply

5

19

POWER ON

Power supply on

5

20

AIR CONDITION

Air conditoner

10

OM0231

1

2

3

4

5

6

7

8

9 10

11 12 13 14 15 16 17 18 19 20

OM1150

Fuses in the fuse box

FUSES IN THE BATTERIES COMPARTMENT FUSE 1

BOX A

Main power supply with key

40

FUSE 2

BOX A

Glow plug and fuel transfer supply

40

FUSE 3

BOX B

Charge circuit supply

60

BOX B

–

–

OM1304

Fuses in the batteries compartment

T1-2-8

EX255-EX285

COMPONENT LAYOUT PUMP AND RELATED PARTS

5

6

7

3-4 8

2

1

12

11

10

9 SM3004

1 2 3 4 5 6

-

Pilot Filter Pilot Relief Valve EC Motor EC Sensor Pilot Pump Regulator (Pump 2)

7 8 9 10 11 12

-

N Sensor Regulator (Pump 1) Pump Delivery Pressure Sensor (Pump 1) Pump 1 Pump Delivery Pressure Sensor (Pump 2) Pump 2

EX255-EX285

T1-2-9

COMPONENT LAYOUT OTHER COMPONENTS

Shockless Valve

Swing Device

4

1

5

9 8

6 7

SM0626 T157-01-01-011

Travel Device

SM0627 T157-07-03-018

Solenoid Valve Unit

FRONT

10 11 12

2

13 3 SM0628 T157-01-01-012

1 2 3 4 5 6 7

-

Swing Relief Valve Counterbalance Valve Travel Relief Valve Shockless Valve Pilot Pressure Switch (Boom Raise) Check Valve Shockless Valve

SM0629 W157-02-11-020

8 9 10 11 12 13

-

Check Valve Pilot Pressure Sensor (Arm Roll-In) Solenoid Valve Unit (SC) Solenoid Valve Unit (SD) Solenoid Valve Unit (SI) Solenoid Valve Unit (SG)

T1-2-10

EX255-EX285

COMPONENT LAYOUT NOTES

SECTION 2

EX255-EX285

SYSTEM

CONTENTS Group 1 -

Control system

Outline .................................................... T2-1-1 Engine control ........................................ T2-1-2 Pump control .......................................... T2-1-8 Valve control ..........................................T2-1-10 Other control functions ......................... T2-1-14

Group 2 -

Hydraulic system

Main circuit .......................................... T2-2-1 Pilot circuit ........................................... T2-2-2 Neutral circuit ...................................... T2-2-3 Single actuator operation .................... T2-2-3 Combined operation ............................ T2-2-4

Group 3 -

Electrical system

Outline ................................................... T2-3-1 Electric power circuit (Key Switch: OFF) ................................. T2-3-2 Bulb Check Circuit (Key Switch: ON) ..... T2-3-4 Accessory Circuit (Key Switch: ACC) .... T2-3-6 Preheat Circuit (Key Switch: ON or START) .................. T2-3-8 Starting Circuit (Key Switch: START) ........................... T2-3-10 Charging Circuit (Key Switch: ON) ................................. T2-3-12 Surge Voltage Prevention Circuit ......... T2-3-16 Engine Stop Circuit (Key Switch: OFF) ............................... T2-3-18 Engine and pump control circuit .......... T2-3-20 Monitor circuit ...................................... T2-3-24

EX255-EX285

T2-1-1

CONTROL SYSTEM OUTLINE Microcomputer built-in main controller (MC) is provided to control machine operation. Electronic sensing signals from the engine control dial, various sensors and switches are sent to the MC.

After processing the sensing signals in the logic circuits, the MC sends out the control signals to the EC motor and solenoid valve unit to control the engine, pump, and valve operations.

Sensing signals (Input signals)

Control signals (Output signals)

• EC sensor • Engine control dial • Pump control pressure sensor • Pump delivery pressure sensor • N sensor • Pressure switches • (Travel - Front - Boom raise) • Pilot pressure sensor • (Arm roll-in) • Auto-idle switch • Learning switch • Power boost switch • HP mode switch • E mode switch • Travel mode switch • Work mode switch • Key switch

→ → → → →

→ EC motor:

→ → Solenoid valve (SD): → → → → → → → → →

Engine control • Normal control • HP mode control • E mode control • Auto-Idle control • Engine learning control Pump control • Speed sensing control

MC

→ Solenoid valve (SC, SG, SI):

Valve control • Power Boost control • Arm regenerative control • Travel motor swash angle control

→ EC Motor → Solenoid Valve Unit (SC, SG)

Work Mode Control • General Purpose Mode • Grading Mode • Precision Mode • Attachment Mode

T2-1-2

EX255-EX285

CONTROL SYSTEM ENGINE CONTROL The engine control system has the following control functions: • • • • •

Normal control HP mode control E mode control Auto-Idle control Engine learning control.

Layout of engine control system Pilot pressure sensor (Arm Roll-in)

Pressure switch (Travel)

Pressure switch (Front)

Learning switch

P/V Key switch

EC sensor

Engine control dial

ENGINE M Auto-Idle switch

A/I

MC EC motor

HP mode switch

H/P E mode switch

E

Pump delivery pressure sensor (Pump 1, 2)

SM0101

EX255-EX285

T2-1-3

CONTROL SYSTEM Normal Control Purpose: To control engine speed in response to the operation angle of the engine control dial on the switch . Operation: In response to the operation angle of the engine control dial, the MC drives the EC motor, causing the governor lever to move to control engine speed.

NOTE - Normally, the governor lever does not come into with the full side stopper even if the engine control dial is turned to the full speed position. (Refer to HP Mode Control).

The EC sensor s the position of the EC motor to the MC. This confirms that the EC motor moves according to commands from the MC.

P/V

Engine control dial

EC sensor

ENGINE M

Stop

Full

MC A/I

EC motor

Governor lever

H/P E

SM0102

T2-1-4

EX255-EX285

CONTROL SYSTEM HP Mode Control Purpose: To instantaneously increase the engine speed only when a little more hydraulic power is required for arm roll-in operation. For example, to increase the arm roll-in power while conducting a deep ditching work.

Engine speed HP mode operation line

100 min-1 (rpm)

Operation: Only when the following conditions are satisfied, the MC drives the EC motor to operate the engine faster than normal operation. • • • •

1800 min-1 (rpm)

Engine Control Dial Setting: 1600 min-1 or faster HP Mode Switch: ON Operation: Arm Roll-In Average Delivery Pressures of Pump 1 and 2: Higher Range

NOTE - The engine governor stopper position is adjusted in accordance with the HP mode operation. Therefore, the governor lever does not come into with the stopper in the Normal Control mode.

1600 min-1 (rpm)

Fast Idle (Max. Speed)

Slow Idle Slow Idle


SM0103

Pilot pressure sensor (Arm Roll-in)

P/V

Engine control dial

ENGINE M

Min.

Max.

MC A/I

EC motor

Governor lever

HP mode switch

H/P E

Pump delivery pressure sensor

SM0104

EX255-EX285

T2-1-5

CONTROL SYSTEM E Mode Control Purpose: To decrease the engine speed at a fixed rate.

Engine speed

When the E mode switch is not depressed

Operation: When the E mode switch is ON, the MC instructs the EC motor to run the engine in the speed range slower than normal operation in proportion to the engine control dial set angle.

When the E mode switch is depressed Slow Idle

Fast Idle (Max. Speed) Slow Idle


SM0105

P/V

Engine control dial

ENGINE M MC A/I

EC motor

Governor lever

H/P E mode switch

E

SM0106

T2-1-6

EX255-EX285

CONTROL SYSTEM Auto-Idle Control Purpose: To slow the engine speed when all control levers are in neutral to reduce fuel consumption and noise. Operation: When the auto-idle switch is ON and all

control levers are kept in neutral (the pressure switches for travel and front operations are off) for more than four seconds, the MC instructs the EC motor to reduce the engine speed to the auto-idle speed.



P/V

Engine control dial

ENGINE M Auto-Idle switch

A/I

MC EC motor

Governor lever

H/P E

SM0107

EX255-EX285

T2-1-7

CONTROL SYSTEM Engine Learning Control Purpose: To check the governor lever stopper positions to run the engine at full-speed or to stop as engine control standard data. Operation: When the learning switch in the rear console is turned to the engine learning side, the EC motor is driven by the signal from the MC. Then, the EC motor moves the governor lever to the Idle, FULL, and STOP positions in that order. Thereby, the EC sensor checks the stopper positions for the FULL and STOP operation. The signals corresponding to each stopper position are sent to the MC from the EC sensor, and the MC stores the data.

Rear Console

Fuse Box

Learning Switch

Engine Learning

IMPORTANT - Be sure to operate the engine learning control system after replacing the engine, engine control cable, EC motor, or MC. The procedure is listed in the Technical Manual "Troubleshooting" on page T5-4-60.

Neutral (OFF)

SM0108

NOTE - The replacement of batteries does not require operation of the engine learning control system.

Learning switch

P/ V

Key switch

EC Sensor

ENGINE M

Stop

Full

MC A/I

EC Motor

Governor Lever

H/P E SM0109

T2-1-8

EX255-EX285

CONTROL SYSTEM PUMP CONTROL The pump operation is regulated by the speed sensing system and the pump control valve. The speed sensing system works via the MC.

The pump control valve is provided in the control valve. (Refer to the Control Valve Group in the COMPONENT OPERATION Section).

EX255-EX285

T2-1-9

CONTROL SYSTEM Speed Sensing Control Purpose: To control the pump drive torque in response to the variation of loads to the engine or the output of the hydraulic pumps to utilize the engine output more efficiently. Operation: The target engine speed is selected by setting the engine speed with the engine control dial. The MC receives signals for the target engine speed, and actual engine running speed from the N sensor. After processing these input data, the MC sends out the control signals to the solenoid valve unit (SD).

According to the control signals from the MC, the solenoid valve unit (SD) supplies pilot oil pressure to the pump regulators to control the pump flow rate. When poor quality fuel is used or if the machine is operated at high altitudes, the engine output torque may decrease, causing the engine to run slower than the target speed. As the MC in the speed sensing control system instructs the solenoid valve unit (SD) to reduce the pump flow rate, the pump drive torque is reduced. Thereby, engine speed reduction or engine stall is avoided.

N sensor

Engine control dial Solenoid Valve unit

MC

S D

ENGINE REG

REG

SM0110

T2-1-10

EX255-EX285

CONTROL SYSTEM VALVE CONTROL The valve control consists of the power boost control, arm regenerative control, and travel motor swash angle control.

Pump control pressure sensor (5-Spool Side) Pilot pressure sensor (Arm Roll-In) Pressure switch (Boom Raise) Travel motor swash angle selector valve Power Boost switch


Travel motor


Travel mode switch

Relief valve

P/V Arm cylinder

MC

To MC

S G Pump delivery pressure sensor Solenoid valve unit

SI

S C Arm regenerative valve

REG

Swing motor

From pump control pressure sensor (4-Spool Side)

REG

Pump control pressure sensor (4- Spool Side)

SM0111

EX255-EX285

T2-1-11

CONTROL SYSTEM Power Boost Control Purpose: To increase hydraulic power by temporarily increasing the main relief pressure. Operation: When the power boost switch is turned

ON, the MC magnetizes solenoid valve unit (SG) for 8 seconds. When magnetized, solenoid valve unit (SG) supplies pilot oil pressure to the relief valve to increase the relief set pressure.

Relief Valve Power Boost switch

MC

Solenoid Valve Unit

SM0112

T2-1-12

EX255-EX285

CONTROL SYSTEM Arm Regenerative Control Purpose: To increase arm roll-in speed and prevent the arm roll-in hesitation. Operation: When the signals to the MC from the pump delivery pressure sensor (pump 2), pilot pressure sensor (arm roll-in), and pressure switch (boom raise) fall into the following conditions, the MC magnetizes the solenoid valve unit (SC). Then, the solenoid valve (SC) starts to deliver the pilot pressure to actuate the arm regenerative valve, closing the return circuit to the hydraulic oil tank from the arm cylinder rod side. Thereby, the return oil from the arm cylinder rod side

is combined with the pump delivery oil and supplied to the arm cylinder bottom side, increasing the arm roll-in speed and preventing arm roll-in hesitation.

Operation Conditions: - Pump Delivery Pressure Sensor (Pump 2): Delivery pressure from pump 2 is low (requiring less arm operating force). - Pilot Pressure Sensor (Arm Roll-In): Output is large (operating the arm control lever with a great stroke). - Pressure Switch (Boom Raise): ON

Pilot pressure sensor (Arm Roll-In) Pressure Switch (Boom Raise)

Bucket Arm cylinder

MC

Arm 1 Bucket cylinder

Pump delivery pressure sensor (Pump 2)

Solenoid valve unit Arm regenerative valve

SM0113

EX255-EX285

T2-1-13

CONTROL SYSTEM Travel Motor Swash Angle Control Purpose: To change fast/slow travel speed. Operation: When the travel mode switch is in position, the travel motor swash angle is held at a large angle, causing the machine to travel at a slow speed. When the travel mode switch is in position and the signals to the MC from the pressure switch (travel), pump delivery pressure sensors (pump 1 and 2) fall into the following conditions, the MC magnetizes solenoid valve (SI), allowing pilot oil pressure to change the travel motor swash angle control valve port. Thereby, the travel motor swash angle is reduced to cause the machine to travel at a fast speed.

Pump control Pressure Sensor (5-Spool Side)

Operation Conditions: - Pressure Switch (Travel): ON - Pressure Switch (Front): OFF - Pump Delivery Pressure Sensors (Pump 1 and 2): Pump delivery pressure is low. - Pump Displacement Target Angle (controlled by the MC according to signals from sensors and switches): Large NOTE - Even if the track is revolved with the track raised, one side pump displacement target angle remains small so that the travel motor speed does not increase. The pump displacement target angle is different from the travel motor displacement target angle.

Travel motor swash angle control valve Travel motor

Pressure switch (Front): OFF signal Pressure switch (Travel): ON signal

Left side travel

Right side travel

Travel mode switch

MC

To MC

Pump delivery Pressure Sensors (Pump 1 and 2)

Solenoid valve unit

Pump control Pressure Sensor (4-Spool side)

Front pump control Pressure Sensor (4-Spool side)

SM0114

T2-1-14

EX255-EX285

CONTROL SYSTEM OTHER CONTROL FUNCTION Work Mode Control The work mode includes the four modes of GENERAL PURPOSE, GRADING, PRECISION, and ATTACHMENT, which can be selected by the work mode switch.

of the full speed to be set when the engine control dial is placed in the full position. The main relief pressure is increased in boom raise operation. (Refer to T2-1-11)

GENERAL PURPOSE MODE Normal control is applied.

NOTE - Operating speed is reduced but operating force is unchanged.

GRADING MODE To decrease the arm leveling speed, the arm regenerative control is deactivated. (Refer to T2-1-12)

ATTACHMENT MODE Only when the attachment option kit is installed, this function works. In proportion to the auxiliary pilot valve lever stroke, the engine speed is controlled by the MC so as to meet the installed attachment operation. The engine speed setting for the attachment mode is made by the Dr.EX.

PRECISION MODE In all work modes, engine speed is reduced to 70 %

EX255-EX285

T2-2-1

HYDRAULIC SYSTEM MAIN CIRCUIT The main pumps (pump 1 and pump 2) draw hydraulic oil from the hydraulic oil tank. Pump 1 delivers oil to the 4-spool control valve while pump 2 delivers oil to the 5-spool control valve. Pressure oil from the main pumps are routed to the motors and cylinders in response to respective control valve spool shifts. Return oil from the motors and cylinders flows back

to the hydraulic oil tank via the control valves and the oil cooler. When oil temperature is low (viscosity is high), return oil flowing through the oil cooler will be hampered because of the increased flow resistance in the oil cooler. If that happens, the by check valve opens, allowing the return oil to directly flow back to the hydraulic oil tank.

Boom Cylinder Arm cylinder Positioning cylinder (*) Bucket cylinder Center t

Swing motor Travel (R) Travel (L)

Bucket Boom 1

Aux. Hydraulic oil tank

Boom 2

Full-flow filter

Arm 1 Suction filter By check valve

Swing

Arm 2 Pump 1 Engine

Pump 2

Oil cooler Pressure oil Return oil (*) Triple articulation version

Center t

Left travel motor

Right travel motor

SM3005

T2-2-2

EX255-EX285

HYDRAULIC SYSTEM PILOT CIRCUIT control circuit, and in the swing parking brake release line.

Pressure oil from the pilot pump acts as working pressure in pilot operating circuit, in the pump/valve

Posit. pilot valve

Left pilot valve

Right pilot valve

Travel pilot valve

(*) Pilot operating circuit

Pilot shut-off valve

Manifold for shockless valves, pressure sensor, and for pressure switch

Swing motor

Hydraulic oil tank

Swing parking brake release

Suction filter

Solenoid valve unit SG

Pump / Valve control circuit

SI

Main pump regulator 2

Control valve SD

1

SC Pilot pump

Relief valve

Travel motor

Pilot filter

Travel motor


SM3006

EX255-EX285

T2-2-3

HYDRAULIC SYSTEM NEUTRAL CIRCUIT

SINGLE ACTUATOR OPERATION

When the control levers are in neutral, pressure oil from the main pumps returns to the hydraulic oil tank via the control valves. (Refer to the Control Valve Group in the COMPONENT OPERATION Section).

Pressure oil from pump 1 flows to the spools (Travel (R), Bucket, Boom 1, and Arm 2) in the 4-spool side section in the control valve. Pressure oil from pump 2 flows to the spools (Swing, Arm 1, Boom 2 , Aux., and Travel (L)) in the 5-spool side section in the control valve. When arm or boom is operated, pressure oil from both pumps is combined and flows together into the respective cylinder.

Left travel motor

Right travel motor

Pump control valve

Travel (R)

Travel (L)

Bucket cylinder

Bucket Aux.

Boom 2 Boom cylinder

Arm cylinder Boom 1 Arm 1 Arm 2 Swing Pump control valve

4-Spool side

5-Spool side

Hydraulic oil tank

Swing motor

Pump 2

Pump 1

SM0117

T2-2-4

EX255-EX285

HYDRAULIC SYSTEM COMBINED OPERATION Swing and Boom Raise Operation When swing and boom raise operations are performed at the same time, pilot pressure shifts the swing, boom 1, and boom 2 spools in the control valves. Then, pressure oil from pump 1 flows into the boom cylinder via the parallel age in the 4-spool side section in the control valve to raise the boom. Pressure oil from pump 2 flows into the swing motor to

swing the upperstructure. A portion of the pressure oil from pump 2 is detoured to the boom cylinder. The detoured oil flow is combined with the oil flow from pump 1 after flowing through the parallel age and boom 2 spool in the 5-spool side section in the control valve. The boom is raised by combined oil flow from pump 1 and pump 2.

Parallel age

Boom cylinder Boom 2

Boom 1

Swing

Parallel age

4-Spool Side

5-Spool Side

Swing motor

Pump 2

Pump 1

SM0118

EX255-EX285

T2-2-5

HYDRAULIC SYSTEM Travel and Arm Roll-In Operation When travel and arm roll-in operations are performed at the same time, pilot pressure shifts the travel, arm 1, and arm 2 spools. Pressure in the non-travel signal pilot pressure circuit rises due to arm spool movement, shifting flow combiner valve. Then, pressure oil from pump 1 flows into the right travel motor via the travel (R) spool, actuating it. A portion of the pressure oil from pump 1 is detoured

Left travel motor

to the left travel motor via the flow combiner valve and travel (L) spool, actuating it. For this reason, the machine can travel straight even when the arm rollin operation is performed at the same time, blocking oil flow from pump 2 to the left travel motor. Pressure oil from pump 2 flows into the arm cylinder via the arm 1 spool, actuating it.

Flow combiner valve

Right travel motor

Pilot pump Travel (R)

Travel (L)

Signal Pilot Pressure Circuit

Arm Cylinder

Arm 1

Arm 2

Pump 2

Pump 1

SM0119

T2-2-6

EX255-EX285

HYDRAULIC SYSTEM NOTES

EX255-EX285

T2-3-1

ELECTRICAL SYSTEM OUTLINE The electrical system is roughly classified into the main circuit, control circuit, and monitor circuit. • Main circuit: Related to circuit for the engine and accessories. • Control circuit: The control circuit of the engine, hydraulic pump, and valves (including actuators such as solenoid valves, MC (Main Controller), switch box, sensors, and pressure switches, and so on). • Monitor circuit: This circuits indicates machine operating conditions. (The circuits consisting of the monitors, sensors, and switches, and soon).

In this group, the main functions and construction of the main circuit and some functions of control and monitor circuit are explaned. • Electric Power Circuit: Supplies electric power to all electric system on this machine. (Key Switch, Batteries, Fuses (Fuse Box and Fusible links), Battery Relay)

• Preheat Circuit: Helps start the engine in cold weather. (Key Switch, QOS Controller, Glow relay, Glow plugs) • Starting Circuit: Starts the engine. (Key Switch, Starter, Starter Relay) • Charging Circuit: Recharges batteries and supplies electricity to the system. (Alternator, Regulator) • Surge Voltage Prevention Circuit: Prevents surge voltage from occurring when the engine is stopped. (Anti Load Dump Relay) • Engine Stop Circuit: Stops the engine with the EC motor (MC, EC Motor).

• Bulb Check Circuit: Checks for blown warning lights and indicator bulbs on monitor.

• Engine and pump control circuit: Operates the EC motor in order to control the engine speed. Control the pump displacement (Main Controller (MC). EC motor, Engine control dial, E and HP mode switch, pressure switches, pressure sensors, solenoid valve unit).

• Accessory Circuit: Works with the key switch placed in the ACC position.

• Monitor control circuit: Shows the operation conditions of the excavator. (Monitor , pressure switches and sensors).

T2-3-2

EX255-EX285

ELECTRICAL SYSTEM ELECTRIC POWER CIRCUIT (Key switch: OFF) The battery negative terminal is grounded to the vehicle. Current from the positive terminal flows as follows with the key switch OFF.

→ Fuse link 2 (40 A) → Glow relay (Power Source)

Battery →

Terminal 1 -

Radio (Backup Power Source) Monitor (Backup Power Source)

Terminal 2 -

MC (Power Source)

Terminal 3 -

MC (EC Motor)

Terminal 4 -

Auxiliary source (relay box)

→

Relay box

(terminal 14 - Relay R1 Anti Load Dump)

→

Terminal B -

Key switch

→

→ Fuse link 1 (40 A) → Fuse box

Coolant temperature switch

Glow plugs

Alternator

to Monitor (42)

Safety relay

Starter motor

Battery relay

Batteries

Glow relay

To fuel transfer pump motor (opt)

Fuse link

Q.O.S. Controller

Relay box

to monitor (18)

Fuse box

to Monitor (43)

Key switch

EX255-EX285 T2-3-3

ELECTRICAL SYSTEM

SM5607

Auxiliary power

EC motor

Radio (pow. b.u.)

MC pow. supply

T2-3-4

EX255-EX285

ELECTRICAL SYSTEM BULB CHECK CIRCUIT (Key switch: ON) When the key switch is turned to the ON position, key switch terminal B connects with key switch terminals M and ACC. The current from terminal M flows throught the diode D2, located inner the relay box, and excites the battery relay.

Then, the battery power is routed to the monitor through the battery relay, the fuse box and the wiper box, turning the warning lights and indicators on (for bulb check).

Batteries

Glow relay

To fuel transfer pump motor (opt)

Alternator

To monitor (42)

Safety relay

Starter motor

Glow plugs


Battery relay

Fuse link

QOS Controller

Relay box

To motor (18)

Fuse box

To monitor (43)

Monitor

Key switch

Wiper box

EX255-EX285 T2-3-5

ELECTRICAL SYSTEM

SM5608

T2-3-6

EX255-EX285

ELECTRICAL SYSTEM ACCESSORY CIRCUIT (Key Switch: ACC) When the key switch is turned to the ACC position, terminal ACC is connected to terminal B in the key switch.

Then, the battery current flows through the fuse box terminal 15, 16 and 17, to each accessory circuits (horn, radio, cigar lighter, power outlet, room lamp.

Batteries

Fuse link

Horn

Radio

Room light

Key switch

To monitor (30)

EX255-EX285 T2-3-7

ELECTRICAL SYSTEM

SM5609

Power outlet

Cigar lighter

T2-3-8

EX255-EX285

ELECTRICAL SYSTEM PREHEAT CIRCUIT (Key switch: ON or START) When the key switch is turned to the ON or START position, the key switch terminal B is connected to terminal M in the key switch. The current from terminal M flows to terminal #1 of QOS controller via the fuse #18 and supply power to glow relay. Throught the relay box. When the coolant temperature switch is OFF, QOS controller allows to preheat the engine for approx. 30 seconds. When QOS controller terminal #4 is grounded, glow plug relay comes ON, so that the glow plugs are heated.

Terminal #6 of QOS controller grounds to vehicle for 8 seconds while preheat, therefore glow signal is ON. (When preheat is not done, glow signal is ON for 0.3 seconds to check the blown bulb.)

NOTE - Coolant temperature switch becomes OFF when coolant temperature is less than 10 °C (50 °F).

Glow plugs

N.C. ≥ 10 °C


Batteries

Glow relay

Fuse link

QOS Controller

Relay box

To monitor (18)

Fuse box

Key switch

Monitor

EX255-EX285 T2-3-9

ELECTRICAL SYSTEM

SM5610

T2-3-10

EX255-EX285

ELECTRICAL SYSTEM STARTING CIRCUIT (Key Switch: START) When the key switch is turned to the START position, terminal B on the key switch is connected to terminals, M, and ST. The current from terminal M magnetizes the battery relay, leading the battery current to terminals B on the starter and starter relay via the battery relay. Terminal ST of the key switch is connected to terminal S on the starter relay so that the battery current flows through the coil in the starter relay, allowing the relay to close the circuit. Then, the battery current can flow to terminal C on the starter, closing the inner starter relay. Thereby, the starter begins to rotate. The current from terminal M flows to the MC, instructing that the key switch is positioned at ON or START. When this signal arrives at the MC, the MC actuates the EC motor which moves the governor lever.

Starter Relay Operation • When the key switch is turned to the START position, key switch terminal B and ST have continuity in the key switch. Then, the current flows to the base of transistor (Q2) via resistance R4 in the starter relay, switching transistor (Q2) ON. Thereby, the current flows through coil (L) of relay, closing the circuit between starter terminals B and C. Then, the starter begins to rotate. • Once the engine is started, the alternator begins to charge the batteries so that the voltage at starter relay terminal R rises. When the voltage at terminal R reaches 21 to 22 V, zener diode (Z) comes ON. Accordingly, transistor (Q1) is switched ON so that the base current to transistor (Q2) is cut, switching transistor (Q2) OFF. At this time, continuity between starter terminal B and C is opened. Then, the starter is switched OFF. Capacitor C1 shown in the figure is used to stabilize the operating voltage. Diode D4 protects the circuit from damage when the batteries are inversely connected.

Starter Relay S

B R4 (1) R3

To Alternator Terminal L

R

R2

L

C (2)

D2

Z

D3

Q1

(1) C M B

Q2

(2) C1

C

Starter

E D4

12V B ST

Key Switch

Batteries 12V

SM4015A

Alternator

To monitor (42)

Safety relay

Starter motor

Batteries

Battery relay

Fuse link

Relay box

To monitor (18)

Fuse box

Main controller (MC)

Key switch

EX255-EX285 T2-3-11

ELECTRICAL SYSTEM

SM5611

T2-3-12

EX255-EX285

ELECTRICAL SYSTEM CHARGING CIRCUIT (Key Switch: ON) After the engine starts and the key switch is released, the key switch is returned to the ON position. With the key switch kept ON, key switch terminal B is connected to terminals ACC and M. After the engine starts, the alternator begins power

generation. Current from terminal B on the alternator flows to the batteries through the battery relay recharging the batteries. In addition, this current from Alternator terminal L flows to the monitor to turn off the charge lamp.

Starter motor

Alternator

Batteries

Battery relay

Monitor

Relay box

Fuse box

Key switch

EX255-EX285 T2-3-13

ELECTRICAL SYSTEM

SM5612

T2-3-14

EX255-EX285

ELECTRICAL SYSTEM Power Generation The alternator consists of field coil FC, stator coil SC, and diodes D. The regulator consists of transistors T1 and T2, zener diode ZD, and resistors R1 and R2. Alternator terminal B is connected to: B→R→RF→(R)→R1→Base B for Transistor T1 When the key switch BS is turned ON, the battery voltage flows to base B for transistor T1 in the regulator, allowing current to flow from collector C to emitter E. Accordingly, field coil FC is grounded through transistor T1.

At first, the current does not flow to field coil FC. When the rotor starts to rotate, alternating voltage is generated in stator coil SC due to residual magnetism in the rotor. Thereby, the current starts to flow through field coil FC, magnetizing the rotor further and increasing generating voltage. As generating voltage increases, the flowing current through field coil FC is increased further, causing the generating voltage to increase more. Thus, the batteries are recharged.

Alternator

Regulator B

R RF

L (R)

BS

R3

R4

R5

R6 D Monitor R2

ZD Batteries

B

SC

E

FC

(F)

R1

C

D1

B C

T2 E T1

(E) E

SM4056A

EX255-EX285

T2-3-15

ELECTRICAL SYSTEM Regulator Operation When the generating voltage increases higher than the set voltage of zener diode ZD, the current from the alternator flows through the zener diode to base B for transistor T2, connecting collector C to emitter E. Accordingly, the current flowing through base B for transistor T1 is cut so that transistor T1 is turned OFF. Thereby, the current flowing through field coil FC is cut, causing the SC generating voltage to decrease.

Then, when the voltage to be applied to zener diode ZD becomes lower than the set voltage of zener diode ZD, transistor T2 is turned OFF, turning transistor T1 ON again. Thus, the current is allowed to flow through field coil FC to increase the generating voltage by stator coil SC. As this operation is repeated, the alternator generating voltage is maintained at the specified level.

RF

R3

BS

R4

R5

R6

ZD

R2

B

SC A

E

C FC

R1

(F)

E

D1

T2

B C

E T1

(E)

SM4057

T2-3-16

EX255-EX285

ELECTRICAL SYSTEM SURGE VOLTAGE PREVENTION CIRCUIT When the engine is stopped (key switch is OFF), the current from key switch terminal M is cut so that battery relay is turned OFF. The engine does not stop immediately by the key switch OFF, due to inertia and the alternator continues to generate electricity. Because the alternator generating current dose not flow to the batteries, the surge voltage (Voltage rise) is developed in the circuit. This is the cause of failure of electrical parts and components. On of this, the surge voltage prevention circuit has been provided.

While the batteries are being recharged, the generating current from terminal L on the alternator is led to terminal #42 on the monitor, turning the output transistor ON for terminal #18 on the monitor. In the conditions, the batteries current holds the Anti Load Dump relay R1, located in the relay box, energised. Accordingly, even if the key switch is turned OFF while the engine is running, the battery current can be supplied through the anti load dump relay (R1) to magnetize the battery relay, holding the battery relay ON until the alternator stops generating.

Alternator

Safety relay

Starter motor

Batteries

Battery relay

Fuse link

Relay box

Fuse box

Monitor

Key switch

EX255-EX285 T2-3-17

ELECTRICAL SYSTEM

SM5613

T2-3-18

EX255-EX285

ELECTRICAL SYSTEM ENGINE STOP CIRCUIT (Key Switch: OFF) When the key switch is turned from the ON position to the OFF position, the signal instructing the MC that the key switch is ON is cut.

Then, the MC moves the EC motor to the stop position causing the engine to stop.

Batteries

Fuse link

Fuse box

To monitor (39)/ To Radio

Key switch

Main Controller (MC)

EC Sensor

EC Motor

EX255-EX285 T2-3-19

ELECTRICAL SYSTEM

SM5614

T2-3-20

EX255-EX285

ELECTRICAL SYSTEM ENGINE AND PUMP CONTROL CIRCUIT The main controller (MC) monitors all digging functions, travel functions, and hydraulic pump functions Further the main controller stores possible malfunction conditions of hydraulic and electrical system generating faults codes that can be detected from the diagnostic instrument (Dr.EX). The main controller(MC) receives as input signals: - from switch the signals related to the travel speed, the auto idle position and work mode selection; - from the R.H. control lever hand grip the input signal of power boost; - from engine speed control dial the engine speed signal and mode switches E and HP signals. To provide the required functions, the main controller (MC), compares these input signals with instant conditions detect from various pressure switches and sensors and provide output signals for the engine speed control (by means of the operation of EC motor), and for the pump control circuit (by means of solenoid valves operation).

• Engine speed control circuit The engine speed control circuit consists of engine control dial, E and HP mode switches Auto Idle switch, N sensor and EC motor and angle sensor assembly. The engine control dial adjusts the engine revolutions independently of positions of E mode, HP mode switches. The engine control dial sends an electrical signal to the main controller proportionally to the engine control dial angle. (This signal can be detected from Dr.EX with monitor function by selecting: Target engine speed). The N sensor supply signal to the main controller indicating the engine speed. (This signal can be detected from Dr.EX with monitor function by selecting: Actual engine speed). In order to change the engine speed, the main controller sends signals to the EC motor, that revolves and controls the governor lever. (This signal can be detected from Dr.EX with monitor function by selecting: EC motor position).

The EC angle sensor detects the position of EC motor and supplies signals to the main controller to indicate the position of the governor lever. (This signal can be detected from Dr.EX with monitor function by selecting: EC angle). The main controller (MC) compares and processes the input signals and if the engine requires engine speed changes, it supplies power to the EC motor in order to change the position of governor lever.

Fuse box

From fuse link 3 60 A


Solenoid valve group

Key switch

Pressure switch

To/from monitor

N Sensor


EC Motor

From relay box (R14)

Pressure sensor

to monitor

EX255-EX285 T2-3-21

ELECTRICAL SYSTEM

SM5615

T2-3-22

EX255-EX285

ELECTRICAL SYSTEM • Pump control circuit The pump control circuit consists of pilot pressure switches related to boom up, Front attachment and travel, Pump 1 and 2 delivery pressure sensors, Arm roll-in pilot pressure sensor , Pump 1 and 2 control pressure sensors, work mode selector, travel mode selector and solenoid valve group.

(The operation of each pressure sensor can be detected from Dr.EX with monitor function by selecting: Pump 1 or 2 Delivery pressure, Pump 1 or 2 Control pressure, Arm Roll-in pilot pressure. The Dr EX will detect the electrical signal and will show as pressure value of the related Sensors)

The pilot pressure switches related to the boom up (located on the shockless valve), front attachment and travel (located on control valve), when receive the actuating pressure, send a ground signal to the MC controller. (The operation of each pressure switch can be detected from Dr.EX with monitor function by selecting: Pressure switch. The Dr EX will detect the pressure switch ON or OFF condition showing or deleting the related pressures switch abbreviation BmH, Fr, Tr ).

As result of the position of the Work mode selector, travel mode selector and the actual condition detected from various pressure switches and sensors, the MC controller processes the output signal to operate the pump regulator solenoid valve (SD), the travel motor swash angle solenoid valve (SI), the arm regenerative solenoid valve (SC), and the relief pressure solenoid valve (SG). (The operation of each solenoid valve can be detected from Dr.EX with monitor function by selecting the individual solenoid valve. The Dr EX will detect the control electrical signal and will show as controlled pressure value from each related solenoid valve).

The Pump 1 and 2 delivery and control pressure sensors located on the pump device) and the Arm Roll-in pilot pressure sensor (located on shockless valve) send to controller MC an electrical signal that is proportional to related pressure to be controlled.

Fuse box



Solenoid valve group

Key switch

Pressure switch

To/from monitor

N Sensor


EC Motor

From relay box (R14)

Pressure sensor

to monitor

EX255-EX285 T2-3-23

ELECTRICAL SYSTEM

SM5615

T2-3-24

EX255-EX285

ELECTRICAL SYSTEM MONITOR CIRCUIT The monitor circuit consists of circuits to operate the hour meter, coolant temperature gauge, fuel gauge, engine oil level indicator, engine oil pressure indicator, coolant level indicator, engine overheat indicator, alternator charging indicator, fuel low level indicator, air cleaner restriction indicator, hydraulic oil level indicator and engine pre-heat indicator. Hour meter operates when alternator is charging and anti load dump relay is energized. Monitor gauges receive signal from sensors to indicate fuel level and engine coolant temperature. The monitor controller contains a logic circuit and transistors to control ground signals for monitor indicator lights. Monitor controller receives signals from engine oil level switch, coolant level switch, hydraulic oil level switch, engine overheating switch, engine oil pressure switch, fuel low level switch, air filter restriction switch, Q.O.S. controller and alternator.

Monitor controller provides voltages to transistors if temperature, pressures or levels are outside normal limits to illuminate indicator lights. Engine oil level switch is closed when oil level in the oil pan is OK. Coolant level switch is closed when coolant level in the recovery tank is OK. Hydraulic oil level switch is closed when level in the hydraulic oil tank is OK. Fuel low level switch is open when the fuel level in the fuel tank is above the reserve Engine overheat switch is open when coolant temperature is within normal operating range. Engine oil pressure switch opens above 98 kPa (14.2 psi) and closes when the oil pressure is below. Engine air filter restriction switch closes when vacuum is above approx. 635 mm (25 in.) water , and opens when vacuum is below. The pre-heating temperature switch is closed when engine coolant temperature is lower to 10°C (50 °F).

NOTE: Shown with engine stopped and correct liquid level.

Fuse box

From fuse link 3 (60 A)

From fuse link 1 (40 A)

Key switch

Wiper box

Relay box Monitor

} to wiper box

EX255-EX285 T2-3-25

ELECTRICAL SYSTEM

SM5616

Relay box

Alternator

T2-3-26

EX255-EX285

ELECTRICAL SYSTEM NOTES:

SECTION 3

EX255-EX285

COMPONENT OPERATION

CONTENTS Group 1 -

Pump device Group 5 -

Outline ................................................. T3-1-1 Main pump .......................................... T3-1-2 Regulator ............................................. T3-1-5 Pilot pump ........................................... T3-1-13 N sensor (Engine speed sensor) ......... T3-1-13 Pump pressure sensor ........................ T3-1-13

Group 2 -

Outline ................................................. T3-5-1 Travel reduction gear ............................ T3-5-3 Travel motor ......................................... T3-5-5 Travel brake valve ................................ T3-5-10 Parking brake ....................................... T3-5-13

Swing device Group 6 -

Outline ................................................. T3-2-1 Swing motor ........................................ T3-2-3 Swing parking brake ............................ T3-2-6 Valve unit ............................................. T3-2-7 Swing reduction gear ........................... T3-2-9

Group 3 -

Other components (Upperstructure)

Pilot shut-off valve ............................... T3-6-1 Shockless valve ................................... T3-6-2 Solenoid valve unit .............................. T3-6-4 Pilot relief valve ................................... T3-6-6 EC motor ............................................. T3-6-6

Control valve

Outline ................................................. T3-3-1 Hydraulic circuit ................................... T3-3-6 Flow combiner valve ............................ T3-3-8 Pump control valve .............................. T3-3-10 Main relief valve .................................. T3-3-12 Overload relief valve ............................ T3-3-13 Arm regenerative valve ........................ T3-3-14 Boom anti-drift valve, arm anti-drift valve ............................... T3-3-16 Bucket flow control valve ..................... T3-3-16 Travel flow control valve ....................... T3-3-18 Travel/boom lower selector valve ...................................... T3-3-18 Boom regenerative valve ..................... T3-3-20

Group 4 -

Travel device

Pilot valve

Outline ................................................. T3-4-1 Operation ............................................ T3-4-3

Group 7 -

Other components (Undercarriage)

Swing bearing ...................................... T3-7-1 Center t .......................................... T3-7-2 Track adjuster ...................................... T3-7-3

EX255-EX285

T3-1-1

PUMP DEVICE OUTLINE The pump device consists of a transmission, main pump, and pilot pump. The transmission receives engine power via coupling, then divides and transmits the power to pump 1 (1), pump 2 (2) and pilot pump (3) via gears. Gear ratios on the main pump drive side and the pilot pump side are 1. Main pumps (1 and 2) are variable displacement,

bent-axis plunger-type pumps equipped with pump delivery pressure sensors (5) and engine speed sensor (4) for controlling of the pumps and valves. These main pumps are incorporated into a single housing. Pilot pump (3) is a gear-type pump.

4

3

2

1

Transmission SM3016

Transmission

5 SM3017

1 2 3

- Pump 1 - Pump 2 - Pilot Pump

SM3018

4 5

- Engine Speed Sensor (N Sensor) - Pump Delivery Pressure Sensor

T3-1-2

EX255-EX285

PUMP DEVICE MAIN PUMP Operation Main pump consists of pump 1 and pump 2, and supplies hydraulic oil to actuate main components such as motors and/or cylinders. Shaft (3) is connected to cylinder block (6) via seven plungers (4).

Therefore, the rotation of shaft (3) is transmitted to cylinder block (6), causing cylinder block (6) to slide along the surface of valve plate (5). Plungers (4) reciprocate in the cylinder bores, thus discharging hydraulic oil to the hydraulic circuits.

SM0005

1 2

6

3

4 5 SM0004

1 2 3

- Regulator - Housing - Shaft

SM0006

4 5 6

- Plunger - Valve Plate - Cylinder Block

EX255-EX285

T3-1-3

PUMP DEVICE

4

5

3

6

SM0007

T3-1-4

EX255-EX285

PUMP DEVICE Increasing and Decreasing Main Pump Oil Flow Rate When the displacement angle of cylinder block (3) is changed, the stroke length of plunger (2) changes. Thus, oil flow rate of the main pump is controlled by changing the displacement angle of cylinder block (3). Servo piston (6) is ted to valve plate (4) with pin (5).

When servo piston (6) is moved up or down, valve plate (4) moves too, changing the displacement angle of cylinder block (3); cylinder block (3) is kept in with the surface of valve plate (4) and slides along it.

Maximum displacement angle

2

3

α 5 2 6

3

SM0006

SM0008

Minimum displacement angle

α

SM0009

2 3 4

- Plunger - Cylinder Block - Valve Plate

4

5 6

- Pin - Servo Piston

EX255-EX285

T3-1-5

PUMP DEVICE REGULATOR Regulator Construction pump pressure and the pilot pressure from the solenoid valve unit (SD) are routed to the section 2 of the regulator. (Note that, viewed from a regulator, two main pumps are said to be the applicable main pump and the other main pump). Upon receiving various signal pressures stated above, the regulator outputs a pilot pressure to servo piston (10) to change the displacement angle of cylinder block (11), thus controlling the pump oil flow rate.

Both main pumps (1 and 2) are equipped with a regulator. Upon receiving various signal pressures, the regulator controls main pump oil flow rate not to exceed the engine horsepower. Regulator mainly consists of spring (1), sleeve B (2), spool B (3), piston (4), load piston (5), spool A (6), sleeve A (7), outer spring (8), and inner spring (9). The pump control pressure is routed to section 1 and the applicable main pump pressure, the other main

1

2

3

4

}

Section I

} 5

6

7

8

Section II

9 SM0010

12

11

10

SM0006

1 2 3 4

-

Spring Sleeve B Spool B Piston

5 6 7 8

-

Load Piston Spool A Sleeve A Outer Spring

9 10 11 12

-

Inner Spring Servo Piston Cylinder Block Link

T3-1-6

EX255-EX285

PUMP DEVICE Regulator Functions The regulator functions to control pump oil flow rate as follows:

• Control by Pump Control Pressure The pump control valve attached on the control valve regulates the pump control pressure. Upon receiving the pump control pressure from the pump control valve, the regulator increases or decreases the pump flow rate accordingly. When the control valve spool is moved to increase the pump control pressure, the regulator increases the pump flow rate. When the control valve spool is returned to neutral, the pump control pressure decreases. Accordingly, the regulator reduces the pump flow rate to the minimum flow. (Refer to the Control Valve Group).

• Summation Control (Control by monitoring both main pump pressures) If the delivery oil pressure of either of two main pumps increases so that the average pressure of two main pumps exceeds the values set by the P-Q line, the regulator functions to reduce pump oil flow rate of both main pumps to match the P-Q value to the one on the set P-Q line, preventing engine overloading. Since the P-Q line is set using the average pressure of two main pump pressures, delivery rates of both pumps are approximately equal to each other. For this reason, a larger load is applied to the pump delivering high pressure oil while a smaller load is applied to the pump delivering low pressure oil, keeping the total load applied to the pumps equal with the engine horsepower output. (Total Horsepower Control)

• Control by Pilot Pressure Guided from Solenoid Valve Unit (SD) Processing the target engine speed, and the actual engine speed, the main controller MC sends signal to solenoid valve unit (SD). Solenoid valve unit, in turn, routes a pilot pressure to the regulator. Then, the regulator reduces pump delivery rate accordingly. (Speed Sensing (Horsepower Reducing) Control) (Refer to the control system Group in the SYSTEM Section).

Q Flow rate

0

Pump control pressure

Pi

Pressure increase

Q Flow rate Flow rate decrease

0

Pressure

P

Q Flow rate

0

Pressure

P

SM0011

EX255-EX285

T3-1-7

PUMP DEVICE Regulator operation 3

6

2

1

Pi

12 10 Pps 11 9

13 Pd1 Pd2

8

5 SM0012

7 3

4 2

6

1

Pi Pd1 11-12

Pps Pd2

5 9

13 10 7

1 2 3 4 5 6 7

-

Piston Spool B Spring Servo Piston Link Sleeve B Large Chamber

4 8 9 10 11 12 13

-

8 Small Chamber Load Piston Spool A Inner Spring Outer Spring Sleeve A

SM0013

T3-1-8

EX255-EX285

PUMP DEVICE • Flow Rate Control by Pump Control Pressure

Flow rate increase: changed by the movement of the servo piston, increasing the pump flow rate. 6. The movement of servo piston (4) is transmitted to sleeve B (6) via link (5), moving sleeve B (6) in the direction that spool B (2) has moved. When sleeve B (6) moves for the same distance spool B (2) has moved, large chamber (7) is closed to the hydraulic oil tank line, stopping the servo piston movement, thus stopping the increase of pump flow rate at that point.

1. Pump control pressure Pi increases when a control valve spool is moved. 2. Piston (1) pushes spool B (2) and spring (3) to move spool B (2) to the direction indicated by the arrow. 3. Large chamber (7) at the end of servo piston (4) is connected to the hydraulic oil tank line. 4. As a result, servo piston (4) moves to the direction indicated by the arrow. 5. The displacement angle of the cylinder block is

3

6

2

1

Pi

Pressure increase

Pps Q Pd1 Pd2

Flow rate

8

0


Pi 5 SM0014

7

4 SM0015

1234-

Piston Spool B Spring Servo Piston

5678-

Link Sleeve B Large Chamber Small Chamber

EX255-EX285

T3-1-9

PUMP DEVICE Flow rate decrease: 1. When the control valve spool is returned to neutral, the pump control pressure Pi decreases. 2. Spring (3) pushes back piston (1) and spool B (2), returning spool B (2) to the direction indicated by the arrow. 3. As a result, the servo pressure acting on small chamber (8) is also routed to large chamber (7). 4. Servo piston (4) moves in the direction indicated by the arrow, due to the size difference of the pressure receiving area between both chambers.

5. The displacement angle of the pump decreases. 6. The movement of servo piston (4) is transmitted to sleeve B (6) via link (5), moving sleeve B (6) in the direction that spool B (2) has moved. When sleeve B (6) moves for the same distance spool B (2) has moved, large chamber (7) is closed to the hydraulic oil tank line, stopping the servo piston movement, thus stopping the decrease of pump flow rate at that point.

3

6

2

1

Pi

Pressure decrease

Pps Q

Pd1 Pd2

Flow rate

8

0


Pi 5 SM0016

7

1234-

Piston Spool B Spring Servo Piston

5678-

Link Sleeve B Large Chamber Small Chamber

4

SM0017

T3-1-10

EX255-EX285

PUMP DEVICE • Summation Control (Flow Rate Control by Monitoring Both Main Pump Pressures)

Flow Rate Increase: (Note that, viewed from a regulator, two main pumps are said to be the applicable main pump and the other main pump)

indicated by the arrow. 5. As the servo piston moves, the displacement angle of the cylinder block changes, increasing the pump flow rate. 6. The movement of servo piston (4) is transmitted to sleeve A (13) via link (5), moving sleeve A (13) in the direction spool A (10) has moved. When sleeve A (13) moves for the same distance spool A (10) has moved, large chamber (7) is closed to the hydraulic oil tank line, stopping the servo piston movement, thus stopping the increase of pump flow rate at that point.

1. The pressure from the applicable main pump (Pressure Pd1) or from the other main pump (Pressure Pd2) decreases. 2. Inner spring (11) and outer spring (12) pushes load piston (9) and spool A (10), moving them in the direction indicated by the arrow. 3. Large chamber (7) at the end of servo piston (4) is connected to the hydraulic oil tank line. 4. As a result, servo piston (4) moves in the direction

9

13

10

Pi 11 Pps Q

12

Flow rate

Pd1 Pd2

Pressure decrease

8

0

(Summation of two main pump pressures)

Pd 5 SM0018

7

4 SM0015

4 5 7 8 9

-

Servo Piston Link Large Chamber Small Chamber Load Piston

10 11 12 13

-

Spool A Inner Spring Outer Spring Sleeve A

EX255-EX285

T3-1-11

PUMP DEVICE Flow rate decrease: 1. The pressure from the applicable main pump (Pressure Pd1) or from the other main pump (Pressure Pd2) increases. 2. Load piston (9) pushes spool A (10), inner spring (11), and outer spring (12), moving spool A (10) in the direction indicated by the arrow. 3. As a result, the servo pressure acting on small chamber (8) is also routed to large chamber (7). 4. Servo piston (4) moves in the direction indicated

by the arrow, due to the size difference of the pressure receiving area between both chambers. 5. The displacement angle of the pump decreases. 6. When sleeve A (13) moves for the same distance spool A (10) has moved, servo pressure routed to large chamber (7) is shut out, stopping the servo piston movement, thus stopping the decrease of pump flow rate at that point.

13

9

10

Pi 11

Flow rate

Pps

Q

12 Pd1 Pd2

Pressure increase

8

0


Pd 5 7 SM0019

4 SM0020

4 5 7 8 9

-

Servo Piston Link Large Chamber Small Chamber Load Piston

10 11 12 13

-


T3-1-12

EX255-EX285

PUMP DEVICE • Flow Rate Control by Pilot Pressure Guided from Solenoid Valve Unit (SD).

Flow rate decrease: 1. Solenoid valve unit (SD) is activated by signals from the main controller MC, guiding pilot pressure Pps. 2. Pilot pressure Pps, together with the applicable main pump pressure or with the other main pump pressure, acts on load piston (9). 3. Load piston (9) pushes spool A (10), inner spring (11), and outer spring (12), moving spool A (10) in the direction indicated by the arrow. 4. As a result, the servo pressure acting on small

chamber (8) is also routed to large chamber (7). 5. Servo piston (4) moves in the direction indicated by the arrow, due to the size difference of the pressure receiving area between both chambers. 6. The displacement angle of the pump decreases. 7. When sleeve A (13) moves for the same distance spool A (10) has moved, servo pressure routed to large chamber (7) is shut out, stopping the servo piston movement, thus stopping the decrease of pump flow rate at that point.

13

9

10

Pi 11 Pps 12

Pressure increase

Q

Pd1 Pd2

Flow rate

8

0


7

P

4 SM0021 SM0020

4 7 8 9

-

Servo Piston Large Chamber Small Chamber Load Piston

10 11 12 13

-


EX255-EX285

T3-1-13

PUMP DEVICE PILOT PUMP

Suction port

2

1

Drive gear (1) is rotated via the transmission to driven gear (2).

1 2

- Drive gear - Driven gear

Delivery port SM0022

N SENSOR (ENGINE SPEED SENSOR) The N sensor detects engine speed. Engine speed is a necessary signal for various controls of the machine. The N sensor is installed close to the top of the transmission gear; when the gear rotates, gear tooth tops by the top of the N sensor. Then numbers of gear teeth ing by are converted to electrical pulse signals which are sent to the EC. Thereby, engine speed is detected.

4 5 6 7 8

-

4 5 6

Coil Magnet Gear Signal output terminal Power supply (5 V)

7

8 SM0023 SM0024

PUMP PRESSURE SENSOR The pump pressure sensor detects oil pressure. Oil pressure is a necessary signal for various controls of the machine. Oil pressure is received by diaphragm (12). Depending on the extent of deformation of the diaphragm, oil pressure is detected as an electrical signal.

9 10 11 12

-

Grounding terminal Output terminal Power supply (5V) terminal Pressure receiving section (diaphragm)

9

10

11

12

SM0025

T3-1-14

EX255-EX285

PUMP DEVICE NOTE

EX255-EX285

T3-2-1

SWING DEVICE OUTLINE The swing device consists of the valve unit, the swing motor, and the swing reduction gear. The valve unit prevents cavitation and overload of the swing circuit. The swing motor is a swash-plate-type axial plunger

NOTE- The figure shows the swing device installed on EX255

motor (with a built-in parking brake for swing), and is driven by the pressure oil from the pump to rotate the swing reduction gear. The swing reduction gear rotates the upperstructure by rotating the shaft by slow speed and large torque.

Valve unit

Swing motor

Swing reduction gear

SM3019

T3-2-2

EX255-EX285

SWING DEVICE NOTE - The figure shows the swing device installed on EX285.

Valve unit

Swing motor

Swing reduction gear

SM5001

EX255-EX285

T3-2-3

SWING DEVICE SWING MOTOR The swing motor consists of the swashplate, rotor, plungers, valve plate, housing and swing parking brake (consists of spring, brake piston, plate, friction plate and switch valve). The rotor is installed onto shaft with a spline coupling, and the plungers are inserted in rotor. The pressure oil is fed from the pump so that the plungers are pushed.

The shoe of the plunger slides along swash plate, and rotation occurs in rotor. The shaft end is connected to first stage sun gear of the swing reduction gear by a spline coupling. Therfore the rotation of shaft is transmitted to the swing reduction gear.

NOTA - The figure shows the swing motor installed on EX255.

3

9

1-2

8

1 2 3 4 5 6

-

Valve Plate Rotor Housing Plunger Shoe Shaft

4

6

5

7

7 8 9 10 11

-

Swash Plate Switch valve Plate and Friction Plate Brake piston Spring

SM0027

T3-2-4

EX255-EX285

SWING DEVICE NOTE - The figure shows the swing motor installed on EX285.

1

11

10 2

3 9

4

8 5

7

6

SM5007

1 2 3 4 5 6

-

Valve Plate Rotor Housing Plunger Shoe Shaft

7 8 9 10 11

-

Swash Plate Switch valve Plate and Friction Plate Brake piston Spring

EX255-EX285

T3-2-5

SWING DEVICE Swing speed varies depending on the amount of oil delivered from the pump. From port A, high pressure oil is fed so that plunger (3) is pushed from the top to the bottom. Shoe (4) then slides along swash plate (5), developing turning force.

Turning force is transmitted to the swing reduction gear unit via shaft (6). The return oil flows to outlet port B and returns to the hydraulic oil tank. When pressure oil is fed to port B, the motor rotates in the opposite direction.

A

B

1

2

3

4 5

6

SM0028

1 2 3

- Valve Plate - Rotor - Plunger

4 5 6

- Shoe - Swash Plate - Shaft

T3-2-6

EX255-EX285

SWING DEVICE SWING PARKING BRAKE

1

The parking brake is a wet-type multiple disc brake. The brake is released only when brake release pressure enters into brake piston chamber (b), (negative type brake). When swing and/or front attachment operation is made brake release pressure is supplied from the pilot pump. During operations other than swing and/or front, or while the engine is stopped, brake release pressure is routed to the hydraulic oil tank and the parking brake is automatically applied by spring (1).

2 b 3 4 5

• When the swing and/or front function is operated, the brake is released: When the swing and/or front control lever is operated, the control valve spool for swing and/or front function is moved from the neutral position, closing the spool age for the signal pilot pressure circuit. Then, the pilot oil pressure increases, and the increased pressure pilot oil is sent to the pilot port of the switch valve in the brake release circuit. Therefore, the switch valve is opened, allowing the brake release pilot oil pressure from the pilot pump to act on brake piston (2) via the oil pressure timer check valve. Accordingly, brake piston (2) is moved up against spring (1), breaking between friction plates (4) and plates (3). Then, the brake is released.

• When the swing and/or front function is not operated, the brake is applied: When the swing and/or front control lever is not operated, the control valve spool for swing and/or front function is in the neutral position, holding the spool age for the signal pilot pressure circuit open. Then, the pilot oil pressure does not increase. Therefore, the switch valve in the brake circuit is kept closed, allowing the brake release pilot oil pressure on brake piston (2) to flow out to the hydraulic oil tank via the oil pressure timer orifice. Accordingly, brake piston (2) is moved down by spring (1) force so that friction plates (4) come into with plates (3). As friction plates (4) engage the inner circumference of motor housing (5) and plates (3) engage the outer circumference of rotor (6), rotor (6) is braked by friction force developed between plates (3) and friction plates (4).

6 1 2 3

- Spring - Brake Piston - Plate

SM0032

4 5 6

- Friction Plate - Motor Housing - Rotor

When the brake is released (OFF): Oil pressure timer Signal pilot pressure circuit

Brake release pressure

OFF

Swing motor Spool

Switch valve

SM0033

When the brake is applied (ON): Oil pressure timer Signal pilot pressure circuit

Brake release pressure

ON

Swing motor Switch valve Spool

SM0034

EX255-EX285

T3-2-7

SWING DEVICE VALVE UNIT

Relief valve

The valve unit consists of the make-up valve and the relief valve. The make-up valve prevents cavitation in the circuit, and the relief valve prevents surge pressure and overloads in the circuit. Make-Up Valve When swing is stopped, if the upperstructure tends to keep rotating due to inertia force, causing the swing motor to continue rotating further, and to begin sucking oil from the pump, developing cavitation in the motor. The make-up valve sucks hydraulic oil through the return circuit (port M) to compensate for the lack of oil, and prevent cavitation.

Make-up valve

Port M

A

B

Control valve

SM0029

Relief valve

Port M

Make-up valve

Control valve

SM5008

T3-2-8

EX255-EX285

SWING DEVICE Relief Valve When starting or stopping swing operation, oil pressure in the swing circuit becomes high. The relief valve prevents the circuit pressure from rising higher than the specified pressure. Plunger (1) is pushed to the left by pressure Pp at port (P) and pressurereceiving area A2. However, plunger (1) is also pushed back to the right by spring (2) force and pressure Pg at chamber (g) and pressure-receiving area A1. Chamber (g) is routed to port (P) through orifice (m). When force acting on the right is higher than that on the left, the relief valve operates.

Relief valve

PA

PB

Port M

A

B

Control valve

SM0029

g

2

1 m

P

A1

A2

SM0031

EX255-EX285

T3-2-9

SWING DEVICE SWING REDUCTION GEAR The swing reduction gear is a two-stage planetary gear type. Ring gears (2 and 4) in the first and second stages are provided on the inside of the housing. The housing is bolted to the main frame so that ring gears (2 and 4) are held stationary. The motor output shaft of the swing motor drives first stage sun gear (9). Then, rotary power is transmitted to second stage

sun gear (7) via first stage planetary gear (1) and first stage carrier (8). Second stage sun gear (7) rotates shaft (5) via second stage planetary gear (3) and carrier (6). As shaft (5) meshes with the internal gear of the swing bearing bolted to the undercarriage, the upperstructure is rotated.

NOTE - The figure shows the swing reduction gear installed on EX255. 9 8

1

2 3

7

4

6

5

SM3020

1 2 3 4 5

-

First Stage Planetary Gear First Stage Ring Gear Second Stage Planetary Gear Second Stage Ring Gear Shaft (Output Shaft)

6 7 8 9

-

Second Stage Carrier Second Stage Sun Gear First Stage Carrier First Stage Sun Gear

T3-2-10

EX255-EX285

SWING DEVICE NOTE - The figure shows the swing reduction gear installed on EX 285.

9 8

1 2

7

3 4

6

5

SM5002

1 2 3 4 5

-

First Stage Planetary Gear First Stage Ring Gear Second Stage Planetary Gear Second Stage Ring Gear Shaft (Output Shaft)

6 7 8 9

-

Second Stage Carrier Second Stage Sun Gear First Stage Carrier First Stage Sun Gear

EX255-EX285

T3-3-1

CONTROL VALVE OUTLINE The control valve controls oil pressure, flow rate, and flow direction in the hydraulic circuit. A 4-spool side section and a 5-spool side section are bolted together. The control valve is a pilot-pressure-operated type which mainly consists of the main relief valve, pump control valves, flow combiner valve, and main spools.

Machine Front

In the 4-spool side section, the Right Travel, Bucket, Boom 1, and Arm 2 spool sections are arranged in that order as viewed from the machine front. In the 5-spool side section, the Left Travel, Auxiliary, Boom 2, Arm 1, and Swing spool sections are arranged in that order as viewed from the machine front.

Right travel

Bucket

Left travel

Main relief valve

Boom 1

Arm 2

Auxiliary 4-spool side section Boom 2

Arm 1 Swing

Pump control valve (5-spool side)

5-spool side section

Machine Rear

SM0036

T3-3-2

EX255-EX285

CONTROL VALVE Control valve layout Left travel motor

1

3 2

4

5

6

7

8

9

10

Right travel motor

11 12

41

13 14

40

15 16

39

Bucket cylinder

38 37 36 35 34

Boom cylinder

17 18

Arm cylinder

33 32 31

19 20

30 29

21 22 23 26 27 28

24 25

Swing motor

1 2 3

- Hydraulic Timer - Travel Flow Control Valve - Load Check Valve (Travel Parallel Circuit) 4 - Check Valve 5 - Main Relief Valve 6 - Check Valve 7 - Check Valve 8 - Flow Combiner Valve 9 - Load Check Valve (Bucket) 10 - Bucket Flow Control Valve (Switch Valve A) 11 - Bucket Flow Control Valve (Switch Valve B) 12 - Bucket Flow Control Valve (Poppet Valve) 13 - Load Check Valve (Boom 1 Parallel Circuit) 14 - Load Check Valve (Boom 1 Tandem Circuit)

SM0037

15 16 17 18 19

-

20 21 22 23 24 25 26 27 28 -

Overload Relief Valve (Bucket) Overload Relief Valve (Bucket) Overload Relief Valve (Boom) Overload Relief Valve (Boom) Boom Anti-Drift Valve (Check Valve) Boom Anti-Drift Valve (Switch Valve) Boom Regenerative Valve Check Valve Pump Control Valve (4-Spool Side) Check Valve Restriction (4-Spool Side Parallel Circuit) Load Check Valve (Arm Parallel Circuit) Restriction (Arm 1 Parallel Circuit) Load Check Valve (Swing)

29 - Load Check Valve (Arm Tandem Circuit) 30 - Check Valve 31 - Arm Regenerative Valve 32 - Check Valve 33 - Overload Relief Valve (Arm) 34 - Overload Relief Valve (Arm) 35 - Arm Anti-Drift Valve (Check Valve) 36 - Arm Anti-Drift Valve (Switch Valve) 37 - Load Check Valve (Boom 2 Parallel Circuit) 38 - Travel/Boom Lower Selector Valve 39 - Check Valve 40 - Load Check Valve (Travel Tandem Circuit) 41 - Pump Control Valve (5-Spool Side)

EX255-EX285

T3-3-3

CONTROL VALVE Section A

A

H B

G

5

C D E F

41

8

SM0036

SM0038

Section C

Bucket

Auxiliary

15 12 11

39

Section D 9 Boom 2

16 Boom 1

Section B

SM0040

L. Travel

R. Travel

38

17 37 3 2

20 21 19 13

14 40

10 18 SM0039

SM0041

T3-3-4

EX255-EX285

CONTROL VALVE Control valve layout Right travel motor

Left travel motor

1

3 2

4

5

6

7

8

9

10 11 12

41

13 14 40

15 16

39

Bucket cylinder

38 37 36 35 34

Boom cylinder

17 18

Arm cylinder

33 32 31

19 20

30 29

21 22 23 26 27 28

24 25

Swing motor

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

- Hydraulic Timer - Travel Flow Control Valve - Load Check Valve (Travel Parallel Circuit) - Check Valve - Main Relief Valve - Check Valve - Check Valve - Flow Combiner Valve - Load Check Valve (Bucket) - Bucket Flow Control Valve (Switch Valve A) - Bucket Flow Control Valve (Switch Valve B) - Bucket Flow Control Valve (Poppet Valve) - Load Check Valve (Boom 1 Parallel Circuit) - Load Check Valve (Boom 1 Tandem Circuit) - Overload Relief Valve (Bucket) - Overload Relief Valve (Bucket)

SM0037

17 - Overload Relief Valve (Boom) 18 - Overload Relief Valve (Boom) 19 - Boom Anti-Drift Valve (Check Valve) 20 - Boom Anti-Drift Valve (Switch Valve) 21 - Boom Regenerative Valve

31 32 33 34 35

22 - Check Valve 23 - Pump Control Valve (4-Spool Side) 24 - Check Valve 25 - Restriction (4-Spool Side Parallel Circuit) 26 - Load Check Valve (Arm Parallel Circuit) 27 - Restriction (Arm 1 Parallel Circuit) 28 - Load Check Valve (Swing) 29 - Load Check Valve (Arm Tandem Circuit) 30 - Check Valve

37 -

-

36 -

38 39 40 41 -

Arm Regenerative Valve Check Valve Overload Relief Valve (Arm) Overload Relief Valve (Arm) Arm Anti-Drift Valve (Check Valve) Arm Anti-Drift Valve (Switch Valve) Load Check Valve (Boom 2 Parallel Circuit) Travel/Boom Lower Selector Valve Check Valve Load Check Valve (Travel Tandem Circuit) Pump Control Valve (5-Spool Side)

EX255-EX285

T3-3-5

CONTROL VALVE Section E (2)

Arm 1 Arm 2

31

32 Section E (1) Section F Arm 1

Arm 2 Swing SM0042

36 34 35

28

24 26

25

27 29

23 22

33

SM0043

SM0045

30

Section H

Section G 1

4

7

6

SM0044

SM0046

T3-3-6

EX255-EX285

CONTROL VALVE HYDRAULIC CIRCUIT Main Circuit Pressure oil from pump 1 and from pump 2 is routed to the 4-spool side section in the control valve and to the 5-spool side section in the control valve, respectively. A parallel age is provided in both right and left main circuits, making combined operations possible. The main circuit pressure is restricted by the main relief valve. Moreover, two overload relief valves are provided in each of boom, arm, and bucket circuits. Also, a pump control valve is provided at the most downstream position of each of right and left neutral ages.

Signal Pilot Pressure Circuit The pilot pressure from the pilot pump flows through the control valve. When the causes the travel signal pilot pressure circuit to be restricted, increasing the travel signal pilot pressure, thus turning on the pressure switch (travel) and shifting the travel/boom lower selector valve. When a control lever other than the travel levers is operated, the signal pilot pressure in the front att. signal pilot pressure circuit increases, thus turning on the pressure switch (front) and shifting the flow combiner valve, travel flow control valve, and swing parking brake shift valve.

Flow combiner valve Swing parking brake shift valve



Neutral age

Main relief valve Signal pilot pressure circuit Left travel motor Pump control valve (5-spool side)

Right travel motor

Auxiliary Bucket Travel flow control valve Travel/Boom lower selector valve Boom Arm Overload relief valves

Overload relief valves


Parallel ages

Swing

Main circuits

Neutral age

5-spool side

4-spool side Pilot pump

Pump 2

Pump 1

SM0047

EX255-EX285

T3-3-7

CONTROL VALVE Pilot Valve Guided Pilot Pressure Circuit Pilot pressure via the pilot valve exerts on the control valve spools, shifting them. At the same time, it also exerts on switch valves. (Arm anti-drift valve, Boom anti-drift valve, Bucket flow control valve) Besides shifting of control valve spools (when control levers are operated), the pilot valve guided pilot pressure functions as follows: • When the arm roll-in lever is operated, the pilot pressure via the pilot valve exerts on the bucket flow control valve and the anti-drift valve (switch valve), shifting them. • When the boom raise lever is operated, the pilot pressure exerts on the bucket flow control valve as the valve shift pressure.

• When the boom lower lever is operated, the pilot pressure exerts on the boom anti-drift valve (switch valve), shifting it. In addition, an air bleed circuit is provided in the top part of the control valve, automatically bleeding air trapped in the circuit.

Solenoid Valve Guided Pilot Pressure Circuit The pilot pressure guided via the solenoid valve unit (SG and SC) shifts the main relief valve and the arm regenerative valve. (Refer to the Control System Group in the SYSTEM Section).

Main relief valve From the solenoid valve unit (SG)

1

Bucket flow control valve

2

11

12

8 5 3

13

4

14

6 Arm anti-drift valve

5

5

Arm regenerative valve

8

7

8

From the solenoid valve unit (SC)

9

7

Air bleed circuit

10

Pump 2

1 2 3 4 5

-

Left Travel Forward Left Travel Reverse Auxiliary Auxiliary Boom Raise

Boom anti-drift valve

Pump 1

6 7 8 9 10

-

Boom Lower Arm Roll-out Arm Roll-in Swing Left Swing Right

SM0048

11 12 13 14

-

Right Travel Reverse Right Travel Forward Bucket Roll-in Bucket Roll-out

T3-3-8

EX255-EX285

CONTROL VALVE FLOW COMBINER VALVE When a control lever other than the travel levers is operated, the signal movement of the control valve spool restricts the signal pilot pressure in the front attachment signal pilot pressure circuit, increasing

the pilot pressure to shift the flow combiner valve. As a result, the pressure oil from the pump 1 is routed to both right and left travel spools, securing straight travel in travel combined operations.

EX255-EX285

T3-3-9

CONTROL VALVE

Front attachment signal pilot pressure circuit Left travel motor

Flow combiner valve

Right travel motor

Pilot pump

Arm cylinder

Pump 2

Pump 1

SM0049

T3-3-10

EX255-EX285

CONTROL VALVE PUMP CONTROL VALVE A pump control valve is provided on the most downstream part of the neutral age in each of the 4spool and 5-spool side sections. The pump control pressure altered by the pump control valve exerts on the regulator, changing the pump displacement angle. (Refer to the Pump Device Group in this section).

In addition, the pump control pressure sensor detects the pump control pressure, sending signals to MC for travel motor displacement angle control. (Refer to the Control System Group in the SYSTEM Section).

Pump control valve (5-spool side) To the pump 2 regulator and to pump control pressure sensor

Neutral age


To the pump 1 regulator and to the pump control pressure sensor

4-spool side 5-spool side

Neutral age

SM0050

EX255-EX285

T3-3-11

CONTROL VALVE Operation with Control Valve Spool Activated When a control valve spool is shifted, oil flowing through the neutral age and through the pump control valve decreases. As oil flowing through the pump control valve decreases, the pump control valve spool shifts to the left, increasing the relief valve set pressure, thus

raising the pump control pressure. This increased pump control pressure exerts on the regulator and, in return, the regulator increases the pump displacement angle, increasing the pump delivery oil flow.

From the pilot pump Pump control pressure age Pump control pressure sensor

Hydraulic oil tank Pressure increase

Pump control valve

To the regulator Neutral age Small oil flow SM0051

Operation with Control Valve Spools in Neutral Position When control valve spools are returned to the neutral position, the neutral age is fully opened and all pump oil flow goes through the neutral age and the pump control valve so that the pump control valve spool moves to the right, decreasing the relief valve set pressure so as to have the lowest pump control pressure.

As the pump control pressure decreases to a minimum, the regulator decreases the pump displacement angle to have the minimum pump delivery flow, contributing to fuel efficiency.

From the pilot pump Pump control pressure age Pump control pressure sensor

Hydraulic oil tank

Pressure Decrease

Pump control valve

To the regulator Neutral age

Large oil flow

SM0052

T3-3-12

EX255-EX285

CONTROL VALVE MAIN RELIEF VALVE The main relief valve regulates main circuit pressure. The set pressure of the main relief valve is shifted by the pilot pressure guided via the solenoid valve unit (SG). (Refer to the Control System Group in the SYSTEM Section).

When oil pressure at port Hp matches the spring set force, the pilot poppet opens. Oil at port Hp flows to port Lp through age A. As the pilot poppet opens, oil pressure in spring chamber A decreases, opening the main poppet, thus directly routing pressure oil at port Hp to port Lp.

Valve Operation When the pilot pressure is not guided to the main relief valve via the solenoid valve unit (SG):

Main poppet Pilot poppet

Lp

Port SG

Hp

Lp Spring A

age A SM0053

When the pilot pressure is guided to the main relief valve via the solenoid valve unit (SG): When the pilot pressure via the solenoid valve unit exerts on port (SG), the piston is pushed to the left in the set position, increasing the compressional force

of spring B, thus requiring higher port Hp pressure to open the pilot poppet. For this reason, the main relief valve set pressure increases.

Pilot poppet Piston

Lp

Port SG

Hp

Lp Spring B

SM0054

EX255-EX285

T3-3-13

CONTROL VALVE OVERLOAD RELIEF VALVE (With Make-Up Function) Overload relief valves are provided in each port of the boom, bucket, and arm cylinders, and regulate oil pressure in the cylinder circuits to protect them from damage due to excessive high pressure that might develop if a cylinder is moved by excessive external force.

1

Moreover, these relief valves function to suction oil from the return (hydraulic oil tank) line to prevent the occurrence of cavitation if negative oil pressure arises in a cylinder (the make-up function).

2

3

4

5

10

9

8

G

7

6

SM0055

1 2 3 4 5

-

Spring Plug Pilot Poppet Spring Spring

6 7 8 9 10

-

Adjusting Screw Plug Main Poppet Sleeve Piston

T3-3-14

EX255-EX285

CONTROL VALVE ARM REGENERATIVE VALVE The arm regenerative valve is shifted by the pilot pressure guided via the solenoid valve unit (SC). When the arm regenerative valve is shifted, the return oil line from the cylinder rod side is closed. Then, the return oil is combined with the pump delivery oil to be supplied to the cylinder bottom side,

increasing the arm roll-in speed, improving the arm controllability in general, and preventing arm movement hesitation from occurring in arm roll-in operations. (Refer to the Control System Group in SYSTEM Section).

Arm cylinder

From the solenoid valve unit (SC) Arm regenerative valve

SM0056

EX255-EX285

T3-3-15

CONTROL VALVE

Arm regenerative valve

Arm 1 From the solenoid valve unit (SC)

Pump 2

Pump 1

SM0057

T3-3-16

EX255-EX285

CONTROL VALVE BOOM ANTI-DRIFT VALVE, ARM ANTIDRIFT VALVE An anti-drift valve is provided on the bottom side of the boom cylinder and on the rod side of the arm cylinder so as to reduce cylinder drift. When the control valve spool is in neutral, the switch valve part of the anti-drift valve is not shifted and the pressure in the boom cylinder bottom side (the arm cylinder rod side) exerts on the check valve of the anti-drift valve via the switch valve, closing the check valve.

When the arm roll-in or boom lower is operated, the pilot pressure via the pilot valve shifts the switch valve of the anti-drift valve. The oil pressure exerted on the check valve is returned to the hydraulic oil tank via the restriction in the switch valve. (The check valve is designed to close by a signal pressure, which arises when the switch valve is not shifted, and to open when the signal pressure is not exerted (when the switch valve is shifted.)).

Boom cylinders

Boom 1 Boom lower pilot pressure

Anti-drift valve (check valve) Anti-drift valve (switch valve)

SM0058

BUCKET FLOW CONTROL VALVE The bucket flow control valve restricts the bucket circuit in the combined operations of the bucket, arm roll-in, and boom raise, so as to raise the boom sufficiently. When the arm is rolled in, the arm roll-in pilot pressure shifts switch valve (A) of the bucket flow control valve. If the boom is raised at the same time, the boom raise pilot pressure is routed through the switch

valve (A), shifting the switch valve (B) of the bucket flow control valve. Thus, the back pressure exerting on the poppet valve rises, applying a force to close the poppet valve, thus restricting oil flow through the poppet valve. For this reason, the oil flow to the bucket is restricted, supplying an oil flow to the higher-loadapplied boom raise side.

Arm roll-in pilot pressure Poppet valve Switch valve A

Boom raise pilot pressure Bucket

Switch valve B Bucket pilot pressure

Bucket cylinder

SM0059

EX255-EX285

T3-3-17

CONTROL VALVE

Bucket flow control valve

Arm anti-drift valve

Boom anti-drift valve

Pump 2

Pump 1

SM0048

T3-3-18

EX255-EX285

CONTROL VALVE TRAVEL FLOW CONTROL VALVE When the front attachment is operated while traveling, the non-travel signal pilot pressure exerts on the travel flow control valve, which is located in the parallel circuit, after flowing through the hydraulic

timer, so as to gradually restrict the parallel circuit. As the parallel circuit is gradually restricted, shock loads, occurring due to the front attachment operation, are reduced.

Hydraulic timer

To the travel motor Left travel spool

Non-travel signal pilot pressure

Travel flow control valve

Non-travel spool

SM0060

Travel parallel circuit

TRAVEL/BOOM LOWER SELECTOR VALVE The boom lower operation is actuated by the oil flow via the boom 1 section. However, in travel-combined operations, the oil flow from pump 1 does not flow in the downstream boom 1 spool as it goes to the upstream travel spool. If the boom is positioned up in the air at the moment, the boom would be lowered by its own weight. However, if the travelcombined boom lower operation is performed with the base machine raised off the ground, the boom does not lower.

To prevent this from occurring, in travel-combined boom lower operations, the boom 2 spool is shifted to route the oil flow from pump 2 to the boom lower section so that the boom lowers to sufficiently perform the machine jack-up operation. When the travel spool is shifted, the travel signal pilot pressure shifts the travel/boom lower selector valve, allowing the boom lower pilot pressure to exert on the boom 2 spool. Thus, the boom lower operation is sufficiently performed in travel-combined operations.

Right travel spool

Boom 2 Boom 1

To the boom cylinder

Travel/Boom lower selector valve

Pump 2

SM0061

EX255-EX285

T3-3-19

CONTROL VALVE

Hydraulic timer

Travel flow control valve

Signal pilot pressure circuit

Left travel motor

Right travel motor

Bucket Travel/Boom lower selector valve

Boom

Parallel ages

Pilot pump Pump 2

Pump 1

SM0047

T3-3-20

EX255-EX285

CONTROL VALVE BOOM REGENERATIVE VALVE In boom lower operations, the return oil from the cylinder bottom side is combined with the oil flow from the pump, supplying an additional oil flow to the cylinder rod side, via the check valve in the boom spool.

By this boom regenerative valve operation, the boom lower operation is improved and cavitation is prevented from occurring.

Boom regenerative valve Boom cylinders

Boom 1 Boom lower pilot pressure

SM0062

EX255-EX285

T3-4-1

PILOT VALVE OUTLINE The pilot valve controls pilot pressure oil to move the control valve spools. There are two types of pilot valves. One is for front/swing operation; the other is for travel operation. Both have standard four oil ports. An optional two-oil-port type is available.

Except for the cam construction to push the pusher down, the construction of the pilot valve in both the front/swing pilot valve and the travel pilot valve is the same.

• Right and left pilot valves (Front/Swing) Port No.

Control

1

Bucket roll-out

2

Boom lower

3

Bucket roll-in

4

Boom raise

1

Swing right

2

Arm roll-out

3

Swing left

4

Arm roll-in

Right

Left

3

T 3

4

P 4

T

P

P

2

T

1 SM0065

1

3

2

4 SM0063

T3-4-2

EX255-EX285

PILOT VALVE • Travel pilot valve Port No.

Control

1

Left travel forward

2

Left travel reverse

3

Right travel reverse

4

Right travel forward

T T P

4 P

1

2

T

1

3

2

4

3

SM0064

SM0066

• Positioning pilot valve (triple articulation version) Port No.

Control

1

Positioning raise (Positioning cylinder retraction)

2

Positioning lower (Positioning cylinder extension)

T 1 2 T

1

2

P

P

P T

1

2 SM3043

SM3021

EX255-EX285

T3-4-3

PILOT VALVE OPERATION • Front and Swing Pilot Valve The lower face of spool (8) head is suspended by the upper face of spacer (4); they are kept in by setting force of balance spring (6). Spacer (4) is installed between pusher (3) and spring guide (5) and ed by return spring (7). Piston (9) is located inside spool (8). The lower end of piston (9) makes with the plate, preventing the piston from moving further downward. Above piston (9), a chamber is provided and it is led to the outside of spool (8) through holes provided in spool (8).

In neutral (Corresponding to A to B in the output diagram): When control lever (1) is in the neutral position (no pusher stroke), spool (8) completely blocks pressure oil from entering port P. Since the delivery port is open to port T, pressure at the delivery port equals that in the hydraulic oil tank. When control lever (1) is slightly moved, cam (2) moves together, pressing down on pusher (3). Then, pusher (3), spacer (4), and spring guide (5) move downward as a unit, compressing return spring (7). The lower face of spool (8) is kept in with the upper face of spacer (4) by setting force of balance spring (6) and moves downward together with spacer (4). However, even if control lever (1) is moved further, until clearance (A) at section (a) reaches zero, the delivery port remains open to port T, keeping pressure at the delivery port equal to that in the hydraulic oil tank.

Delivery port pressure (pilot pressure)

1

2

A B

3

Pusher stroke

OUTPUT DIAGRAM

4 5 6 Section (a) (A)

7 8 Port T

(A)=0

Delivery port Port P

9

SM0067

1 2 3 4 5

-

Control Lever Cam Pusher Spacer Spring Guide

6 7 8 9

-

Balance Spring Return Spring Spool Piston

T3-4-4

EX255-EX285

PILOT VALVE Ready to start operation (Corresponding to B to C section in the output diagram): When control lever (1) is tilted slightly further from the position where clearance (A) in section (a) reaches zero, and pusher (3) is pushed downward, spool (8) is moved downward, opening notched section (b) to allow pressure oil at the port P to flow into the delivery port. This oil pressure is also led to the inside of spool (8) via orifice (10), and acts to push spool (8) upward. Until this oil pressure force reaches the setting force of balance spring (6), balance spring (6) will not be compressed so that spool (8) is not moved upward, closing the clearance at section (a), keeping the notch at section (b) opened, and letting the oil pressure to increase at the delivery port. If the oil pressure at the delivery port increases, and the upward-pushing force of spool (8) slightly exceeds the

setting force of balance spring (6), spool (8) moves upward against setting force of balance spring (6). Once spool (8) moves upward, upper clarance at section (a) is opened and lower notch section at section (b) is closed, leading oil pressure at the delivery port to port T, and decreasing oil pressure at the delivery port. When oil pressure at the delivery port decreases, the force to push up spool (8) is reduced so that balance spring (6) stretches to move spool (8) downward, closing both the clearance and the notch at sections (a and b). Thus, original position of spool (8) is kept resumed. The oil pressure will continue to increase until it is equal to setting force of balance spring (6) (shown by the point C in the output diagram).

Delivery port pressure (Pilot pressure)

1

C B

Pusher stroke

OUTPUT DIAGRAM

3

6

8

Section (a)

Port T Clearance (A) reaches zero Delivery port

Section (b)

10 Port P

9 SM0068

1 3 6

- Control Lever - Pusher - Balance Spring

8 - Spool 9 - Piston 10 - Orifice

EX255-EX285

T3-4-5

PILOT VALVE Operation corresponding to the control lever stroke (Corresponding to C to D in the output diagram): As control lever (1) is moved further to push pusher (3) downward, spool (8) is pushed down to open the notch at section (b), increasing oil pressure at the delivery port. As pressure increases, the force to push up spool (8) increases. Then, when force to push up spool (8) exceeds the setting force of balance spring (6), spool (8) starts to move upward, compressing balance spring (6).

When spool (8) moves upward until the clearance at section (a) opens, the delivery port is opened to port T, stopping oil pressure increase at the delivery port and stopping movement of spool (8). Accordingly, when compressed by pusher (3), spring force of balance spring (6) increases in proportion to the pusher stroke, Then, oil pressure increases to counteract against this spring force.


1

D

C Pusher stroke

OUTPUT DIAGRAM 3

6

Section (a)

8 Port T Delivery port

Section (b)

Port P

SM0069

1 3

- Control Lever - Pusher

6 8

- Balance Spring - Spool

T3-4-6

EX255-EX285

PILOT VALVE Operation close to pusher stroke end (Corresponding to D to E in the output diagram): As pusher (3) is pressed down, balance spring (6) is compressed, reducing clearance (B) between pusher (3) and the top of spool (8) (shown at section (c)), finally to zero. After that, pusher (3) directly pushes spool (8). Even if oil pressure at the delivery port increases,

spool (8) cannot move upward, closing the oil age from the delivery port to port T, and opening the oil age from the delivery port to port P. Then, oil pressure at the delivery port increases until it reaches port P pressure.

E


D

Pusher stroke

OUTPUT DIAGRAM

3 Section (c)

Clearance (B) reaches zero

6 8

Port T Delivery port Port P

SM0070

3 6

- Pusher - Balance Spring

8

- Spool

EX255-EX285

T3-4-7

PILOT VALVE Full stroke operation (Corresponding to E to F section in the output diagram): Even if control lever (1) is tilted further to push down pusher (3), spool (8) moves downward along with pusher (3), only widening the notch at lower section (b) of spool (8). Thus, oil pressure at the delivery port is kept same as at port P. Pusher (3) can be pressed down until spring guide (5) comes into with the shoulder (sec-

tion (d)) of the casing. This position is the stroke end of pusher (3) (corresponding to F position in the output diagram). This process corresponds with E to F section in the output diagram. The total stroke of the control lever is decided by dimension C.


1

E F

Pusher stroke

OUTPUT DIAGRAM

3

Section (d)

C

5 8

Port T Delivery port Section (b) Port P

SM0071

1 3

- Control Lever - Pusher

5 8

- Spring Guide - Spool

T3-4-8

EX255-EX285

PILOT VALVE • Travel Pilot Valve In neutral (Corresponding to A to B in the output diagram): Lever - In Neutral (Pusher Stroke: A to B) In neutral, spool (6) closes port P (the input port) and tank port T is connected to delivery port through clearance (A). Thus, the pressure at delivery port is the same as that at tank port T. When the control lever is moved slightly from A to B, pusher (2) and spring guide (3) together move down against return spring (5) and balance spring (4). At this time, as both oil pressures above and below spool (6) are the same as the tank pressure, spool (6) moves down together with spring guide (3) until clearance (A) becomes zero.

Operation corresponding to the control lever stroke (Corresponding to C to D in the output diagram): Lever - Operated (Pusher Stroke: C to D — Metering) When the control lever is moved further to push pusher (2) down, port P is connected to delivery port through notch (B) and age in spool (6), routing pilot pump pressure. However, when the pressure applied into spool (6) overcomes the balance spring force, spool (6) moves up, closing port P. When pusher (2) is moved further down, compressing return spring (5) and balance spring (4), the larger the balance spring force; thus, the output pressure increases in proportion to the increase in the balance spring force.

Full stroke operation: Lever - Full Stroke (Pusher Stroke) When the control lever is moved full stroke, pusher (2) is moved down until spring guide (3) comes into with the shoulder of the valve casing (Lever Stroke End), opening notch (B) further to port P. The output pressure (pilot pressure to the control valve) remains at the pilot system pressure (the port P pressure). Dimension (C) in the figure right shows the control lever full stroke.


D

C A

B

Pusher stroke

OUTPUT DIAGRAM SM0072

EX255-EX285

T3-4-9

PILOT VALVE Pusher stroke: A to B 1

2

3 4 5 Port T Clearance A: 0

(A) Port P

6


Pusher stroke: C to D

SM0075

Pusher stroke: full stroke

2 2

(C)

4 5 Port T

3

Port T (B)

6

Port P

Port P

6

Delivery port


SM0074

1 2 3

- Cam - Pusher - Spring Guide

4 5 6

- Balance Spring - Return Spring - Spool

T3-4-10

EX255-EX285

PILOT VALVE NOTE

EX255-EX285

T3-5-1

TRAVEL DEVICE OUTLINE The travel device consists of travel motor (14), planetary reduction gears (1 to 10, 12, 13), and sprocket (11). NOTE - The figure shows the travel device installed on EX255. 3

1

2

4

5 8 7

11

6 9

12

10 13

14 SM3022

1 2 3 4 5 6 7

-

Cover First Stage Sun Gear First Stage Planetary Gear First Stage Carrier Second Stage Sun Gear Second Stage Planetary Gear Second Stage Carrier

8 9 10 11 12 13 14

-

Third Stage Sun Gear Third Stage Planetary Gear Ring Nut Sprocket Housing (Ring Gear) Hub (Third Stage Carrier) Travel Motor

T3-5-2

EX255-EX285

TRAVEL DEVICE NOTE - The figure shows the travel device installed on EX285.

12

13

14

4 5 6 8 9

3

7 1 10

2 11

SM5003

1 2 3 4 5 6 7

-

Ring Gear Propel Shaft First Stage Planetary Gear First Stage Carrier Second Stage Sun Gear Second Stage Carrier Second Stage Planetary Gear

8 9 10 11 12 13 14

-

Third Stage Sun Gear Third Stage Carrier Third Stage Planetary Gear Sprocket Drum Housing Travel Motor

EX255-EX285

T3-5-3

TRAVEL DEVICE TRAVEL REDUCTION GEAR Third stage carrier (2) is part of the hub and as the housing (1) (ring gear) and sprocket (11) are bolted together, they all rotate.

The travel reduction gear is a third stage planetary gear type. The travel motor rotates first stage sun gear (7) and this driving force is transmitted to the housing (1) via first stage planetary gear (8), first stage carrier (6), second stage sun gear (5), second stage planetary gear (9), second stage carrier (4), third stage sun gear (3), and third stage planetary gear (10).

NOTE - The figure shows the travel reduction gear installed on EX255.

10

2

3

9

1

8

5 7

6

4

12

1

2

3

4

5

9

6

12 12 7

11

8 11

10

Third Second First stage stage stage SM3023

1 2 3 4 5 6

-

Ring Gear (housing) Third Stage carrier Third Stage Sun Gear Second Stage Carrier Second Stage Sun Gear First Stage Carrier

7 8 9 10 11 12

-

First Stage Sun gear (Propel Shaft) First Stage Planetary Gear Second Stage Planetary Gear Third Stage Planetary Gear Sprocket Hub

T3-5-4

EX255-EX285

TRAVEL DEVICE NOTE - The figure shows the travel reduction gear installed on EX285.

1

2

3

4

5

6 7

8

12

10

9 1 2

3

4

5

9

6

11 7

8

12 11

10

Third stage

Second stage

First stage

SM5004

1 2 3 4 5 6

-

Ring Gear (housing) Third Stage Carrier Third Stage Sun Gear Second Stage Carrier Second Stage Sun Gear First Stage Carrier

7 8 9 10 11 12

-

Propel Shaft First Stage Planetary Gear Second Stage Planetary Gear Third Stage Planetary Gear Sprocket Hub

EX255-EX285

T3-5-5

TRAVEL DEVICE TRAVEL MOTOR This travel motor is a variable-displacement bentaxis axial-plunger type that includes a parking brake (wet-multi-disc negative type). The main parts of the motor are plate (1), valve plate (2), rotor (14), plungers (13), center shaft (5), drive disc (7), servo piston (16), parking brake piston (12), friction plates (11), and plates (10).

Rotor (14) is pre-loaded against valve plate (2) by spring (4). As oil pressure in the rotor bores increases, the pressure acts on end faces (A) of the rotor bores and assists spring (4) to force rotor (14) against valve plate (2).

NOTE - The figure shows the travel motor installed on EX255.

1

2

3

4 5 6

7

8 9 16 10 11 15

12

14 A

13

1 2 3 4 5 6 7 8

-

Plate Valve Plate Disc Spring Spring Center Shaft Housing Drive Disc Roller Bearing

9 10 11 12 13 14 15 16

-

Roller Bearing Plate Friction Plate Brake Piston Plunger Rotor Link Servo Piston

SM3024

T3-5-6

EX255-EX285

TRAVEL DEVICE NOTE - The figure shows the travel motor installed on EX285.

3

2

1

4 5 6

7

8

10

10 16

15

14

13

12

9

11

11 12 A

SM5005

1 2 3 4 5 6 7 8

-

Plate Valve Plate Disc Spring Spring Center Shaft Housing Drive Disc Roller Bearing

9 10 11 12 13 14 15 16

-

Roller Bearing Plate Friction Plate Brake Piston Plunger Rotor Link Servo Piston

EX255-EX285

T3-5-7

TRAVEL DEVICE Pressure oil supplied to port AM of the valve plate (1) flows into the rotor bores (2) underneath port AM, pushing the plungers (3). The vertical component force (FV) of plunger pushing force (F) rotates the drive disc (4). As the drive disc (4) rotates, the rotor (2) also rotates.

When the plungers (3) moves to port BM side, oil is routed to the hydraulic oil tank. Whether pressure oil from the pump is supplied to port AM or BM determines travel direction.

1

2

3 BM

4 AM

FR FV F

SM0080

1 2

- Valve plate - Rotor

3 4

- Plunger - Drive disc

T3-5-8

EX255-EX285

TRAVEL DEVICE Travel Speed Selection Servo piston (1) is interconnected to valve plate (6) via link (5) so that when servo piston (1) is moved, swash angle of rotor (7) is shifted through valve plate (6), leading to travel speed change.

• Slow speed When the slow speed travel mode is selected, the MC (Main Controller) does not send out an electronic control signal to the solenoid valve unit (SI). Therefore, speed change pilot pressure is not routed to servo piston (1). Thus, spool (3) is held down by spring (2). Then, pressure oil P from the motor port is led to both chambers “B” and “C”.

Since the pressure-receiving area in chamber “C” is larger than that in chamber “B”, servo piston (1) moves upward, increasing swash angle to the maximum. Accordingly, as the stroke of the plungers in the motor is increased, slower revolution of the travel motor for low speed mode is obtained.

6 1

7

2 Drain

P

B

3 5 4

Pilot pressure

C

SM0081

1 2 3 4

-

Servo Piston Spring Spool Orifice

5 6 7

- Link - Valve Plate - Rotor

EX255-EX285

T3-5-9

TRAVEL DEVICE • Fast speed

travel mode

When the fast speed travel mode is selected, corresponding to travel loads, the MC sends out an electronic control signal to the solenoid valve unit (SI). Therefore, speed change pilot pressure is routed to chamber “D”, moving spool (3) upward. Then, age “E” opens and oil in chamber “C” is drained through the inner ages in spool (3). As pressure oil P from the motor port is led to

chamber “B”, servo piston (1) is moved down, reducing the swash angle of rotor (7). Accordingly, as the stroke of the plungers in the motor is decreased, faster revolution of the travel motor for fast speed mode is obtained. (Refer to the Control System Group in the SYSTEM Section).

1 6 7

2 Drain

P B

3

E

5

Pilot pressure

4

Drain

P C

D Position of servo piston at initial stage of fast speed travel operation

Pilot pressure

Position of servo piston during stage of fast speed travel operation

SM0082

1 2 3 4

-

Servo Piston Spring Spool Orifice

5 6 7

- Link - Valve Plate - Rotor

T3-5-10

EX255-EX285

TRAVEL DEVICE TRAVEL BRAKE VALVE The travel brake valve is located on the travel motor head and consists of the following valves.

- Overload Relief Valve (4): Prevents overloads and surge pressure in the motor circuit.

- Check Valve (1): Ensures smooth starts and stops, and prevents cavitation from occurring in the motor circuit by functioning together with counterbalance valve (5).

- Counterbalance Valve (5): Ensures smooth starts and stops and prevents overrunning when traveling down slopes.

- Reducing Valve (2): Reduces parking brake release pressure and prevents sudden operation of the brake.

- Servo-Piston Operating Shuttle Valve (6): Leads divided hydraulic oil flow for travel motor operation to the servo-piston.

- Parking Brake Release Shuttle Valve (3): Leads travel motor drive pressure to the parking brake.

NOTE - The figure shows the travel brake valve installed on EX255.

Section B-B

1 1

3 2

A

4 AM

B

BM

5 C

BV

AV

Section A-A

A

Section C-C

6

SM0083

1 2 3

- Check Valve - Reducing Valve - Parking Brake Release Shuttle Valve

4 5 6

- Overload Relief Valve - Counterbalance Valve - Servo-Piston Operating Shuttle Valve

EX255-EX285

T3-5-11

TRAVEL DEVICE NOTE - The figure shows the travel brake valve installed on EX285.

2

6

4

6 3 4 Section B-B

1 1

3

Section C-C

5 A 4

4

2

1

BM

AM

C .

.

. C . AV

B

BV 5

Section A-A

A

1 2 3

- Check Valve - Reducing Valve - Parking Brake Release Shuttle Valve

4 5 6

- Overload Relief Valve - Counterbalance Valve - Servo-Piston Operating Shuttle Valve

SM5010

T3-5-12

EX255-EX285

TRAVEL DEVICE Travel Operation When supply oil from the control valve is routed to port BV, supply oil flows around spool CB, opens check valve BC (9) and is led to motor port BM. However, return oil from motor port AM is blocked by check valve AC (8) and spool CB (7). As supply oil pressure at port BV increases, supply oil is routed to chamber “G” through orifice “F” in spool CB (7), moving spool CB (7) to the left against spring force. Consequently, return oil from motor port AM starts to flow into port AV through notch “H” in spool CB (7), allowing the travel motor to rotate. When the travel levers are returned to the neutral position, the oil in both ports AV and BV are routed to the hydraulic oil tank through the control valve. Thus, oil pressure in chamber “G” decreases, and spool CB (7) is moved back to the original position by spring force. Then, the oil flow circuit is blocked, causing the travel motors to stop rotating.

draws oil, oil pressure at port BV and chamber “G” decreases, causing spool CB (7) to move to the right. Then, the return oil flow from the motor is restricted by the spool, increasing pressure at port AM. The increased pressure at port AM brakes the motor. Thus, the restricted return oil flow increases the pressure at port BV again, moving spool CB (7) back to the left. This repeat movement of the spool (hydraulic brake action) prevents the machine from overrunning.

Circuit Protectors If pressure in the circuit increases over the setting pressure of the overload relief valve (4), this valve opens to relieve peak pressure to the lower pressure side to protect the motor from overloading. This valve also functions to release shock pressure caused by inertia force developing when the motor stops. When the motor draws oil because of pumping operation, check valve BC (9) opens to make up vacuum, so that cavitation will not develop in the circuit.

Descending Operation When the machine travels down a slope, the travel motors are forcibly driven by the machine weight so that the motor draws oil like a pump. When the motor

7

4 9

8 AM

BM

AV

BV

H

G

F SM0084

4 7

- Overload relief valve - Spool CB

8 9

- Check valve AC - Check valve BC

EX255-EX285

T3-5-13

TRAVEL DEVICE PARKING BRAKE

NOTE - The figure shows the parking brake installed on EX255.

When the brake is applied:

When the brake is released: M K

1 2

3 M 4 5

6

5

6

SM3025

1 2 3

- Disc Spring - Piston - Friction Plate

4 5 6

- Plate - Housing - Drive Disc

T3-5-14

EX255-EX285

TRAVEL DEVICE NOTE - The figure shows the parking brake installed on EX285.

When the brake is applied:

When the brake is released:

5

6

SM5006

1 2 3

- Disc Spring - Piston - Friction Plate

4 5 6

- Plate - Housing - Drive Disc

EX255-EX285

T3-5-15

TRAVEL DEVICE The parking brake is a negative-type brake released when oil pressure “K” is applied to parking brake chamber “M”. Whenever the travel control valve spools are in neutral, the parking brake is automatically applied. Friction plates (3) are connected to drive disc (6), and plates (4) to motor housing (5) via spline coupling respectively. When disc spring (1) pushes piston (2) to the right, friction plates (3) come into with plates (4), applying the parking brake.

chamber “G” located at the end of spool CB (9). Parking brake release pressure is blocked by spool CB (9). When pressure increases, spool CB (9) moves to the right. Pressurized oil flows to reducing valve (7) via the orifice “I” of spool CB (9), then flows to parking brake chamber “M” to release the travel parking brake. When the machine is not traveling: Pressure oil from the travel motor is not routed through shuttle valve (8), and parking brake chamber “M” is led to the drain circuit through reducing valve (7). Piston (2) is gradually forced to the right by disc spring (1), making friction plates (3) come into with plates (4).

Starting to travel: When travel lever is pulled reverse, pressurized oil from the pump flows to port AM via the control valve. The pressurized oil flows to the travel motor and

K

7

Drain

AM BM

G

I

9

8

SM0086

7 8

- Reducing valve - Shuttle valve

9

- Spool CB

T3-5-16

EX255-EX285

TRAVEL DEVICE NOTE

EX255-EX285

T3-6-1

OTHER COMPONENTS (Upperstructure) PILOT SHUT-OFF VALVE

To pilot valve

The pilot shut-off valve is a manual-operated switch valve. The spool in the pilot shut-off valve is rotated by moving the pilot control shut-off lever to turn on or off the pilot oil flow to the pilot valves.

To hydrayulic oil tank From pilot pump

From pilot valve

To shockless valve

SM0087

• Valve Operation with Pilot Control Shut-Off Lever in LOCK Position The pilot shut-off valve is set in the neutral position. Pressure oil from the pilot pump does not flow into the pilot valves, but it is routed to the shockless valve. Pilot oil on the pilot valve side is routed to the hydraulic tank as drain ages in the pilot shutoff valve open.

From pilot valve

To shockless valve

To hydraulic oil tank

From pilot pump SM0088

• Valve Operation with Pilot Control Shut-Off Lever in UNLOCK Position The pilot shut-off valve is set in the operating position, allowing pressure oil from the pilot pump to flow into the pilot valves. The pilot pressure can be and will be routed to the control valve to operate the respective hydraulic cylinders and/or motors as the pilot valves are operated, in other words, as the control levers are operated.

To pilot valve

From pilot pump SM0089

T3-6-2

EX255-EX285

OTHER COMPONENTS (Upperstructure) SHOCKLESS VALVE

2

1

Check valves, pilot pressure sensor (for arm roll in), and pilot pressure switch (for boom raise) are built into the shockless valve block in addition to the shockless valves. The shockless valves regulate secondary pilot pressure (pilot pressure between the pilot valves and the control valve spools) for the arm roll-out and for boom raise functions, preventing abrupt and rapid movement of the respective control valve spools.

6 5

3

4

SM0090

7

• When the arm roll out or the boom raise is operated, secondary pilot pressure from the pilot valve is routed to the side B of the shockless valve. Immediately after operating the control lever, the secondary pilot pressure routed to the side B flows to the control valve spool via orifice (9). As the secondary pilot pressure increases, check valve (7) opens.

To control valve spool

A

B

From pilot valve

8

9

SM0091

7 • Return oil from the control valve spool flows back to the hydraulic oil tank via orifice (9). As the pressure at the side A increases, spool (8) moves in proportion to the pressure increase, regulating the return oil flow. A

From control valve spool

To hydraulic oil tank via pilot valve

B

9

8

SM0092

1 2 3 4 5 6 7 8 9

-

Shockless Valve Pilot Pressure Switch (Boom Raise) Check Valve Check Valve Shockless Valve Pilot Pressure Sensor (Arm Roll In) Check Valve Spool Orifice

EX255-EX285

T3-6-3

OTHER COMPONENTS (Upperstructure) Warm-up circuit When the pilot shut-off valve is in the LOCK position, pilot oil via the pilot shut-off valve flows into the shockless valve. The oil is heated as it flows through the restriction located at the inlet of the shockless valve.

For this reason, the pilot circuit is warmed as this heated oil flows into the shockless valve and into the pilot valves.

To pilot valve

To control valve

To pilot valve

To control valve

To pilot valve

To control valve

To pilot valve

To control valve

Shockless valve Pilot shut-off valve

From pilot pump

SM0093

T3-6-4

EX255-EX285

OTHER COMPONENTS (Upperstructure) SOLENOID VALVE UNIT

Front

The solenoid valve unit functions to control the pump regulator, control valve and travel motor servo piston upon receiving signals from the main controller MC. The solenoid valve unit consists of four solenoid valves (SC), (SD), (SI), and (SG). (Refer to the Control System Group in the SYSTEM Section). SC : Controls the arm regenerative valve located in the control valve. SD : Controls the pump regulator. (Speed Sensing) SI

: Controls the travel motor servo piston. (Travel Speed Selection)

SG : Functions to increase the main relief valve pressure setting

SC SD

SG SI

SM0094

EX255-EX285

T3-6-5

OTHER COMPONENTS (Upperstructure) Proportional Solenoid Valve Upon receiving an electric current signal from the MC, the proportional solenoid valve outputs hydraulic pressure proportional to the degree of the electric current. • When not energized (In neutral): The spring pushes the spool to the right, connecting the output port S to the tank port T. • When energized: The solenoid pushes the spool to the left for a distance proportional to the electric current flowing through the solenoid. Pilot oil from port (P) flows

into output port S, increasing the pressure at output port S. The pressure at port S acts on the two banks of walls on the spool. (See detail “a.”). Because of the pressure receiving area difference between the two walls, the pressure at port S acts as a force to push the spool to the right. As the pressure at port S increases, the force to push the spool to the right also increases. When this force overcomes the force to push the spool to the left by solenoid, the spool moves back to the right side, closing the age between output port S and port P. As a result, pressure increase at port S stops.

Spool

S

T

Spring

P

Solenoid

a

a

SM0095

T3-6-6

EX255-EX285

OTHER COMPONENTS (Upperstructure) PILOT RELIEF VALVE The pilot relief valve functions to regulate the pilot pump pressure oil routed to port P to a set constant pressure.

Pilot relief valve

P

A

T

SM2200

EC MOTOR The EC motor is used to control engine speed. A worm gear is incorporated into the EC motor to prevent a loss of synchronism from occurring. The EC sensor is provided to detect the degrees of the EC

Output shaft

motor rotation to calculate the governor lever position. (Refer to the Control System Group in SYSTEM Section).

Worm gear

Output gear

Sensor gear Motor

EC sensor Worm wheel SM0097

EX255-EX285

T3-7-1

OTHER COMPONENTS (Undercarriage) SWING BEARING This bearing is a single-row shear ball-type bearing, comprising outer race (1), inner race (3), balls (6), s (5), and seals (2), (4). Outer race (1) is bolted to the upperstructure and inner race (3) is bolted to the undercarriage.

The internal gear of inner race (3) engages with the output shaft of the swing reduction gear.

1

2 5

3

6 4

SM0098

1 2 3

- Outer Race - Seal - Inner Race

4 5 6

- Seal - s - Ball

T3-7-2

EX255-EX285

OTHER COMPONENTS (Undercarriage) CENTER T The center t is a 360° rotating t. When the upperstructure is rotated, the center t avoids twisting of hoses and allows hydraulic oil to flow smoothly to or from the travel motors. Spindle (1) is attached to the main frame, and body (2) is bolted to the swing center of the undercarriage.

To left travel motor (Reverse)

To right travel motor (Forward)

To left travel motor (Forward)

To right travel motor (Reverse)

Hydraulic oil flows to the right and left travel motors via spindle (1) and the oil ports of body (2). Seals (3) prevent oil leaks between spindle (1) and body (2) into adjacent ages.

To left travel motor (Forward)

To right travel motor (Forward)

To left travel motor (Reverse)

To right travel motor (Reverse)

1 Pilot pressure for travel speed selection

Pilot pressure for travel speed selection

Drain

2 Drain

Drain

3 Drain Forward Reverse Pilot pressure for travel speed selection

SM0099

1 2

- Spindle - Body

3

- Seal

EX255-EX285

T3-7-3

OTHER COMPONENTS (Undercarriage) TRACK ADJUSTER The track adjuster located on the side frame is composed of spring (5) and adjuster cylinder (6). Spring (5) absorbs loads applied to the front idler. Adjuster cylinder (6) adjusts track sag.

CAUTION Do not loosen valve (1) quickly or loosen too much since high-pressure grease in the adjusting cylinder may spout out. Loosen carefully, keeping body parts and face away from valve (1). Never loosen grease fitting.

• Grease is applied through grease fitting into chamber (A) of adjuster cylinder (6) as illustrated below. The pressure of the grease pushes piston rod (8) out and decreases track sag. • To increase track sag, loosen valve (1) 1 to 1.5 turns counterclockwise to release grease from the track adjuster cylinder through the grease discharge hole.

1

Grease fitting

Grease discharge hole

1

2

3

4

A

5

6

7

SM0100

1 2 3 4

-

Valve Nut Flange Spacer

5 6 7

- Spring - Adjuster Cylinder - Piston Rod

T3-7-4

EX255-EX285

OTHER COMPONENTS (Undercarriage) NOTE

COPYRIGHT BY FIAT - HITACHI EXCAVATORS S.p.A. Documentation Centre Strada di Settimo, 323 - S. MAURO T.SE ( TO ) ITALY


Print No. 604.13.082 - X - 2001 Printed by Satiz - Turin (Italy) Coordinamento Editoriale Satiz - Torino

-

EXCAVATOR TECHNICAL MANUAL TROUBLESHOOTING (Tier 2)



-

ENGINEERING

-

EX255-EX285

IN-1







• The Service Manual for EX255-EX285 Excavators consists of the following book/print numbers:

- The Technical Manual-Troubleshooting includes the technical information needed for operational performance tests, and troubleshooting procedures.

BOOK

PRINT NUMBER


604.13.191


604.13.196

- Workshop Manual

604.13.201

IN-2

EX255-EX285




UNITS USED SI Units (International System of Units) are used in this manual. MKSA system units and English units are also indicated in parentheses just behinds SI units. Example: 24.5 MPa (250 kgf/cm2, 3 560 psi) A table for conversion from SI units to other system units is shown below for reference purposes.

Quantity


Into (Others)

Multiply by

Quantity


Into (Others)

Multiply by

Lenght

mm

in

0.03937

Pressure

MPa

kgf/cm2

10.197

mm

ft

0.003281

MPa

psi

145.0

L

US gal

0.2642

kW

CV-PS

1.360

kW

HP

1.341

Volume

L

US qt

1.057

3

yd

1.308

Temperature

°C

°F

°C x 1.8 + 32

kg

lb

2.205

Velocity

km/h

mph

0.6214

m Mass Force Torque

Power

N

kgf

0.10197

N

lbf

0.2248

N.m

kgf.m

0.10197

N.m

lbf.ft

0.7375

min Flow rate

-1

rpm

1.0

L/min

US gpm

0.2642

mL/rev

cc/rev

1.0

EX255-EX285

S-1

SAFETY PRECAUTIONS RECOGNISE SAFETY INFORMATION • This is your SAFETY ALERT SYMBOL. - When you see this symbol on your machine or in this Manual, be alert of the potential for personal injury. - Follow recommended precautions and safe operating practices.

S0021

UNDERSTAND SIGNAL WORDS • In this Manual you will find the following words: - DANGER; - WARNING; - CAUTION. referring to different hazard risks. These words are always accompanied by the safety alert symbol.

DANGER WARNING

DANGER: indicates an imminent hazardous situation which, if not avoided, will result in death or serious injury.

CAUTION

WARNING: indicated a potential hazardous situation which, if not avoided, could result in death or serious injury.

IMPORTANT

CAUTION: indicates a potential hazardous situation which, if not avoided, may result in minor or moderate injury.

NOTE

IMPORTANT: indicates a situation which, if not avoided, may cause damage to the machine. NOTE: indicates an additional explanation for information purposes.

ENVIRONMENTAL PROTECTION • This Manual also contains this symbol accompanying instructions for correct behaviour as regards environmental protection. S0024

S-2

EX255-EX285

SAFETY PRECAUTIONS FOLLOW SAFETY PRECAUTIONS • Carefully read and observe all safety signs on the machine and read all safety precautions in this Manual. • Safety signs should be installed, maintained, and replaced when necessary. - If a safety sign or this Manual are damaged or missing, obtain a replacement from your FIAT KOBELCO Dealer in the same way you order a spare part (be sure to detail machine model and serial number upon ordering). • Learn how to operate the machine and its controls correctly and safely. • Allow only trained, qualified, authorised personnel to operate the machine.

S0022

• Keep the machine in proper working conditions. - Unauthorised changes to the machine may impair function and/or safety and affect machine life. • Safety messages in this Chapter “SAFETY PRECAUTIONS”, are intended to illustrate basic safety procedures of the machine. However, it is impossible for these safety messages to cover every hazardous situation you may encounter. If you have any doubts, consult your direct supervisor prior to operating or servicing the machine.

PREPARE FOR EMERGENCIES • Be prepared if a fire starts or an accident occurs. - Keep the first-aid kit and fire extinguisher on hand. - Thoroughly read and understand the label attached to the fire extinguisher to use it properly. - Establish emergency priority procedures to cope with fires and accidents. - Keep emergency numbers for doctors, ambulance service, hospitals and fire department posted near the telephone. S0023

EX255-EX285

S-3

SAFETY PRECAUTIONS WEAR PROTECTIVE CLOTHING • Wear close-fitting clothing and safety equipment appropriate to the job. You need: - A hard hat; - Safety shoes; - Safety glasses or face shield; - Heavy gloves; - Ear protection; - Reflective clothing; - Waterproof clothing; - Respirator or filter mask. Be sure to correctly wear equipment and clothing for the job. - Do not take any chances. - Avoid wearing loose clothing, jewellery, or other items that can catch on control levers or other parts of the machine.

S0025

• Operating equipment safely requires the full attention of the operator. Do not wear radio or music headphones while operating the machine.

PROTECT AGAINST NOISE • Prolonged exposure to loud noise can cause impairment or loss of hearing. - Wear a suitable hearing protection such as earmuffs or earplugs to protect objectionable or uncomfortably loud noise.

S0026

INSPECT THE MACHINE • Inspect the machine carefully every day or workshift by an attentive visual inspection of machine outside prior to starting it to prevent damages and personal injuries. - In the walk-around inspection, be sure to cover all points detailed in the Chapter "MAINTENANCE", paragraph "EXTERNAL VISUAL INSPECTION" of the OPERATION AND MAINTENANCE INSTRUCTION MANUAL.

S0027

S-4

EX255-EX285

SAFETY PRECAUTIONS USE HAND HOLDS AND STEPS • Falling is one of the major causes of personal injury. - When you get on and off the machine, always face the machine and maintain a three-point with the steps and handrails. - Do not use any control as a handhold. - Never jump off the machine. Never get on and off a moving machine. - Be careful of slippery conditions of platforms, steps, and handrails when leaving the machine.

S0028

ADJUST THE OPERATOR'S SEAT • A seat poorly adjusted for operator or work requirements may quickly fatigue the operator leading to improper operations. - The seat should be adjusted whenever machine operator changes. - The operator should be able to fully press the pedals and correctly move the control levers with his back resting against the seat back. - If not, move the seat fore and aft, and check again. S0029

EX255-EX285

S-5

SAFETY PRECAUTIONS FASTEN SEAT BELT • Should the machine overturn, the operator may become injured and/or thrown from the cab. Not only, the operator may be crushed by the overturning machine resulting in serious injury or even death. - Prior to operating the machine, thoroughly examine belt webbing, buckle, and attaching hardware. If any item is damaged or worn, replace the seat belt or component before operating the machine.

S0030

- Be sure to remain seated with the seat belt securely fastened at all times when the machine is in operation to minimise injury hazard in case of accident. - After a significant accident, replace the seat belts even though they do not look damaged.

MOVE AND SAFELY

OPERATE

MACHINE

• Bystanders can be run over. - Pay the utmost attention not to run over bystanders. - Be sure and aware of the location of bystanders before moving, swinging or operating the machine. - If fitted, keep the travel alarm and horn sounding to warn people that the machine is about to move. S0031

- When operating, swinging, or moving the machine in a congested area use a signal man. - Co-ordinate hand signals before starting the machine.

S-6

EX255-EX285

SAFETY PRECAUTIONS OPERATE ONLY FROM THE DRIVER'S SEAT • Inappropriate engine starting procedures may cause the machine unexpected movement, possibly resulting in serious injury and even death. - Start the engine only from the operator’s seat. - NEVER start the engine while standing on the track or on the ground. - Do not start the engine by shorting across starter motor terminals. S0032

- Before starting the engine, ensure that all control levers are in the neutral position.

KEEP RIDERS OFF THE MACHINE • Riders on the machine are subject to injuries such as being struck by foreign objects and being thrown off the machine. - Only machine operator is machine. Keep riders off.

allowed on the

- Riders also obstruct the operator’s visibility, resulting in the machine being operated unsafely. S0033

CONFIRM DIRECTION WHERE THE MACHINE IS TO BE DRIVEN • Incorrect travel controls operation may result in serious injury and even death. - Before driving the machine, be aware of the undercarriage position relative to the operator’s position. If travel motors are located at the front of the cab, the machine will move reverse when travel controls are moved towards cab front. S0037

EX255-EX285

S-7

SAFETY PRECAUTIONS AVOID INJURY FROM BACK-OVER AND SWING ACCIDENTS • If any person is present near the machine when backing or swinging the upperstructure, the machine may hit or run over that person, resulting in serious injury or death. • To avoid back-over and swing accidents: - Always look around BEFORE YOU BACK UP AND SWING THE MACHINE. BE SURE THAT ALL BYSTANDERS ARE CLEAR. - Keep the travel alarm in working condition (if equipped). - ALWAYS BE ALERT FOR BYSTANDERS MOVING INTO THE WORK AREA. USE THE HORN OR OTHER SIGNAL TO WARN BYSTANDERS BEFORE MOVING MACHINE.

S0042

- USE A SIGNAL PERSON WHEN BACKING UP IF YOUR VIEW IS OBSTRUCTED. ALWAYS KEEP THE SIGNAL PERSON IN VIEW. - Use hand signals, which conform to your local regulations, when work conditions require a signal person. - No machine motions shall be made unless signals are clearly understood by both signalman and operator. - Learn the meanings of all flags, signs, and markings used on the job and confirm with the person in charge of signalling. - Keep windows, mirrors, and lights clean and in good condition. - Dust, heavy rain, fog, etc., can reduce visibility. As visibility decreases, reduce speed and use proper lighting. - Read and understand all operating instructions in the OPERATION AND MAINTENANCE INSTRUCTION MANUAL.

S0043

S-8

EX255-EX285

SAFETY PRECAUTIONS DRIVE MACHINE SAFELY •

Before starting the machine carefully read the OPERATION AND MAINTENANCE INSTRUCTION MANUAL. (Refer to the OPERATING INSTRUCTIONS chapter).

• Before moving the machine, confirm which way to move travel pedals/levers for the corresponding direction you wish to go. - Pushing down on the front of the travel pedals or pushing the levers forward moves the machine towards the idlers. (Refer to the OPERATION AND MAINTENANCE INSTRUCTION MANUAL).

S0038

• Traveling on a grade may cause the machine to slip or to overturn, possibly resulting in serious injury or death. - When traveling up or down a grade, keep the bucket in the direction of travel, approximately 20 to 30 cm (A) above the ground. - If machine starts to skid or becomes unstable, lower the bucket immediately.

S0039

- Traveling across the face of a slope may cause the machine to skid or to overturn. When travelling (ascending/descending) on a slope, be sure to point the tracks uphill/downhill.

S0004

- Turning on an incline may cause the machine to tip over. If turning on an incline is absolutely unavoidable, do so at a place where the slope is gentle and the surface is firm. - When operating on a grade and the fuel reserve indicator light lights, immediately refuel.

WRONG S0005

EX255-EX285

S-9

SAFETY PRECAUTIONS AVOID OVERTURNING • The danger of tipping is always present when operating on a grade, possibly resulting in serious injury or death. • To avoid tipping: - Be extra careful before operating on a grade. - Prepare machine operating area flat by grading. - Keep the bucket low to the ground and close to the machine. - Reduce machine operating speed to avoid tipping or slipping. - Avoid changing direction when travelling on grades. - NEVER attempt to travel across a grade steeper than 15 degrees. - Reduce swing speed as necessary when swinging loads.

S0002

• Be careful when working on frozen ground. - Temperature increases will cause the ground to become soft and make ground travel unstable.

S0047

PARK MACHINE SAFELY • To avoid accidents: - Park machine on a level surface. - Lower bucket to the ground. - Turn auto-idle (A/I) switch off. - Run engine at slow idle speed without load for 5 minutes. - Turn key-start switch to OFF to stop engine. - Remove the ignition key from the key switch. - Pull the safety lever (pilot-control shut-off lever) to the LOCK position. - Close windows, roof window, and cab door. - Lock all access doors and compartments.

S0049

S-10

EX255-EX285

SAFETY PRECAUTIONS AVOID INJURY FROM UNEXPECTED MACHINE MOVEMENT • Death or serious injury may result if you attempt to get on or off a moving machine. • To avoid roll-aways: - Select level ground when possible to park machine. - Do not park the machine on a grade. - Lower the bucket and/or other work tools to the ground. Thrust the bucket teeth into the ground if you must park on a grade. - Turn the auto-idle switch off. - Run the engine at slow idle speed without load for 5 minutes to cool down the engine. - Stop the engine and remove the key from the key switch. - Pull the pilot shut-off lever to LOCK position. - Block both tracks. - Position the machine to prevent overturning. - Park a reasonable distance from other machines.

S0040

S0041

PROVIDE SIGNALS FOR JOBS INVOLVING A NUMBER OF MACHINES • For jobs involving several machines, provide signals commonly known by all personnel involved. Also, appoint a signal person to co-ordinate the job site. Make sure that all personnel obey the signal person’s directions.

S0036

EX255-EX285

S-11

SAFETY PRECAUTIONS INVESTIGATE JOB SITE BEFORE HAND • When working at the edge of an excavation or on a road shoulder, the machine could overturn, possibly resulting in serious injury or death. - Investigate the configuration and ground conditions of the job site beforehand to prevent the machine from overturning and prevent the ground, stockpiles, or banks from collapsing. - Make a work plan. Use machines appropriate to the work and job site. - Reinforce ground, edges, and road shoulders as necessary. Keep the machine well back from the edges of excavations and road shoulders. - When working on an incline or road shoulder, employ a signal person as required. Confirm that your machine is equipped with a F.O.P.S. (Falling Object Protective Structure) cab before working in areas where there is the possibility of falling stones or landslides. - When footing is weak, reinforce the ground before starting the work. - When working on frozen ground, be extremely alert. As ambient temperature rises, footing becomes loose and slipped.

S0034

PROTECT AGAINST FALLING STONES AND LANDSLIDES • Confirm that your machine is equipped with a F.O.P.S. (Falling Object Protective Structure) cab before working in areas where there is the possibility of falling stones.

S0035

S-12

EX255-EX285

SAFETY PRECAUTIONS DIG WITH CAUTION • Accidental severing of underground cables or gas lines may cause an explosion and/or fire, possibly resulting in serious injury or death. - Before digging, check the location of cables, gas lines, and water lines. - Keep the minimum distance required by law from cables, gas lines, and water lines. If a fiber optic cable should be accidentally severed, do not look into the end. Doing so may result in serious eye injury. - local authorities and/or the utility companies directly (electric power, gas, telephone, water, sewers, telecommunications, etc.) to obtain information about underground utility lines.

S0009

OPERATE WITH CAUTION • If the front attachment or any other part of the machine hits against an overhead obstacle, such as a bridge, both the machine and the overhead obstacle will be damaged, and personal injury may results as well. - Take care to avoid hitting overhead obstacles with the boom or arm.

S0008

AVOID ELECTRIC LINES • Serious injury or death can result if the machine or front attachments are not kept a safe distance from electric lines. - When operating near an electric line, NEVER move any part of the machine or load closer than 3 m plus twice the line insulator length (L). - Check and comply with any local regulations that may apply. - Wet ground will expand the area that could cause any person on it to be affected by electric shock. - Keep all bystanders or co-workers away from the site.

L

S0205

EX255-EX285

S-13

SAFETY PRECAUTIONS KEEP PERSONNEL CLEAR FROM WORKING AREA • A person may be hit severely by the swinging front attachment or counterweight and/or may be crushed against an other object, resulting in serious injury or death. - Keep all persons clear from the area of operation and machine movement. - Before operating the machine, set up barriers to the sides and rear area of the bucket swing radius to prevent anyone from entering the work area.

S0044

NEVER MOVE THE BUCKET OVER ANY ONE • Never lift, move, or swing bucket above anyone or a truck cab. Serious injury or machine damage may result due to bucket load spill or due to collision with the bucket.

S0045

AVOID UNDERCUTTING • In order to retreat from the edge of an excavation if the footing should collapse, always position the undercarriage perpendicular to the edge of the excavation with the travel motors at the rear. - If the footing starts to collapse and if sufficient retreat is not possible, do not panic. Often, the machine can be secured by lowering the front attachment, in such cases.

S0011

S-14

EX255-EX285

SAFETY PRECAUTIONS NEVER UNDERCUT A HIGH BANK • The edges could collapse or a land slide could occur causing serious injury or death.

S0048

SAFETY LOADS MOVING • The excavator is no lifting and transportation means, therefore it should not be used to position loads accurately. Should it be exceptionally used to lift and lay building components, special caution must be taken as follows: - The machine must be equipped without failure with the appropriate variant supplied, upon request, by FIAT KOBELCO. Also, totally comply with the safety precautions for the operation of the excavator as a lifting equipment. - Secure the loads to be raised using cables or chains fastened with appropriate hooking mechanisms. - Never hook cables or chains to the bucket teeth. - Nobody should be allowed to remain under the raised load or within the excavator operating range for any reason whatever. S0165

- Never exceed specified loading capacity. Incorrect fastening of slings or chains may cause boom/arm failure or failure of the lifting means with consequent bodily injuries and even death. - Always ensure that slings and chains used for lifting are adequate to the load and in good condition. - All loading capacities are referred to the machine on a level surface and should be disregarded when working on a slope.

EX255-EX285

S-15

SAFETY PRECAUTIONS SAFETY TRANSPORTING • The danger of tipping is present when loading/ unloading the machine onto/from a truck or trailer bed. - Be sure to observe local regulations when transporting the machine on public roads. - Provide an appropriate truck or trailer for transporting the machine. • Take the following precautions when loading/ unloading the machine: 1. Select firm level ground. 2. Be sure to use a loading dock or ramp. 3. Be sure to have a signal person when loading/ unloading the machine. 4. Always turn the auto-idle (A/I) switch OFF when loading or unloading the machine, to avoid unexpected speed increase due to unintentional operation of a control lever. 5. Always select the slow speed mode with the travel speed selector. In the high speed mode, travel speed may automatically increase. 6. Avoid steering while driving up or down the ramp as it is extremely dangerous. If steering is unavoidable, first move back to the ground or flatbed, modify travelling direction, and begin to drive again. 7. Do not operate any levers besides the travel levers when driving up or down the ramp. 8. The top end of the ramp where it meets the flatbed is a sudden jolt. Take care when traveling over it. 9. Prevent possible injury from machine tipping while the upperstructure is rotating. 10. Keep the arm tucked under and rotate the upperstructure slowly for best stability. 11. Securely fasten machine frame using chains or cables. Refer to “TRANSPORT” chapter in the OPERATION AND MAINTENANCE INSTRUCTION MANUAL for details.

S0052

S-16

EX255-EX285

SAFETY PRECAUTIONS SAFE MAINTENANCE • To avoid accidents: - Understand maintenance procedure before starting the work. - Kepp the working area clean and dry. - Do not spray water or steam inside the cab. - Do not lubricate or service the machine when it is in motion. - Kepp hands, feet and clothes far from moving parts. Prior to service in the machine: 1. Park the machine on the level ground. 2. Lower the bucket to the ground. 3. Switch off the Auto-Idle (A/I). 4. Let the engine idle with no load for at least five minutes until it has cooled down. 5. Move the key-start switch to the OFF position to stop the engine. 6. Remove the ignition key from the start switch. 7. Apply the "Maintenance in progress" tag . This tag can be applied o the left-hand control lever, safety lever or cab door. 8. Move the safety lever (pilot-control shut-off lever) to the LOCK position. 9. Let the engine cool down. - Do not leave the machine unattended if servicing requires the engine running . - If the machine is to be raised, place boom and arm at an angle 90 to 110°. Lock machine components which should be raised for maintenance or repair using suitable ing means. - Never work under a machine kept raised by the boom. - Inspect certain component regularly, repair or replace as necessary. Refer to the the OPERATION AND MAINTENANCE INSTRUCTION MANUAL. - Keep all components in good condition and properly install. Immediately repair any fault. - Immediately repair any damage.Replace worn or failed components. Remove grease, oil, debris build-ups. - Disconnect the negative cable (−) from the battery before carry out any work on the electrical system or arc-welding on the machine.

S0053

S0054

EX255-EX285

S-17

SAFETY PRECAUTIONS WARN OTHERS OF SERVICE WORK • Unexpected machine movement can cause serious injury. - Before performing any work on the machine, attach a maintenance in progress tag. This tag can be applied o the left-hand control lever, safety lever or cab door.

S0055

MACHINE PROPERLY • Never attempt to work on the machine without securing the machine first. - Always lower the attachment or tool to the ground before working on the machine. - If you must work on a lifted machine or attachment, securely the machine or attachment. - Do not the machine on cinder blocks, bollow tires, or props that may crumble under continuous load. - Do not work under a machine that is ed solely by a jack.

S0054

STAY CLEAR OF MOVING PARTS • Entanglements in moving parts can cause serious injury. • To prevent accidents, care should be taken to ensure that hands, feet, clothing, jewelry and hair do not become entangled when working near rotating parts.

S0056

S-18

EX255-EX285

SAFETY PRECAUTIONS DISPOSE OF WASTE IN THE APPROPRIATE MANNER • Waste improperly disposed of represents a danger for the envinronment. Potentially dangerous waste used on the FIAT KOBELCO excavators includes lubricants, fuel, coolant, brake fluid, filters and batteries. - Used sealed containers when discharging fluids. Do not use containers for food or beverages which may induce drinking. - Do not spill waste over the ground, into drains, or water beds. S0064

- Obtain information about the correct methods to recycle or dispose of waste from local Authorities, collection centres or your Dealer.

WORK IN A CLEAN AREA • Before starting an operation, clean the working area. Clear the area from all the objects that can be dangerous for mechanics or people in the working area.

S0166

PROPERLY LIGHT THE WORKING AREA • Properly and safely light the working area. - Use safe portable lamps in order to work inside and under the machine. - Make sure that the lamp is shielded by a cage; the incandescent filament of a lamp, accidentally broken, can cause fuel or oil fire.

F1480

S0167

EX255-EX285

S-19

SAFETY PRECAUTIONS REGULARLY WASH THE MACHINE • Remove all the traces of grease, oil and deposits, in order to avoid people accidents or damages to things. - Do not spray water or steam in the cab.

F1462

S0153

F1463

S0058

STORE ATTACHMENTS SAFELY • Stored attachments such as buckets, hydraulic breakers and blades can fall and cause serious injury or death. - Securely store attachments and implements to prevent falling. - Keep bystanders away from storage areas.

PREVENT ACID SCALDS • The sulphuric acid, contained in the battery, is poisonous. It is strong enough to scald the skin, corrode clothes and cause blindness, if it is sprayed into the eyes. To avoid dangers: - Fill the batteries in airy areas. - Wear eye protections and rubber gloves. - Avoid breathing the electrolyte vapours when topping up. - Avoid spilling or dripping the electrolyte. - Use proper emergency starting techniques. If you are touched with acid sprays: - Rinse your skin well with water. - Put on your skin sodium bicarbonate or clay to help the acid neutralization. - Rinse your eyes with water for 10-15 minutes. - Immediately see a doctor. If you have swallowed the acid: - Drink a big quantity of water or milk, swallow milk of magnesia, scrabbled eggs or vegetal oil. - Immediately see a doctor.

F1474

S0168

S-20

EX255-EX285

SAFETY PRECAUTIONS STARTING THE ENGINE WITH BOOSTER BATTERIES • Battery gas may explode causing serious damages and injuries. - If the engine is to be started using booster batteries, ensure to comply with all procedures detailed in the chapter “OPERATING INSTRUCTIONS” of the OPERATION AND MAINTENANCE INSTRUCTION MANUAL. - The operator should be sitting in the driver’s seat to keep the machine under control when the engine starts. Starting the engine with booster batteries is a two man operation.

S0001

- Do not use batteries that have been stored in the cold for a long time. - Mistakes in following procedures detailed for starting the engine with slave batteries may cause the batteries to explode or machine to move unexpectedly.

PREVENT BATTERY EXPLOSIONS • Battery gas can explode. - Keep sparks, lighted matches, and flames away from the top of battery. - Never check battery charge by placing a metal object across the posts. Use a voltmeter or hydrometer. - Do not charge a frozen battery; it may explode. Warm battery to 16 °C.

• Battery electrolyte is poisonous. If the battery should explode, battery electrolyte may be splashed into eyes, possibly resulting in blindness. - Be sure to wear eye protection when checking electrolyte specific gravity.

S0001

EX255-EX285

S-21

SAFETY PRECAUTIONS PREVENT BURNS Hot spraying fluids: • After operation, engine coolant is hot and under pressure. Hot water or steam is contained in the engine, radiator and heater lines. Skin with escaping hot water or steam can cause severe burns. - To prevent possible injury from hot spraying water. DO NOT remove the radiator cap until the engine is cool. When opening, turn the cap slowly to the stop. Allow all pressure to be released before removing the cap. - The hydraulic oil tank is pressurized. Again, be sure to release all pressure before removing the cap.

S0019

Hot fluids and surfaces: • Engine oil, reduction gear oil and hydraulic oil also become hot during operation. The engine, hoses, lines and other parts become hot as well. - Wait for the oil and components to cool down before starting any maintenance or inspection work. S0059

KEEP CLEAN THE MACHINE Keep clean the engine compartment, radiator, batteries, hydraulic pipes, fuel tank and operator's position. The engine compartment temperature can quickly rise, after stopping the engine. IN THESE CASES, BE CAREFUL TO POSSIBLE FIRES. Open the access doors in order to quicken the engine cooling process and clean the compartment.

S0177

S-22

EX255-EX285

SAFETY PRECAUTIONS AVOID HIGH-PRESSURE FLUIDS • Fluids such as diesel fuel or hydraulic oil under pressure can penetrate the skin or eyes causing serious injury, blindness or death. - Avoid this hazard by relieving pressure before disconnecting hydraulic or other lines. SA0016

- Tighten all connections before applying pressure. - Search for leaks with a piece of cardboard; take care to protect hands and body from highpressure fluids. Wear a face shield or goggles for eye protection. SA0017

- In an accident occurs, see a doctor familiar with this type of injury immediately. Any fluid injected into the skin must be surgically removed within a few hours or gangrene may result.

SA0018

PREVENT PARTS FROM FLYING OFF • Grease in the track adjuster is under high pressure. Failure to follow the precautions below may result in serious injury, blindness, or death. - NEVER attempt to remove GREASE FITTING or VALVE ASSEMBLY. - As pieces may fly off, be sure to keep body and face away from valve.

• Travel reduction gears are under pressure. - As pieces may fly off, be sure to keep body and face away from AIR RELEASE PLUG to avoid injury. REDUCTION GEAR OIL is hot. Wait for gear oil to cool down, then gradually loosen the air release plug to release pressure.

F3635

S0178

EX255-EX285

S-23

SAFETY PRECAUTIONS PROTECT AGAINST FLYING DEBRIS • If flying debris hit eyes or any other part of the body, serious injury may result. - Guard against injury from flying pieces of metal or debris; wear goggles or safety glasses. - Keep bystanderds away from the working area before striking any object.

S0046

HANDLE FLUIDS SAFELY - AVOID FIRES • Handle fuel with care: it is highly flammable. If fuel ignites, an explosion and/or a fire may occur, possibly resulting in serious injury or death. - Do not refuel the machine while smoking or when near open flame or sparks. - Always stop the engine before refuelling the machine. - Fill the tank outdoors.

S0050

• All fuels, most lubrificants, and some antifreeze fluids are flammable. - Store flammable fluids well away from fire hazards. - Do not burn or puncture pressurized containers. - Do not store oily rags; they can ignite and burn spontaneously.

S0051

S-24

EX255-EX285

SAFETY PRECAUTIONS PREVENT FIRES • Check for Oil Leaks: - Fuel, hydraulic oil and lubricant leaks can lead to fires. - Check for missing or loose clamps, kinked hoses, lines or hoses that rub against each other, damage to the oil-cooler, and loose oil-cooler flange bolts which may cause oil leaks. - Tighten, repair or replace any missing, loose or damaged clamps, lines, hoses, oil-cooler and oilcooler flange bolts. - Do not bend or strike high-pressure lines. - Never install bent or damaged lines, pipes, or hoses. • Check for Shorts circuits which could cause fires: - Clean and tighten all electrical connections. - Check before each shift or after about ten (10) hour operation for loose, kinked, hardened or frayed electrical cables and wires. - Check before each shift or after about ten (10) hour operation for missing or damaged terminal caps. - DO NOT OPERATE MACHINE if cable or wires are loose, kinked, etc.. • Clean up Flammables: - Spilled fuel and lubricans, and trash, grease, debris, accumulated coal dust, and other flammables may cause fires. - Prevent fires by inspecting and cleaning the machine daily and by removing spilled or accumulated flammables immediately. • Check Key-start Switch: - If a fire breaks out, failure to stop the engine will escalate the fire, hampering fire fighting. - Always check key-start switch function before operating the machine every day: 1. Start the engine and run it at slow idle. 2. Turn the key-start switch to the OFF position to confirm that the engine stops. - If any abnormalities are found, be sure to repair them before operating the machine. • Check Heat Shields: - Damaged or missing heat shields may lead to fires. - Damaged or missing heat shields must be repaired or replaced before operating the machine.

S0051

EX255-EX285

S-25

SAFETY PRECAUTIONS EVACUATING IN CASE OF FIRE • If a fire breaks out, evacuate the machine in the following way: - Stop the engine by turning the key-start switch to the OFF position if there is time. - Use a fire extinguisher if there is time. - Exit the machine.

S0060

BEWARE OF EXHAUST FUMES • Prevent asphyxiation. Engine exhaust fumes can cause sickness or death. - If you must operate in a building, be sure there is adequate ventilation. Either use an exhaust pipe extension to remove the exhaust fumes or open doors and windows to bring enough outside air into the area.

S0061

USE APPROPRIATE TOOLS • Use tools appropriate for the job to be performed. - Inappropriate tools, parts and procedures might generate dangerous conditions. - Use tools of correct size to tighten or loosening securing elements, in order to avoid injuries caused by a wrench getting out of control. - Do not use U.S. Standard or British Standard tools on metric fasteners and vice versa. • Use only FIAT KOBELCO genuine spare parts (please refer to the PARTS CATALOG).

S0120

S-26

EX255-EX285

SAFETY PRECAUTIONS AVOID HEATING NEAR PRESSURIZED FLUID LINES Flammable spray can be generated by heating near pressurized fluid lines, resulting in severe burns to yourself and bystanders. Do not heat by welding, soldering, or using a torch near pressurized fluid lines or other flammable materials. Pressurized lines can be accidentally cut when heat goes beyond the immediate flame area. Install temporary fire resistant guards to protect hoses or other materials when welding, soldering, etc. S0062

AVOID APPLYING HEAT TO LINES CONTAINING FLAMMABLE FLUIDS - Do not weld or flame cut pipes or tubes that contain flammable fluids. - Clean them thoroughly with non-flammable solvent before welding or flame cutting them.

REMOVE PAINT BEFORE WELDING OR HEATING • Hazardous fumes can be generated when paints is heated by weiding, soldering, or using a torch. If inhaled, these fumes may cause sickness. - Avoid breathing potentially toxic fumes and dust. - Do all such work outside or in a well-ventilated area. - Dispose of paint and solvents properly. - Remove paint before welding or heating: 1. If you sand or grind paint, avoid breathing the dust. Wear an approved respirator. 2. If you use solvent or paint stripper, remove stripper with soap and water before welding. Remove solvent or paint stripper containers and other flammable material from area. Allow fumes to disperse at least 15 minutes before welding or heating.

S0063

TECHNICAL MANUAL

EX255-EX285

TROUBLESHOOTING


Section 4 -

OPERATIONAL PERFORMANCE TEST

Group 1 Group 2 Group 3 Group 4 Group 5

Introduction Standard Engine Test Excavator Test Component Test

Section 5 -

TROUBLESHOOTING

Group Group Group Group Group Group Group

Diagnosing Procedure Component Layout Troubleshooting A Troubleshooting B Troubleshooting C Electrical System Inspection Harness Check

1 2 3 4 5 6 7

SECTION 4

EX255-EX285

OPERATIONAL PERFORMANCE

CONTENTS Group 1 -

Introduction

Operational performance test ............... T4-1-1 Preparation for performance tests ........ T4-1-2

Group 2 -

Standard

EX255 Operational Performance standard tables .................................... T4-2-1 EX255 Main pump P-Q diagram ........... T4-2-5 EX285 Operational Performance standard tables .................................... T4-2-6 EX285 Main pump P-Q diagram ........... T4-2-10

Group 3 -

Engine Test

Engine speed ....................................... T4-3-1 Engine check and adjustment .............. T4-3-3

Group 4 -

Excavator Test

Travel speed ......................................... T4-4-1 Track revolution speed ......................... T4-4-2 Mistrack check .................................... T4-4-3 Travel parking function check ................................................... T4-4-4 Swing speed ........................................ T4-4-5 Swing function drift check .................... T4-4-6 Swing motor leakage ............................ T4-4-7 Swing bearing play ............................... T4-4-8 Maximum swingable slant angle .................................................... T4-4-9 Hydraulic cylinder cycle time ............... T4-4-10 Dig function drift check ........................ T4-4-12 Control lever operating force ................ T4-4-13 Control lever stroke .............................. T4-4-14 Combined boom raise/swing function check ..................................... T4-4-15

Group 5 -

Component Test

Primary pilot pressure .......................... T4-5-1 Secondary pilot pressure ..................... T4-5-3 Solenoid valve set pressure ................. T4-5-4 Main pump delivery pressure ............... T4-5-6 Main relief valve set pressure .............. T4-5-7 Overload relief valve set pressure ............................................... T4-5-11 Main pump flow test ............................. T4-5-14 Swing motor drainage ........................... T4-5-18 Travel motor drainage ........................... T4-5-20

EX255-EX285

T4-1-1

INTRODUCTION OPERATIONAL PERFORMANCE TEST Use operational performance test procedure to quantitatively check all system and functions on the machine.

Purpose of Performance Tests 1. To comprehensively evaluate each operational function by comparing the performance test data with the standard values. 2. According to the evaluation results, repair, adjust, or replace parts or components as necessary to restore the machine’s performance to the desired standard. 3. To economically operate the machine under optimal conditions.

Kinds of Tests 1. Base machine performance test is to check the operational performance of each system such as engine, travel, swing, and hydraulic cylinders. 2. Hydraulic component unit test is to check the operational performance of each component such as hydraulic pump, motor, and various kinds of valves.

Performance Standards “Performance Standard” is shown in tables to evaluate the performance test data.

Precautions for Evaluation of Test Data 1. To evaluate not only that the test data are correct, but also in what range the test data are. 2. Be sure to evaluate the test data based on the machine operation hours, kinds and state of work loads, and machine maintenance conditions. The machine performance does not always deteriorate as the working hours increase. However, the machine performance is normally considered to reduce in proportion to the increase of the operation hours. Accordingly, restoring the machine performance by repair, adjustment, or replacement shall consider the number of the machine’s working hours.

Definition of “Performance Standard” 1. Operation speed values and dimensions of the new machine. 2. Operational performance of new components adjusted to specifications. Allowable errors will be indicated as necessary.

T4-1-2

EX255-EX285

INTRODUCTION PREPARATION FOR PERFORMANCE TESTS Observe the following rules in order to carry out performance tests accurately and safely. THE MACHINE 1. Repair any defects and damage found, such as oil or water leaks, loose bolts, cracks and so on, before starting to test. TEST AREA 1. Select a hard and flat surface. 2. Secure enough space to allow the machine to run straight more than 20 m (65 ft 7 in), and to make a full swing with the front attachment extended. 3. If required, rope off the test area and provide signboards to keep unauthorized personnel away.

SM0131

PRECAUTIONS 1. Before starting to test, agree upon the signals to be employed for communication among coworkers. Once the test is started, be sure to communicate with each other using these signals, and to follow them without fail. 2. Operate the machine carefully and always give first priority to safety. 3. While testing, always take care to avoid accidents due to landslides or with high-voltage power lines. Always confirm that there is sufficient space for full swings. 4. Avoid polluting the machine and the ground with leaking oil. Use oil pans to catch escaping oil. Pay special attention to this when removing hydraulic pipings. MAKE PRECISE MEASUREMENT 1. Accurately calibrate test instruments in advance to obtain correct data. 2. Carry out tests under the exact test conditions prescribed for each test item. 3. Repeat the same test and confirm that the test data obtained can be produced repeatedly. Use mean values of measurements if necessary.

SM3026

EX255

T4-2-1

STANDARD EX255 OPERATIONAL PERFORMANCE STANDARD TABLES The standard Performance values related to excavator test are listed in the table 1 shown below. In table 2 are listed the standard performance related to component test. Refer to the Group T4-3 to T4-5 for performance test procedures. Values indicated in parentheses are reference values. The following switch positions shall be selected and the hydraulic oil temperature shall be maintained as

indicated below as the preconditions of performance tests unless otherwise instructed in each performance test procedure: Engine Control Dial : Fast Idle E Mode Switch : OFF HP Mode Switch : OFF Work Mode Switch : General Purpose Mode Hydraulic Oil Temperature : 50 ± 5 °C (122 ± 9 °F) NOTE - 1 kgf = 9.807 N

Table 1 - Excavator performance (EX255) Ref. pag.

Performance test designation

T4-3-1/2

ENGINE SPEED

Fast idle speed with E and HP modes OFF

2180 ± 100

Fast idle speed with E mode ON

1980 ± 50

Fast idle speed with HP mode ON

50 or more higher than fast idle speed measured with E and HP modes OFF and arm roll-in circuit relieved

1200 ± 100

ENGINE COMPRESSION PRESSURE MPa (kgf/cm2)

(mm)

NOZZLE INJECTION PRESSURE MPa (kgf/cm2) INJECTION TIMING (Before TDC)

Extend the arm cylinder to relieve the arm roll-in circuit

850 ± 100

Auto-idle speed (A/I)

VALVE CLEARANCE (IN, EX)

Remarks

(rpm)

Slow idle speed

T4-3-3

Performance standard EX255

(deg.)

3 (31)

0.4 18.1 (185)

8°

With the engne hot (approx. 75 °C) – Allowable limit: 2.5 (26) – Difference cylinder pressure compression exceeding 200 kPa (2.0 kgf/cm2) is inacceptable

With the engine cold

T4-2-2

EX255

STANDARD Performance test designation

Ref. pag.

13.2 ± 1

Slow speed

20 ± 2

TRACK REVOLUTION SPEED

26.5 ± 2 28.8 ± 2

MISTRACK (mm/20 m) (With fast and slow travel speed modes)

200 or less

TRAVEL PARKING FUNCTION CHECK

1/6 or less

(rev)

(mm/5 min)

Travel slow speed only

0

SWING SPEED (s/3 rev)

T4-4-7

SWING FUNCTION DRIFT CHECK

SWING MOTOR LEAKAGE SWING BEARING PLAY

13.3 ± 1

(mm/180°)

1500 or less

(mm/5 min)

0

(mm) MAXIMUM SWINGABLE SLANT ANGLE (deg.) HYDRAULIC CYLINDER CYCLE TIME

T4-4-10

(s/3 rev)

EX255 EX255 LC

Travel motor leak

Remarks

(s/20 m)

Fast speed

T4-4-9 T4-4-8

T4-4-6

T4-4-5

T4-4-4

T4-4-3

T4-4-2

T4-4-1

TRAVEL SPEED


1.3 or less 19.2° or more

2950 arm (Mono) or 2158 arm (Triple articulation) and 1.1 m3 bucket (SAE heaped) 2950 arm (Mono) or 2158 arm (Triple articulation) and 1.1 m3 bucket (SAE heaped) Allowable limit: 4.3 mm 2950 arm (Mono) and 1.1 m3 bucket (SAE heaped) 2950 arm (Mono) or 2158 arm (Triple articulation) and 1.1 m3 bucket (SAE heaped)

(s)

Boom (Mono version)

Raise Lower

3.1 ± 0.3 2.5 ± 0.3

Boom (Triple articulation version)

Raise Lower

4.1 ± 0.3 3.6 ± 0.3

Arm

Roll-in Roll-out

3.9 ± 0.3 2.6 ± 0.3

Bucket

Roll-in Roll-out

4.1 ± 0.3 2.5 ± 0.3

Positioning (Triple ariticulation version)

Roll-in Roll-out

6.0 ± 0.3 3.9 ± 0.3

EX255

T4-2-3

STANDARD Ref. pag.


T4-4-12

DIG FUNCTION DRIFT CHECK

20 or less

Positioning cylinder (Triple articulation version)

20 or less

Arm cylinder

20 or less

Bucket cylinder

20 or less Mono Triple articulation

T4-4-13

CONTROL LEVER OPERATING FORCE

T4-4-14

150 or less 150 or less

(kgf)

Boom lever

2.0 or less

Arm lever

2.0 or less

Bucket lever

1.7 or less

Swing lever

1.7 or less

Travel lever

2.5 or less

CONTROL LEVER STROKE

(mm)

Boom lever

105 ± 10

Arm lever

105 ± 10

Bucket lever

83 ± 10

Swing lever

83 ± 10

Travel lever

115 ± 10

BOOM RAISE/SWING (Bucket empty)

(s)

Bucket teeth height: H

(mm) Mono

NOTE - 1 kgf = 9.807 N.

Remarks

2950 arm (Mono) or 2158 arm (Triple articulation) and 1.1 m3 bucket (SAE heaped)

(mm/5 min)

Boom cylinder

Total drop

T4-4-15


3.7 ± 0.3

6700 or more

2950 arm (mono) and 1.1 m3 bucket (SAE heaped)

T4-2-4

EX255

STANDARD Table 2 - Component performance standard (EX255) Performance standard EX255

Remarks

(kgf/cm2)

40 +10 –5

SECONDARY PILOT PRESSURE

(kgf/cm2)

(34 ÷ 40)

SOLENOID VALVE SET PRESSURE

(kgf/cm2)

Value indicated on Dr. EX ± 2

MAIN PUMP DELIVERY PRESSURE

(kgf/cm2)

25 +15 –7

Value indicated on Dr. EX

MAIN RELIEF VALVE SET PRESSURE

(kgf/cm2)

Boom, Arm and Bucket

350 +20 –5


Swing

330 +20 –5


Travel

350 +20 –5


Power Boost

370 +20 –10


T4-5-7

PRIMARY PILOT PRESSURE

T4-5-3


T4-5-6 T4-5-4

T4-5-1

Ref. pag.

T4-5-14

T4-5-11

OVERLOAD RELIEF VALVE SET PRESSURE (kgf/cm2)

(Engine: Fast idle and slow idle) Value indicated on Dr. EX (Lever: Full stroke)

Reference values at 50 L/min

Boom (raise/lower), arm roll-in and bucket roll-in

380 +10 –0

Arm roll-out and bucket roll-out

400 +10 –0

MAIN PUMP FLOW TEST

(Engine: Fast idle)

(L/min)

––

Refer to page T4-2-5

With constant maximum speed

(L/min)

0.2 ÷ 1.0

Allowable limit: 2.0

With the motor relieved

(L/min)

8

Allowable limit: 16

With the track jacked up

(L/min)

1.5 ÷ 2.0



(L/min)

(1.5 ÷ 4.8)

T4-5-18

SWING MOTOR DRAINAGE

T4-5-20

TRAVEL MOTOR DRAINAGE

NOTE - 1 kgf/cm2 = 0.09807 MPa.

Allowable limit: (5.2)

EX255

T4-2-5

STANDARD EX255 MAIN PUMP P-Q DIAGRAM (Reference: Measured at Test Stand)

Points on P-Q Line

• Rated Engine Speed : 2000 min–1 (rpm) • Hydraulic Oil Temperature : 50 ± 5 °C

A B C D

NOTE - Refer to T4-5-14.

Delivery Pressure kgf/cm2 144 202 354 370

Flow Rate L/min 196+3 –6 (154) 84 ± 10 –

The value indicated in parentheses is only a reference value.

NOTE - 1 kgf/cm2 = 0.09807 MPa.

L/min

A

•

▲

B

• Flow Rate (Q1 + Q2) / 2

C

•

D

•

▲

Delivery Pressure (P1 + P2) / 2

kgf/cm2

SM3027

T4-2-6

EX285

STANDARD EX285 OPERATIONAL PERFORMANCE STANDARD TABLES The standard Performance values related to excavator test are listed in the table 1 shown below. In table 2 are listed the standard performance related to component test. Refer to the Group T4-3 to T4-5 for performance test procedures. Values indicated in parentheses are reference values. The following switch positions shall be selected and the hydraulic oil temperature shall be maintained as

indicated below as the preconditions of performance tests unless otherwise instructed in each performance test procedure: Engine Control Dial : Fast Idle E Mode Switch : OFF HP Mode Switch : OFF Work Mode Switch : General Purpose Mode Hydraulic Oil Temperature : 50 ± 5 °C (122 ± 9 °F) NOTE - 1 kgf = 9.807 N

Table 1 - Excavator performance (EX285) Ref. pag.


T4-3-1/2

ENGINE SPEED

Fast idle speed with E and HP modes OFF

2230 ± 100

Fast idle speed with E mode ON

2030 ± 50

Fast idle speed with HP mode O

50 or more higher than fast idle speed measured with E and HP modes OFF and arm roll-in circuit relieved

Slow idle speed

900 ± 100

Auto-idle speed (A/I)

1200 ± 100

VALVE CLEARANCE (IN, EX)

(mm)

NOZZLE INJECTION PRESSURE MPa (kgf/cm2) INJECTION TIMING (Before TDC)

Remarks

(rpm)

ENGINE COMPRESSION PRESSURE MPa (kgf/cm2)

T4-3-3


(deg.)

3 (31)

0.4 18.1 (185)

8°

Extend the arm cylinder to relieve the arm roll-in circuit

With the engne hot (approx. 75 °C) – Allowable limit: 2.5 (26) – Difference cylinder pressure compression exceeding 200 kPa (2.0 kgf/cm2) is inacceptable

With the engine cold

EX285

T4-2-7

STANDARD Performance test designation

Ref. pag.

T4-4-9 T4-4-8 T4-4-7

T4-4-6

T4-4-5

T4-4-4

T4-4-3

T4-4-2

T4-4-1

TRAVEL SPEED

14.1 ± 1.0

Slow speed

23.2 ± 2.0

TRACK REVOLUTION SPEED

(s/3 rev)

EX285 EX285 LC

32.5 ± 2.0 34.5 ± 2.0

MISTRACK (mm/20 m) (With fast and slow travel speed modes)

200 or less

TRAVEL PARKING FUNCTION CHECK

1/6 or less

Travel motor leak

Remarks

(s/20 m)

Fast speed

(rev)

(mm/5 min)

Travel slow speed only

0

SWING SPEED (s/3 rev) SWING FUNCTION DRIFT CHECK

SWING MOTOR LEAKAGE

16 ± 1.0

(mm/180°)

1300 or less

(mm/5 min)

0

3100 arm (Mono) or 2120 arm (Triple articulation) and 1.05 m3 bucket (SAE heaped) 3100 arm (Mono) or 2120 arm (Triple articulation) and 1.05 m3 bucket (SAE heaped)

SWING BEARING PLAY (mm) MAXIMUM SWINGABLE SLANT ANGLE (deg.)

HYDRAULIC CYLINDER CYCLE TIME

T4-4-10


1.3 or less 18,7° or possibly more

Allowable limit: 4.3 mm 3100 arm (Mono) and 1.05 m3 bucket (SAE heaped)


(s)

Boom (Mono version)

Raise Lower

3.4 ± 0.3 2.7 ± 0.3

Boom (Triple (articulation version)

Raise Lower

5.0 ± 0.3 4.1 ± 0.3

Arm

Roll-in Roll-out

3.9 ± 0.3 2.8 ± 0.3

Bucket

Roll-in Roll-out

4.5 ± 0.3 2.7 ± 0.3

Positioning (Triple ariticulation version)

Roll-in Roll-out

6.0 ± 0.3 4.4 ± 0.3

T4-2-8

EX285

STANDARD Ref. pag.


T4-4-12

DIG FUNCTION DRIFT CHECK

20 or less

Positioning cylinder (Triple articulation version)

15 or less

Arm cylinder

20 or less

Bucket cylinder

15 or less Mono Triple articulation

T4-4-13

CONTROL LEVER OPERATING FORCE

T4-4-14

150 or less 150 or less

(kgf)

Boom lever

2.0 or less

Arm lever

2.0 or less

Bucket lever

1.7 or less

Swing lever

1.7 or less

Travel lever

2.5 or less

CONTROL LEVER STROKE

(mm)

Boom lever

105 ± 10

Arm lever

105 ± 10

Bucket lever

83 ± 10

Swing lever

83 ± 10

Travel lever

115 ± 10

BOOM RAISE/SWING (Bucket empty)

(s)

Bucket teeth height: H

(mm)

NOTE - 1 kgf = 9.807 N.

Remarks


(mm/5 min)

Boom cylinder

Total drop

T4-4-15


3.8 ± 0.3

7000 or more

3100 arm (mono) and 1.05 m3 bucket (SAE heaped)

EX285

T4-2-9

STANDARD Table 2 - Component performance standard (EX285) Performance standard EX285

Remarks

(kgf/cm2)

40 +10 –5

SECONDARY PILOT PRESSURE

(kgf/cm2)

(34 ÷ 40)

SOLENOID VALVE SET PRESSURE

(kgf/cm2)

Value indicated on Dr. EX ± 2

MAIN PUMP DELIVERY PRESSURE

(kgf/cm2)

25 –+15 7


MAIN RELIEF VALVE SET PRESSURE

(kgf/cm2)

Boom, Arm and Bucket

350 +20 –5


Swing

292 +20 –5


Travel

350 +20 –5


Power Boost

+20 370 –10


T4-5-7

PRIMARY PILOT PRESSURE

T4-5-3


T4-5-6 T4-5-4

T4-5-1

Ref. pag.

T4-5-14

T4-5-11

OVERLOAD RELIEF VALVE SET PRESSURE (kgf/cm2)

Engine: Fast idle and slow idle) Value indicated on Dr. EX (Lever: Full stroke

Reference values at 50 L/min

Boom (raise/lower), arm roll-in and bucket roll-in

380 +10 –0

Arm roll-out and bucket roll-out

400 +10 –0

MAIN PUMP FLOW TEST

(Engine: Fast idle)

(L/min)

––

Refer to page T4-2-5

With constant maximum speed

(L/min)

––



(L/min)

––

Allowable limit: 31

With the track jacked up

(L/min)

(3.0)

Measured at test stand


(L/min)

(6.0)

Measured at test stand

T4-5-18

SWING MOTOR DRAINAGE

T4-5-20

TRAVEL MOTOR DRAINAGE

NOTE - 1 kgf/cm2 = 0.09807 MPa.

T4-2-10

EX285

STANDARD EX285 MAIN PUMP P-Q DIAGRAM (Reference: Measured at Test Stand)

Points on P-Q Line

• Rated Engine Speed : 2050 min–1 (rpm) • Hydraulic Oil Temperature : 50 ± 5 °C

A B C D

NOTE - Refer to T4-5-14.

Delivery Pressure kgf/cm2 150 206 354 370

Flow Rate L/min +3 207–6 (160) 84 ± 10 (76)

The value indicated in parentheses is only a reference value.

NOTE - 1 kgf/cm2 = 0.09807 MPa.

L/min

A

•

▲

B

• Flow Rate (Q1 + Q2) / 2

C

•

D

•

▲

Delivery Pressure (P1 + P2) / 2

kgf/cm2

SM3027

EX255-EX285

T4-3-1

ENGINE TEST ENGINE SPEED Summary: 1. Use Dr.EX. if Dr.EX is not available, use an engine tachometer. 3

2. Measure the engine speeds in each mode.

NOTE - Measure the engine speed before performing all other tests to check that the engine speed meets specification. Because, if the engine speed is not adjusted correctly, all other performance data will be unreliable.

Preparation: 1. Connect Dr.EX to the diagnosing connector beside the fuse box located behind the operator’s seat, and select the monitor function. When using an engine tachometer, install speed pickup (2) to injection pipe (3). 2. Warm up the machine until the engine coolant temperature reaches 50 °C (122 °F) or more, and hydraulic oil is 50 ± 5 °C (122 ± 9 °F).

2

1 SM5401

IMPORTANT - Never attempt to the readjust stopper (1).

T4-3-2

EX255-EX285

ENGINE TEST Measurement: 1. No Load Engine Speed 1-1. Measure the engine slow idle speed, fast idle speed (in normal mode), and fast idle speeds (in both E and HP modes). 1-2. Select the switch positions as shown below. 1-3. Start measurement from the slow idle speed. 1-4. Measure while changing the engine control dial, E mode switch, and HP mode switch.

Engine Control Dial

E Mode Switch

HP Mode Switch

AutoIdle Switch

Work Mode Switch

Slow Idle

OFF

OFF

OFF

General Purpose Mode

Fast Idle (Normal Mode)

OFF

OFF

OFF


Fast Idle (E Mode)

ON

OFF

OFF


Fast Idle (HP Mode)

OFF

ON

OFF


E Mode Switch

HP Mode Switch

Engine Control Dial

SM0631

2. No Load Auto-Idle Speed 2-1. Select the switch positions as shown below. Engine Control Dial

E Mode Switch

HP Mode Switch

AutoIdle Switch

Work Mode Switch

Fast Idle

OFF

OFF

ON


2-2. 2-3.

Start the engine and operate the bucket lever. Return the lever to the neutral position. Wait approx. 4 seconds until the engine speed is automatically reduced. Then, measure the reduced engine speed.

Evaluation: Refer to the Performance Standard Table in Group T4-2. Auto-Idle Switch

Work Mode Switch

SM0612

EX255-EX285

T4-3-3

ENGINE TEST ENGINE CHECK AND ADJUSTMENT To perform the compression pressure measurement, the check and adjustment of valve clearance, the check of injection nozzle and check and adjustment of injection timing, make reference to the Workshop Manual - Section 5.

T4-3-4

EX255-EX285

ENGINE TEST NOTES

EX255-EX285

T4-4-1

EXCAVATOR TEST TRAVEL SPEED Summary: Measure the time required for the excavator to travel a 20 m (65.6 ft) test track.

Preparation: 1. Adjust the track sag on both side tracks equally. 2. Prepare a flat and solid test track 20 m (65.6 ft) in length with extra length of 3 to 5 m (9.8 to 16 ft) on both ends for machine acceleration and deceleration. 3. Hold the bucket 0.3 to 0.5 m (12 to 20 in) above the ground with the arm and bucket rolled-in. 4. Maintain hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F).

Arm Rolled-In, Bucket Rolled-In

End

Bucket Height: 0.3 to 0.5 m Start 20 m

Acceleration Zone 3 to 5 m

Deceleration Zone 3 to 5 m

SM0138

Measurement: 1. Measure both the slow and fast speeds of the machine. 2. Select the following switch positions: Travel Mode Switch

Engine E Mode HP Mode Work Auto-Idle Control Switch Switch Mode Switch Dial Switch

Slow Mode

Fast Idle

OFF

OFF


OFF

Fast Mode

Fast Idle

OFF

OFF


OFF

3. Start traveling the machine in the acceleration zone with the travel levers to full stroke. 4. Measure the time required to travel 20 m (65.6 ft). 5. After measuring the forward travel speed, turn the upperstructure 180° and measure the reverse travel speed. 6. Repeat steps 4. to 5. three times in each direction and calculate the average values.

Evaluation: Refer to the Performance Standard Table in Group T4-2.

T4-4-2

EX255-EX285

EXCAVATOR TEST TRACK REVOLUTION SPEED Summary: Measure the track revolution cycle time with the track raised off ground. Preparation: 1. Adjust the track sag of both side tracks to be equal. 2. On the track to be measured, mark one shoe with chalk. 3. Swing the upperstructure 90° and lower the bucket to raise the track off ground. Keep the boom-arm angle between 90 to 110° as shown. Place blocks under the machine frame.

Mark

SM0139

WARNING Securely the raised track using wooden blocks.

4. Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F). Measurement: 1. Select the following switch positions: Travel Mode Switch

90 ÷ 110°


Slow Mode

Fast Idle

OFF

OFF


OFF

Fast Mode

Fast Idle

OFF

OFF


OFF

2. Operate the travel control lever of the raised track to full stroke. 3. Measure the time required for 3 revolutions in both directions after a constant track revolution speed is obtained. 4. Raise the other side and repeat the above procedures. 5. Repeat steps 2. to 4. three times and calculate the average values. Evaluation: Refer to the Performance Standard Table in Group T4-2. NOTE - The measurement data obtained through the raised track revolution test may have wide variations. Therefore, the evaluation based on the results obtained from the 20 m travel speed check described before is more recommendable.

EX255-EX285

T4-4-3

EXCAVATOR TEST MISTRACK CHECK Summary: 1. Allow the machine to travel 20 m (65.5 ft). Measure the maximum tread deviation from the tread chord line drawn between the travel start and end points to check the performance equilibrium between both sides of the travel device systems (from the main pump to the travel motor). 2. If measured on a concrete surface, the tread deviation has a trend to decrease.

Maximum Distance

Acceleration Zone: 3 to 5 m 20 m

Preparation: 1. Adjust the track sag of both tracks to be equal. 2. Provide a flat, solid test yard 20 m (65.5 ft) in length, with extra length of 3 to 5 m (9.8 to 16 ft) on both ends for machine acceleration and deceleration. 3. Hold the bucket 0.3 to 0.5 m (12 to 20 in) above the ground with the arm and bucket rolled in. 4. Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F). Measurement: 1. Measure the amount of mistracking in both fast, and slow travel speeds. 2. Select the following switch positions: Travel Mode Switch


Slow Mode

Fast Idle

OFF

OFF


OFF

Fast Mode

Fast Idle

OFF

OFF


OFF

3. Start traveling the machine in the acceleration zone with the travel levers at full stroke. 4. Measure the maximum distance between a straight 20 m (65.5 ft) tread chord line and the tread made by the machine. 5. After measuring the tracking in forward travel, turn the upperstructure 180° and measure in reverse travel. 6. Repeat steps 3. to 5. three times and calculate the average values. Evaluation: Refer to the Performance Standard Table in Group T4-2.

SM0140

T4-4-4

EX255-EX285

EXCAVATOR TEST TRAVEL PARKING FUNCTION CHECK Summary: To measure the parking brake function on a specified slope.

Preparation: 1. The surface of the test slope shall be even with a gradient of 20% (11.31°). 2. Mark a white line on the travel device cover. 3. Hold the bucket 0.2 to 0.3 m (8 to 12 in) above the ground with the arm and bucket fully rolled in. 4. Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F).

0,2 ÷ 0,3 m

SM0141

Measurement: 1. Measure in the fast travel mode. 2. Select the following switch positions: Travel Mode Switch Fast Mode

Engine E Mode HP Mode Work Auto-Idle Control Switch Switch Mode Switch Dial Switch Fast Idle

OFF

OFF


OFF

3. Measure the displacement (revolution angle) of the travel device cover until the parking brake is applied. 3-1. Climb the slope and place the travel levers in neutral. 3-2. Measure the displacement from the mark position on the travel device cover when the levers are placed in neutral to that position when the machine stops moving. 4. Measure the travel parking brake slip amount while parked. 4-1. Climb the slope and place the travel levers in neutral. 4-2. Stop the engine. 4-3. After the machine stops, put alignment marks on a track link or shoe, and the track side frame. 4-4. After 5 minutes, measure the distance between the marks on the track link or shoe and the track side frame.


Position where the machine Position when the travel comes to a stop levers are in neutral Displacement (Revolution Angle) Mark

SM0142

Alignment marks on the track side frame and shoe when the machine comes to a stop Displacement measured after 5 minutes

SM0143

EX255-EX285

T4-4-5

EXCAVATOR TEST SWING SPEED Summary: Measure the time required to swing three complete turns. Preparation: 1. Check the lubrication of the swing gear and swing bearing. 2. Place the machine on flat, solid ground with ample space for swinging. Do not conduct this test on slopes. 3. With the arm rolled out and bucket rolled in, hold the bucket so that the height of the bucket pin is the same as the boom foot pin. The bucket must be empty. 4. Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F).

WARNING Prevent personal injury. Always make sure that the area is clear and that co-workers are out of the swing area before starting the measurement.

Measurement: 1. Select the following switch positions: Engine Control Dial

E Mode Switch

HP Mode Switch

Work Mode Switch

AutoIdle Switch

Fast Idle

OFF

OFF


OFF

2. Operate swing control lever fully. 3. Measure the time required to swing 3 turns in one direction. 4. Operate swing control lever fully in the opposite direction and measure the time required for 3 turns. 5. Repeat steps 2. to 4. three times and calculate the average values.


The same height as the boom foot pin height

SM0144

T4-4-6

EX255-EX285

EXCAVATOR TEST SWING FUNCTION DRIFT CHECK Summary: Measure the swing drift on the bearing outer circumference when stopping after a 180° full-speed swing. Preparation: 1. Check the lubrication of the swing gear and swing bearing. 2. Place the machine on flat, solid ground with ample space for swinging. Do not conduct this test on a slope. 3. With the arm rolled out and bucket rolled in, hold the bucket so that the height of the bucket pin is the same as the boom foot pin. The bucket must be empty. 4. Make two chalk marks: one on the swing bearing and one directly below it on the track frame. 5. Swing the upperstructure 180°. 6. Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F).

Two chalk marks SM0145

WARNING Prevent personal injury. Always make sure that the area is clear and that coworkers are out of the swing area before starting the measurement.

Measurement: 1. Select the following switch positions:

SM0146

Measure difference between marks

Engine Control Dial

E Mode Switch

HP Mode Switch

Work Mode Switch

AutoIdle Switch

Fast Idle

OFF

OFF


OFF Marking on the Track Frame

Marking on the Swing Bearing

2. Operate the swing control lever fully and return it to the neutral position when the mark on the upperstructure aligns with that on the track frame after swinging 180°. 3. Measure the distance between the two marks. 4. Align the marks again, swing 180°, then test in the opposite direction. 5. Repeat steps 3. to 5. three times each and calculate the average values. Evaluation: Refer to the Performance Standard Table in Group T4-2.

SM0147

EX255-EX285

T4-4-7

EXCAVATOR TEST SWING MOTOR LEAKAGE Summary: Check for upperstructure drift while suspending a load on a slope. Preparation: 1. Check the lubrication of the swing gear and swing bearing. 2. Park the machine on a smooth slope with a gradient of 26.8 %. 3. Load bucket fully. In lieu of loading the bucket, weight (W: tons) of the following specification can be used. W = M x 1.5 where: M = Bucket heaped capacity (m3) 1.5 = Soil specific gravity 4. With the arm rolled out, and bucket rolled in, position the arm top pin height to be level with the boom foot pin. 5. Swing the upperstructure to position it 90° to the slope. Make aligning marks on the swing bearing periphery and track frame using tape, as illustrated. 6. Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F).

SM0148

Measurement: 1. Select the following switch position: E Mode Switch

HP Mode Switch

Work Mode Switch

AutoIdle Switch

OFF

OFF


OFF

2. Maintain the engine at slow idle. After five minutes, measure the difference between the marks along the swing bearing periphery and the track frame. 3. Perform the measurement in both right and left swing directions. 4. Perform the measurement three times in each direction and calculate the average values. Evaluation: Refer to the Performance Standard Table in Group T4-2.

Measure difference between marks

Marking on the Track Frame Marking on the Swing Bearing SM0147

T4-4-8

EX255-EX285

EXCAVATOR TEST SWING BEARING PLAY Summary: Measure the swing bearing play using a dial gauge to check the wear of bearing races and balls. Preparation: 1. Check swing bearing mounting bolts for looseness. 2. Check the lubrication of the swing bearing. Confirm that bearing rotation is smooth and without noise. 3. Install a dial gauge on the track frame as shown, using a magnetic base. 4. Position the upperstructure so that the boom aligns with the tracks facing towards the front idlers. 5. Position the dial gauge so that its needle point comes into with the bottom face of the bearing outer race. 6. Bucket should be empty.

SM0149

Measurement: 1. With the arm rolled out and bucket rolled in, hold the bucket so that the height of the bucket pin is the same as the boom foot pin. Record the dial gauge reading (h1). 2. Lower the bucket to the ground and use it to raise the front idler 0.5 m (20 in). Record the dial gauge reading (h2). 3. Calculate bearing play (H) from this data (h1 and h2) as follows: H=h2-h1

SM0150

Measurement: (h2)

Measurement: (h1)

The same height as the boom foot pin height

SM0144


SM0152

EX255-EX285

T4-4-9

EXCAVATOR TEST MAXIMUM SWINGABLE SLANT ANGLE Summary: With the upperstructure swung 90° to the slope, check the maximum slant angle on which the upperstructure can swing to the uphill side.

Preparation: 1. Check that the swing gear and bearing are well lubricated. 2. Load bucket fully. In lieu of loading the bucket, weight (W: tons) of the following specification can be used. W = M x 1.5 where: M = Bucket heaped capacity (m3) 1.5 = Soil specific gravity 3. With the arm cylinder fully retracted and the bucket cylinder fully extended, hold the arm top pin to the position flush with the boom foot pin height. 4. Climb a slope and swing the upperstructure 90° to the slope. 5. Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F).


E Mode Switch

HP Mode Switch

Work Mode Switch

AutoIdle Switch

Fast Idle

OFF

OFF


OFF

2. Operate the swing lever to full stroke to swing the upperstructure to the uphill side. 3. If the machine can swing, measure the cab floor slant angle. 4. Increase the slope angle and repeat steps 2. and 3. Check both clockwise and counterclockwise. 5. Perform the measurement three times.


SM0148

T4-4-10

EX255-EX285

EXCAVATOR TEST HYDRAULIC CYLINDER CYCLE TIME Measure the cycle time of the boom, positioning, arm, and bucket cylinders.

Preparation: 1. To measure the cycle time of the boom cylinders: With the arm rolled out and the empty bucket rolled in, lower the bucket to the ground, as shown. 2. To measure the cycle time of the positioning cylinder (triple articulation) With the empty bucket rolled in and arm rolled out, raise the boom to the maximum height. 3. To measure the cycle time of the arm cylinder: With the empty bucket rolled in, position the arm so that it is vertical to the ground. Lower the boom until the bucket is 0.5 m (20 in) above the ground. 4. To measure the cycle time of the bucket cylinder: The empty bucket should be positioned at midstroke between roll-in and roll-out, so that the sideplate edges are vertical to the ground. 5. Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F).

SM0153

0.5 m


SM0154

Engine Control Dial

E Mode Switch

HP Mode Switch

Work Mode Switch

AutoIdle Switch

Fast Idle

OFF

OFF


OFF

SM0155

EX255-EX285

T4-4-11

EXCAVATOR TEST 2. To measure cylinder cycle times: (Cylinder full stroke includes cylinder cushioning zone) – Boom cylinders: Measure the time it takes to raise the boom, and the time it takes to lower the boom. To do so, position the boom at one stroke end, then move the control lever to the other stroke end as quickly as possible. – Positioning cylinder (triple articulation): Measure the time it takes to extend and retract the positioning cylinder. To do so, position the cylinder at one stroke end, then move the control pedal to the other stroke end as quickly as possible. – Arm cylinder: Measure the time it takes to roll in the arm, and the time it takes to roll out the arm. To do so, position the arm at one stroke end, then move the control lever to the other stroke end as quickly as possible. – Bucket cylinder: Measure the time it takes to roll in the bucket, and the time it takes to roll out the bucket. To do so, position the bucket at one stroke end, then move the control lever to the other stroke end as quickly as possible. 3. Repeat each measurement three times and calculate the average values.


T4-4-12

EX255-EX285

EXCAVATOR TEST DIG FUNCTION DRIFT CHECK Summary: Measure dig function drift, which can be caused by oil leakage in the control valve and boom, arm, and bucket cylinders, with the loaded bucket.

Extended Distance

Retracted Distance

Retracted Distance

Same Height

NOTE - When testing the dig function drift just after cylinder replacement, slowly operate each cylinder to its stroke end to purge air.

Bucket Bottom

SM0156

Preparation: 1. Load bucket fully. In lieu of loading the bucket, weight (W: tons) of the following specification can be used. W = M x 1.5 where: M = Bucket heaped capacity (m3) 1.5 = Soil specific gravity 2. Position the arm cylinder with the rod 50 mm (2 in) extended from the fully retracted position. 3. Position the positioning cylinder (triple articulation) with the rod 50 mm (2 in) extended from the fully retracted position. 4. Position the bucket cylinder with the rod 50 mm (2 in) retracted from the fully extended position. 5. With the arm rolled out and the bucket rolled in, hold the bucket so that the height of the bucket pin is the same as the boom foot pin. 6. Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F).

Measurement: 1. Stop the engine. 2. Five minutes after the engine has been stopped, measure the change in the position of the bottom of the bucket, as well as the boom, positioning (triple articulation), arm and bucket cylinders. 3. Repeat step 2. three times and calculate the average values.

Evalution: Refer to the Performance Standard Table in Group T4-2.

Arm Cylinder Extension (and positioning cylinder for triple articulation)

Mark

SM0157

Boom and Bucket Cylinder Retraction Mark

Mark

SM0158

EX255-EX285

T4-4-13

EXCAVATOR TEST CONTROL LEVER OPERATING FORCE Summary: Use a spring scale to measure the maximum resistance of each control lever as illustrated.

Preparation: Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F).

Measurement: 1. Start the engine. 2. Select the following switch positions: Engine Control Dial

E Mode Switch

HP Mode Switch

Work Mode Switch

AutoIdle Switch

Fast Idle

OFF

OFF


OFF

SM0159


3. Operate each boom, arm, bucket and swing lever to at full stroke and measure the maximum operating force for each. 4. Lower the bucket to the ground to raise one track off the ground. Operate the travel lever to full stroke and measure the maximum operating force required. When finished, lower the track and then jack-up the other track. 5. Repeat steps 3. to 4. three times and calculate the average values.


SM0160

T4-4-14

EX255-EX285

EXCAVATOR TEST CONTROL LEVER STROKE Summary: Measure each lever stroke at the lever top using a ruler.

NOTE - When the lever has play, take a half of this value and add it to the measured stroke.

Preparation: Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F). SM0161

Measurement: 1. Stop the engine. 2. Measure each lever stroke at the lever top from neutral to the stroke end using a ruler. 3. Repeat step 2. three times and calculate the average values. Evaluation: Refer to the Performance Standard Table in Group T4-2.

EX255-EX285

T4-4-15

EXCAVATOR TEST COMBINED BOOM RAISE/SWING FUNCTION CHECK Summary: Check boom raise and swing movement and speeds while operating both functions simultaneously. Preparation: 1. Start the engine and run it at fast idle. Operate the boom raise function and check to be sure that the cylinder movement is smooth, with out sticking. 2. With the arm fully rolled out and bucket fully rolled in, lower the bucket to the ground. The bucket must be empty. 3. Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F).

SM0162



E Mode Switch

Fast Idle

OFF

HP Mode Switch OFF

Work Mode Switch

AutoIdle Switch


OFF

SM0163

2. Raise the boom and swing simultaneously, both at full stroke. 3. When the upperstructure rotates 90°, release the control levers to stop both functions. Measure the time required to swing 90° and the height (H) of the bucket teeth. 4. Repeat steps 2. to 3. three times and calculate the average values. Evaluation: Refer to the Performance Standard Table in Group T4-2. SM0164

T4-4-16

EX255-EX285

EXCAVATOR TEST NOTES

EX255-EX285

T4-5-1

COMPONENT TEST PRIMARY PILOT PRESSURE Preparation: 1. Properly shut down the engine. 2. Press the air release valve on top of the hydraulic oil tank to release any remaining pressure. 3. Remove the plug from the pilot pump delivery port. Install adapter (75301519) and pressure gauge (75301518) on the port. : 6 mm Plug

4. Start the engine. Confirm that no oil leakage is observed at the pressure gauge connection. 5. Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F). SM0165


E Mode Switch

HP Mode Switch

Work Mode Switch

AutoIdle Switch

Fast Idle

OFF

OFF


OFF

Slow Idle

OFF

OFF


OFF

2. Measure the pilot pressure in each specified setting above. 3. Repeat the measurement three times and calculate the average values.


T4-5-2

EX255-EX285

COMPONENT TEST Primary Pilot Pressure Adjustment Adjustment: Adjust the setting pressure of relief valve (1) (the primary pilot pressure) as necessary. 1

: 36 mm

SM0166

1. Remove plug (3). 2. Install the estimated necessary number of shims (2). 3. Tighten plug (3). : 49 Nm (5 kgf•m, 36 lbf•ft)

4. Check the relief pressure of relief valve (1). 3 Change in Relief Pressure

2

Shim Thickness (mm) kPa

kgf/cm2

psi

0.25

78

0.8

11

0.5

157

1.6

23

1.0

304

3.1

44

SM2201

EX255-EX285

T4-5-3

COMPONENT TEST SECONDARY PILOT PRESSURE Preparation: 1. Properly shut down the engine. 2. Press the air release valve on top of the hydraulic oil tank to release any remaining pressure. 3. Install pressure gauge (75301518) and tee (75301520) to the end of pilot line (1) at the respective control valve spool end, as illustrated.

1

: 14 mm, 17 mm 4. Start the engine. Confirm that no oil leakage is observed at the pressure gauge connection. 5. Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F).


E Mode Switch

HP Mode Switch

Work Mode Switch

AutoIdle Switch

Fast Idle

OFF

OFF


OFF

Slow Idle

OFF

OFF


OFF

SM0168

2. Measure the pilot pressure in each specified setting above with the corresponding control lever operated full stroke. 3. Repeat the measurement three times and calculate the average values.


SM0169

T4-5-4

EX255-EX285

COMPONENT TEST SOLENOID VALVE SET PRESSURE Measure solenoid valve set pressure with both the Dr.EX and the pressure gauge.

Preparation: 1. Properly shut down the engine. 2. Press the air release valve on top of the hydraulic oil tank to release any remaining pressure. 3. Disconnect line (1) from the solenoid valve to be measured. Install hose (75301482), tee (75301521), adapter (75301522), and pressure gauge (75301518) to the disconnected end at the solenoid valve side, as illustrated. : 17 mm, 19 mm, 22 mm

1

Connect Dr.EX to the machine for solenoid valve set pressure monitoring. 4. Start the engine. Confirm that no oil leakage is observed at the pressure gauge connection. 5. Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F).

SM0629

Solenoid Valve Pressure Gauge


1 Engine Control Dial

E Mode Switch

HP Mode Switch

Work Mode Switch

Travel Mode Switch

Fast Idle

OFF

OFF


Fast Speed Mode

Hose

Tee

Adapter

SM0171

2. Operate as instructed below for each measuring solenoid valve: Solenoid Valve SG: Repeat pressing and releasing of the power boost switch. Solenoid Valve SD: Perform a combined operation. Relieve both actuators. Solenoid Valve SC: Perform a combined operation of boom raise and arm roll-in. Solenoid Valve SI: Drive the machine, then stop the machine. 3. Read the values on both Dr.EX and the pressure gauge. 4. Repeat the measurement three times and calculate the average values.

Evaluation: The average value read on the pressure gauge shall be within ± 0.2 MPa (±2 kgf/cm2, ± 28 psi) of the value indicated on Dr.EX.

EX255-EX285

T4-5-5

COMPONENT TEST Solenoid Valve Set Pressure Adjustment Procedure

IMPORTANT - Do not loosen the adjusting screw excessively. The O-ring on the threads may come off the sealing surface, causing oil leakage.

1. Mark the end of the adjusting screw with a white marker for the record of the original position. (Take care not to touch any part of the screw threads with the white marker). 2. Loosen lock nut (7). Turn adjusting screw (8) to adjust the set pressure of the solenoid valve. 3. Retighten lock nut (7).

The distance between the lock nut end and screw end should be 4.0 mm (0.157 in) or less. SM0172

: 13 mm : 4 mm : 8.8 N•m (0.9 kgf•m, 6.5 lbf•ft)

Reference: Standard Change in Pressure Turns

1/4

1/2

3/4

1

kPa

98

196

294

392

kgf/cm2

1

2

3

4

psi

14

28

43

57

8

7 SM0173

Adjusting Screw

4. Check the set pressure of the solenoid valve. Pressure Increase

Pressure Decrease

SM0174

T4-5-6

EX255-EX285

COMPONENT TEST MAIN PUMP DELIVERY PRESSURE The main pump delivery pressure can also be measured with Dr.EX.

Preparation: 1. Properly shut down the engine. 2. Press the air release valve on top of the hydraulic oil tank to release any remaining pressure. 3. Remove the plug from the main pump delivery port. Install adapter (75301519), hose (75301523) and pressure gauge (75301524) on the port. : 6 mm Or connect Dr.EX to the machine for main pump delivery pressure monitoring. 4. Start the engine. Confirm that no oil leakage is observed at the pressure gauge connection. 5. Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F). SM0175


E Mode Switch

HP Mode Switch

Work Mode Switch

AutoIdle Switch

Fast Idle

OFF

OFF


OFF

2. Measure the pressure with the control levers in neutral. 3. Repeat the measurement three times and calculate the average values.


EX255-EX285

T4-5-7

COMPONENT TEST MAIN RELIEF VALVE SET PRESSURE Summary: Measure the main relief valve setting pressure at the main pump delivery port. The main relief pressure can also be measured with Dr.EX. Preparation: 1. Properly shut down the engine. 2. Press the air release valve on top of the hydraulic oil tank to release any remaining pressure. 3. Remove the plug from the main pump delivery port. Install adapter (75301519), hose (75301523) and pressure gauge (75301524) on the port. : 6 mm Or connect Dr.EX to monitor the main pump delivery pressure. 4. Start the engine. Confirm that no oil leakage is observed at the pressure gauge connection. 5. Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F). Measurement: 1. Select the following switch positions: Engine Control Dial

E Mode Switch

HP Mode Switch

Work Mode Switch

Fast Idle

OFF

OFF


2. Relieve each actuator to measure main relief pressures. First, slowly operate bucket, arm, and boom control levers to the stroke end to relieve each function one at a time. 3. As for the swing function, secure the upperstructure so it is immovable. Slowly operate the swing lever to relieve the swing function. 4. As for the travel function, secure the tracks against an immovable object. Slowly operate the travel levers to relieve the travel function. Evaluation: Refer to the Performance Standard Table in Group T4-2. Reference: If the measure pressures for all functions are lower than the specified range, the probable cause is a decrease of the main relief valve setting pressure. If the relief pressure of a particular function is lower, the probable cause is other than main relief valve.

SM0175

T4-5-8

EX255-EX285

COMPONENT TEST Main Relief Pressure Setting Adjustment Procedure Main Relief Valve

Adjustment: Adjust the pressure setting of the main relief valve using plug (3) (for the low-side relief pressure setting) and plug (5) (for the high-side relief pressure setting) after loosening lock nut (1). • High-Side Relief Pressure Setting Adjustment Procedure 1. Loosen lock nut (1). Lightly tighten plug (3) until the end of plug (3) comes into with piston (2). Retighten lock nut (1). : 27 mm : Plug (3): 19.5 N•m (2 kgf•m, 14.5 lbf•ft) : Lock Nut (1): 68 to 78 N•m (7 to 8 kgf•m, 51 to 58 lbf•ft)

SM0168

2. Loosen lock nut (4). Turn plug (5) to adjust the relief pressure setting referring to the table below. : 27 mm, 32 mm : Lock Nut (4): 78 to 88 N•m (8 to 9 kgf•m, 58 to 65 lbf•ft)

3 1 5

• Low-Side Relief Pressure Setting Adjustment Procedure 3. Loosen lock nut (1). Turn plug (3) counter clockwisely until the specified value is obtained referring to the table below. Retighten lock nut (1). : 27 mm : Lock Nut (1): 59 to 68 N•m (6 to 7 kgf•m, 43 to 51 lbf•ft)

4 2

4. Recheck the set pressures.

Reference: Standard Change in Pressure Change in Relief Pressure: Plug (5) (High-Side Relief Pressure) Turns MPa kgf/cm2 psi

1/4 7.1 72.5 1031

1/2 14.2 145 2062

3/4 21.3 217.5 3093

1 28.4 290 4120

SM0177

Plug

5-3

Change in Relief Pressure: Plug (3) (Low-Side Relief Pressure) Turns MPa kgf/cm2 psi

1/4 5.3 54 770

1/2 10.7 109 1550

3/4 16.0 163 2320

1 21.3 217 3090

Pressure Increase

Pressure Decrease

SM0178

EX255-EX285

T4-5-9

COMPONENT TEST Swing Relief Valve

Swing Relief Pressure Setting Adjustment Procedure Adjustment: Adjust the pressure setting of the swing relief valve using adjusting screw (1) after loosening lock nut (2). 1. Loosen lock nut (2). 2. Turn adjusting screw (1) adjust the pressure setting referring to the table below. 3. Retighten lock nut (2). 4. Recheck the set pressure. : 24 mm, 32 mm : 177 N•m (18 kgf•m, 130 lbf•ft)

SM0179

1 2

SM0180

Reference: Standard Change in Pressure 1 Turns MPa kgf/cm2 psi

1/4 2.9 30 430

1/2 5.8 59.5 850

3/4 8.7 89 1270

1 11.7 119 1690

Pressure Increase

Pressure Decrease

SM0181

T4-5-10

EX255-EX285

COMPONENT TEST Travel Relief Pressure Setting Adjustment Procedure Adjustment: Adjust the pressure setting of the travel relief valve using adjusting screw (1) after loosening lock nut (2). : 19 mm : 6 mm 1. Loosen lock nut (2). 2. Turn adjusting screw (1) to adjust the pressure setting referring to the table below. Travel Relief Pressure Valve

3. Retighten lock nut (2).

SM0182

: 49 N•m (5 kgf•m, 36 lbf•ft) 1 2

SM0183

Reference: Standard Change in Pressure Turns MPa kgf/cm2 psi

1/4 2.9 30 430

1/2 5.9 60 850

3/4 8.8 90 1280

1 11.8 120 1710

Adjusting screw

Pressure Increase

Pressure Decrease

SM0174

EX255-EX285

T4-5-11

COMPONENT TEST OVERLOAD RELIEF VALVE SET PRESSURE Summary: Measuring the set pressure of the overload relief valves on the machine is not recommended for the following reasons: 1. The circuit pressure must be increased by applying an external force while blocking the return circuit from the control valve. This measuring method is hazardous and the results obtained with this method are unreliable. 2. Pressure setting of the overload relief valve must be made at a specified oil flow rate normally far smaller than the main pump delivery flow rate. Accordingly, even if the main relief valve set pressure can be reset higher than the overload relief valve set pressure, the main pump supplies too much oil to correctly measure the setting pressure of the overload relief valve. For this reason, in order to correctly measure the set pressure of the overload relief valve, the overload relief valve unit must be removed from the machine and tested on a test stand. 3. If the overload relief valve performance must be checked on the machine, however, measure the main relief pressure while releasing each front function respective to the measuring overload relief valve. And, assume that the overload relief valve is functioning correctly if the obtained main relief pressure is within the specified value range. Measure the main pressure of the front functions as follows:

Preparation: 1. Properly shut down the engine. 2. Press the air release valve on top of the hydraulic oil tank to release any remaining pressure. 3. Remove the plug from the main pump delivery port. Install adapter (75301519), hose (75301523) and pressure gauge (75301524) on the port. : 6 mm Or connect Dr.EX to the machine for main pump delivery pressure monitoring. 4. Start the engine. Confirm that no oil leakage is observed at the pressure gauge connection. 5. Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F).

SM0175

T4-5-12

EX255-EX285

COMPONENT TEST Measurement: 1. Select the following switch positions: Engine Control Dial

E Mode Switch

HP Mode Switch

Work Mode Switch

Fast Idle

OFF

OFF


2. Slowly operate bucket, arm, and boom control levers to the stroke ends to relieve each function one at a time. 3. Read the pressures on the pressure gauge while releasing the front functions. 4. Perform the measurement for the bucket, arm, and boom, in that order. 5. Repeat the measurement three times and calculate the average value for each front function.

Evaluation: 1. Performance of the overload relief valves are normal if the measured main relief pressures are within the specified value range. Refer to the Performance Standard Table in Group T4-2.

EX255-EX285

T4-5-13

COMPONENT TEST Overload Relief Valve Set Pressure Adjusting Procedure

NOTE - In principle, adjust the overload relief valve set pressure on a test stand.

1

Adjustment: Adjust the pressure setting of the overload relief valve using adjusting screw (2) after loosening lock nut (1). 1. Loosen lock nut (1). 2. Turn adjusting screw (2) to adjust the pressure setting referring to the table below.

2

3. Retighten lock nut (1).

SM0185

: 17 mm : 6 mm : 29.5 N•m (3.0 kgf•m, 22 lbf•ft) 4. Recheck the set pressures.

Reference: Standard Change in Pressure Turns MPa kgf/cm2 psi

1/4 5.2 54 770

1/2 10.6 108 1540

3/4 15.9 162 2300

1 21.1 216 3070

Adjusting Screw

Pressure Increase

Pressure Decrease

SM0174

T4-5-14

EX255-EX285

COMPONENT TEST MAIN PUMPS FLOW TEST Summary: To test the performance of the main pumps, measure the flow rate by connecting a portable flowmeter to the main pump delivery connections.

Preparation: 1. Shut the engine. Press the air release valve on the top of the hydraulic oil tank to discharge residual pressures.

NOTE - Prior to starting the disconnection of the pipings, check the primary piloting pressure, which must fall within the required values. 2. Connect a vacuum pump to the oil filler neck on the hydraulic oil tank. NOTE - Operate the vacuum pump while the portable flowmeter is connected to the main pumps.

3. Disconnect hoses A and B from the main pumps. Connect test pipes (6) and (7) to hoses A and B disconnected.

7. Disconnect the vacuum pump. Bleed the air from the pump by loosening plug K on the pump, until oil flows out the port of plug K. 8. Connect a pick-up of engine tachometer to the engine injection pipes. Disconnect sensor N terminal. Fully open both loading regulation valves (2) and (3). 9. Start the engine check the portable flow meter connection for any leakage.

Measurement: 1. Maintain the hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F). 2. Select the following switch positions: Engine Control Dial

E Mode Switch

HP Mode Switch

Work Mode Switch

Auto Idle Switch A/I

Treavel Mode Switch

Fast idle

OFF

OFF

Gen. mode

OFF

Fast mode

4. Connect test pipes (4) and (5) with the half flanges and bolts to the main pumps. Connect portable flowmeter kit (75298406) (1), (2) and (3) as illustrated in the figure. Eliminate as far as possible all curves in the hoses and secure them appropriately to prevent all movements.

3. Gradually close the loading regulation pump relative to the pump involved by the test to obtain the pressures specified in diagram P-Q and measure the flow rate of the pump and the engine speed. Repeat step 3. for all pressure points specified in curve P-Q. To test the other pump, proceed in the same manner with the other loading valve.

5. Disconnect hose SA (pump 1 control) from main pump 1 regulator and plug the hose. Disconnect hose SA (pump 2 control) from main pump 2 regulator and plug the hose.

4. Repeat the measurement three times and calculate the average values.

6. Disconnect hose PA from the pilot system pump and install a T-t between pilot pump and hose PA. To the free port of the T-t, install another T-t to which two hoses have to be connected. The other end of hoses have to be connected to ports SA and SB on the pump regulators left free when pipes SA and SB have been disconnected. (This shall make the pumps operate at maximum displacement angle).

EX255-EX285

T4-5-15

COMPONENT TEST Evaluation: 1. Convert the measured pump flow rate into the one for the rated pump speed using the following formula.

2. Specified Pump Flow Rate Refer to the Pump P-Q Diagram in Group T4-2.

Converted Pump Flow Rate: Qc = Ns x Q / Ne Where: Qc: Converted Pump Flow Rate Q : Measured Pump Flow Rate Ns : Rated Engine Speed EX255 = 2000 rpm EX285 = 2050 rpm Ne : Measured Engine Speed

A

6

K B 4 SB

7

8

SA

2

5 1 3 PA

SB

Pilot pump

SA

T-t T-t To ports SA, SB on pump regulators

PA hose SM5403

T4-5-16

EX255-EX285

COMPONENT TEST Regulator Adjustment

4 6 5

1 2

9 3 10

7 8

SM0187

1 2 3 4 5

-

Lock Nut (For Minimum Flow Adjustment) Adjusting Screw (For Minimum Flow Adjustment) Lock Nut (For Maximum Flow Adjustment) Adjusting Screw(For Maximum Flow Adjustment) Lock Nut (For Pilot Pressure Characteristic Adjustment)

6

- Adjusting Screw (For Pilot Pressure Characteristic Adjustment) 7 - Lock Nut (For P-Q Line Adjustment) 8 - Adjusting Screw (For P-Q Line Adjustment) 9 - Lock Nut (For P-Q Line Adjustment) 10 - Adjusting Screw (For P-Q Line Adjustment)

EX255-EX285

T4-5-17

COMPONENT TEST Adjustment Item

Adjustment Procedure

Remarks

1. Minimum Flow Rate

Loosen lock nut (1) and turn adjusting screw (2). Rotating adjusting screw (2) 1/4 a turn clockwise increases the minimum pump flow rate by 6.47 cm3/rev. (0.39 in3/rev).

1) Do not turn the adjusting screw more than two turns. 2) Securely retighten lock nut (1) after the adjustment.

Loosen lock nut (3) and turn adjusting screw (4). Rotating adjusting screw (4) 1/4 a turn clockwise decreases the maximum pump flow rate by 5.39 cm3/rev. (0.33 in3/rev).

1) Do not turn the adjusting screw more than two turns. 2) Do not increase the maximum flow rate. In other words, do not turn the adjusting screw counterclockwise. Increasing the maximum flow rate (turning the adjusting screw counterclockwise), however, will be required after adjusting the pilot pressure characteristics. 3) Securely retighten lock nut (3) after the adjustment.

Loosen lock nut (5) and turn adjusting screw (6). Rotating adjusting screw (6) 1/4 a turn clockwise decreases the flow rate by 10.77 cm3/rev. (0.66 in3/rev).

1) Do not turn the adjusting screw more than one turn. 2) When adjusting screw (6) is turned clockwise, the maximum flow rate will also be decreased. To maintain the maximum flow rate unchanged, turn adjusting screw (4) counterclockwise twice as much as adjusting screw (6) is turned. This ratio of 2 (adjusting screw (4) counter clockwise turn) to 1 (adjusting screw (6) clockwise turn) is to counterbalance. 3) Securely retighten lock nut (5) after the adjustment.

A: Loosen lock nut (7) and turn adjusting screw (8). Rotating adjusting screw (8) 1/4 a turn clockwise increases the maximum pump flow rate by 10.77 cm3/rev. (0.66 in3/rev.). B: Loosen lock nut (9) and turn adjusting screw (10). Rotating adjusting screw (10) 1/4 a turn clockwise increases the maximum pump flow rate by 2.60 cm3/rev. (0.16 in3/rev).

1) Do not turn the adjusting screws more than one turn. 2) Rotate the adjusting screws watching the engine performance. 3) Securely retighten lock nut (7) or (9) after the adjustment.

Q

Pi 2. Maximum Flow Rate Q

Pd 3. Pilot Pressure Characteristics (Pi-Q Line) Q

Pi

4. P-Q Line (Torque Adjustment) Q

A

B Pd

T4-5-18

EX255-EX285

COMPONENT TEST SWING MOTOR DRAINAGE Summary: To check swing motor performance, measure the amount of oil draining from the swing motor while swinging the upperstructure.

NOTE - The amount of drain oil from the swing motor will change depending on hydraulic oil temperature. Maintain hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F).

1

WARNING Prevent personal injury. Always make sure that the area is clear and that co-workers are out of the swing area before starting the measurement. Also, take care not to fall off the machine while the measurement.

Preparation: 1. Maintain hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F). Rotate the swing motor to warm the inside of the motor. 2. Properly shut down the engine. Press the air release valve (1) on top of the hydraulic oil tank to release any remaining pressure.

OM0400

2

3. Disconnect the swing motor drain hose (2) at the hydraulic oil tank end. Install plug (75301529) to the disconnected end on the hydraulic oil tank. : 22 mm : 39 N•m (4 kgf•m, 29 lbf•ft)

Preconditions for Measurement: 1. Select the following switch positions: Engine Control Dial

E Mode Switch

HP Mode Switch

Work Mode Switch

AutoIdle Switch

Fast Idle

OFF

OFF


OFF

SM0189

EX255-EX285

T4-5-19

COMPONENT TEST Measurement: 1. Amount of Oil Drained While Swinging the Upperstructure (1) Fully retract the arm cylinder. Fully extend the bucket cylinder. Raise the boom so that the arm tip pin height is the same as the boom foot pin height. Be sure that the bucket is empty. (2) Start the engine. Operate and hold the swing lever full stroke. Start draining oil measurement after the swing speed reaches a constant maximum speed. The measuring time should be more than 45 seconds. (3) Repeat the measurement at least three times in both clockwise and counterclockwise directions, and calculate the average values. 2. Amount of Oil Drained While Relieving Swing Motor Circuit (1) Thrust the bucket teeth into the ground as illustrated so that the upperstructure does not rotate when the swing lever is operated full stroke. (2) Start the engine. Operate and hold the swing lever full stroke. Start drain oil measurement when drain oil starts coming out of the drain hose end. The measuring time should be more than 45 seconds. (3) Repeat the measurement at least three times in both clockwise and counterclockwise directions, and calculate the average values.

The same height as boom foot pin height

SM0144

SM0190

Evaluation: Refer to the Performance Standard Table in Group T4-2. * Conversion of the amount of drain oil measured into the per-minute value First measure the amount of drain oil using a calibrated container. Then, convert the measured drain oil into the per-minute value using the formula below: ∆Q = 60 x q / t Where: ∆Q : Amount of drain oil per minute (L/min) t : Time measured (seconds) q : Total amount of drain oil (L) SM0191

T4-5-20

EX255-EX285

COMPONENT TEST TRAVEL MOTOR DRAINAGE Summary: To check travel motor performance, measure the amount of oil draining from the travel motor while rotating the travel motor with the measuring side track jacked up.

NOTE - The amount of drain oil from the travel motor will change depending on hydraulic oil temperature. Maintain hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F).

1

Preparation: 1. Maintain hydraulic oil temperature at 50 ± 5 °C (122 ± 9 °F). Rotate the travel motor to warm the inside of the motor. 2. Properly shut down the engine. Press the air release valve (1) on top of the hydraulic oil tank to release any remaining pressure. 3. Disconnect the travel motor drain hose (2) at the travel motor end. Install plug (75301525) to the disconnected end. Connect the drain hose (3/416UN) to the travel motor.

OM0400

2

: 22 mm, 27 mm : 93 N•m (9.5 kgf•m, 69 lbf•ft) Preconditions for Measurement: 1. Select the following switch positions: Engine Control Dial

E Mode Switch

HP Mode Switch

Work Mode Switch

AutoIdle Switch

Fast Idle

OFF

OFF


OFF

SM0182

EX255-EX285

T4-5-21

COMPONENT TEST Measurement: 1. Amount of oil drained while travel motor is rotating (1) Start the engine. Jack up the measuring side track using the front attachment, as illustrated.

90° ÷ 110°

WARNING Securely the raised track using wooden blocks.

SM0139

(2) Rotate the raised track with the travel lever operated full stroke. Start drain oil measurement after the track rotation speed reaches a constant maximum speed. The measuring time should be more than 45 seconds. (3) Repeat the measurement at least three times in both forward and reverse directions, and calculate the average values. Evaluation: Refer to the Performance Standard Table in Group T4-2. * Conversion of the amount of drain oil measured into the per-minute value SM0193

First measure the amount of drain oil using a calibrated container. Then, convert the measured drain oil into the per-minute value using the formula below: ∆Q = 60 x q / t Where: ∆Q : Amount of drain oil per minute (L/min) t : Time measured (sec.) q : Total amount of drain oil (L)

T4-5-22

EX255-EX285

COMPONENT TEST NOTES

SECTION 5

EX255-EX285

TROUBLESHOOTING

INDEX Group 1 -

Diagnosing Procedure

Group 4 -

Troubleshooting B

Introduction ........................................... T5-1-1

Troubleshooting B Procedure .................. T5-4-1

Diagnosing Procedure ......................... T5-1-2

Relationship between Machine Trouble

Dr.EX .................................................... T5-1-4 Dr.EX Start-Up Procedure ................... T5-1-4

Symptoms and Parts in Trouble ........ T5-4-2 Correlation between Trouble

Dr.EX Fault Code ................................. T5-1-5

Symptoms and Part Failures .......... T5-4-12

Dr.EX Monitoring Function ................... T5-1-6

Engine Troubleshooting ...................... T5-4-18

Dr.EX Special Function

Actuator Control System

(Service Mode) ................................. T5-1-7 Adjustable Data List ........................... T5-1-14

Troubleshooting ............................... T5-4-32 Front Attachment Control System Troubleshooting ............................... T5-4-38 Swing System Troubleshooting ........... T5-4-50

Group 2 -

Component Layout

Travel System Troubleshooting ........... T5-4-53

Main Components ................................ T5-2-1

Troubleshooting for Other Functions .. T5-4-58

Electrical System (Overall System) ..... T5-2-2

Engine Speed Adjustment and

Electrical System (Cab) ........................... T5-2-3 Electrical System (Monitor and Switch s) .............. T5-2-5 Pump and Related Parts ........................ T5-2-6

Engine Learning ............................. T5-4-60 Exchange Inspection Method ............... T5-4-61 Boom Lowering Method when Engine Stalls ........................... T5-4-63

Other Components ................................. T5-2-7

Group 5 -

Troubleshooting C

Troubleshooting C Procedure ............... T5-5-1

Group 3 -

Troubleshooting A

Malfunction of Coolant

Troubleshooting A Procedure .............. T5-3-1

Temperature Gauge .......................... T5-5-2

Fault Codes .......................................... T5-3-2

Malfunction of Fuel Gauge ................... T5-5-4

Fault Code 01 ....................................... T5-3-4

Malfunction of Fuel Level

Fault Code 02, 03 ................................. T5-3-5 Fault Code 04, 05 ................................. T5-3-6

Indicator ............................................ T5-5-6 Malfunction of Indicator Light

Fault Code 06 ....................................... T5-3-7

Check System ................................... T5-5-8

Fault Code 07 ....................................... T5-3-8

Malfunction of Level Check Switch ....... T5-5-8

Sensor Operating Range List .............. T5-3-9

Malfunction of Engine Oil Level Indicator .......................................... T5-5-10

INDEX Malfunction of Coolant Level Indicator ........................................... T5-5-12 Malfunction of Hydraulic Oil Level Indicator .......................................... T5-5-14 Malfunction of Alternator Indicator .... T5-5-16 Malfunction of Engine Oil Pressure Indicator .......................................... T5-5-18 Malfunction of Overheat Indicator .......................................... T5-5-20 Malfunction of Air Filter Restriction Indicator .......................................... T5-5-22 Malfunction of Buzzer ........................ T5-5-24 Malfunction of Hour Meter ................. T5-5-26

Group 6 -

Electrical System Inspection

Precautions for Inspection and Maintenance ..................................... T5-6-1 Instructions for Disconnecting Connectors ....................................... T5-6-3 Fuse Continuity Test ............................. T5-6-4 Inspection and Replacement of Maxi Fusible Links .................................... T5-6-5 Battery Voltage Check ........................... T5-6-6 How to Troubleshoot Alternator Malfunctions ...................................... T5-6-7 Continuity Check ................................... T5-6-8 Voltage and Current Check .................. T5-6-10 Wiper Controller .................................... T5-6-14 Replacement of Relay ......................... T5-6-16 Relay Box ............................................. T5-6-18 Replacement of QOS Controller .......................................... T5-6-20 Replacement of Power Outlet ................ T5-6-21

Group 7 -

Harness Check

Circuit Check .......................................... T5-7-1

EX255-EX285

T5-1-1

DIAGNOSING PROCEDURE INTRODUCTION Each troubleshooting section group is presented in an orderly fashion so as to make the inspecting and troubleshooting procedures easy to follow. Use the troubleshooting section to guide you in locating the source of any problems that may arise. The troubleshooting section consists of 6 groups: the component layout, the troubleshooting A (using fault codes), troubleshooting B (starting with symptoms), troubleshooting C (gauges and indicators), the electrical system inspection procedures, and harness check groups. • Component Layout Diagrams • Troubleshooting A (using fault codes) Use these charts when the self-diagnosing function of Dr.EX shows any fault codes. (The controller automatically diagnoses and memorizes malfunctions that have occurred in the signal sending system.) Example: Fault Code 01 EC Sensor Failure • Troubleshooting B (starting with symptoms) Use these charts when the machine is exhibiting trouble and when Dr.EX does not indicate any fault codes. Example: Even if engine control dial is operated, engine speed does not change. • Troubleshooting C (Gauges and indicators) Use these charts when any gauges or indicators malfunction. Example: The fuel gauge does not operate. • Electrical System Inspection Procedure Refer to this group for precautions and inspection procedures of the electrical system when or before performing inspections on the electrical system. Example: Fuse Inspection • Harness Check Refer to this group for information about the test harnesses. Example: 75301706D

T5-1-2

EX255-EX285

DIAGNOSING PROCEDURE DIAGNOSING PROCEDURE These six basic steps are essential for efficient troubleshooting: 1. Study the System Study the machine’s technical manuals. Know the system and how it works, and what the construction, functions and specifications of the system components are.

2. Ask the operator Before inspecting, get the full story of malfunctions from your star witness ···· the operator.

SM0600

(a) How is the machine being used? (Find out if the machine is being operated correctly) (b) When was the trouble noticed, and what types of work the machine doing at that time? (c) What are the details of the trouble? Is the trouble getting worse, or did it appear suddenly for the first time? (d) Did the machine have any other troubles previously? If so, which parts were repaired before?

3. Inspect the machine Before starting the troubleshooting procedure, check the machine’s daily maintenance points, as shown in the operator’s manual.

SM0601

Also, check the electrical system, including the batteries, as troubles in the electrical system such as low battery voltage, loose connections and blown fuses will result in malfunction of the controllers, causing total operational failure of the machine. Fuse failure is often caused by a fine crack in the fuse, and such fine cracks are very hard to detect by visual inspection.

SM0602

EX255-EX285

T5-1-3

DIAGNOSING PROCEDURE 4. Operate the machine yourself. If the trouble cannot be confirmed, stop the engine and obtain further details of the malfunction from the operator. Also, check for any incomplete connections of the wire harnesses.

5. Perform troubleshooting CAUTION Never attempt to disconnect harnesses or hydraulic lines while the engine is running. The machine may malfunction or pressurized oil may spout, possibly resulting in personal injury. Be sure to stop the engine before disconnecting harnesses or hydraulic lines.

SM0603

Connect the diagnostic analyzer, Dr.EX, to the MC (Main Controller) to obtain malfunction records. If any fault codes are displayed on the monitor, check sensing signal circuits, referring to Troubleshooting A.

SM0604

If no fault code is indicated on the monitor, go to the troubleshooting B group. Note that Dr.EX will be necessary in the troubleshooting B procedures for monitoring real time component performance.

*Note that the fault codes displayed do not necessarily indicate machine trouble. The controller stores even temporary electrical malfunctions, such as a drop in battery output voltage or disconnections of the switches, sensors, etc., for inspections. For this reason, the “RETRIAL” is required to erase the accumulated fault codes from the controller memory and to confirm if any fault codes are indicated after the “RETRIAL”.

SM0605

6. Trace possible causes Before reaching a conclusion, check the most likely causes again. Try to identify the actual cause of the trouble. Based on your conclusion, make a plan for appropriate repairs to avoid consequent malfunctions. SM0606

T5-1-4

EX255-EX285

DIAGNOSING PROCEDURE Dr.EX Dr.EX (75301336) is a handy micro computer used for diagnosing malfunctions of the machine control system, including the MC (Main Controller). When the Dr.EX is connected to the MC, malfunctions recorded in the MC memory are indicated as fault codes on the Dr.EX display. (Self-Diagnosing Function) Input signals from the sensors or switches that are connected to the MC, or output signals from the MC to solenoid valves can be monitored on a real-time basis while the machine is being operated. (Real-Time Monitoring Function)

Dr.EX START-UP PROCEDURE 1. Connect the harness of the Dr.EX to the diagnosing connector of the MC, located near fuse box behind the operator’s seat. Start

NOTE - Only this connecting harness can be used to connect the Dr.EX to the controller. Do not use any other harness to connect Dr.EX to the controller. Initial Screen

2. Turn the key switch to the ON position or start the engine. 3. Turn the Dr.EX ON. After a few seconds, following patterns will appear on the Dr.EX display: 3-1.

Initial Pattern

3-2.

Model Code Pattern Example : Model : EX200-5 Ver : XXXX

3-3.

Function Selection Pattern F-1 : “Self-diagnosing Results” F-2 : “Monitor Data” F-3 : “Special Functions”

4. Select key F1 (Proceed according to the instructions that appear on the display.) NOTE - For the operation procedure of the Dr.EX, refer to the Dr.EX OPERATOR’S MANUAL.

Can not communicate with MC Check MC power source and/or communication harness

Model Code Confirmation

OK?

OK

SelfDiagnosing

Self-Diagnosing Results (Fault Code)

Retrial B

Self-Diagnosing Results (Fault Code)

Function Selection

Record

Not OK

Dr. EX Other Software

Monitor Data

Special Functions

Data Selecting Pattern

Monitor Data Display

EX255-EX285

T5-1-5

DIAGNOSING PROCEDURE Dr.EX FAULT CODE Fault Code

Trouble

Corrective Action

01

EC sensor failure

1) Perform “Retrial B.” 2) Check harness. 3) Replace EC sensor.

02 03

Pump 1 delivery pressure sensor failure Pump 2 delivery pressure sensor failure

1) Perform “Retrial B.” 2) Check harness. 3) Replace the pump delivery pressure sensor.

04 05

Pump 1 control pressure sensor failure Pump 2 control pressure sensor failure

1) Perform “Retrial B.” 2) Check harness. 3) Replace the pump control pressure sensor.

06

Arm roll-in pilot pressure sensor failure

1) Perform “Retrial B.” 2) Check harness. 3) Replace the arm roll-in pilot pressure sensor.

07

Engine control dial failure

1) Perform “Retrial B.” 2) Check harness. 3) Replace the engine control dial.

T5-1-6

EX255-EX285

DIAGNOSING PROCEDURE Dr.EX MONITORING FUNCTION Dr.EX has a function to monitor the command signals from the MC and the input signals to the MC from various switches and sensors.

Monitor Item

Description

Pump 1 Control Pressure ○

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kgf/cm2 ○

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kgf/cm2 ○

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kgf/cm2

Input from the PC pressure sensor (5-spool side)

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V

Input from the arm roll-in pilot pressure sensor

Pump 2 Control Pressure ○

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Input from the pump 2 delivery pressure sensor

Arm Roll-In Pilot Pressure ○

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Input from the pump 1 delivery pressure sensor

Pump 2 Delivery Pressure ○

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Input Signal from EC Sensor

Pump 1 Delivery Pressure ○

kgf/cm2

Input from the PC pressure sensor (4-spool side) ○

EC Angle ○

Display Unit and Form

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Accelerator Angle ○

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Dial Angle ○

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Input from the engine control dial

Arm Regenerative Proportional Solenoid Valve Output ○

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Engine Learning Control

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S, G, P, A ○

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EP ○

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AI ○

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HP ○

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Pd

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Lo. Hi

On/off state of the key switch ○

○

BmH, Fr, Tr

Selected travel mode

Key Switch ○

○

ON/off state of the power boost switch

Selected Travel Mode Switch ○

○

On/off state of the HP mode switch

Power Boost Switch ○

○

On/off state of the auto-idle switch

HP Mode Switch ○

○

rpm

On/off state of the E mode switch

Auto-Idle Switch ○

○

rpm

Selected work mode

E Mode Switch ○

○

kgf/cm2

On/off state of the pressure switches

Selected Work Mode Switch ○

○

step

Pressure Switch ○

○

kgf/cm2

EC Motor Position ○

○

kgf/cm2

Input from the N sensor ○

○

kgf/cm2

Target engine speed under loaded condition. (Approx. 150 min-1 difference from engine speed under no load.)

Actual Engine Speed ○

○

The value of the command signal to the solenoid valve unit SG

Target Engine Speed ○

○

The value of the command signal to the solenoid valve unit SD

Power Boost Pressure ○

○

The value of the command signal to the solenoid valve unit SI

Pump Proportional Solenoid Valve Output ○

○

The value of the command signal to the solenoid valve unit SC

Travel Motor Displacement Angle Change Pressure ○

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Ky ○

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Done, Undone, Aborted

EX255-EX285

T5-1-7

DIAGNOSING PROCEDURE Dr.EX SPECIAL FUNCTION (SERVICE MODE) 1. Purpose Some data in the MC (Main Controller), such as the flow rate in the attachment mode, engine speed in the E mode, can be changed as required. 2. Parts pertaining to the special function. Dr.EX Learning Switch Key Switch

MC

3. Operation • How to Turn Dr.EX in the Service Mode 1) Turn the key switch OFF. Wait 10 seconds or more. 2) Connect the Dr.EX. 3) Turn the learning switch to the Engine Learning position. 4) Turn the key switch to the ON position. (Do not start the engine.) 5) Turn on the switch on the Dr.EX.

• On the following pages, the service mode s on the Dr.EX and the service mode operating procedure are shown.

T5-1-8

EX255-EX285

DIAGNOSING PROCEDURE

Dr.EX VER **** F1 : Start

F10 : Model Menu

F1

Press

▼ Model: XXXX-X Ver

: XXXX

Is model correct ? F1 : Correct F5 : ESC

F1

Press

▼ Service mode selected In service mode, self diagnosis operation and / or monitor display will not be conducted. F1 : Rechecked F5 : ESC

F1 ▼ 1

Press

Service mode related to Dr.EX screen s, beginning with the start screen, are shown along with the corresponding Dr.EX key operations. However, Dr.EX screen s which are not related to the Dr.EX key operation are excluded.

EX255-EX285

T5-1-9


1

▼ Select Functions F3 : Special Functions

F5 : ESC

F3

Press

A ▼

F5 : ESC

Press

F8

Press

▼

F7 ▼

Select Functions F6 : F7 : Learning Data Display F8 : Parameter Change

Select learning data to be displayed. F6 : EC Motor Stop Position F7 : EC Motor Maximum Speed Position F5 : ESC ▼

F8

F6

Press

Press

F5

Press

▼ Select Item F6 : Li Speed F7 : E Speed F8 : P Speed F3 : Next

EC Motor Stop Position -XXXX digit F5 : ESC

F3 ▼ 2

Press

F5 : ESC

Learning data is displayed.

T5-1-10

EX255-EX285


2

▼ Select Item F6 : AI Speed Control F8 : Crusher (L) Engine Speed Control F4 : Prev. ↑

F5

An example of “F7: Breaker Engine Speed Control” operation is shown on the next page.

Press

F5 : ESC ▼

F5

Press

3

(Press F4 to return to the previous screen.) ▼ End (Returns to (A) on the previous page.)

EX255-EX285

T5-1-11


3

▼

F3 : Next F5 : ESC F7 : HELP

F5

Press

Breaker Engine Speed Control HELP Adjustable Range : -500 to+100 rpm Initial : 0 rpm Minimum Adjusting Deviation : 10 rpm

▼

Press

▼

Input the adjusting deviation you want.

F7

▼

Breaker Engine Speed Control adjustable range in HELP

F5 : ESC ▼

F3

Press

Values Adjusted In Tens

▼ Breaker Engine Speed Control 123 0 rpm 12 12 12 rpm

F1 : Execute F2 : Corr F4 : Prev. F5 : ESC F7 : HELP

F7

Press

F5

Press

▼

Current : Adjustment :

“-100” is entered as an example here. SFT SFT 3 SFT SFT

Press (“123” on the upper right corner of the screen will change to “ABC”.) Press (“-” will be displayed in the Adjustment field.) Press (“ABC” on the upper right corner of the screen will change to “123”.)

* 1

Press (“-1” will be displayed in the Adjustment field.)

. 0


. 0


▼ Breaker Engine Speed Control 123 Current : 0 rpm Adjustment : -100 rpm F1 : Execute F2 : Corr F4 : Prev. F5 : ESC F7 : HELP

F1 ▼ 4

Press

NOTE - Confirm that “123” is displayed on the upper right corner of the screen before pressing key

T5-1-12

EX255-EX285


4

▼

∗Adjusting Deviation∗ ∗Data Confirmation∗ Adjusting Deviation Data Name : Breaker Engine Speed Control F3 : Next

F5 : ESC

F3

The value input on the previous page will be displayed again in the Adjustment field.

Press

▼

Current : 0 rpm Adjustment : -100 rpm

F1 : Execute F4 : Prev. F5 : ESC

F1

Press

▼ Adjustment was made as follows : Adjusting Deviation Data Name : Breaker Engine Speed Control

F3 : Next

F3

The last screen for the Breaker Engine Speed Control will be displayed.

Press

▼ Current : 0 rpm Adjustment : -100 rpm

F4 : Prev

Turn off Dr.EX. ▼ End

F5 : ESC

EX255-EX285

T5-1-13

DIAGNOSING PROCEDURE • Check the engine performance (Check if the engine speed has been changed), as follows: IMPORTANT - Be sure to turn the learning switch to the OFF (Neutral) position before checking the engine performance. Because the MC does not perform the engine, pump, and valve controls if the learning switch is in the Engine Learning position, engine speed change cannot be confirmed properly. 1) Turn the key switch OFF. 2) Wait 10 or more seconds. 3) Turn the learning switch to the OFF (Neutral) position. 4) Disconnect Dr.EX. (This step can be omitted if you wish to monitor the engine speed on Dr.EX.) 5) Turn the key switch to the ON position. 6) Start the engine. 7) Operate the machine to check the engine performance.

T5-1-14

EX255-EX285

DIAGNOSING PROCEDURE ADJUSTABLE DATA LIST Adjustable Data

Values Adjusted In

Adjustable Range

Set Adjustment Value Before Factory Shipment

Li Mode Speed

10’s min-1 (rpm)

0 to 120 min-1 (rpm)

0 min-1 (rpm)

E Mode Speed

10’s min-1 (rpm)

-120 to 120 min-1 (rpm)

0 min-1 (rpm)

-1

P Mode Speed

10’s min (rpm)

-120 to 120 min (rpm)

0 min-1 (rpm)

AI Mode Speed

10’s min-1 (rpm)

-120 to 100 min-1 (rpm)

0 min-1 (rpm)

-1

-1

-1

Breaker Engine Speed

10’s min (rpm)

-500 to 100 min (rpm)

0 min-1 (rpm)

Crusher Engine Speed

10’s min-1 (rpm)

-500 to 100 min-1 (rpm)

100 min-1 (rpm)

EX255-EX285

T5-2-1

COMPONENT LAYOUT MAIN COMPONENTS

SM5601

1 2 3 4 5 6 7 8 9 10 11

-

Bucket Cylinder Arm Cylinder Boom Cylinder Center t Swing Bearing Swing Device Fuel Tank Hydraulic Oil Tank Control Valve Pilot Filter, Pilot Relief Valve Pump Device

12 13 14 15 16 17 18 19 20 21

-

Engine Radiator Oil Cooler Intercooler Battery Travel Device Shockless Valve Pilot Shut-Off Valve Travel Pilot Valve Front/Swing Pilot Valve

T5-2-2

EX255-EX285

COMPONENT LAYOUT ELECTRICAL SYSTEM (overall system)

SM5402

1 2 3 4 5 6 7,8 9 10 11 12 13 14 15 16 17 18 -

Wiper Motor Monitor Relays, Relays box Windshield Horn Work Light Fuel Sensor with Low Fuel Level Switch Solenoid Valve Unit Pressure Switch (Travel) Hydraulic Oil Level Switch PC Pressure Sensor (Upper: 4-Spool Side) PC Pressure Sensor(Lower: 5-Spool Side) EC Motor EC Sensor Pump Delivery Pressure Sensor 1 Pump Delivery Pressure Sensor 2 N (Engine Speed) Sensor

19 20 21 22 23 24 25 26 27 28 29

-

30 31 32 33

-

Engine Oil Pressure Switch Coolant Temperature Switch (Engine Preheat Circuit) Engine Oil Level Switch (on oil pan) Overheat Switch Coolant Temperature Sensor Battery Relay Coolant Level Switch Battery Starter Relay Air Cleaner Restriction Switch Pressure Switch (Boom Raise), Pressure Sensor (Arm Roll-In) Pressure Switch (Front) Fuse Box MC (Main Controller) QOS Controller

EX255-EX285

T5-2-3


SM5603

1 2 3 4 5 6 7 8 9 10 11 12

-

Relay box Air conditioner relays (if installed) Connection for cab light (ceiling) WWES connection for wiper cut-off microswitch Heater connection Air conditoner connection Loudspeakers connection Cab ground Main controller (MC) Q.O.S. controller Load momentum alarm buzzer provision Load momentum alarm relay provision (R1)

13 14 15 16 17 18 19 20 21 22 23 24

-

Breaker relay (R2) variant provision R.H. Rotation bucket relay (R3) variant provision L.H. Rotation bucket relay (R4) variant provision Cab light relay (R5) Rear cab light relay (R6) A, B, K junction connector C, D juncton connector E, F junction connector G, H junction connector Dr. EX. connector Engine learning switch Fuse box

T5-2-4

EX255-EX285


1

2

3

4

8

5

7

6

SM5604

1 2 3 4 5 6

-

Connectors for monitor and switch s Cigarette lighter Connectors to cab harness Connectors not used Windshield wiper controller (1) connector for breaker switch (2) connector for cab light switch (3) connector for bucket rotation (4) connector for load momentum alarm switch (5) connector for rear cab light

7 8

- Connector not used - Connector

EX255-EX285

T5-2-5

COMPONENT LAYOUT ELECTRICAL SYSTEM (monitor and switch s)

10 24

11

1

12

2

23

13

22

14

21 20

15 16 17

19 3 18

T157-07-02-001 SM0610

5 25 6 4

32 7 8

26

31

27

9

28

30

T157-01-01-009 SM0611

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

-

Monitor Switch Power Boost Switch Key Switch Cigar Lighter HP Mode Switch E Mode Switch Engine Control Dial Air Conditioner Warm Up Complete Indicator Fuel Gauge E Mode Indicator Auto-Idle Indicator Hydraulic Oil Level Indicator Preheat Indicator Air Filter Restriction Indicator

29

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

T157-01-01-018 SM0612

-

Fuel Level Indicator Overheat Indicator Alternator Indicator Engine Oil Pressure Indicator Engine Oil Level Indicator Coolant Level Indicator HP Mode Indicator Coolant Temperature Gauge Work Light Switch Wiper Switch Travel Mode Switch Work Mode Switch Buzzer Stop Switch Auto-Idle Switch Washer Switch Level Check Switch

T5-2-6

EX255-EX285

COMPONENT LAYOUT PUMP AND RELATED PARTS

5

6

7

3-4 8

2

1

12

11

10

9 SM3004

1 2 3 4 5 6

-

Pilot Filter Pilot Relief Valve EC Motor EC Sensor Pilot Pump Regulator (Pump 2)

7 8 9 10 11 12

-

N Sensor Regulator (Pump 1) Pump Delivery Pressure Sensor (Pump 1) Pump 1 Pump Delivery Pressure Sensor (Pump 2) Pump 2

EX255-EX285

T5-2-7

COMPONENT LAYOUT OTHER COMPONENTS

Shockless Valve

Swing Device

4

1

5

9 8

6 7

SM0626 T157-01-01-011

Travel Device

SM0627 T157-07-03-018

Solenoid Valve Unit

FRONT

10 11 12

2

13 3 SM0628 T157-01-01-012

1 2 3 4 5 6 7

-

Swing Relief Valve Counterbalance Valve Travel Relief Valve Shockless Valve Pilot Pressure Switch (Boom Raise) Check Valve Shockless Valve

SM0629 W157-02-11-020

8 9 10 11 12 13

-

Check Valve Pilot Pressure Sensor (Arm Roll-In) Solenoid Valve Unit (SC) Solenoid Valve Unit (SD) Solenoid Valve Unit (SI) Solenoid Valve Unit (SG)

T5-2-8

EX255-EX285

COMPONENT LAYOUT Control valve

Right travel motor

Left travel motor

3 2

1

4

5

6

7

8

9

10 11 12

41

13 14

40

15 16

39

Bucket cylinder

38 37 36 35 34

Boom cylinder

17 18

Arm cylinder

33 32 31

19 20

30 29

21 22 23 26 27 28

24 25

Swing motor

1 - Hydraulic Timer 2 - Travel Flow Control Valve 3 - Load Check Valve (Travel Parallel Circuit) 4 - Check Valve 5 - Main Relief Valve 6 - Check Valve 7 - Check Valve 8 - Flow Combiner Valve 9 - Load Check Valve (Bucket) 10 - Bucket Flow Control Valve (Switch Valve A) 11 - Bucket Flow Control Valve (Switch Valve B) 12 - Bucket Flow Control Valve (Poppet Valve) 13 - Load Check Valve (Boom 1 Parallel Circuit) 14 - Load Check Valve (Boom 1 Tandem Circuit)

SM0037

15 16 17 18 19

-

20 21 22 23 24 25 26 27 28 -



EX255-EX285

T5-2-9

COMPONENT LAYOUT Section A

A

H B

G

5

C D E F

41

8

SM0036

SM0038

Section C

Bucket

Auxiliary

15 12 11

39

Section D 9 Boom 2

16 Section B

Boom 1

SM0040

L. Travel

R. Travel

38

17 37 3 2

20 21 19 13

14 40

10 18 SM0039

SM0041

T5-2-10

EX255-EX285

COMPONENT LAYOUT

Left travel motor

3 2

1

4

5

6

7

8

9

10

Right travel motor

11 12

41

13 14

40

15 16

39 38 37 36 35 34

Bucket cylinder

Boom cylinder

17 18

Arm cylinder

33 32 31

19 20

30 29

21 22 23 26 27 28

24 25

Swing motor SM0037

1 - Hydraulic Timer 2 - Travel Flow Control Valve 3 - Load Check Valve (Travel Parallel Circuit) 4 - Check Valve 5 - Main Relief Valve 6 - Check Valve 7 - Check Valve 8 - Flow Combiner Valve 9 - Load Check Valve (Bucket) 10 - Bucket Flow Control Valve (Switch Valve A) 11 - Bucket Flow Control Valve (Switch Valve B) 12 - Bucket Flow Control Valve (Poppet Valve) 13 - Load Check Valve (Boom 1 Parallel Circuit) 14 - Load Check Valve (Boom 1 Tandem Circuit)

15 16 17 18 19

-

20 21 22 23 24 25 26 27 28 -



EX255-EX285

T5-2-11

COMPONENT LAYOUT Arm 1

Section E (2)

Arm 2

31

32

Section E (1) Arm 1

Section F

Arm 2 Swing SM0042

36 34 35

28

24 26

25

27 29

23 22

33 30

SM0045

SM0043

Section H Section G 1

4

7

6

SM0044

SM0046

T5-2-12

EX255-EX285

COMPONENT LAYOUT NOTE:

EX255-EX285

T5-3-1

TROUBLESHOOTING A TROUBLESHOOTING A PROCEDURE Use troubleshooting A procedure when fault codes are shown on Dr.EX. Ž How to Read the Troubleshoting Flow Charts YES(OK)

(2)

After checking or measuring item (1), select either Yes (OK) or No (NOT OK) and proceed to item (2) or (3), as appropriate.

(1) (3) NO(NG)

Key switch: ON

Special instructions or reference item are indicated in the spaces under the box. Incorrect measuring or checking methods will render troubleshooting impossible, and may damage components as well.

Explanation of how to use lamp harness kit required. Refer to “Harness Check” Group (Group T5-7) in this section.

Use the Dr. EX troubleshooting/monitor function for the description in a double line box.

Causes are stated in a thick-line box. Scanning through thick-line boxes, possible causes can be seen without going through the flow chart.

NOTE - For all connector drawings illustrated in this group, harness end connector terminals seen from the open end side are shown.

SM0630

T5-3-2

EX255-EX285

TROUBLESHOOTING A FAULT CODES

FAULT CODE

TROUBLE

CORRECTIVE ACTION

01

EC sensor failure

1) Perform “Retrial B”. 2) Check harness. 3) Replace EC sensor.

02 03

Pump 1 delivery pressure sensor failure Pump 2 delivery pressure sensor failure

1) Perform “Retrial B”. 2) Check harness. 3) Replace the pump delivery pressure sensor.

04 05

Pump 1 control pressure sensor failure Pump 2 control pressure sensor failure

1) Perform “Retrial B”. 2) Check harness. 3) Replace the pump control pressure sensor.

06

Arm roll-in pilot pressure sensor failure

1) Perform “Retrial B”. 2) Check harness. 3) Replace the arm roll-in pilot pressure sensor.

07

Engine control dial failure

1) Perform “Retrial B”. 2) Check harness. 3) Replace the engine control dial.

EX255-EX285

T5-3-3

TROUBLESHOOTING A

T5-3-4

EX255-EX285

TROUBLESHOOTING A FAULT CODE 01 (EC SENSOR FAILURE)

NO

YES

YES Disconnect EC sensor connector. Check if resistance between EC sensor side connector terminals No.1 and No.3 is 1.7 ± 0.4 kΩ. Connect test harness between EC sensor connector halves. Turn engine control dial and check if voltage changes as specified.

Check if breakage or short circuit exists between MC 22P connector terminal No.D15 and EC sensor terminal No. 2.

Disconnect EC sensor connector. Check if voltage between harness end connector terminals No.1 and No.3 is 5 ± 0.5 V. • Key switch: ON

• After replacement, refer to page T5-4-60.

YES

YES Check if voltage between harness end connector terminals NO No.1 and vehicle frame is 5 ± 0.5 V. • Key switch: ON • 5 ± 0.5 V for the voltage change standard values.

Harness failure between MC and EC sensor.

Harness breakage between MC and EC sensor terminal No.3.

Harness breakage between MC and EC NO sensor terminal No.1.

NO

• Test harness: 75301706D • Refer to page T5-3-9 for the voltage change standard values.

Faulty MC

Faulty EC sensor • After replacement, refer to page T5-4-60.

Connector (harness end connector terminals seen from the open end side) Main Controller (22P): “D” is added for each terminal number in the text.

1 2 2 3 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

EC Sensor 1

2

3

EX255-EX285

T5-3-5

TROUBLESHOOTING A FAULT CODE 02 (PUMP 1 DELIVERY PRESSURE SENSOR FAILURE) FAULT CODE 03 (PUMP 2 DELIVERY PRESSURE SENSOR FAILURE) Checking Instruction: • It is unlikely for both pump delivery pressure sensors (for pumps 1 and 2) to fail simultaneously. For this reason, if faults codes 2 and 3 are indicated, the probable cause is harness failure.

YES Disconnect the pump delivery pressure sensor connector. Check if voltage between harness end connector terminals No.1 and No.3 is 5 ± 0.5 V.

NO

Switch pump delivery pressure sensors (for pumps 1 and 2) with each other. Perform “RETRIAL.” Check if indicated fault code changes to the one for the other pump delivery pressure sensor.

• Key switch: ON

Check if breakage or short circuit exists between MC 22P connector terminal No. D16 (pump 1)/ No. D17 (pump 2) and pump delivery pressure sensor terminal No.2.

YES

Faulty EC sensor NO • After replacement, refer to page T5-4-60.


Harness failure between MC and pump delivery pressure sensor.

Harness failure between MC and pump delivery pressure sensor terminal No.3.

Harness failure between MC and pump NO delivery pressure sensor terminal No.1.

Faulty pump delivery pressure sensor.

YES


1 2 2 3 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Pump Delivery Pressure Sensor

1

2

3

T5-3-6

EX255-EX285

TROUBLESHOOTING A FAULT CODE 04 (PUMP 1 CONTROL PRESSURE SENSOR FAILURE) FAULT CODE 05 (PUMP 2 CONTROL PRESSURE SENSOR FAILURE) Checking Instruction: • It is unlikely for both pump control pressure sensors (ones in 4-spool side and in 5-spool side control valves) to fail simultaneously. For this reason, if faults codes 04 and 05 are indicated, the probable cause is harness failure.

YES

Disconnect pump control pressure sensor connector. Check if voltage between harness end connector terminals No.1 and No.3 is 5 ± 0.5 V.

NO

Switch pump control pressure sensors (ones in 4-spool side and in 5spool side control valves) with each other. Perform “RETRIAL.” Check if the indicated fault code changes to the one for the other pump control pressure sensor.

• Key switch: ON

Check if breakage or short circuit exists between MC 22P connector terminal No. D14 (4-spool side)/No. D19 (5-spool side) and pump control pressure sensor terminal No.2.

YES

Faulty MC NO • After replacement, refer to page T5-4-60.


Harness failure between MC and pump control pressure sensor.

Harness breakage between MC and pump control pressure sensor terminal No.3.

Harness breakage between MC and NO pump delivery pressure sensor terminal. Faulty pump control pressure sensor.

YES


1 2 2 3 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Pump Control Pressure Sensor

1

3 2

EX255-EX285

T5-3-7

TROUBLESHOOTING A FAULT CODE 06 (ARM ROLL-IN PILOT PRESSURE SENSOR FAILURE)

YES

YES

Disconnect pilot pressure sensor connector. Check if voltage between harness end connector terminals No.1 and No.3 is 5 ± 0.5 V.

NO

• Key switch: ON

Replace pilot pressure sensor with pump control pressure sensor. Perform “RETRIAL.” Check if fault code disappears.

Check if breakage or short circuit exists between MC 22P connector terminal No.D18 and pilot pressure sensor terminal No.2.

Harness failure between MC and pilot pressure sensor.

Faulty MC NO • After replacement, refer to page T5-4-60.


Harness breakage between MC and pilot pressure sensor terminal No.3.

Harness breakage between MC and pilot NO pressure sensor terminal No.1.

YES

Faulty pilot pressure sensor (arm roll-in).


1 2 2 3 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Pilot Pressure Sensor

3

1 2

T5-3-8

EX255-EX285

TROUBLESHOOTING A FAULT CODE 07 (ENGINE CONTROL DIAL FAILURE)

YES

YES

Disconnect engine control dial connector. Check if voltage between harness end connector terminals No.5 and No.7 i 5 ± 0.5 V.

NO Disconnect engine control dial connector. Check if resistance between engine control dial side terminals No.5 and No.7 is 5 ± 0.5 kΩ. With the engine control dial connected, insert test probe from back of engine control dial. Turn engine control dial and check if voltage changes as specified.

• Key switch: ON

Check if breakage or short circuit exists between MC 22P connector terminal No.D21 and engine control dial terminal No.6.

Faulty MC

NO • After replacement, refer to page T5-4-60.


• Refer to page T5-3-9 for the voltage change standard values.

Harness failure between MC and engine control dial.

Harness breakage between MC and engine control dial terminal No.7.

Harness breakage between MC and enNO gine control dial terminal No.5. Faulty engine control dial.

YES


1 2 2 3 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Engine Control Dial 4 3 5 6

7 8

2 1 9

EX255-EX285

T5-3-9

TROUBLESHOOTING A SENSOR OPERATING RANGE LIST 1. Preconditions for measurement • Hydraulic Oil Temperature: 50 ± 5 °C (122 ± 9 °F) • Unless otherwise instructed, set the switches as follows: Engine Control Dial

E Mode Switch/HP Mode Switch

Work Mode Switch

Auto-Idle Switch

Max. Position

OFF


OFF

• Monitor using the Dr.EX.

SM0631

2. Sensor Operating Range Item Engine Control Dial

Required Control/Switch Operation At minimum speed position

0.3 to 1.0 V

At maximum speed position

4.0 to 4.7 V

Engine control dial at Min. position

2.5 to 2.7 V

Engine control dial at Max. position with HP mode switch turned OFF

3.3 to 3.7 V

EC Sensor Engine control dial at Max. position with HP mode switch turned ON

Control Levers: Neutral Pump Delivery Pressure Sensor

Pilot Pressure Sensor

Boom Raised to stroke end and main relief valve relieved

2 25+15 -7 kgf/cm

2 350+20 -5 kgf/cm

Control Levers: Neutral Pilot Control Shut-Off Lever: Locked Position

0 to 1.0 kgf/cm2

Control Lever: Full Stroke Pilot Control Shut-Off Lever: Unlocked Position

34 to 40 kgf/cm2

Control Levers: Neutral Pump Control Pressure Sensor

0.2 V or more larger than the voltage obtained above (with the engine control dial at Max. position with HP mode switch turned OFF)

One Track Jacked-Up Travel Lever (Raised track side): Full Stroke

NOTE - 1 kgf/cm2 = 0,09807 MPa

10 to 16 kgf/cm2 30 to 40 kgf/cm2

T5-3-10

EX255-EX285

TROUBLESHOOTING A

EX255-EX285

T5-4-1

TROUBLESHOOTING B TROUBLESHOOTING B PROCEDURE Apply troubleshooting B procedure when no fault code is displayed on the Dr.EX although the machine’s operation is abnormal. On the front section pages of this group T5-4, are tables indicating the relationship between machine trouble symptoms and related parts which may cause such trouble if failed.

Start the troubleshooting with more probable causes selected by referring to these tables.

• How to Read the Troubleshooting Flow Charts

YES (OK)

(2)

• After checking or measuring item (1), select either Yes (OK) or No (NOT OK) and proceed to item (2) or (3), as appropriate.

(1) (3) NO(NG)

Key switch: ON

• Special instructions or reference item are indicated in the spaces under the box. Incorrect measuring or checking methods will render troubleshooting impossible, and may damage components as well.

• Explanation of how to use lamp harness kit required. Refer to “Harness Check” Group (Group 7) in this section.

• Use the Dr. EX troubleshooting/monitor function for the description in a double line box.

• Causes are stated in a thick-line box. Scanning through thick-line boxes, possible causes can be seen without going through the flow chart.

T5-4-2

EX255-EX285

TROUBLESHOOTING B RELATIONSHIP BETWEEN MACHINE TROUBLE SYMPTOMS AND PARTS IN TROUBLE Part Name

Part function

Control System Trouble

Machine Symptoms

Trouble shooting Procedures

This table indicates the probable machine trouble symptoms by part item when each part is failed and procedures to determine if the part has failed.

EC Motor

EC Sensor

• To operate governor lever.

• To detect the slow-idle speed governor lever position (2.5 V).

• To instruct the engine target speed governor lever position.

• Governor lever does not move.

• Whenever key switch is ON, governor lever position is learned as in the slow idle speed position differing from the correct position. Accordingly, engine speed is controlled afterward with the discrepancy which occurred at this time.

• Even if engine control dial is operated, engine speed is unchanged. • If harness to engine control dial is broken, target speed 1600 min-1 is used as the backup value

• Even if engine control dial is • If the discrepancy occurred to the • Engine speed is constantly operated, engine speed does slower side, engine speed is held at 1600 min-1. changed by engine control dial. not increase from slow (Auto-idle function However, engine speed control speed range. operates, and engine can range stays slower than normal. be stopped by turning key • Starter rotates but engine (Note: If the discrepancy occurred switch.) fails to start occasionally. to the faster side, when engine • While engine is running at a control dial is turned to the fastest faster than specific speed, if position, EC motor continues harness to EC motor is bromoving. However, EC motor is a ken, engine stalls. worm gear type so that governor • While engine is running at a lever is kept holding at the full stroke position. If engine control dial slower than specific speed, if is turned to the slowest position, harness to EC motor is brogovernor lever returns to the slow ken, engine becomes unconidle position.) trollable. • When engine is started, engine speed fluctuates. • Engine start may become difficult -

By Dr.EX SelfDiagnosing Function

-

By Dr.EX Monitor Function

Fault code 01 is displayed.


Monitor Item: EC Angle

Monitor item: Target Engine Speed

By Lamp Harness • Install test harness Check (75301706B). Then, check output signal from EC and check if harness is normal -

By Other Check/ Measurements

Note

Descriptions in (Operational Principle) Technical Manual

Engine Control Dial

• Engine is stopped by EC motor. No engine stop is provided. However, a fuel shut-off cable is installed

T2-1

-

-

-

-

• If EC sensor is failed, engine learning operation becomes impossible.

T2-1

-

T2-1

EX255-EX285

T5-4-3

TROUBLESHOOTING B

Pump Control Pressure Sensor

Pump Delivery Pressure Sensor

N Sensor

• To detect pump control valve pressure in control valve to control the travel motor swash angle.

Ž To detect both right and left pump delivery pressures to control speed sensing system, HP mode circuit, arm regenerative circuit, and travel motor swash angle.

• To detect engine speed to control speed sensing system.

• To increase relief setting pressure temporarily.

• Sensor output is reduced to zero and travel motor swash angle is held to the maximum angle.

• When pump delivery pressure sensor output is 0 V or 5 V, the following symptoms appear.

• Speed sensing system does not function.

• If solenoid valve unit (SG) is not energized, pilot pressure at port SG is 0 MPa (0 kgf/cm2).

• Even if travel mode switch is turned to the fast mode position, travel speed does not change to the fast range.

• Travel speed is changed to the slow speed range. However, automatic up shifting to the fast speed range from slow speed range is impossible. • HP mode does not work. • When combined operation is made, arm speed is slow (when delivery pressure sensor for pump 2 has failed).

• Engine stalls when the machine is operated at a high altitude or under heavy operating conditions.

• Main relief pressure set is unchanged from the standard setting pressure of 34 MPa (350 kgf/cm2). Even if the power boost switch is depressed, main relief pressure does not increase. Digging force does not increase.

Fault codes 04 and 05 are displayed.

Fault codes 02 and 03 are displayed.

-

-

Monitor items: Pump 1 Control Pressure Pump 2 Control Pressure

-

-

-

-

• Install lamp harness (75301514). Then, check output signal from MC and check if harness is normal.

-

-

-

-

-

-

• Proportional solenoid valve is used for the ONOFF valve so that whether the power boost switch is depressed or not, as long as an output signal from MC is measure by means of test harness, the control of solenoid valve unit is normal. If any output signal is detected, a broken wire harness may be a cause. See NOTE at the end of TABLE.

• Evaluation by Dr.EX 0.25 V or Less: Discontinuity 4.75 V or More: Short Circuit

T2-1

T2-1

Monitor item: Actual Engine Speed

Solenoid Valve Unit (SG)

T2-1

Monitor item: Power boost pressure

T2-1

T5-4-4

EX255-EX285

TROUBLESHOOTING B

Part Name Part function


Machine Symptoms

Solenoid Valve Unit (SD)

Solenoid Valve Unit (SI)

• To reduce pump swash angle by guiding pilot pressure to regulator to operate the speed sensing control system.

• When arm is rolled in, arm speed is increased by guiding return oil from arm cylinder rod side to bottom side.

• To increase travel speed by decreasing travel motor swash angle when fast travel mode is selected and pump delivery pressure is low.

• Pilot pressure is not fed to regulator.

• If solenoid valve unit (SC) is not energized, pilot pressure at port SC is 0 MPa (0 kgf/cm2). Thereby, arm regenerative function does not work.

• Travel speed is held in slow speed range.

• Engine may stall under heavy conditions such as operation at a high altitude.

• When leveling, arm speed becomes very slow.

• Travel speed does not increase even if travel mode switch is turned to the fast travel speed position.

By Dr.EX SelfDiagnosing Function Trouble shooting Procedures

Solenoid Valve Unit (SC)

-

-

-


Monitor item: Pump proportional Solenoid valve output

Monitor item: Arm regenerative proportional solenoid valve output

Monitor item: Travel motor displacement angle change pressure

By Lamp Harness Check

• Install test harness (75301514). Then, check output signal from MC and check if harness is normal.




-

-

-

Note

Descriptions in (Operational Principle)Technical Manual

Output signal MC must be measured with the solenoid valve connected. See NOTE at the end of table.

T2-1



T2-1

T2-1

EX255-EX285

T5-4-5

TROUBLESHOOTING B

Pressure Switch (Travel)

Pressure Switch (Front)

• To detect that travel spool is operated (for auto-idle operation and travel motor swash angle control).

• To detect that front and/or swing spool is operated (for auto-idle operation).

• To detect boom raise pilot pressure (for arm regenerative control).

• To detect arm roll-in pilot pressure (for HP mode control and arm regenerative control).

• No signal is sent to MC.




• Even if machine is traveled with auto-idle switch ON, engine speed does not increase. • When traveling on a flat area in the fast travel mode, travel speed is slow.

• Even if either front or swing control lever is operated with auto-idle switch ON, engine speed does not increase.

• As arm regenerative function does not work, when boom is raised and arm is rolled in, arm speed is slower than normal (difficult to discern). • When beginning to level a ground surface, bucket is slightly lowered into the ground.

• When the combined operation of swing and arm roll-in is made, arm regenerative function does not work so that arm speed is slow when starting to roll in (difficult to discern). • Arm speed is slow when leveling. • HP mode does not function when arm is rolled in.

-

-

-


Monitor item: Pressure Switch While operating front or swing function, monitor to check if pressure switch is ON or OFF.

Monitor item: Pressure Switch. While raising boom, monitor to check if pressure switch is ON or OFF

Monitor item: Arm Roll-In Pilot Pressure

-

-

-

-

-

-

-

-

• It is possible to check if pressure switch has failed or if a port is clogged by switching the pressure switch with an adjacent one (for front).

• It is possible to check if pressure switch has failed or if a port is clogged by switching the pressure switch with an adjacent one (for travel).

-

-

T2-1

T2-1

Monitor item: Pressure Switch While traveling, monitor to check if pressure switch is ON or OFF.

Pressure Switch (Boom Raise)

T2-1

Pilot Pressure Sensor (Arm Roll-In)

T2-1

T5-4-6

EX255-EX285

TROUBLESHOOTING B


Learning Switch • To start learning engine control ON: 0 V → Learning OFF: 5 V → Normal Control


Machine Symptoms


• To operate power boost function ON: 0 V → Boost function works. OFF: 5 V → Boost function does not work.

HP Mode Switch • To control HP mode operation ON: 0 V → HP Mode. OFF: 5 V → Standard Mode.

• Engine learning does not function.

• Breaking of Wire: Boost function does not work. Short Circuit: Boost function works for 8 seconds after key switch is turned ON, but becomes inoperative afterwards.

• If trouble is caused by circuit discontinuity, engine control system operates normally. (Only engine learning function fails.) • If trouble is caused by a short circuit, the learning mode operates when key switch is turned ON. Therefore, engine may stall 5 seconds after engine starts.

• Power boost function does not work if whether a wire is broken or short circuit occurs.

• Broken Wire: Even if HP mode switch is depressed, HP mode does not operate. • Short Circuit: Even if HP mode switch is turned OFF, HP mode is not deactivated.

-

-

-

By Dr.EX SelfDiagnosing Function Trouble shooting Procedures

Power Boost Switch

Monitor item: Engine Learning Control

Monitor item: Power Boost Switch

-

Monitor item: HP Mode Switch


-

-

-


-

-

-

Note

-

-

-


T2-1

T2-1

T2-1

EX255-EX285

T5-4-7

TROUBLESHOOTING B

E Mode Switch • To select E mode. ON: 0 V → E Mode OFF: 5 V → Standard Mode

Travel Mode Switch

MC

Pump Control Valve

• To change travel speed at two stages.

• To control engine, pump, and valve operations.

• To develop pump control pressure in response to the oil flow rate ing through the center by age in the control valve.

Fast Travel Mode: 0 V → Traveling at fast speed Slow Travel Mode: 5 V

-

• Discontinuity in Switch: Travel speed is kept in slow range (5 V).

• Problems may differ depending on the trouble. (Machine troubles shown below signify that the logic circuit in MC has some faults.)

• If the pump control valve spool is seized, or the spring is broken, pump control pressure does not change.

• Broken Wire: Even if E mode switch is depressed, engine runs at full speed. • Short Circuit: Engine speed is not increased up to full speed.

• Even if travel mode switch is turned to the fast travel mode position, travel speed is un-changed.

• Even if key switch is turned to the ON position, EC motor does not rotate to the start position so that engine cannot start. Or, even if engine is started, engine speed does not increase. • Pump swash angle is held to a minimum, all function speeds are slow.

• When the 5-spool side pump control valve is faulty: 1.Left track travel speed only is slow. 2.Swing function is also slow. 3.Arm speed is slow when leveling. 4.Single operation of bucket, boom, or arm is almost normally performed. • When 4-spool side pump control valve is faulty: 1.Bucket single operation speed is very slow. 2.Boom is not raised when leveling. 3.Right track travel speed only is slow. 4.Single operation of boom, arm, or swing is almost normally performed.

-

-

Procedures may differ depending on the locations of failures.

-

Monitor item: Selected Travel Mode Switch

-

-

-

-

-

-

-

-

-

-

-

• Before suspecting a failure in MC, check the fuse in this control circuit.

-

Monitor item: E Mode Switch

T2-1

T2-1

-

Monitor items: Pump 1 Control Pressure Pump 2 Control Pressure

T3-3

T5-4-8

EX255-EX285

TROUBLESHOOTING B



Machine Symptoms


Flow Combiner Valve

Restriction in Arm 1 Parallel age

Check Valve and Restriction in 4-Spool Side Parallel Circuit

• To supply hydraulic oil to both right and left travel spools from pump 1 when the combined operation of travel and front/swing is made.

• To ensure lateral thrust force of the front by swing function.

• To supply hydraulic oil from pump 1 to arm 1 spool in pump 2 side.

• When the combined operation of travel and front/swing is made, hydraulic oil is not supplied to the left travel spool, or oil flow to the left travel spool is insufficient.

• If the restriction is clogged, hydraulic oil does not flow through the arm 1 parallel circuit.

• If the check valve is seized and kept closed, or the restriction is clogged, hydraulic oil does not flow from pump 1 to arm 1 spool. • If the check valve is seized and kept opened, hydraulic oil from pump 2 flows to the pump 1 side.

• While traveling straight, the machine mistrack when the swing lever is operated.

• Arm speed is slow when leveling.

• When check valve is kept closed, or restriction is clogged: Arm speed is slow when leveling. • When check valve is kept opened: Left travel speed is slow.


-

-

-


-

-

-


-

-

-


-

-

-

Note

-

-

-

Descriptions in (Operational Principle) Technical Manual

T3-3

T3-3

T3-3

EX255-EX285

T5-4-9

TROUBLESHOOTING B

Arm Regenerative Control Valve

Travel Flow Control Valve

• To increase arm speed by allowing the return oil from the arm cylinder rod side to flow into the arm cylinder bottom side when the valve is switched by pilot pressure oil led from solenoid valve unit (SC)

• To reduce the shock load developed when single travel operation is switched to the combined operation of travel and front by gradually restricting oil flow in the travel parallel circuit.

• To ensure the boom lower force when the combined operation of travel and boom lower is made.

• To prevent the arm drift caused by inner leakage of hydraulic oil in control valve. Only when arm rollin operation is made, antidrift valve (check valve) in the arm cylinder return circuit is forcibly opened so that the arm is rolled in.

• Arm regenerative function does not operate.

• Oil flow is not restricted properly.

• Boom 2 spool does not move when the combined operation of travel and boom lower is made. • Boom 2 spool is moved even if the single operation of boom lower is made.

• Check valve does not open if the changeover valve is seized.

• Arm speed is very slow when leveling.

• When fully closed: Great shock is felt when changed from travel single operation to travel combined operation. • When fully opened: The boom is not raised when the combined operation of travel down a slope and boom raise with the bucket loaded is made. (Boom is raised when boom single operation is performed.)

• When fully opened: Boom lower speed is very fast. With swing lever fully stroked, swing speed is slow when the combined operation of swing and boom lower is made. • When fully closed: With the front lowered while traveling, the track of the base machine is not raised off the ground.

• If check valve does not open fully, arm roll-in speed is slow. • If check valve is kept opened, arm drift increases due to the control valve inner leakage. • According to the degree of seizure in check valve, arm roll-in operation becomes jerky, or slower.

T3-3

Travel and Boom Lower Selector Valve

Arm Anti-Drift Valve

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

T3-3

T3-3

T3-3

T5-4-10

EX255-EX285

TROUBLESHOOTING B

Part Name

Boom Anti-Drift Valve

Boom Regenerative Valve

Part function

• To prevent the boom drift caused by inner leakage of hydraulic oil in control valve. Only when boom lower operation is made, anti-drift valve (check valve) in the boom cylinder return circuit is forcibly opened so that boom is lowered.

• To prevent boom hesitation when lowering boom by allowing the return oil from the boom cylinder bottom side to flow into the boom cylinder rod side.

• To restrict the bucket circuit to assist boom to raise when the combined operation of bucket, arm roll-in, and boom raise is made.


• Check valve does not open if the switch valve is seized.

• With check valve kept closed, boom lower speed becomes slow. • With check valve kept opened, the track of the base machine is not raised off the ground by lowering the boom.

• Bucket circuit is always restricted if the switch valve is seized.

Machine Symptoms

• If check valve does not open, boom is not lowered. • If check valve is kept opened, boom drift increases due to the control valve inner leakage. • According to the degree of seizure in check valve, boom lower operation becomes jerky, or slower.

• Same as described in the above column.

• Bucket speed is slow if poppet valve is seized and kept closed, or switch valve is seized so that the poppet valve is closed. • Boom is not raised when the combined operation of bucket, arm roll-in, and boom raise is made with poppet valve fully opened, or if the switch valve is seized so that the poppet valve is fully opened.


Bucket Flow Control Valve


-

-

-


-

-

-


-

-

-


-

-

-

Note

-

-

-


T3-3

T3-3

T3-3

EX255-EX285

T5-4-11

TROUBLESHOOTING B NOTE - The measurement of the control voltage of proportional solenoid valves SG, SI, SD and SC, must be performed with test harness (75301514) meaning that the main controller (MC) output must be connected to the load of the solenoid valve. Under this test configuration, the normal control voltage changes from 5 through 10 Volt. On the other hand, when measuring the control voltage directly on the connector disconnected from the solenoid valve (harness side) the voltage measured is always 24 Volt and this is irrelevant in troubleshooting the solenoid valve.

T5-4-12

EX255-EX285

TROUBLESHOOTING B CORRELATION BETWEEN TROUBLE SYMPTOMS AND PART FAILURES Engine Control

Trouble Symptom

EC EC Motor Sensor

Pump / Valve Control

Eng. Coolant QOS Sol. Pump Pump N Cont. Temp. Con- Valve Deliv. Deliv. SenDial Sw. troller Unit Press. Press. sor (PreSD Sensor Sensor heat Pump Pump Circuit) 2 1

Arm Roll In Sensor

Switch Press. Press. AutoSw. Sw. Idle Travel Front Sw. Act.

Learning Sw.

HP Mode Sw.

E-1 Starter does not rotate E-2 Although starter rotates, engine does not start. E-3 Engine runs slower than normal at all operation speeds. Slow idle speed is faster or slower than normal. E-4 Even if engine control dial is turned, engine speed is unchanged. E-5 Even if HP mode switch is depressed, HP mode does not operate. E-6 Engine does not stop even if key switch is turned OFF. E-7 Auto-idle function does not function. E-8 Engine speed does not change, even if E mode is depressed. E-9 Engine stalls several seconds after engine starts. E-10 Engine stalls when machine is operated at high altitude or under adverse conditions. E-11 Engine is hard to start at low ambient temperature. A-1. All actuators speeds are slow A-2. When single travel operation is made, left side track slow but right side track is normal. Single swing operation is slow. Bucket operation is normal. Arm speed is slow when leveling. (All above symptoms occurred at the same time). A-3. When single travel operation is made, right side track is slow but left side track is normal. Single swing operation is normal. Boom hardly raises when leveling. (All the above symptoms occurred at the same time). A-4. Actuator does not stop, even after control lever is in the neutral position.

NOTE - The above table shows the correlation between machine operation trouble and related parts which may cause trouble. However, the correlations in this table are described based on the condition supposing that each occurs independently.

If any other trouble occur at the same time, find out the faulty parts causing the trouble by checking all suspected parts in each symptom.

EX255-EX285

T5-4-13

TROUBLESHOOTING B

Switch E Mode Sw.

Key Sw.

MC (Main Contr.)

Engine Eng. Elec. Parts

Eng. Unit

Pump Governor

Main Pump Unit

Pilot Pump

Control Valve Spool

Pump Cont. Valve 5Spool Side

Pump Cont. Valve 4Spool Side

Other Main Relief Valve

Pilot Valve

Pilot Relief Valve

Note

Check battery Check fuel system Check fuel shut-off handle. Check engine control cable. Be sure to operate engine learning whenever engine is replaced. Check engine control cable.

Check if fuel system is clogged

: being linked closely. Checking the part is required. : being linked, but if this parts is faulty another type of trouble will be prominent. Therefore this part may not be the main cause of the trouble.

T5-4-14

EX255-EX285

TROUBLESHOOTING B Pump/Valve Control

Sw.

Sol. Sol. Pump Arm Press. Valve Valve Deliv. Roll in Sw. Unit SG Unit SC Press. Sensor Boom Sensor Raise Pump 2

Power Boost Sw.

Control valve Spool

Main Relief Valve

Overload Relief Valve

Load Check Valve

Boom ReCheck RestricValve genertion & Reative Arm 1 stric. Valve Parallel 4-Spool Parallel

F-1 All front attachment functions are weak. F-2 Digging force is not increased even if power boost switch is depressed. F-3 Some cylinders do not move or speeds are slow. F-4 Boom lower single operation is fast. F-5 Arm speed is slow in a combined operation. Arm speed is slow in leveling operation. F-6 Bucket digging single operation is slightly slow. Bucket digging single operation is jerky. F-7 Arm starting speed is slow during combined operations. Arm operation is jerky. During arm roll-in single operation, arm starting speed is slightly slow which often occurs at low temperature. F-8 Boom starting speed is slow during combined operations. Boom operation is jerky. Boom starting speed is slightly slow during boom lower single operation. F-9 When operating the control lever to raise boom or to roll-out arm, boom or arm starts to move after slightly moving in the reverse direction. F-10 Front attachment cylinders drift is large. S-1 Swing speed is slow or swing function does not operate. S-2 Swing speed is slow during combined operation with boom lower.

NOTE - The above table shows the correlation between machine operation trouble and related parts which may cause trouble. However, the correlations in this table are described based on the condition sup-

posing that each occurs independently.If any other trouble occur at the same time, find out the faulty parts causing the trouble by checking all suspected parts in each symptom.

EX255-EX285

T5-4-15

TROUBLESHOOTING B Control valve Arm Regenerative Valve

Travel Boom Lower Select. Valve

Arm Anti Drift Valve

Boom Anti Drift Valve

Others Bucket Swing ShockFlow Device less Cont. Valve Valve

Pilot Cylinder Valve

Note

Check the work mode switch position Take care not to confuse power boost operation with HP mode

Check the work mode switch position


T5-4-16

EX255-EX285

TROUBLESHOOTING B

Pump/Valve Control

Trouble Symptom

Sol. PC PC Valve Press. Press. Unit Sensor Sensor SI 5 Spool 4 Spool Side Side

Pump Pump. Press Deliv. Deliv. Sw. Press. Press. Travel Sensor Sensor Pump Pump 2 1

T-1 Both right and left side tracks do not move or move slowly. T-2 When a single travel operation is shifted to a combined operation with front functions, a shock load is felt. T-3 One side track does not move or moves slowly. Or the machine cannot travel straight (mistracks). T-4 During a combined operation of travel and front attachment function, the machine mistracks. T-5 Steering power and gradeability are insufficient in the fast travel mode. T-6 Travel mode does not change to the fast speed range. O-1 The wiper does not operate, or will not retract.

NOTE - The above table shows the correlation between machine operation trouble and related parts which may cause trouble. However, the correlations in this table are described based on the condition supposing that each occurs independently. If any other trouble occur at the same time, find out the faulty parts causing the trouble by checking all suspected parts in each symptom.

Sw. Travel Spool Mode Switch

Control valve Load Check Valve

Flow Travel Comb. Boom Valve Lower Select Valve

Others Travel Device

Center t .

EX255-EX285

T5-4-17

TROUBLESHOOTING B

Others Pilot valve

Remarks .

Refer to A1.

.

Refert to T-6.

Refer to the troubleshooting section.


T5-4-18

EX255-EX285

TROUBLESHOOTING B ENGINE TROUBLESHOOTING E-1 Starter Does Not Rotate.

Faulty starter or disconnected starter ground line.

YES

Related Fault Code: None Checking Instructions • Measure each voltage by referring to the tables below. • Electronic system such as MC has nothing to do with the trouble obstructing the rotation of starter.

YES

• Key switch: ON↔START

Check if each terminal voltage on starter is normal with key switch turned to the positions in the following table.

Key switch Terminal

With key switch positioned at START, voltage at terminal C does not increase to 24 volts.

ON ON (Engine START (Engine not running) running)

C

0

24

0

B

24

24

24

M

0

24

0

Starter Relay Terminal Voltage Unit: Volt

NO

Key switch Terminal

• Voltage: 24 volts or more • Density: 1.26 or more

NO

With key switch positioned as shown in the following table, check if each terminal voltage is normal.

Unit: Volt

Starter Terminal Voltage

Check if battery voltage and electrolyte density are normal.

Regardless of key switch position ON or START, voltage at terminal B is 0 (zero).

ON ON (Engine START (Engine not running) running)

B

24

24

C

0

24

0

E

0

0

0

R

0

0

12

S

0

24

0

With key switch positioned at START, voltage at terminal S does not increase to 24 volts.

Faulty Battery

24

Faulty starter or disconnected starter ground line.

(When key switch is turned to START, in case voltage at terminal B is 18 V or lower, battery is faulty.)

• Starter Terminal Voltage Check.

• Starter Relay Voltage Check.

(Seen from the back of the connector.) SM5401

SM6117

EX255-EX285

T5-4-19

TROUBLESHOOTING B

YES

Faulty harness between battery relay and starter.

Check if battery relay clicks when key switch is turned OFF from the ON position. • Key switch: ON↔OFF

Faulty battery relay NO YES

With key switch in START, voltage at terminal S does not increase to 24 V.

Terminal No.1 voltage: 0 V Measure voltage at key switch terminals No. 1 and No. 6.

Check if fusible link (40 A) has blown.

NO

• Key switch: START

Faulty harness between fusible link and key switch.

Blown fusible link 1 (40A).

Terminal No.1 voltage: 24 V Terminal No.6 voltage: 0 V Faulty key switch.

Terminal No.1 voltage: 24 V Terminal No.6 voltage: 24 V

Voltage at terminal B is 0 V.

Faulty harness between key switch terminal No. 6 and starter relay terminal S. Broken harness between both terminals B on starter and starter relay.

With key switch in START, voltage at terminal C is 0 V but voltage at starter relay terminal C is 24 V.

Broken harness between both terminals C on starter and starter relay.

With key switch in START, voltage at all terminals other than C is normal. Voltage at terminal C does not increase to 24 V.

Faulty starter relay.

• Key Switch Voltage Check NOTE - Remove the key switch from the console.

View A

SM0633

T5-4-20

EX255-EX285

TROUBLESHOOTING B E-2

Although Starter Rotates, Engine Does Not Start.

Related Fault Code: None Checking Instructions • Check the governor lever and the fuel shut-off lever positions while the engine is cranking. If their positions are normal, the engine and the fuel system may be faulty.

YES

Faulty engine. • Refer to engine Section.

With key switch ON, check if governor lever moves to the starting position. • Key switch : ON Check EC motor activating circuit.

NO

• Governor Lever and Fuel Shut-Off Lever

4

2

3

1 SM5402

1 - Governor Control Cable (From EC Motor) 2 - Fuel Shut-Off Cable [Handle (Emergency Engine Stop)] 3 - Fuel Shut-Off Lever 4 - Governor Lever

EX255-EX285

T5-4-21

TROUBLESHOOTING B • Governor Lever Position AB-

Key Switch OFF (Engine Stop Position) Key Switch ON (Engine Start Position)

B FULL

A

STOP

P STO

L FUL SM5404

• Fuel Shut-Off Lever AB-

Fuel Cut Handle Pulled Position Fuel Cut Handle Returned Position

A

B

SM5405

T5-4-22

EX255-EX285


Engine Runs Slower than Normal at All Operation Speeds. Slow Idle Speed is Faster or Slower than Normal.

Related Fault Code: 01 Checking Instructions • Before the engine learning operation is carried out, or when the engine learning operation is made in a wrong procedure, the engine may run slower at all operation speeds. • If the EC sensor is faulty, the governor lever position which is located when the key switch is turned ON, is learned as the idle position. Then, the engine is controlled based on this engine learning operation. Accordingly, the engine runs with discrepancy from the standard control speed. Further more, this trouble may not reemerge as the extent of discrepancy in the governor lever position differs each time when the key switch is turned ON. • Refer to the Control System Group titled “Engine Learning Control” in the SYSTEM Section in the Operational Principle book (Technical Manual). • Even if the EC motor control becomes abnormal, the governor lever position is constantly kept at the full stroke end since the EC motor is a worm gear type. Accordingly, the engine does not stall.

NO Check governor lever or EC motor cable for proper operation.

Restore governor lever or EC motor cable to correct operation. YES

YES

Faulty EC sensor. • After replacement, refer to T5-4-60.

Check if fault code 01 is displayed. NO

Check if the trouble is reconditioned after engine learning operation is conducted. • Refer to T5-4-60.

YES

NO

End.

Monitor the engine learning operation. • Monitor item: Engine Learning Control

EX255-EX285

T5-4-23

TROUBLESHOOTING B

OK

Check if governor lever comes in with the stopper when conducting engine learning operation.

YES

NO

Faulty engine or fuel system.

Faulty control cable. Faulty engine governor lever adjustment. • Refer to T5-4-60.

NOT OK

Failure in MC. Faulty learning switch, or harness between learning switch and MC. • After replacement, refer to T5-4-60.

T5-4-24

EX255-EX285


Even If Engine Control Dial is Turned, Engine Speed is Unchanged.

Related Fault Code: 07 Checking Instructions • Refer to the Control System group titled “Engine Learning Control” in the SYSTEM Section in the Operational Principle book (Technical Manual).

YES

Faulty engine control dial or broken harness between engine control dial and MC. YES

Check if fault code 07 is displayed. NO

Connect Lamp Harness (75301706B) to EC motor. Check if the lamp comes ON when engine control dial is turned.

Faulty EC motor. • After replacement, refer to T5-4-60.

NO

Failure in MC or broken harness between MC and EC motor. • After replacement, refer to T5-4-60.

EX255-EX285

T5-4-25


Even If HP Switch is Depressed, HP Mode Does NOT Operate. (Standard Mode Operates Normally.)

Related Fault Codes: 02, 03, and 06 Checking Instructions • The pressure switches check if the HP mode is requested so that if these pressure switches fail, the HP mode does not operate. • Refer to the Control System group titled “HP Mode Control” in the SYSTEM Section on the Operational Principle book (Technical Manual).

Faulty HP mode switch, or broken harness between HP mode switch and MC.

NO

NO

Check if fault code is displayed.

Monitor HP mode switch. Check if indication of “HP” is displayed or deleted on Dr. EX screen by operating the HP mode switch on the right console ON or OFF.

• Monitor item: HP Mode Switch

YES

YES

Faulty sensors, or broken harness between MC and sensors. • Fault codes: Pump 1 delivery pressure sensor: 02 Pump 2 delivery pressure sensor: 03 Pilot pressure sensor (arm roll-in): 06

Check if governor lever comes into with fullspeed side stopper when hydraulic oil pressure is relieved by arm rollin operation.

YES

Faulty engine or poor quality fuel.

Failure in MC. NO • After replacement, refer to T5-4-60.

T5-4-26

EX255-EX285


Engine Does Not Stop Even If Key Switch is Turned OFF. (When the engine does not stop, be sure to start checking after stopping the engine by pulling the engine stop handle located under the seat stand).

Related Fault Codes: 01 and 07 Checking Instruction • Trouble symptoms such as “Engine runs slower than normal at all operation speed” or “Even if engine control dial is turned, engine speed is unchanged” are sure to exist at the same time. Perform the troubleshooting of all symptoms.

E-7

Auto-Idle Function Does Not Function.

Related Fault Code: None Checking Instruction • When trouble corresponding to E-1 to E-6 exist,

perform the troubleshooting of them beforehand. • Refer to the Control System group titled “Auto-Idle

Control” in the SYSTEM Section in the Operational Principle book (Technical Manual).

NO

YES

Monitor auto-idle switch. Check if indication of “AI” is displayed or deleted on Dr.EX screen by operating the auto-idle switch on the right ON or OFF. • Monitor item: Auto-Idle Switch

Monitor pressure switches (travel and front attachment). Check if indication of “Tr” and “Fr” is displayed or deleted on Dr.EX screen by operating each of the travel and front control levers.

Faulty pressure switches (travel, and front attachment). Faulty harness between MC and pressure switches. Filter in the pilot signal circuit is clogged.

NOTE - Pressure switches (travel, and front attachment) are installed on the control valve.

• Monitor item: Pressure Switch

Failure in MC YES • After replacement, refer to T5-4-60.

NO

Faulty auto-idle switch, or broken harness between auto-idle switch and MC.

EX255-EX285

T5-4-27


Engine Speed Does Not Change Even If E Mode Switch is Depressed.

Related Fault Code: None Checking Instructions • If trouble corresponding to E-1 to E-7 exist, perform the troubleshooting of them beforehand. • Refer to the Control System group titled “E Mode Control” in the SYSTEM Section in the Operational Principle book (Technical Manual).

Monitor E mode switch. Check if indication of “E” or “P” is displayed alternately on Dr.EX screen by operating the E mode switch on the right console ON or OFF.

E-9

Faulty E mode switch, or broken harness between E mode switch and MC.

NO

Failure in MC. YES • After replacement refer to T5-4-60.

Engine Stalls Several Seconds After Engine Starts.

Related Fault Code: None Checking Instructions • Refer to the Control System group titled “Engine Learning Control” in the SYSTEM Section on the Operational Principle book (Technical Manual). • If engine learning switch is set to the engine learning side, engine comes to a stop 5 seconds after engine is started.

YES Check if engine learning switch is turned ON.

NO

Return the switch to neutral.

End. Faulty learning switch, or short circuit of harness between learning switch and MC. Or, check if the fuel system is clogged.

SM0108

T5-4-28

EX255-EX285


Engine Stalls When Machine is Operated at High Altitude, or under Adverse Conditions.

Related Fault Code: None Checking Instruction • If speed sensing control does not function, engine may stall under adverse operating conditions.

NO

NO


Monitor engine speed. Check if engine runs at abnormal speed.

• Monitor item: Pump Proportional Solenoid Valve Output • Refer to Operational Performance Test section.

• Monitor item: Actual Engine Speed

YES

Referring to the displayed fault code, check suspectable parts.

Monitor output signal from solenoid valve unit (SD). With a pressure gauge installed to port SD, compare the pressure gauge reading with the monitored pressure by Dr.EX. Check if pressure values indicated on both the pressure gauge and the Dr.EX vary identically.

YES

Faulty N sensor or faulty harness between N sensor and MC.

NO

YES

Disconnect harness from solenoid valve unit (SD) and connect test harness (75301514) between solenoid valve unit (SD) and the disconnected harness. Check if the solenoid valve control voltage is present.

Disassemble and check regulator.

EX255-EX285

T5-4-29

TROUBLESHOOTING B

YES

NO

Faulty solenoid valve unit (SD).

Broken harness between solenoid valve and MC.

NOTE - The measurement of the control voltage of proportional solenoid valves SG, SI, SD and SC, must be performed with test harness (75301514) meaning that the main controller (MC) output must be connected to the load of the solenoid valve. Under this test configuration, the normal control voltage changes from 5 through 10 Volt. On the other hand, when measuring the control voltage directly on the connector disconnected from the solenoid valve (harness side) the voltage measured is always 24 Volt and this is irrelevant in troubleshooting the solenoid valve.

T5-4-30

EX255-EX285

TROUBLESHOOTING B E-11 Engine is Hard to Start at Low Ambient Temperature. (Even if preheated, engine is hard to start or does not start at a low ambient temperature or in a cold climate district.)

Related Fault Code: None Checking Instruction • Check if electricity is conducted to glow plugs and glow plugs are normal.

YES

Faulty engine coolant temperature switch.

Disconnect engine coolant temperature switch. Check if voltage at glow plug is 20 to 24 V.

YES

• Key switch: ON NO

With engine coolant temperature switch disconnected, ground glow relay terminal No.4 to vehicle frame. Check if voltage at glow plug is 20 to 24 V. • Key switch : ON • Without removing connector, ground the terminal to vehicle frame using a jumper wire, like a clip, from the reverse side of the connector.

NO

Faulty QOS controller.

With engine coolant temperature switch, and glow relay disconnected, check if voltage at glow relay harness end connector terminal No.1 and No.3 is 20 to 24 V.

• Measurement of Glow Plug Voltage and Resistance

Remove Copper Plates. Standard: 20 to 24 V

Standard: 10 Ω or Less

SM4049

SM4050

EX255-EX285

T5-4-31

TROUBLESHOOTING B

YES

Faulty glow relay.

10 Ω or less

NO

• Refer to engine shop section. • Refer to T5-4-60 after replacing the engine.

Measure glow plug resistance. • Key switch: OFF • After removing copper plates connecting glow plugs, measure the glow plug resistance.

Faulty engine.

∞Ω

Replace glow plug.

T5-4-32

EX255-EX285

TROUBLESHOOTING B OVERALL ACTUATOR SYSTEM TROUBLESHOOTING A-1 All Actuator Speeds are Slow. Related Fault Code: None Checking Instructions • In case the speed is normal without power, main relief valve may be faulty (F-1). If speed is extremely slow, the pump control system may have malfunction (A-2, or A-3) or the pilot system may be faulty. • If N sensor fails, only an abnormal value like 0 min-1 (rpm) is displayed.

Normal. Select general purpose mode

YES

Check if precision work mode is selected.

NO

NO

NO

Check if any fault codes are displayed.

YES

• Arm: Fully rolled in. • Monitor item: Arm roll-in pilot pressure

Monitor actual engine speed. Check if abnormal speed is monitored. • Monitor item: Actual Engine Speed

Check if secondary pilot pressure is normal.

YES

Faulty N sensor or broken harness in N sensor circuit.

Referring to the displayed fault code, check faulty parts.

EX255-EX285

T5-4-33

TROUBLESHOOTING B

NO

YES

NO

End

YES

Faulty pilot pump or clogged pilot filter.

After disassembling, cleaning, and adjusting pilot relief valve, check if an abnormal condition still remains.

Trace the causes of trouble by checking other symptoms.

T5-4-34

EX255-EX285

TROUBLESHOOTING B A-2

When Single Travel Operation is Made, Left Side Track is Slow But Right Side Track is Normal. Single Swing Operation is Slow. Single Bucket Operation is Normal. Arm Speed is Slow When Leveling. (All above symptoms occurred at the same time.)

Related Fault Code: None Checking Instructions • Due to some reasons, pump 2 delivery rate is reduced to the minimum (approx. 20 L/min). Accordingly, left side track and swing function speeds are too slow as they are actuated by pressure oil from pump 2. • Arm and boom cylinders are also actuated by pressure oil from pump 1 so that arm and boom speed is slightly reduced when the single operation of arm or boom is made. However, when the level crowding operation is made, oil flow to boom cylinders has priority over arm cylinder. Then, almost no oil flow is supplied to arm cylinder, reducing arm speed. • Refer to “Control Valve” and “Pump Device” groups in COMPONENT OPERATION Section in the Operational Principle book (Technical Manual).

YES

NO

Check if pump control pipe lines are correctly connected.

NO


YES

Reconnect correctly.

Referring to the displayed fault code, check suspected parts.

NO

Monitor pump control pressure by operating control lever. Check if pump control pressure increases. • Swing or travel left • Monitor item: Pump 2 Control Pressure

YES

Faulty pump control valve (5 spool side).

Check regulator for pump 2.

EX255-EX285

T5-4-35


When Single Travel Operation is Made, Right Side Track is Slow But Left Side Track is Normal. Single Bucket Operation is Slow. Single Swing Operation is Normal. Boom Hardly Raises When Leveling. (All the above symptoms occurred at the same time.)

Related Fault Code: None Checking Instructions • Due to some reasons, pump 1 delivery rate is reduced to the minimum (approx. 20 L/min). Accordingly, right side track and bucket function speeds are too slow as they are actuated by pressure oil from pump 1. • Arm and boom cylinders are also actuated by pressure oil from pump 2 so that arm and boom speed is slightly reduced when the single operation of arm or boom is made. However, when the level crowding operation is made, oil flow to arm cylinder has priority over boom cylinders. Then, almost no oil flow is supplied to boom cylinders, causing boom to become immovable. • Refer to “Control Valve” and “Pump Device” groups in COMPONENT OPERATION Section in the Operational Principle book (Technical Manual).

YES

NO

Check if pump control pipe lines are correctly connected.

NO


YES

Reconnect correctly.

Referring to the displayed fault code, check suspected parts.

NO

Monitor pump control pressure by operating control lever. Check if pump control pressure increases. • Bucket or travel right. • Monitor item: Pump 1 Control Pressure

YES

Faulty pump control valve (4 spool side).

Check regulator for pump 1.

T5-4-36

EX255-EX285


Actuator Does Not Stop Even After Control Lever is Returned to Neutral.

Related Fault Code: None Checking Instruction • Sticking of pilot valve spool or control valve main spool may be the cause of the trouble.

YES

Faulty Pilot Valve. • When control lever is in neutral, pilot pressure is guided to control valve spool.

Check if actuator stops when pilot control shut-off lever is raised.

Faulty Control Valve. NO • Pilot pressure is not guided to control valve spool. However, control valve is kept open as spool is stuck.

EX255-EX285

T5-4-37

TROUBLESHOOTING B

T5-4-38

EX255-EX285

TROUBLESHOOTING B FRONT ATTACHMENT CONTROL SYSTEM TROUBLESHOOTING F-1

All Front Cylinder Functions are Weak.

Related Fault Code: None Checking Instructions • If motion speed is normal and power is weak, main relief valve may be faulty (F-1). If motion speed is too slow, pump control system may have malfunction (A-2, or A-3) and pilot system also may be faulty.

NOTE - 1 kgf/cm2=98.07 kPa

350 to 370 kgf/cm2 Monitor pump 1 and 2 delivery pressures. • Monitor item: Pump 1 Delivery Pressure Pump 2 Delivery Pressure • Relieve boom, arm, or bucket.

F-2

• E mode switch: OFF • HP mode switch: OFF • Work mode: General purpose mode.

Less than 350 kgf/cm2

Main Relief Valve is normal. Trace the cause of the trouble by checking other symptoms. Adjust main relief valve.

Digging Force is Not Increased Even If Power Boost Switch is Depressed.

Related Fault Code: None Checking Instruction • Refer to the Control System Group titled “Power Boost” in the SYSTEM Section in the Operational Principle book (Technical Manual). Pressure increases from less than 350 kgf/cm2 to 370 kgf/cm2. Monitor the delivery pressures from pumps 1 and 2. • Monitor items: Pump 1 Delivery Pressure Pump 2 Delivery Pressure • With power boost switch depressed, check the pump delivery pressure.

Pressure does not increase.

Monitor power boost switch. Check if the indication of “Pd” is displayed or deleted on Dr.EX by operating power boost switch. • Monitor items: Power Boost Switch

NO

YES

Faulty power boost switch, or broken harness between power boost switch and MC. Measure oil pressure at the port of solenoid valve unit (SG). • With power boost switch depressed, check pressure change. • Refer to Operational Performance Test section

Normal (HP mode operation might have been mistaken for Power Boost operation.)

EX255-EX285

T5-4-39


NOTE - 1 kgf/cm2=98.07 kPa

Pressure does not change.

Disconnect harness from solenoid valve unit (SG) and connect test harness (75301514) between solenoid valve unit (SG) and the disconnected harness. Check when the switch is actuating if the solenoid valve control voltage is present. • Power boost switch: ON

Pressure increases from less than 5 kgf/cm2 up to 10 kgf/cm2.

Faulty main relief valve.

YES

NO

Faulty solenoid valve unit (SG).

Faulty harness between solenoid valve and MC.

T5-4-40

EX255-EX285

TROUBLESHOOTING B F-3

Some Cylinders Do Not Move or Speeds are Slow.

Related Fault Code: None Checking Instructions • Discriminate whether the cause of the trouble is in the pilot system or in the main circuit system. • If other functions (travel, swing) are normal, the pilot pump is considered to be normal. • If bucket single operation speed is slow, refer to F-6 as well. • If arm roll-in single operation speed is slow, refer to F-7 as well. • If boom lower single operation speed is slow, refer to F-8 as well. YES

YES Check if the pilot valve delivery pressure is normal by monitoring or measuring. • Pilot valve delivery pressure: Refer to Operational Performance Test section. • Monitor Item: Arm Roll-In Pilot Pressure • When measuring the pilot valve delivery pressure for boom raise or lower, bucket roll-in or roll-out, or arm roll-out, install a pressure gauge to the control valve pilot oil port.

Monitor pump control pressure by slowly operating the control lever. Check if the control pressure changes smoothly.

NO

• Monitor item: Pump 1 Control Pressure Pump 2 Control Pressure

NO

Check if overload relief pressure is normal.

YES

Check if the pilot valve delivery pressure is correct at the inlet port of the shockless valve.

5

4

Control valve spool is sticking.

NO

Faulty pilot valve

YES

Shockless valve spool sticking

• Only when operating arm roll-out or boom raise.

2 1 1 2 3 4 5 6 7 8

6 7

8

SM0634

Faulty overload relief valve

NO

Shockless Valve

3

Faulty cylinder (Seal kits are faulty.)

-

From swing left pilot valve From swing right pilot valve From bucket roll-out pilot valve From bucket roll-in pilot valve From boom raise pilot valve From boom lower pilot valve From arm roll-out pilot valve From arm roll-in pilot valve

EX255-EX285

T5-4-41


Boom Lower Single Operation Speed is Fast.

Related Fault Code: None Checking Instructions • When the speed is too fast, travel/boom lower selector valve may be sticking.

NO

Trace the cause of the trouble by checking other types of trouble.

Check if travel/boom lower selector valve is scored or stuck.

YES

Faulty travel/boom lower selector valve.

T5-4-42

EX255-EX285


Arm Speed is Slow in a Combined Operation. Arm Speed is Slow in leveling Operation.

Related Fault Codes: 03 or 06 Checking Instructions • Refer to the Control System Group titled “Arm Regenerative Control” in the SYSTEM section in the Operational Principle book (Technical Manual). • When arm speed is slow in only a combined operation with boom lowering, travel/boom lower selector valve may be faulty. • Refer to the Control Valve group in the COMPONENT OPERATION section in the Operational Principle book (Technical Manual).

NOTE - When the grading mode is selected, arm regenerative control does not function so that arm speed becomes slow.

NO Check if any fault codes are displayed. • Fault codes: Pump delivery pressure sensor (Pump 2): 03 Pilot pressure sensor (Arm roll-in): 06

Monitor the output signal from solenoid valve unit (SC). Install a pressure gauge to port SC and compare the monitored pressures by Dr. EX with the gauge readings. Check if both pressures vary identically.

• Monitor Item: Arm Regenerative Proportional Solenoid • Perform a combined operation of boom raise and arm roll-in. • Measurement: Refer to Operational Performance Test section.

NOTE - If other fault codes are displayed, check the suspected parts referring to the displayed fault code. YES

NO

Disconnect harness from solenoid valve unit (SC). Connect test harness (75301514) between solenoid valve unit (SC) and the disconnected harness. Check when a combined operation is performed, the solenoid valve control voltage is present.

YES

NO

Faulty solenoid valve unit (SC)

Broken harness between solenoid valve and MC.

• Perform the combined operation of boom raise and arm roll-in.

YES

Faulty sensor or broken harness between MC and sensors.

EX255-EX285

T5-4-43


Faulty arm regenerative valve

YES

Check if arm regenerative valve on 5-spool control valve is seized or stuck.

Faulty check valve or restriction (in 4-spool control valve).

YES

NO

Check if check valve or restriction in the parallel age in the 4-spool control valve is seized, bound, or clogged.

YES

NO

Check if the restriction in arm 1 parallel age in 5spool control valve is clogged.

NO

Faulty restriction (in 5-spool control valve)


T5-4-44

EX255-EX285

TROUBLESHOOTING B F-6 Bucket Digging Single Operation is Slightly Slow. Bucket Digging Single Operation is Jerky. Related Fault Code: None Checking Instructions • Refer to A-3. • Refer to Control Valve group in the COMPONENT OPERATION section in the Operational Principle book (Technical Manual).

NO Check if bucket flow control valve in control valve is seized or bound. YES

F-7


Cleaning or replacement of bucket flow control valve.

Arm Starting Speed is Slow during Combined Operations. Arm Operation is Jerky. During Arm Roll-in Single Operation, Arm Starting Speed is Slightly Slow which Often Occurs at Low Temperature.

Related Fault Code: None Checking Instructions • Refer to Control Valve group in the COMPONENT

OPERATION section in the Operational Principle book (Technical Manual).

NO


Check if anti-drift valve is seized or bound. YES

Cleaning or replacement of anti-drift valve.

EX255-EX285

T5-4-45


Boom Starting Speed is Slow during Combined Operations. Boom Operation is Jerky. Boom Starting Speed is Slightly Slow during Boom Lower Single Operation.

Related Fault Code: None Checking Instructions • Refer to Control Valve group in the COMPONENT


NO NO

Check if boom anti-drift valve is seized or stuck. YES

Check if boom anti-drift valve is seized or stuck.

YES

Trace the cause of the trouble by checking other symptoms.

Cleaning or replacement of boom regenerative valve.

Cleaning or replacement of boom anti-drift valve.

T5-4-46

EX255-EX285


When Operating the Control Lever to Raise Boom or to Roll-out Arm, Boom or Arm Starts to Move after Slightly Moving in the Reverse Direction.

Related Fault Code: None

YES YES

Faulty anti-drift valve

Check if anti-drift valve for arm or boom is sized or bound. Cylinder internal leakage NO

Check if load check valve in control valve operates correctly. • Disassemble and visually check.

Faulty load check valve NO

EX255-EX285

T5-4-47

TROUBLESHOOTING B NOTE - 1. During the initial stage of operation, oil pressure and flow rate from the pump is low. Therefore, if the load check valve is malfunctioning, the oil in the bottom side of the boom cylinder flows back into the circuit through the load check valve, causing the boom cylinder to temporarily retract. 2. If the clearance between the piston and the cylinder barrel is poor, oil pressure in the bottom side (A) leaks to rod side (B). As oil pressure and flow rate from the pump is low during the initial stage of operation, and if the amount of oil leaking through the gap between the piston and the barrel is large, the cylinder is temporarily retracted. In addition, cylinder force is reduced. In this case, the cylinder drift is also increased.

(B)

When the load check valve is malfunctioning:

(A)

SM0635

T5-4-48

EX255-EX285


Front Attachment Cylinder Drift is Large.

Related Fault Code: None

YES

Normal

Check if each front attachment cylinder drift is within the specified value.

NO NO

NO

Check if the cylinder drift is reduced when pilot shut-off valve is closed.

Check if manual boom lowering valve in boom section in 4-spool control valve is correctly adjusted. YES

Correctly adjust manual boom lowering valve and lock it up. Check if the symptom is deleted when the overload valve is temporarily switched with one in an other cylinder circuit.

Faulty pilot valve YES

• Boom Cylinder Internal Leakage Check

1. With the bucket cylinder fully retracted and the arm cylinder slightly extended from the fully retracted position, lower the bucket tooth tips onto the ground. 2. Disconnect hoses to the boom cylinder rod side. Then, drain oil from hoses and cylinders. (Plug the disconnected hose ports.) 3. Retract the arm cylinder to lift the bucket above the ground. At this time, if oil flows out of the pipes from which the hoses were disconnected and the boom cylinder is retracted, internal leakage in the boom cylinder exists. If no oil flows out of the pipes from which the hoses were disconnected but the boom cylinder is retracted, internal leakage in the control valve exists.

SM0636

EX255-EX285

T5-4-49

TROUBLESHOOTING B

Manual Boom Lowering Valve

1 2

NO NO

Check if internal leakage in cylinder exists.

SM0637

YES

YES

Control valve spool is scored, spring is damaged, or spool end is loose.

Faulty cylinder (replace seal kit.)

Adjustment Procedure: Tighten (1). Then, tighten (2).

Faulty overload relief valve.

Tightening Torque: (1)- 7 N⋅m (0.7 kgf⋅m) (2)- 13 N⋅m (1.3 kgf⋅m)

T5-4-50

EX255-EX285

TROUBLESHOOTING B SWING SYSTEM TROUBLESHOOTING S-1

Swing Speed is Slow or Swing Function Does not Operate.

Related Fault Code: None Checking Instructions • Check whether the pilot system is malfunctioning or

the main hydraulic system is malfunctioning. • If other functions (front attachment or travel) ope-

rate normally, the pilot pump is considered to be normal. If the pilot system is malfunctioning, the cause of the trouble may exist in the pilot system after the pilot valve. • When the left travel speed is also slow, refer to A-2.

YES

YES

YES

Check if the pilot secondary pressure is normal. • Specification: Refer to Operational Performance Test section.

Monitor the pump control pressure. While slowly operating the control lever, check if the pump control pressure changes smoothly. • Monitor item: Pump 2 Control Pressure

NO

• Measurement: Refer to Operational Performance Test section.

Check if swing relief pressure is normal. • Monitor item: Pump 2 Delivery Pressure • Specification: Refer to Operational Performance Test section.

Check if swing motor oil drain amount is normal.

NO

Faulty swing relief valve

Seized control valve spool

Faulty pilot valve NO

EX255-EX285

T5-4-51

TROUBLESHOOTING B

NO YES

Check if swing motor parking brake release valve is stuck or seized. YES

NO

Faulty swing reduction device

Faulty swing motor parking brake release valve

Faulty swing motor

T5-4-52

EX255-EX285

TROUBLESHOOTING B S-2

Swing Speed is Slow during Swing Combined Operation with Boom Lower.

Related Fault Code: None Checking Instructions • Refer to Control Valve group in the COMPONENT OPERATION section in the Operational Principle book (Technical Manual).

YES

Clean or replace travel/boom lower selector valve.

Check if travel/boom lower selector valve is stuck. NO


EX255-EX285

T5-4-53

TROUBLESHOOTING B TRAVEL SYSTEM TROUBLESHOOTING T-1

Both Right and Left Travel Side Tracks Do Not Move or Move Slowly.

Related Fault Code: None Checking Instructions • Pilot valves, travel motors, control valve spools in both right and left travel systems are unlikely to be faulty at the same time. • If both travel systems do not operate, the pilot system, which is applied to both side travel motors, may be faulty. If the pilot pump delivery pressure is lower than specification, the front attachment does not operate as well. Refer to A-1.

T-2

When a Single Travel Operation is Shifted to a Combined Operation with Front Functions, a Shock Load is Felt.

Related Fault Code: None Checking Instructions • Travel flow control valve might be seized. • Refer to Control Valve group in the COMPONENT


T5-4-54

EX255-EX285

TROUBLESHOOTING B T-3

One Side Track does not Move or Move Slowly, or the Machine cannot Travel Straight (Mistracks).

Related Fault Code: None Checking Instructions • If one side system only does not operate, pilot valve, control valve, travel motor, or center t might be faulty. • If a symptom such as bucket or swing function speed is slow, or arm roll-in or boom raise speed is slow during a leveling operation is recognized at the same time, refer to A-2 and A-3.

YES

Check if travel pilot secondary pressure is normal.

YES

NO

• Relieve travel system. • Monitor Item: Pump 1 Delivery Pressure Pump 2 Delivery Pressure • Specification: Refer to Operational Performance Test section.

Check if the symptom is reversed when right and left travel line hoses connected to top of center t are switched with each other.

• Measurement: Refer Operational Performance Test section

Check if travel relief pressure in slow speed side system is normal. NO

Check if travel motor oil drain amount is normal. Switch rear and front or right and left travel relief valves with each other. Check if symptom is reversed.

Seized control valve spool

YES

Faulty pilot valve NO

• Relation between Faulty Seal Position and

Mistrack Direction

Seal No.

Traveling

Pivot Turn

1

External oil leakage

←

Seal Position

2

1 3

2

4 Left Travel (Reverse)

5

Left Travel (Forward)

4 5 6 7

6

7

3

External oil leakage

←

Right Travel (Reverse) Right Travel (Forward)

SM0638

EX255-EX285

T5-4-55

TROUBLESHOOTING B

NO

Faulty travel motor YES YES

YES

Faulty travel reduction device

Disassemble and clean travel motor servo piston. Check if same symptom arises.

Disassemble and clean travel motor counterbalance valve. Then, recheck if same symptom arises.

Faulty travel motor servo piston NO Faulty counterbalance

NO NO

Faulty center t

Faulty travel relief valve

YES Piping Location

1

2

Front

6

3

5

4

1 2 3 4 5 6

-

Left Travel (Forward) Right Travel (Forward) Pilot Right Travel (Reverse) Left Travel (Reverse) Drain

SM0639

T5-4-56

EX255-EX285

TROUBLESHOOTING B T-4

During a Combined Operation of Travel and Front Function, the Machine Mis-tracks.

YES

Faulty load check valve

Related Fault Code: None NO

Check if load check valve is normal.

NO


Check if flow combiner valve is normal. Faulty flow combiner valve YES

T-5

Steering Power and Gradeability are Insufficient in the Fast Travel Mode. (Normal in the Slow Travel Mode)

Related Fault Codes: None Monitor travel motor swash angle. After installing a pressure gauge to solenoid valve unit (SI) port, repeat traveling and travel pressure relief operation. Check if the pressure value displayed on Dr.EX equals is to the pressure gauge reading and vary identically.

T-6


YES

• Monitor item: Travel Motor Displacement Angle Change Pressure • Travel mode: Fast • Measurement: Refer to Operational Performance Test section.

Seized solenoid valve unit (SI) NO

Travel Mode Does Not Change to the Fast Speed Range.

Related Fault Codes: 02, 03, 04, and 05 Checking Instructions • Refer to the Control group titled “Travel Motor Swash Angle Control” in the SYSTEM section in the Operational Principle book (Technical Manual). NO

Check if any fault codes are displayed.

Monitor travel mode switch. Check if “Lo” or “Hi”, displayed on Dr.EX, changes alternately each time the travel switch is operated. • Monitor item: Selected Travel Mode Switch

YES

Faulty sensor or broken harness between sensors and MC.

NO

YES

Monitor travel pressure switch. Check if the display “Tr” is indicated or deleted on Dr.Ex screen each time travel lever is operated or released.

Faulty travel mode switch or broken harness between travel mode switch and MC.

• Monitor item: Pressure Switch • Fault code: • Pump delivery pressure sensor (Pump 1): 02 Pump delivery pressure sensor (Pump 2): 03 Pump control pressure sensor (4-Spool Side): 04 Pump control pressure sensor (5-Spool Side): 05

NOTE - If any other fault codes are displayed, check suspected parts referring to the displayed fault codes.

EX255-EX285

T5-4-57


Faulty travel pressure switch, broken harness between travel pressure switch and MC, or clogged filter in travel pilot signal circuit.

NO

YES

Monitor travel motor swash angle. After installing a pressure gauge to solenoid valve unit (SI) port, repeat traveling and stopping. Check if the pressure value displayed on Dr. EX equals to the pressure gauge reading and that both vary identically.

• Monitor item: Travel motor swash angle control pressure • Travel mode: Fast • Measurement: Refer to Operational Performance Test section.

NO

Disconnect harness from solenoid valve unit (SI). Connect test harness (75301514) between solenoid valve unit (SI) and the disconnected harness. Check when travel mode selector is actuated, the solenoid valve control voltage is present. • Travel mode: Fast

YES

YES

NO

Faulty solenoid valve unit (SI).

Broken harness between solenoid valve and MC. Faulty travel motor or travel reduction gear.

T5-4-58

EX255-EX285

TROUBLESHOOTING B TROUBLESHOOTING FOR OTHER FUNCTIONS O-1

Wiper Does Not Operate, or Retract.

Related Fault Code: None Checking Instructions • The wiper is controlled by a wiper box in which the relay circuit are operated by the monitor . • When the wiper does not work, check first that the motor and the relevant linkage are operative, using an auxiliary power source and the test herness. • If the wiper motor works properly when is powered throught the test harness, check the upper latch of front window and wiper cut-off switch for proper operation.

• The windshield wiper motor and washer pump con-

trol relays are moulded inside the wiper controller and cannot be replaced. The wiper controller must be considered as an assembly.

YES

YES

As illustrated to the right, connect test harness (75301706C) between power outlet and wiper motor. Check if wiper operates.

Remove the test harness and reconnect the disconnected harness to the original position. • Key switch: ON

NO

Faulty wiper box.

YES

End

NO

Faulty cab harness

Replace the monitor assembly. Check if wiper operates.

• Key switch: ON NO, or lamp does not light normally.

NOTE - When the wiper motor is normal, lamp S comes ON while the wiper is moving within the operating range. Then, only when the wiper reaches the intermittent stop position, both lamps B and S light for a moment at the same time.

YES

Faulty wiper motor or link

Check correct operation of wiper cut-off switch.

NO

Faulty wiper cutoff switch.

EX255-EX285

T5-4-59

TROUBLESHOOTING B • Electrical Circuit When Test Harness is Connected. Power outlet

Lamp S

Wiper Motor Lamp B

Ground

SM0640

• Wiper’s Operating Range

Intermittent Stop Position Retracted Position

Wiper Range

SM0641

• Test Harness Connection

Lamp B Lamp S Wiper Motor Power outlet

Test Harness SM5618

T5-4-60

EX255-EX285

TROUBLESHOOTING B ENGINE SPEED ADJUSTMENT AND ENGINE LEARNING When the following repair or inspection is made, or when engine speeds deviate from the specifications, perform the engine speed adjustment and engine learning. • When the engine, engine control cable, or EC motor is removed. • When MC is replaced. Engine Speed Adjustment: 1. Turn the key switch to START and run the engine. (Note: Turn the air-conditioner switch OFF.) 2. Turn the engine control dial to the minimum speed position. (EC sensor voltage is set to 2.5 V.) 3. Loosen the bolt tightening the control lever to the EC motor output axis. 4. While checking the engine actual speed with Dr.EX or a tachometer, adjust the control lever to conform the slow idle speed specification. Specification: Refer to Operational Performance Test section. 5. Tighten the bolt to secure the control lever to the EC motor output axis.

Bolt Tightening Control Lever SM0643

: 13 N⋅m (1.3 kgf⋅m, 9.4 lbf⋅ft) NOTE - Take care not to allow oil or grease to stick to the motor output axis. 6. Perform engine learning. Engine Learning : Rear cover

1. Turn the key switch OFF. NOTE - If the engine does not stop with the key switch OFF, pull the fuel shut-off handle under the operator's seat to stop the engine 2. 3. 4. 5. 6. 7.

Remove Dr.EX. Wait for 5 seconds. Turn the engine learning switch ON. Turn the key switch ON. Wait for 5 seconds. Turn the key switch OFF. Wait for 5 seconds. Turn the engine learning switch OFF. Check the engine speed.

Fuse box

Engine Learning switch

Engine Learning side

Neutral position (OFF) SM0108

EX255-EX285

T5-4-61

TROUBLESHOOTING B EXCHANGE INSPECTION METHOD Exchange inspection method is used to check if a part and/or a component is normal by replacing or switching the part/component with one being identical in performance characteristics. Pump 2 (5-Spool Side)

Some of sensors and solenoid valves used on this machine are identical in performance characteristics. Accordingly, the exchange inspection method is effective to find out if a part/component or harness is normal.

PP2

Pump 1 (4-spool Side)

PP1

Example: Abnormal Pump 1 Delivery Pressure Sensor Failure (Fault Code: 02) Check : 1. Switch two delivery sensor connectors from the position shown in Fig.1 to Fig.2. 2. Retry troubleshooting.

Fig. 1 SM0644

Result : If pump 2 delivery pressure is shown as abnormal (Fault Code: 03), the pump 1 delivery pressure sensor is faulty.

Pump 2 (5-Spool Side)

If pump 1 delivery pressure is shown as abnormal (Fault Code: 02), the harness which was connected to the pump 1 delivery pressure sensor is faulty.

PP1

Pump 1 (4-spool Side)

PP2

Fig. 2 SM0645

T5-4-62

EX255-EX285

TROUBLESHOOTING B Exchange Inspection Method Application Fault Code

Trouble

Application

01

EC Sensor Failure

Not Applicable

02 03

Pump 1 Delivery Pressure Sensor Failure Pump 2 Delivery Pressure Sensor Failure

Applicable Applicable

04 05

Pump 1 Control Pressure Sensor Failure Pump 2 Control Pressure Sensor Failure

Applicable Applicable

06

Arm Roll-In Pilot Pressure Sensor Failure

Applicable (Pump Control Pressure Sensor)

07

Engine Control Dial Failure

Not Applicable

EX255-EX285

T5-4-63

TROUBLESHOOTING B BOOM LOWERING METHOD WHEN ENGINE STALLS Excavator not equipped with hose rupture protection valve In case the engine has stalled and is difficult to restart while the boom is raised above the ground, lower the boom in the following method.

WARNING Ensure that nobody stands under or near the front equipment prior to beginning the boom lowering procedure.

1

2

1. Loosen lock nut (1) and loosen screw (2) half turn. The boom will start lowering. The lowering speed can be slightly adjusted by loosening a bit more screw (2).

NOTE: never loosen screw (2) more than 2 turns, since it could come out.

2. After lowering the bucket to the ground, tighten screw (2) then lock nut (1) to the torques here below: Lock nut (1) - Wrench: 13 mm - Tightening torque: 1.3 daNm Screw (2) - Allen wrench: 4 mm - Tightening torque: 0.7 daNm

NOTE: in the event the screw and the lock nut are not adequately tightened, excessive leakages could occur. Make sure that screw and lock nut are tightened to the specified torque.

S0014

T5-4-64

EX255-EX285

TROUBLESHOOTING B Excavator equipped with hose rupture protection valve In case the engine has stalled and it is difficult to restart while the boom is raised above the ground, lower the boom with the following method.

WARNING Ensure that nobody stands under or near the front equipment prior to beginning the boom lowering procedure.

1. Remove protection cap (1) from the relief valve of the hose rupture protection valve located on the boom right cylinder.

1

3 2

2. Make a reference mark on the relief valve and the lock nut, in correspondence with the hole on the setting screw. 3. Loosen lock nut (2). 4. Loosen, very slowly, setting screw (3) to lower the front equipment to the ground. 5. Return the setting screw and the relevant lock nut into their original position, making reference to the mark made as per point 2.

NOTE: it is sufficient to perform the procedure explained above on one hose rupture protection valve only.

OM0416

EX255-EX285

T5-5-1

TROUBLESHOOTING C TROUBLESHOOTING C (TROUBLESHOOTING FOR MONITOR) PROCEDURE Use troubleshooting C when any monitors, such as gauges or indicators malfunction. • How to Read Troubleshooting Flow Charts

YES(OK)

(2) • After checking or measuring item (1), select either Yes (OK) or No (NOT

(1)

OK) and proceed to item (2) or (3), as appropriate. (3) NO(NG)

• Special instructions or reference item are indicated in the spaces under the box. Incorrect • Key switch: ON

measuring or checking methods will render troubleshooting impossible, and may damage components as well.

• Causes are stated in a thick-line box. Scanning through thick-line boxes, possible causes

can be seen without going through the flow chart.

NOTE - For all connector drawings illustrated in this group, harness end connector terminals seen from the open end side are shown.

Wire Harness Side

Open End Side Harness End Connector SM0646

T5-5-2

EX255-EX285

TROUBLESHOOTING C MALFUNCTION OF COOLANT TEMPERATURE GAUGE Providing that: • Be sure to inspect wiring connections prior to troubleshooting.

YES Gauge pointer does not move at all. (It does not rise from zero.)

Remove coolant temperature sensor terminal, ground harness side terminal to vehicle. Does pointer swing to the (H) side? NO

• Key switch : ON

With sensor terminal disconnected, remove 20P connector from monitor, and check continuity between terminal No.47 and sensor terminal.

YES Gauge pointer swings over scale.

When removing coolant temperature sensor, does pointer swing back to zero? • Key switch : ON

NOT OK (Continuity)

NO

With sensor terminal disconnected, remove 20P connector of monitor, and check continuity between harness side terminal and ground. OK (No continuity)

Gauge pointer swings unstably.

Remove coolant temperature sensor terminal, and ground harness side terminal to vehicle. Does the pointer swing to [H] side, and stably? • Key switch : ON

YES

NO

EX255-EX285

T5-5-3

TROUBLESHOOTING C Approximate Temperature on Coolant Temperature Gauge 105 °C (221 °F) 95 °C (203 °F)

Faulty coolant temperature sensor. OK (Continuity)

NOT OK (No continuity)

70 °C (158 °F)

Failure in monitor.

Faulty harness (breakage) between monitor and sensor. SM0647

Coolant Temperature Sensor Faulty coolant temperature sensor. Faulty harness (short circuit) between monitor and sensor.

Failure in monitor.

Coolant Temperature

Resistance

(50 °C) (122 °F)

(153.9 Ω)

80 °C (176 °F)

51.9±10 Ω

100 °C (212 °F)

27.4±4 Ω

(120 °C) (248 °F)

(16.1 Ω)

NOTE - The value indicated in parentheses is only a reference value. Faulty coolant temperature sensor.

Failure in monitor.

Connector (harness end connector terminals seen from the open end side)

Monitor (20P)

29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

T5-5-4

EX255-EX285

TROUBLESHOOTING C MALFUNCTION FUEL GAUGE Providing that: • Be sure to inspect wiring connections prior to troubleshooting.

YES Gauge pointer does not swing. (It does not rise from zero.)

Remove connector of fuel sensor, short-circuit terminals C and A of harness side connector by using a jumper wire. Does pointer swing to (FULL) side? NO

• Key switch : ON

With sensor connector disconnected, remove 20P connector of monitor, and check continuity between terminal No.46 of monitor and terminal C of fuel sensor.

YES Gauge pointer swings over scale.

When fuel sensor connector is removed, does pointer swing back to zero? • Key switch : ON

Gauge pointer swings unstably.

NO

Remove connector of fuel sensor, and short-circuit terminals C and A of harness side connector by using jumper wire. Does pointer swing to [FULL] side, and stably? • Key switch : ON

With sensor connector disconnected, remove the 20P connector of monitor, and check continuity between terminal C of harness side connector and ground.

YES

NO

NOT OK (Continuity)

OK (No continuity)

EX255-EX285

T5-5-5

TROUBLESHOOTING C Fuel Sensor

1 mm=0.03937 in Float

FULL 257 mm 3/4

138.6 mm

Faulty fuel sensor. OK (Continuity)

22° R370

33°

70.5 mm 1/2

Failure in monitor. 228 mm

27° 28° Resistance

1/4 292 mm

NOT OK (No continuity)

Faulty harness (breakage) between monitor and fuel sensor.

Reserve 338 mm EMPTY SM0648

Faulty fuel sensor. Faulty harness (short- circuit) between monitor and fuel sensor.

Float

Resistance (Ω)

FULL

10+0 -4

3/4

26

1/2

38±5

1/4

53

EMPTY

90+10 0

Failure in monitor.


Faulty fuel sensor.

Monitor (20P) Fuel Sensor

Failure in monitor.

29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

C B A C B A

Level signal Reserve signal Ground

T5-5-6

EX255-EX285

TROUBLESHOOTING C MALFUNCTION OF FUEL LEVEL INDICATOR (RESERVE) Providing that: • Be sure to inspect wiring connections prior to troubleshooting. YES

YES Although fuel gauge pointer shows E, the indicator does not come ON.

Check if indicator comes ON when key witch is turned ON

With fuel sensor connector removed, short circuit terminals B and A of harness side connector by using a jumper wire. Does indicator light? • Key switch : ON

• Key switch : ON

NO

Reconnect fuel level sensor connector Remove 12P connector of monitor, and check continuity between terminal No.2 of connector and vehicle ground.

NO

YES

Even if fuel is in tank, the indicator comes ON.

Check if indicator goes OFF when fuel level sensor connector is removed. • Key switch : ON NO

Disconnect fuel level sensor connector and 12P connector of monitor, and check continuity between terminal No.2 of connector and vehicle ground.

NOT OK (Continuity)

OK (No Continuity)

EX255-EX285

T5-5-7

TROUBLESHOOTING C

Faulty fuel level sensor.

YES

NO

Failure in monitor.

Faulty harness (breakage) between monitor and low fuel level switch.

Burned out indicator light.

Faulty fuel level sensor.

Faulty harness (short circuit) between monitor and fuel level sensor.

Failure in monitor.


Monitor (12P)

1 2 7 8

3 4 5 6 9 10 11 12

T5-5-8

EX255-EX285

TROUBLESHOOTING C MALFUNCTION OF INDICATOR LIGHT CHECK SYSTEM YES

Indicator does not come ON when indicator light check switch is turned ON.

Check if all indicators do not come ON.

NO

Check power line. • Fuse • Disconnect 20P monitor connector. Then, check continuity between harness side terminal No.30 and fuse terminal No.6.

Perform troubleshooting for the individual indicator which does not come ON.

Connector (harness end connector terminals seen from the open end side) Monitor (20P)

29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

MALFUNCTION OF LEVEL CHECK SWITCH Process to be taken: • This troubleshooting is applied when only the level check switch malfunctions. If power is not supplied at all when key switch is turned ON, or indicator does not come ON when indicator light check is conducted, perform troubleshooting for these failures first. Required Condition: • Park the machine on level surface.

YES YES Check if indicator does not come ON when level check switch is depressed.

Check if all indicators do not come ON.

Check if oil and coolant levels are correct. NO

NO

Faulty level switch or harness (breakage).

Refill engine oil, hydraulic oil, or coolant.

Perform troubleshooting for individual indicator which does not come ON.

EX255-EX285

T5-5-9

TROUBLESHOOTING C MALFUNCTION OF PREHEAT INDICATOR Providing that: • Be sure to inspect wiring connections prior to troubleshooting. Reference: • The preheat system operates when the coolant temperature is 10 °C (50 °F) or lower. • During preheat operation, the preheat indicator stays ON for 8 seconds.

YES Preheat indicator comes ON even if preheat system is not in operation.

Faulty QOS controller

Check if preheat indicator goes OFF when QOS controller is disconnected.

With QOS controller disconnected, remove 20P connector from monitor. Check for continuity between monitor harness end connector terminal No.43 and vehicle frame.

• Key switch : ON NO

YES

NO

YES Preheat indicator does not come ON during preheat operation.

With QOS controller disconnected, remove 20P connector from monitor. Check for continuity between monitor harness end connector terminal No.43 and vehicle frame.

NO

• Without disconnecting the connector, insert a jumper wire such as a clip into the back of the connector and ground to the vehicle frame.


29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

Q.O.S. Controller

3 2 6 5

1 4

Faulty monitor.

Faulty QOS controller

With QOS controller disconnected, ground harness end connector terminal No.6 to vehicle frame. Check if preheat indicator comes ON. • Key switch : ON

Short-circuited harness between QOS controller and monitor.

YES

NO

Broken harness between QOS controller and monitor.

Faulty monitor.

T5-5-10

EX255-EX285

TROUBLESHOOTING C MALFUNCTION OF ENGINE OIL LEVEL INDICATOR Providing that: • Indicator light is not burned out. • Other indicators work correctly. • The machine is parked on a level surface. • Be sure to inspect wiring connections prior to troubleshooting.

YES Indicator does not come ON even if the level check switch is depressed.

With engine oil level switch disconnected, check continuity between engine oil level switch connector and vehicle frame.

Reconnect engine oil level switch. Disconnect 12 P connector from monitor. Check for continuity between harness end terminal No. 7 and vehicle frame.

YES

NO

NO

YES Lower than 3.5 mm below LOW level Indicator comes ON even if oil level is lower than the specified level when level check switch is depressed.

Check oil level with oil level gauge.

Higher than 3.5 mm below LOW level

Disconnect engine oil level switch. Check if indicator comes ON when level check switch is depressed. NO

With engine oil level switch disconnected, disconnect 12P connector from monitor. Check for continuity between harness end terminal No.7 and vehicle frame.

EX255-EX285

T5-5-11

TROUBLESHOOTING C Engine Oil Level Switch 1 mm=0.03937 in

Oil Level Gauge

Engine Oil Level Switch ON Indicator ON

Indicator OFF

Faulty in monitor. OFF

A : 3,5 mm

SM6130

Broken harness between engine oil level switch and monitor.

Faulty engine oil level switch.


Monitor (12P)

YES

Short-circuited harness between engine oil level switch and monitor.

Faulty monitor. NO

Faulty engine oil level switch. Normal.

1 2 7 8

3 4 5 6 9 10 11 12

T5-5-12

EX255-EX285

TROUBLESHOOTING C MALFUNCTION OF COOLANT LEVEL INDICATOR Providing that: • Indicator light is not burned out. • Other indicators work correctly. • The machine is parked on a level surface. • Be sure to inspect wiring connections prior to troubleshooting.

YES

Indicator does not come ON even if level check switch is depressed.

With coolant level switch disconnected, check continuity between terminals on level switch 2P connector.

Reconnect coolant level switch. Disconnect 12 P connector of monitor. Check continuity between harness side terminal No.8 and vehicle ground.

YES

NO

NO

YES

YES Indicator comes ON even if coolant level is lower than specified level when level check switch is depressed.

Check coolant level at coolant reservoir. Check if coolant level is lower than LOW mark.

Disconnect coolant level switch. Check if indicator comes ON when level check switch is depressed. NO

NO

Leave coolant level switch disconnected. Disconnect 12 P connector of monitor. Check continuity between harness side terminal No.8 and vehicle ground.

EX255-EX285

T5-5-13

TROUBLESHOOTING C

Coolant Level Switch Coolant Reservoir ON FULL LOW

Failure in monitor.

Radiator

OFF

SM0649

Faulty harness. (breakage)

Connector (harness end connector terminals seen from the open end side) Faulty coolant level switch.

Monitor (12P)

1 2 7 8

YES

NO

Faulty harness. (short circuit)

Failure in monitor.

Faulty coolant level switch.

Normal

3 4 5 6 9 10 11 12

Coolant Level Switch

1

2

T5-5-14

EX255-EX285

TROUBLESHOOTING C MALFUNCTION OF HYDRAULIC OIL LEVEL INDICATOR Providing that: • Indicator light is not burned out. • Other indicators work correctly. • The machine is parked on a level surface. • Be sure to inspect wiring connections prior to troubleshooting.

YES

Indicator does not come ON even if level check switch is depressed.

With hydraulic oil level switch disconnected, check continuity between level switch 2P connector.

Disconnect 12P connector of monitor. Check continuity between harness side terminal No.9 and vehicle ground.

YES

NO

NO

YES

YES Indicator comes ON even if oil level is lower than the specified level when level check switch is depressed.

Check oil level with level gauge. Check if oil can be seen at level gauge.

Disconnect oil level switch. Check if indicator comes ON when level check switch is depressed. NO

NO

Leave hydraulic oil level switch disconnected. Disconnect 12P connector of monitor. Check continuity between harness side terminal No.9 and vehicle ground.

EX255-EX285

T5-5-15

TROUBLESHOOTING C

Hydraulic Oil Level Switch 1 mm=0.03937 in ON 6.2 mm

Failure in monitor.

OFF


Faulty hydraulic oil level switch.

SM0650


Monitor (12P)

YES

NO

Faulty harness. (short circuit)

Failure in monitor.

Faulty hydraulic oil level switch.

Normal

1 2 7 8

3 4 5 6 9 10 11 12

Hydraulic Oil Level Switch

1

2

T5-5-16

EX255-EX285

TROUBLESHOOTING C MALFUNCTION OF ALTERNATOR INDICATOR Providing that: • Be sure to inspect wiring connections prior to troubleshooting.

NOTE - (*) Regulator terminals L is water-resistance type connectors so that it is not practical to measure voltage at these terminals. Measure voltage at starter relay terminal R. Before measuring voltage, check continuity between the starter relay terminal R and regulator terminal L. 13 V or higher

13 V or higher

Alternator indicator does not go off after engine is started.

Measure voltage at monitor 20 P connector terminal No.42. • Engine: Running

Measure voltage at regulator terminal L.

Less than 13 V

• Engine: Running

Less than 13 V

Less than 10 V.

YES

Although alternator output is low, alternator indicator does not come on.

Check voltage at regulator terminal L (*). • Key switch: ON • Engine: Stopped

Check if indicator comes on when key switch is turned to ON position.

10 V or more

• Key switch: ON NO

EX255-EX285

T5-5-17

TROUBLESHOOTING C

Faulty monitor.


Starter Relay

Harness breakage between regulator terminal L and monitor terminal No.42.

E S

R

Monitor (20P)

Faulty regulator or faulty alternator. 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

Faulty monitor.

Faulty regulator.

Blown indicator bulb.

T5-5-18

EX255-EX285

TROUBLESHOOTING C MALFUNCTION OF ENGINE OIL PRESSURE INDICATOR Providing that: • Be sure to inspect wiring connections prior to troubleshooting.

YES

YES

Although engine oil pressure is lower than specification, indicator does not come ON • Key switch: ON • Engine: Stopped

Check if indicator comes ON when key switch is turned to ON position.

• Key switch: ON

• Key switch: ON

NO

YES

Indicator stays ON after engine is started. • Check if oil filter is clogged or not.

Check if indicator goes OFF when engine oil pressure switch is disconnected. • Key switch: ON • Engine: Stopped

With engine oil pressure switch disconnected, check if indicator comes ON when terminal of wire number 33 is grounded to vehicle.

NO

NO

EX255-EX285

T5-5-19

TROUBLESHOOTING C

Engine Oil Pressure Switch Pressure

Faulty engine oil pressure switch.

Reconnect engine oil pressure switch. Check if indicator comes ON when monitor terminal No.10 is grounded to vehicle. • Key switch: ON • Without disconnecting, ground connector to vehicle using a clip from the back of connector.

YES

Broken harness between monitor and engine oil pressure switch.

Approx. 98 kPa (1.0 kgf/cm2, 14.2 psi) or Less

ON

More than Approx. 98 kPa (1.0 kgf/cm2, 14.2 psi)

OFF


Monitor (12P)

NO

Faulty monitor.


Faulty engine oil pressure switch, faulty engine oil lubrication system, or clogged oil filter.

With engine oil pressure switch connected, remove 12P connector from monitor. Check for continuity between harness end connector terminal No.10 and vehicle frame.

Indicator

YES

NO

Short-circuited harness between monitor and engine oil pressure switch.

Faulty monitor.

1 2 7 8

3 4 5 6 9 10 11 12

T5-5-20

EX255-EX285

TROUBLESHOOTING C MALFUNCTION OF OVERHEAT INDICATOR Providing that: • Be sure to inspect wiring connections prior to troubleshooting.

YES

YES Indicator does not come ON even if engine overheats.

Check if indicator comes ON when key switch is turned to HEAT position.

With overheat switch connector disconnected, check if indicator comes ON when terminal of wire number 201 is grounded to vehicle.

NO

• Key switch: ON

• Key switch: ON

NO

YES

Indicator comes ON even if coolant temperature is low.

Check if indicator goes OFF when overheat switch connector is disconnected. • Key switch: ON • Engine: stopped

NO

Disconnect overheat switch connector and 12P connector of monitor. Check if continuity between 12P connector terminal No.1 and vehicle.

YES

NO

EX255-EX285

T5-5-21

TROUBLESHOOTING C

Overheat Switch Coolant Temperature Faulty overheat switch.

Lower than 105 °C (221 °F)

OFF

105 °C (221 °F) or more Reconnect overheat switch connector. Check if indicator comes ON when monitor 12P connector terminal No.1 is grounded to vehicle. • Key switch: ON • Without disconnecting, ground connector to vehicle using a clip from the reverse side of the connector.

YES


ON


NO

Failure in monitor.


Faulty overheat switch.

Faulty harness (short circuit) between monitor and overheat switch.

Failure in monitor.

Indicator

1 2 7 8

3 4 5 6 9 10 11 12

T5-5-22

EX255-EX285

TROUBLESHOOTING C MALFUNCTION OF AIR FILTER RESTRICTION INDICATOR Providing that: • Be sure to inspect wiring connections prior to troubleshooting.

YES

YES When air filter is clogged, indicator does not light.

When key switch is returned to HEAT position, does indicator light?

When restriction switch is disconnected, and harness side terminal of wire number 203 is grounded to vehicle, does indicator light?

NO

• Key switch: ON

• Key switch: ON

NO

YES

Although air filter is not clogged, indicator lights. • Disassembled and visual check • Confirm that air filter is not moist.

When air filter restriction switch is disconnected, does the indicator go out? • Key switch: ON NO

Disconnect air filter restriction switch connector and 12P connector of monitor, and check continuity between terminal No.3 of connector and vehicle ground.

YES

NO

Reconnect restriction switch. Disconnect 12P connector of monitor, and check continuity between terminal No.3 of connector and vehicle ground.

EX255-EX285

T5-5-23

TROUBLESHOOTING C

Air Restriction Switch Pressure

Faulty air restriction switch.

YES

Failure in monitor.

Indicator

62 ± 6 mbar (6.2 ± 0.6 kPa) (635 ± 58 mmH2O) or Less

OFF

More than 62 ± 6 mbar (6.2 ± 0.6 kPa) (635 ± 58 mmH2O)

ON


NO

Faulty harness (breakage) between monitor and air restriction switch. Burned out indicator light.

Faulty air restriction switch.

Faulty harness (short circuit) between monitor and air restriction switch.

Failure in monitor.

1 2 7 8

3 4 5 6 9 10 11 12

T5-5-24

EX255-EX285

TROUBLESHOOTING C MALFUNCTION OF BUZZER NOTE - (*) Regulator terminals L is water-resistance type connectors so that it is not practical to measure voltage at these terminals. Measure voltage at starter relay terminal R. Before measuring voltage, check continuity between the starter relay terminal R and regulator terminal L.

13 V or more Faulty regulator. Buzzer keeps sounding when key switch is turned ON.

Check voltage at monitor terminal No.42. • Key switch: ON (Engine is stopped.)

Less than 13 V

Failure in engine oil pressure system.

YES Buzzer keeps sounding when engine is started.

Check if engine oil pressure indicator is ON.

YES

NO

YES Check if engine is running at 1000 min-1 (rpm) or faster.

Check if buzzer stops when buzzer stop switch is depressed.

Normal

NO

NO

Overheat of engine.

Check if overheat indicator is ON.

NO

Buzzer does not sound even if engine oil pressure indicator or overheat indicator comes ON.

Failure in monitor.

Normal

Check if alternator indicator is ON.

YES

Check voltage at alternator terminal L. • Engine speed: 1000 min-1 (rpm) or faster.

EX255-EX285

T5-5-25

TROUBLESHOOTING C Connector (harness end connector terminals seen from the open end side) Monitor (20P)

Starter Relay

E

29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

S

YES

Normal

Failure in monitor.

NO

Less than 13 V

13 V or more

R

Faulty regulator or alternator.

Check voltage at monitor 20P connector terminal No.42. • Engine speed: 1000 min-1 (rpm) or faster.

Less than 13 V

Faulty harness (breakage) between alternator terminal L and monitor terminal No.42.

Failure in monitor. 13 V or more

T5-5-26

EX255-EX285

TROUBLESHOOTING C MALFUNCTION OF HOUR METER Providing that: • Be sure to inspect wiring connections prior to troubleshooting.

NOTE - (*) Regulator terminals L is water-resistance type connectors so that it is not practical to measure voltage at these terminals. Measure voltage at starter relay terminal R. Before measuring voltage, check continuity between the starter relay terminal R and regulator terminal L.

Broken harness between monitor terminal No.29 and No.6 fuse.

0V NO

Check voltage at monitor 20P connector terminal No.29. 24 V

Hour meter does not count operating hours when engine is running.

Failure in monitor.

Check if alternator indicator is ON. Less than 13 V

Faulty regulator or alternator.

• Engine : Running

YES

Check voltage at alternator terminal L (*). • Engine speed: 1 000 min-1 (rpm) or faster

13 to 14.5 V or more Check voltage at monitor 20P connector terminal No.42. 13 V or more


29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

Starter Relay

E S

R

Less than 13 V

Failure in monitor. Broken harness between alternator terminal L and monitor terminal No.42.

EX255-EX285

T5-6-1

ELECTRICAL SYSTEM INSPECTION PRECAUTIONS FOR INSPECTION AND MAINTENANCE

A 0511

0511

0511

20 ÷ 30 mm

B

C 2,5 R 0679

0511

0511

1. Disconnect the power source. Be sure to remove the negative terminals from the batteries first when taking wire harnesses and connectors off for repair or replacement work. Failure to do so can result in damage to the wire harnesses, fuses, and fusible links and, in some cases, cause fire due to short circuiting. 2. Wire harnesses identification. The wire harnesses used on electrical system of the machine are of three colours: red, white and brown. – The wire harnesses red coloured are used for the main power supply distribution and for direct connection to the positive not controlled by key switch. – The wire harnesses white coloured are used for the all other functions. – The wire harnesses brown coloured are used for ground connection. Each wire is identified by a four digit numerical coding printed on the whole lenght every 20 to 30 mm (A). This coding is also shown on the wiring diagrams of electrical system (B). On the general electrical system diagram attached, numbers and letters are shown before the four digit coding. Numbers mean the wire section shown in mm2. The following letters indicate the wire colours; where W stands for white, R for Red and Br for Brown. See detail (C). 3. Precautions for connecting and disconnecting terminal connectors. 1) When disconnecting harnesses, grasp them by their connectors. Do not pull on the wire itself. Be sure to release the lock first before attempting to separate connectors, if a lock is provided. (Refer to “Instructions for Disconnecting Connector” on page T5-6-3.) 2) Water-resistant connectors keep water out so that if water enters them, water will not easily drain from them. When checking water-resistant connectors, take extra care not to allow water to enter the connectors. In case water should enter the connectors, reconnect only after the connectors are thoroughly dried. 3) Before connecting terminal connectors, check that no terminals are bent or coming off. In addition, as most connectors are made of brass, check that no terminals are rusting. 4) When connecting terminal connectors provided with a lock, be sure to insert them together until the lock “clicks.”

Right

Wrong

SM0651

Right Rust Wrong (deformation) Wrong (Separation) SM0652

T5-6-2

EX255-EX285

ELECTRICAL SYSTEM INSPECTION 4. Precaution for using a circuit tester. 1) Before using a circuit tester, refer to the instructions in the circuit tester manual. Then, set the circuit tester to meet the object to be measured, voltage range and current polarity. 2) Before starting the connector test, always check the connector terminal numbers, referring to the circuit diagram. When the connector size is very small, and the standard probe size is too large to be used for testing, wind a fine piece of sharpened wire or a pin around the probe to make the test easier.

Wind a Piece of Wire

Tester Probe

Sharpen the end of the Wire SM0653

EX255-EX285

T5-6-3

ELECTRICAL SYSTEM INSPECTION INSTRUCTIONS FOR DISCONNECTING CONNECTORS • Push the lock to disconnect. NOTE - 1) Connectors may not be separated if the lock is pushed while the connectors are pulled. Be sure to push the lock first before pulling the connectors. 2) The lock is provide on the female connector (harness side).

SM0654

Locations of This Type Connector Fuel Gauge Hydraulic Oil Level Switch Horn Cab Harness Pressure Switch

Washer Pilot Pressure Switch EC Motor EC Sensor Pump Delivery Pressure Sensor

N Sensor Engine Oil Level Sensor Coolant Level Switch Key Switch Engine Control Dial

Radio Speaker Learning Switch Wiper Monitor

• Pull up the lock to disconnect. Locations of This Type Connector Pressure Switch (Front) Pilot Pressure Sensor Pump Control Pressure Sensor Relè avviamento

• Pull to disconnect. Locations of This Type Connector Solenoid Valve Unit Dr.EX

SM0656

T5-6-4

EX255-EX285

ELECTRICAL SYSTEM INSPECTION FUSE CONTINUITY TEST Fuse failure is often caused by a fine crack in the fuse, and such fine cracks are very hard to detect by visual inspection. Checking fuse continuity with a tester is far superior to sight inspection.

NOTE - All the inside terminals of the fuses in the fuse box are connected to the power source, while the outside terminals are connected to the accessories. Test all fuses using the same method.

(1) Turn the key switch ON In doing so, the battery relay is activated by the current from terminal M of the key switch, and electric power is supplied to all circuit, except the glow relay circuit. (2) Remove the fuse box cover and set the correct voltage measurement range of the tester. (Measurement range: 0 to 30 V) (3) Connect the negative probe to the vehicle ground, and touch the outside terminal of each fuse with the positive probe of the tester. When normal continuity of a fuse is intact, the tester will indicate 20 to 25 volts.

Accessory (Outside)

SM0657

Glow relay

Power Source (Inside) Accessory (Outside)

EX255-EX285

T5-6-5

ELECTRICAL SYSTEM INSPECTION INSPECTION AND REPLACEMENT OF MAXI FUSIBLE LINKS Inspection 1. Remove the negative cable from the battery. 2. Loose the wing nut fixing the protection and open it by rotating forward to gain the access. 3. Withdraw the front cover of the maxi fusible link box and visually inspect the maxi fusible link inside.

Replacement 1. Make sure that the negative cable is removed from the battery. 2. Loose the wing nut fixing the protection and open it by rotating forward to gain the access.

OM5633

3. Withdraw the front cover of the maxi fusible link box. 4. Take out the maxi fusible link and replace it.

Front cover

5. Reinstall the front cover to maxi fusible link box. 6. Reconnect the negative cable to the battery. Maxi fusible

Body

Bottom cover

SM3032

T5-6-6

EX255-EX285

ELECTRICAL SYSTEM INSPECTION BATTERY VOLTAGE CHECK 1. Turn the key switch OFF. Check voltage between the battery positive terminal and the vehicle frame. Normal Voltage: 24 V NOTE - If voltage is abnormal, recharge or replace the battery. 2. Start the engine. Check voltage between the battery positive terminal and the vehicle frame. V

Normal Voltage: 26 to 28 V NOTE - If voltage is abnormal, check the charging system.

SM3034

EX255-EX285

T5-6-7

ELECTRICAL SYSTEM INSPECTION HOW TO TROUBLESHOOT ALTERNATOR MALFUNCTIONS

Terminal R

Terminal L

In general, the alternator indicator remains off when the alternator is generating power. If the alternator indicator comes on while the engine is running, the alternator might be defective. Terminal B

How to check the circuit 1. Stop the engine. Turn the key switch to the ON position. Confirm that the alternator indicator comes on. 2. Measure the voltage between the B and E terminals of the alternator. If the measured voltage is around 24 V, the alternator circuit can be consi-dered normal. If the measured voltage is low, a shortage in battery capacity or looseness of the wire connectors of the alternator circuit might be the cause of the malfunction. When the voltage is 0 V, the wiring between the fuse box and alternator might be loose or disconnected. Also, the alternator cannot generate electricity if the ground line is disconnect. 3. Next, start the engine and measure the voltage generated while as the alternator rotates. As described above, measure the voltage between terminals B and E on the side of the alternator. If the voltage is around 28 V, the alternator is operating normally. If the rated voltage is not being generated, there is some trouble with the alternator or the regulator.

Terminal E

SM6122

T5-6-8

EX255-EX285

ELECTRICAL SYSTEM INSPECTION CONTINUITY CHECK Harness

Single-line continuity check Disconnect both end connectors of the harness and check continuity between both ends: If the ohm-meter reading is: 0 Ω = Continuity ∞ Ω = Discontinuity NOTE - When the one end connector is far apart from the other, connect one end of connector (A) to the machine chassis using a clip. Then, check continuity of the harness through the vehicle frame as illustrated. If the ohm-meter reading is:

0 Ω = Continuity ∞ Ω = Discontinuity

Ω

Connect to the machine chassis.

a

A

Ω

Connect to the machine chassis.

Single-line short-circuit check Disconnect both end connectors of the harness and check continuity between one end connector of the harness and the vehicle frame: If the ohm-meter reading is: 0 Ω = Short circuit is present. ∞ Ω = No short circuit is present. Multi-line continuity check Disconnect both end connectors of the harness, and short-circuit two terminals, (A) and (B), at one end connector, as illustrated. Then, check continuity between terminals (a) and (b) at the other connector. If the ohm-meter reading is ∞ Ω, either line (A) - (a), or (B) - (b) is in discontinuity. To find out which line is discontinued, conduct the single line continuity check on both lines individually, or, after changing the shortcircuit terminals from (A) - (B) to (A) - (C), check continuity once more between terminals (a) and (c).

a

A

a

A

Ω

Short-circuit between the harness and the vehicle frame

SM0660

First short-circuit

a b c

A B C Second short-circuit

Ω NOTE - By conducting the multi-line continuity check twice, it is possible to find out which line is discontinued. With terminals (A) and (C) short-circuited, check continuity between terminals (a) and (c). If the ohm-meter reading is: 0 Ω = Line (B) - (b) has discontinuity. ∞ Ω = Line (A) - (a) has discontinuity. Multi-line short-circuit check Disconnect both end connectors of the harness, and check continuity between terminals (A) and (B) or (C). If the ohm-meter reading is: 0 Ω = Short-circuit exists between the lines. ∞ Ω = No short-circuit exists between the lines.

SM0661

Short-circuit between harnesses.

a b c

A B C

Ω

SM0662

EX255-EX285

T5-6-9

ELECTRICAL SYSTEM INSPECTION

T5-6-10

EX255-EX285

ELECTRICAL SYSTEM INSPECTION VOLTAGE AND CURRENT CHECK Turn switch ON so that the specified voltage (current) is applied to the point to be measured. Then start measuring either voltage or current. Judge if the specified voltage is applied.

Engine

Key Switch

24 Voltage Circuit Start checking in order up to the point where voltage is measured from either power source or actuator side. Thereby, the faulty location in the circuit will be found. Black Probe (Minus) of Tester : To ground (vehicle frame). Red Probe (Plus) of Tester : To location to be measured.

Check Point

Standard

Power Source Circuit Stopped Stopped Stopped Stopped Stopped Stopped

OFF OFF OFF OFF OFF OFF

Between (2) and (1): One Battery Between (3) and (2): One Battery Between (3) and (1): Two Batteries Between (4) and Ground: Power Source Between (5) and Ground: Fusible Link Between (1) and Ground: Backup Current (*)

10 to 12.5 V 10 to 12.5 V 20 to 25 V 20 to 25 V 20 to 25 V 6 mA

Preheat Circuit Stopped Stopped Stopped

ON ON ON

Between (6) and Ground: Key Switch Between (7) and Ground: Glow plugs Between (20) and Ground: QOS Controller power supply

20 to 25 V 20 to 25 V 20 to 25 V

Starting Circuit Started Started Started Started Started Started

START START START START START START

Between (8) and Ground: Key Switch Between (9) and Ground: Battery Relay (Coil) Between (10) and Ground: Battery Relay (Switch) Between (11) and Ground: Starter (B) Between (12) and Ground: Starter (C) Between (13) and Ground: Starter Relay (S)

20 to 25 V 20 to 25 V 20 to 25 V 20 to 25 V 20 to 25 V 20 to 25 V

Charging Circuit Fast Speed Fast Speed Fast Speed Fast Speed Fast Speed

ON ON ON ON ON

Between (14) and Ground: Alternator Generating Voltage (B) Between (10) and Ground: Alternator Generating Voltage Between (15) and Ground: Alternator Generating Voltage Between (16) and Ground: Alternator Generating Voltage (L) Between (17) and Ground: Monitor

26 to 30 V 26 to 30 V 26 to 30 V 13 to 30 V 13 to 30 V

Surge Voltage Prevention Circuit Slow Idling Slow Idling Slow Idling Slow Idling

ON ON ON ON

Between (14) and Ground: Alternator (B) Between (16) and Ground: Alternator (L) Between (18) and Ground: Anti Load Dump Relay Between (10) and Ground: Battery Relay

26 to 30 V 13 to 30 V 26 to 30 V 26 to 30 V

Accessory Circuit Stopped Stopped Stopped Stopped

ON ON ON ON

Between (19) and Ground: Air Conditioning Between (21) and Ground: Horn Between (22) and Ground: Lighter Between (23) and Ground: Radio

20 to 25 V 20 to 25 V 20 to 25 V 20 to 25 V

(*) After disconnection the minus cable to the battery, start measuring.

EX255-EX285

T5-6-11

ELECTRICAL SYSTEM INSPECTION

QOS Controller

Battery Battery Relay Starter

Key Switch

Fuse box

Starter Relay

Glow Relay Fuse box

Alternator

Monitor

Glow Plugs

SM5619

Relay box

SM3036

T5-6-12

EX255-EX285

ELECTRICAL SYSTEM INSPECTION 5 Voltage Circuit • Voltage between terminal No.1 and the vehicle frame (ground) With the key switch turned OFF, disconnect the sensor connector. Measure the voltage between terminal No.1 on the machine harness side connector and the vehicle (ground) under the following conditions. • • • • •

Two polarities

Signal or ground

Power source 1

2

V

Key switch position: ON Tester black terminal (negative): Connected to the vehicle (ground) Tester red terminal (positive): Connected to terminal No.1

SM0664

Ground

Power source 1

Three polarities

Evaluation: If the measuring voltage is within 5±0.5 volts, the circuit up to terminal No.1 is normal.

2

3

V

• Voltage between terminal No.1 and the ground terminal With the key switch turned OFF, disconnect the sensor connector. Measure the voltage between terminal No.1 on the machine harness side connector and the ground terminal (terminal No.2 for two polarities, or terminal No.3 for three polarities) under the following conditions.

SM0665

Two polarities 1

2

V

• Key switch position: ON • Tester black terminal (negative):

Connected to the ground terminal (terminal No.2 or 3) • Tester red terminal (positive): Connected to terminal No.1

SM0666

Three polarities 1

2

3

Evaluation: If the measuring voltage is within 5±0.5 volts, the circuit up to terminal No.1 or the ground terminal is normal. V

SM0667

EX255-EX285

T5-6-13

ELECTRICAL SYSTEM INSPECTION • Check Using False Signal IMPORTANT - On three-polarity connectors, do not short-circuit terminals No.1 and No.2 to No.3 or the vehicle frame (ground), causing harnesses, controllers and fuses to burn due to current overload.

Two polarities

With the key switch turned OFF, disconnect the sensor connector. Short-circuit terminal No.1 (power source) and No.2 (signal) on the machine harness side connector and supply the power source voltage as a false signal to the controller. Check the controller under this condition, using the Dr.EX monitor function. Evaluation: Except for the pressure switch circuits, if the maximum value is displayed, the MC (Main Controller) and the circuits up to the machine harness side connector are normal. When the pressure switch circuits are normal, the Dr.EX monitor displays “ON”.

1

(Pressure switch) (N sensor)

2

Short circuit

SM0668

Three polarities (EC sensor) (Pilot pressure sensor) (Pump control pressure sensor) (Pump delivery pressure sensor)

1

2

3

Short circuit

SM0669

T5-6-14

EX255-EX285

ELECTRICAL SYSTEM INSPECTION WIPER CONTROLLER 2

1

SMW0465

3 5 To wiper motor

4

6

To washer pump

7

SMW0466

1 2 3 4

-

Connector Box Diode 1n5408 (q.ty 3) Relay

5 6 7

- Board - Diode 1N4007 - Wiper controller connector, harness side

EX255-EX285

T5-6-15

ELECTRICAL SYSTEM INSPECTION Replacement of wiper controller 1. Remove screw (1) under the right console to detach cover (2).

2. Remove bolt (3) and turn the console around pin (4). Then, take out lock pin (5). Push pin (4) to the seat side, then remove spacer (6). : 17 mm 3. Move the console to the seat side. 4. Using a sharp-pointed tool, remove cap (9) from cover (7) and duct cover (8) located under the monitor.

13 SM5620

5. Remove cover (7) and duct cover (8).

6. Remove ashtray (10) and the ashtray screw. Remove aux. switch (11).

7. Remove wiper controller cover (12). a

8. Replace the wiper controller (13).

2

5 4

3

1 SM0670

6

View a

7

11

10

SM0671

9

1 2 3 4 5

-

Screw Cover Bolt Pin Lock Pin

6 7 8 9 10

-

Spacer Cover Duct Cover Cap Ashtray

8

12

11 - Aux. Switch 12 - Wiper controller cover 13 - Wiper controller

T5-6-16

EX255-EX285

ELECTRICAL SYSTEM INSPECTION REPLACEMENT OF RELAY (R1, R2, R3, R4, R5, R6) 1. Remove the rear cover (1) by loosen the 3 bolts (3) and the four bolts (2). : 13 mm

2. Remove the bolt (4 and 5) fixing the (6) : 13 mm

R1-R2-R3-R4-R5-R6 SM5621

3. Lift the (6).

2

1

3 SM1126

4. Lift the protection sheet (7). 6

5

4

7

SM3039

EX255-EX285

T5-6-17

ELECTRICAL SYSTEM INSPECTION 5. Identify the relay on the terminal board.

SM5622

6. Replace the relay.

T5-6-18

EX255-EX285

ELECTRICAL SYSTEM INSPECTION RELAY BOX

1

2

SM5623

1

- Relay box

2

- Relay box connector harness side

SM5624

- Diodes d1, d2, d3, d4 : Diode IN4007 D1, D2, D3, D4, D5, D6 : Diode IN5408 - Relay R1: R2: R3: R4:

Anti Load Dump Horn Light 2 Light 1

EX255-EX285

T5-6-19

ELECTRICAL SYSTEM INSPECTION Replacement of relay box 1. Remove the rear cover (1) by loosening the three bolts (3) and the four bolts (2).

1

2

2. Identify the relay box (4).

3

3. Remove the hexagonal screw M6 and the two washer (5).

SM1126

A 4. Disconnect the connector (6).

5. Remove the relay box (4). SM3039

View from A 5 6. Install the new relay box (4). 4

7. Fix the relay box with hexagonal screw M6 and the two washer (5).

8. Install the connector (6) on the relay box. 6 SM5625

9. Reinstall the rear cover by tightening the four bolts (2) and the three bolts (3).

T5-6-20

EX255-EX285

ELECTRICAL SYSTEM INSPECTION REPLACEMENT OF QOS CONTROLLER 1. Remove the rear cover (1) by loosening the 3 bolts (3) and the four bolts (2).

2. Remove the bolts (4 and 5) fixing the (6).

2

1

3. Lift the (6).

4. Lift the protection sheet (7). 3

5. Remove the main controller (MC) (8) by loosening the four bolts (9). Do not disconnect the MC connectors.

SM1126

6

6. Remove the QOS controller (10) by loosening the two bolts (11). Disconnect the connector.

4

5 7. Install the new QOS controller (10) and secure by tightening the two bolts (11). Properly route the QOS controller cable tail and fix by tie-wrap. Connect the connector.

7

SM3039

8. Reinstall main computer (MC) (8) by tightening the four bolts (9), the protection sheet (7) and the (6).

9. Reinstall the rear cover by tightening the four bolts (2) and the three bolts (3).

SM6127

8

9

10

11 SM6128A

EX255-EX285

T5-6-21

ELECTRICAL SYSTEM INSPECTION REPLACEMENT OF POWER OUTLET 1. Gain the access to the rear of and disconnect the connector from power outlet.

2. Open the guard.

Power outlet

OM0376

3. Using the special plier (Fiat Auto code No. 1876044000) unlock the sleeve from the lock ring. Power outlet

4. Withdraw the sleeve from the rear of the .

Guard

SM3041

5. Install the new power outlet inserting the sleeve from the rear of the and pushing the lock ring on the front of the .

SM3042

6. Reconnect the connector to the power outlet.

Special plier Fiat Auto Code No. 1876044000

T5-6-22

EX255-EX285

ELECTRICAL SYSTEM INSPECTION NOTES

EX255-EX285

T5-7-1

HARNESS CHECK CIRCUIT INSPECTION To inspect the circuits of the machine, a test harnesses kit 75301706 has been developed, including dedicated harnesses for the inspection of the various components of the machine, and the test harness 75301514. The kit 75301706 includes harnesses for the check of solenoid valves, harnesses for sensor check and harness for wiper check.

The test harness 75301514 is used to check the solenoid valves installed on solenoid valve unit. To check the circuits, connect the appropriate harness between the male and female connectors of the component to be checked. Then check the normal or abnormal operation of the circuit, measuring with a tester, the power voltage on the free connections.

Solenoid valve test harness Two terminals test harness 75301706A. Use this harness to check the circuit of solenoid valve.

SM6732

Test harness 75301706A

Two-terminal test harness 75301514. Use this harness to check the circuit of solenoid valves SG, SI, SD, SC (installed on solenoid valve unit). (Refer to pages T5-4-28, -39, -42 and -57).

SMW0491

Test harness 75301514

T5-7-2

EX255-EX285

HARNESS CHECK EC motor test harness Test harness 75301706B Use this harness to check the circuit of the EC motor. (Refer to page T 5-4-24).

SM6733

Test harness 75301706B

Sensor test harness Test harness 75301706D Use this harness to measure the signal voltage of the EC angle sensor circuit. (Refer to page T5-3-4)

(Red)

(Blue) (Black) V

SM6734

Test harness 75301706D

Wiper circuit test harness Test harness 75301706C Use this harness to check the wiper circuit. (Refer to page T5-4-58)

SM6735




-

EXCAVATOR WORKSHOP MANUAL (Tier 2)



-

ENGINEERING

-

EX255-EX285

IN-1







• The Service Manual for EX255 andEX285 Excavators consists of the following book/print numbers:

- The Technical Manual -Troubleshooting includes the technical information needed for operational performance tests, and troubleshooting procedures.

BOOK

PRINT NUMBER


604.13.191


604.13.196

- Workshop Manual

604.13.201

IN-2

EX255-EX285




UNITS USED SI Units (International System of Units) are used in this manual. MKSA system units and English units are also indicated in parentheses just behinds SI units. Example: 24.5 MPa (250 kgf/cm2, 3560 psi) A table for conversion from SI units to other system units is shown below for reference purposes.

Quantity


Into (Others)

Multiply by

Quantity


Into (Others)

Multiply by

Lenght

mm

in

0.03937

Pressure

MPa

kgf/cm2

10.197

mm

ft

0.003281

MPa

psi

145.0

L

US gal

0.2642

kW

CV-PS

1.360

US qt

1.057

kW

HP

1.341

Volume

L 3

yd

kg

lb

m Weight Force Torque

3

Power

1.308

Temperature

°C

°F

°C x 1.8 + 32

2.205

Velocity

km/h

mph

0.6214

N

kgf

0.10197

N

lbf

0.2248

N.m

kgf.m

0.10197

N.m

lbf.ft

0.7375

min Flow rate

-1

rpm

1.0

L/min

US gpm

0.2642

mL/rev

cc/rev

1.0

EX255-EX285

S-1

SAFETY PRECAUTIONS RECOGNISE SAFETY INFORMATION • This is your SAFETY ALERT SYMBOL. - When you see this symbol on your machine or in this Manual, be alert of the potential for personal injury. - Follow recommended precautions and safe operating practices.

S0021

UNDERSTAND SIGNAL WORDS • In this Manual you will find the following words: - DANGER; - WARNING; - CAUTION. referring to different hazard risks. These words are always accompanied by the safety alert symbol.

DANGER WARNING

DANGER: indicates an imminent hazardous situation which, if not avoided, will result in death or serious injury.

CAUTION

WARNING: indicated a potential hazardous situation which, if not avoided, could result in death or serious injury.

IMPORTANT

CAUTION: indicates a potential hazardous situation which, if not avoided, may result in minor or moderate injury.

NOTE

IMPORTANT: indicates a situation which, if not avoided, may cause damage to the machine. NOTE: indicates an additional explanation for information purposes.

ENVIRONMENTAL PROTECTION • This Manual also contains this symbol accompanying instructions for correct behaviour as regards environmental protection. S0024

S-2

EX255-EX285

SAFETY PRECAUTIONS FOLLOW SAFETY PRECAUTIONS • Carefully read and observe all safety signs on the machine and read all safety precautions in this Manual. • Safety signs should be installed, maintained, and replaced when necessary. - If a safety sign or this Manual are damaged or missing, obtain a replacement from your FIAT KOBELCO Dealer in the same way you order a spare part (be sure to detail machine model and serial number upon ordering). • Learn how to operate the machine and its controls correctly and safely. • Allow only trained, qualified, authorised personnel to operate the machine.

S0022

• Keep the machine in proper working conditions. - Unauthorised changes to the machine may impair function and/or safety and affect machine life. • Safety messages in this Chapter “SAFETY PRECAUTIONS”, are intended to illustrate basic safety procedures of the machine. However, it is impossible for these safety messages to cover every hazardous situation you may encounter. If you have any doubts, consult your direct supervisor prior to operating or servicing the machine.

PREPARE FOR EMERGENCIES • Be prepared if a fire starts or an accident occurs. - Keep the first-aid kit and fire extinguisher on hand. - Thoroughly read and understand the label attached to the fire extinguisher to use it properly. - Establish emergency priority procedures to cope with fires and accidents. - Keep emergency numbers for doctors, ambulance service, hospitals and fire department posted near the telephone.

S0023

EX255-EX285

S-3

SAFETY PRECAUTIONS WEAR PROTECTIVE CLOTHING • Wear close-fitting clothing and safety equipment appropriate to the job. You need: - A hard hat; - Safety shoes; - Safety glasses or face shield; - Heavy gloves; - Ear protection; - Reflective clothing; - Waterproof clothing; - Respirator or filter mask. Be sure to correctly wear equipment and clothing for the job. - Do not take any chances. - Avoid wearing loose clothing, jewellery, or other items that can catch on control levers or other parts of the machine.

S0025

• Operating equipment safely requires the full attention of the operator. Do not wear radio or music headphones while operating the machine.

PROTECT AGAINST NOISE • Prolonged exposure to loud noise can cause impairment or loss of hearing. - Wear a suitable hearing protection such as earmuffs or earplugs to protect objectionable or uncomfortably loud noise.

S0026

INSPECT THE MACHINE • Inspect the machine carefully every day or workshift by an attentive visual inspection of machine outside prior to starting it to prevent damages and personal injuries. - In the walk-around inspection, be sure to cover all points detailed in the Chapter "MAINTENANCE", paragraph "EXTERNAL VISUAL INSPECTION" of the OPERATION AND MAINTENANCE INSTRUCTION MANUAL.

S0027

S-4

EX255-EX285

SAFETY PRECAUTIONS USE HAND HOLDS AND STEPS • Falling is one of the major causes of personal injury. - When you get on and off the machine, always face the machine and maintain a three-point with the steps and handrails. - Do not use any control as a handhold. - Never jump off the machine. Never get on and off a moving machine. - Be careful of slippery conditions of platforms, steps, and handrails when leaving the machine.

S0028

ADJUST THE OPERATOR'S SEAT • A seat poorly adjusted for operator or work requirements may quickly fatigue the operator leading to improper operations. - The seat should be adjusted whenever machine operator changes. - The operator should be able to fully press the pedals and correctly move the control levers with his back resting against the seat back. - If not, move the seat fore and aft, and check again.

S0029

EX255-EX285

S-5

SAFETY PRECAUTIONS FASTEN SEAT BELT • Should the machine overturn, the operator may become injured and/or thrown from the cab. Not only, the operator may be crushed by the overturning machine resulting in serious injury or even death. - Prior to operating the machine, thoroughly examine belt webbing, buckle, and attaching hardware. If any item is damaged or worn, replace the seat belt or component before operating the machine.

S0030

- Be sure to remain seated with the seat belt securely fastened at all times when the machine is in operation to minimise injury hazard in case of accident. - After a significant accident, replace the seat belts even though they do not look damaged.

MOVE AND SAFELY

OPERATE

MACHINE

• Bystanders can be run over. - Pay the utmost attention not to run over bystanders. - Be sure and aware of the location of bystanders before moving, swinging or operating the machine. - If fitted, keep the travel alarm and horn sounding to warn people that the machine is about to move. S0031

- When operating, swinging, or moving the machine in a congested area use a signal man. - Co-ordinate hand signals before starting the machine.

S-6

EX255-EX285

SAFETY PRECAUTIONS OPERATE ONLY FROM THE DRIVER'S SEAT • Inappropriate engine starting procedures may cause the machine unexpected movement, possibly resulting in serious injury and even death. - Start the engine only from the operator’s seat. - NEVER start the engine while standing on the track or on the ground. - Do not start the engine by shorting across starter motor terminals. S0032

- Before starting the engine, ensure that all control levers are in the neutral position.

KEEP RIDERS OFF THE MACHINE • Riders on the machine are subject to injuries such as being struck by foreign objects and being thrown off the machine. - Only machine operator is machine. Keep riders off.

allowed on the

- Riders also obstruct the operator’s visibility, resulting in the machine being operated unsafely. S0033

CONFIRM DIRECTION WHERE THE MACHINE IS TO BE DRIVEN • Incorrect travel controls operation may result in serious injury and even death. - Before driving the machine, be aware of the undercarriage position relative to the operator’s position. If travel motors are located at the front of the cab, the machine will move reverse when travel controls are moved towards cab front. S0037

EX255-EX285

S-7

SAFETY PRECAUTIONS AVOID INJURY FROM BACK-OVER AND SWING ACCIDENTS • If any person is present near the machine when backing or swinging the upperstructure, the machine may hit or run over that person, resulting in serious injury or death. • To avoid back-over and swing accidents: - Always look around BEFORE YOU BACK UP AND SWING THE MACHINE. BE SURE THAT ALL BYSTANDERS ARE CLEAR. - Keep the travel alarm in working condition (if equipped). - ALWAYS BE ALERT FOR BYSTANDERS MOVING INTO THE WORK AREA. USE THE HORN OR OTHER SIGNAL TO WARN BYSTANDERS BEFORE MOVING MACHINE.

S0042

- USE A SIGNAL PERSON WHEN BACKING UP IF YOUR VIEW IS OBSTRUCTED. ALWAYS KEEP THE SIGNAL PERSON IN VIEW. - Use hand signals, which conform to your local regulations, when work conditions require a signal person. - No machine motions shall be made unless signals are clearly understood by both signalman and operator. - Learn the meanings of all flags, signs, and markings used on the job and confirm with the person in charge of signalling. - Keep windows, mirrors, and lights clean and in good condition. - Dust, heavy rain, fog, etc., can reduce visibility. As visibility decreases, reduce speed and use proper lighting. - Read and understand all operating instructions in the OPERATION AND MAINTENANCE INSTRUCTION MANUAL.

S0043

S-8

EX255-EX285

SAFETY PRECAUTIONS DRIVE MACHINE SAFELY •

Before starting the machine carefully read the OPERATION AND MAINTENANCE INSTRUCTION MANUAL. (Refer to the OPERATING INSTRUCTIONS chapter).

• Before moving the machine, confirm which way to move travel pedals/levers for the corresponding direction you wish to go. - Pushing down on the front of the travel pedals or pushing the levers forward moves the machine towards the idlers. (Refer to the OPERATION AND MAINTENANCE INSTRUCTION MANUAL).

S0038

• Traveling on a grade may cause the machine to slip or to overturn, possibly resulting in serious injury or death. - When traveling up or down a grade, keep the bucket in the direction of travel, approximately 20 to 30 cm (A) above the ground. - If machine starts to skid or becomes unstable, lower the bucket immediately.

S0039

- Traveling across the face of a slope may cause the machine to skid or to overturn. When travelling (ascending/descending) on a slope, be sure to point the tracks uphill/downhill.

S0004

- Turning on an incline may cause the machine to tip over. If turning on an incline is absolutely unavoidable, do so at a place where the slope is gentle and the surface is firm. - When operating on a grade and the fuel reserve indicator light lights, immediately refuel.

WRONG S0005

EX255-EX285

S-9

SAFETY PRECAUTIONS AVOID OVERTURNING • The danger of tipping is always present when operating on a grade, possibly resulting in serious injury or death. • To avoid tipping: - Be extra careful before operating on a grade. - Prepare machine operating area flat by grading. - Keep the bucket low to the ground and close to the machine. - Reduce machine operating speed to avoid tipping or slipping. - Avoid changing direction when travelling on grades. - NEVER attempt to travel across a grade steeper than 15 degrees. - Reduce swing speed as necessary when swinging loads.

S0002

• Be careful when working on frozen ground. - Temperature increases will cause the ground to become soft and make ground travel unstable.

S0047

PARK MACHINE SAFELY • To avoid accidents: - Park machine on a level surface. - Lower bucket to the ground. - Turn auto-idle (A/I) switch off. - Run engine at slow idle speed without load for 5 minutes. - Turn key-start switch to OFF to stop engine. - Remove the ignition key from the key switch. - Pull the safety lever (pilot-control shut-off lever) to the LOCK position. - Close windows, roof window, and cab door. - Lock all access doors and compartments.

S0049

S-10

EX255-EX285

SAFETY PRECAUTIONS AVOID INJURY FROM UNEXPECTED MACHINE MOVEMENT • Death or serious injury may result if you attempt to get on or off a moving machine. • To avoid roll-aways: - Select level ground when possible to park machine. - Do not park the machine on a grade. - Lower the bucket and/or other work tools to the ground. Thrust the bucket teeth into the ground if you must park on a grade. - Turn the auto-idle switch off. - Run the engine at slow idle speed without load for 5 minutes to cool down the engine. - Stop the engine and remove the key from the key switch. - Pull the pilot shut-off lever to LOCK position. - Block both tracks. - Position the machine to prevent overturning. - Park a reasonable distance from other machines.

S0040

S0041

PROVIDE SIGNALS FOR JOBS INVOLVING A NUMBER OF MACHINES • For jobs involving several machines, provide signals commonly known by all personnel involved. Also, appoint a signal person to co-ordinate the job site. Make sure that all personnel obey the signal person’s directions.

S0036

EX255-EX285

S-11

SAFETY PRECAUTIONS INVESTIGATE JOB SITE BEFORE HAND • When working at the edge of an excavation or on a road shoulder, the machine could overturn, possibly resulting in serious injury or death. - Investigate the configuration and ground conditions of the job site beforehand to prevent the machine from overturning and prevent the ground, stockpiles, or banks from collapsing. - Make a work plan. Use machines appropriate to the work and job site. - Reinforce ground, edges, and road shoulders as necessary. Keep the machine well back from the edges of excavations and road shoulders. - When working on an incline or road shoulder, employ a signal person as required. Confirm that your machine is equipped with a F.O.P.S. (Falling Object Protective Structure) cab before working in areas where there is the possibility of falling stones or landslides. - When footing is weak, reinforce the ground before starting the work. - When working on frozen ground, be extremely alert. As ambient temperature rises, footing becomes loose and slipped.

S0034

PROTECT AGAINST FALLING STONES AND LANDSLIDES • Confirm that your machine is equipped with a F.O.P.S. (Falling Object Protective Structure) cab before working in areas where there is the possibility of falling stones.

S0035

S-12

EX255-EX285

SAFETY PRECAUTIONS DIG WITH CAUTION • Accidental severing of underground cables or gas lines may cause an explosion and/or fire, possibly resulting in serious injury or death. - Before digging, check the location of cables, gas lines, and water lines. - Keep the minimum distance required by law from cables, gas lines, and water lines. If a fiber optic cable should be accidentally severed, do not look into the end. Doing so may result in serious eye injury. - local authorities and/or the utility companies directly (electric power, gas, telephone, water, sewers, telecommunications, etc.) to obtain information about underground utility lines.

S0009

OPERATE WITH CAUTION • If the front attachment or any other part of the machine hits against an overhead obstacle, such as a bridge, both the machine and the overhead obstacle will be damaged, and personal injury may results as well. - Take care to avoid hitting overhead obstacles with the boom or arm.

S0008

AVOID ELECTRIC LINES • Serious injury or death can result if the machine or front attachments are not kept a safe distance from electric lines. - When operating near an electric line, NEVER move any part of the machine or load closer than 3 m plus twice the line insulator length (L). - Check and comply with any local regulations that may apply. - Wet ground will expand the area that could cause any person on it to be affected by electric shock. - Keep all bystanders or co-workers away from the site.

L

S0205

EX255-EX285

S-13

SAFETY PRECAUTIONS KEEP PERSONNEL CLEAR FROM WORKING AREA • A person may be hit severely by the swinging front attachment or counterweight and/or may be crushed against an other object, resulting in serious injury or death. - Keep all persons clear from the area of operation and machine movement. - Before operating the machine, set up barriers to the sides and rear area of the bucket swing radius to prevent anyone from entering the work area.

S0044

NEVER MOVE THE BUCKET OVER ANY ONE • Never lift, move, or swing bucket above anyone or a truck cab. Serious injury or machine damage may result due to bucket load spill or due to collision with the bucket.

S0045

AVOID UNDERCUTTING • In order to retreat from the edge of an excavation if the footing should collapse, always position the undercarriage perpendicular to the edge of the excavation with the travel motors at the rear. - If the footing starts to collapse and if sufficient retreat is not possible, do not panic. Often, the machine can be secured by lowering the front attachment, in such cases.

S0011

S-14

EX255-EX285

SAFETY PRECAUTIONS NEVER UNDERCUT A HIGH BANK • The edges could collapse or a land slide could occur causing serious injury or death.

S0048

SAFETY LOADS MOVING • The excavator is no lifting and transportation means, therefore it should not be used to position loads accurately. Should it be exceptionally used to lift and lay building components, special caution must be taken as follows: - The machine must be equipped without failure with the appropriate variant supplied, upon request, by FIAT KOBELCO. Also, totally comply with the safety precautions for the operation of the excavator as a lifting equipment. - Secure the loads to be raised using cables or chains fastened with appropriate hooking mechanisms. - Never hook cables or chains to the bucket teeth. - Nobody should be allowed to remain under the raised load or within the excavator operating range for any reason whatever. S0165

- Never exceed specified loading capacity. Incorrect fastening of slings or chains may cause boom/arm failure or failure of the lifting means with consequent bodily injuries and even death. - Always ensure that slings and chains used for lifting are adequate to the load and in good condition. - All loading capacities are referred to the machine on a level surface and should be disregarded when working on a slope.

EX255-EX285

S-15

SAFETY PRECAUTIONS SAFETY TRANSPORTING • The danger of tipping is present when loading/ unloading the machine onto/from a truck or trailer bed. - Be sure to observe local regulations when transporting the machine on public roads. - Provide an appropriate truck or trailer for transporting the machine. • Take the following precautions when loading/ unloading the machine: 1. Select firm level ground. 2. Be sure to use a loading dock or ramp. 3. Be sure to have a signal person when loading/ unloading the machine. 4. Always turn the auto-idle (A/I) switch OFF when loading or unloading the machine, to avoid unexpected speed increase due to unintentional operation of a control lever. 5. Always select the slow speed mode with the travel speed selector. In the high speed mode, travel speed may automatically increase. 6. Avoid steering while driving up or down the ramp as it is extremely dangerous. If steering is unavoidable, first move back to the ground or flatbed, modify travelling direction, and begin to drive again. 7. Do not operate any levers besides the travel levers when driving up or down the ramp. 8. The top end of the ramp where it meets the flatbed is a sudden jolt. Take care when traveling over it. 9. Prevent possible injury from machine tipping while the upperstructure is rotating. 10. Keep the arm tucked under and rotate the upperstructure slowly for best stability. 11. Securely fasten machine frame using chains or cables. Refer to “TRANSPORT” chapter in the OPERATION AND MAINTENANCE INSTRUCTION MANUAL for details.

S0052

S-16

EX255-EX285

SAFETY PRECAUTIONS SAFE MAINTENANCE • To avoid accidents: - Understand maintenance procedure before starting the work. - Kepp the working area clean and dry. - Do not spray water or steam inside the cab. - Do not lubricate or service the machine when it is in motion. - Kepp hands, feet and clothes far from moving parts. Prior to service in the machine: 1. Park the machine on the level ground. 2. Lower the bucket to the ground. 3. Switch off the Auto-Idle (A/I). 4. Let the engine idle with no load for at least five minutes until it has cooled down. 5. Move the key-start switch to the OFF position to stop the engine. 6. Remove the ignition key from the start switch. 7. Apply the "Maintenance in progress" tag . This tag can be applied o the left-hand control lever, safety lever or cab door. 8. Move the safety lever (pilot-control shut-off lever) to the LOCK position. 9. Let the engine cool down. - Do not leave the machine unattended if servicing requires the engine running . - If the machine is to be raised, place boom and arm at an angle 90 to 110°. Lock machine components which should be raised for maintenance or repair using suitable ing means. - Never work under a machine kept raised by the boom. - Inspect certain component regularly, repair or replace as necessary. Refer to the the OPERATION AND MAINTENANCE INSTRUCTION MANUAL. - Keep all components in good condition and properly install. Immediately repair any fault. - Immediately repair any damage.Replace worn or failed components. Remove grease, oil, debris build-ups. - Disconnect the negative cable (−) from the battery before carry out any work on the electrical system or arc-welding on the machine.

S0053

S0054

EX255-EX285

S-17

SAFETY PRECAUTIONS WARN OTHERS OF SERVICE WORK • Unexpected machine movement can cause serious injury. - Before performing any work on the machine, attach a maintenance in progress tag. This tag can be applied o the left-hand control lever, safety lever or cab door.

S0055

MACHINE PROPERLY • Never attempt to work on the machine without securing the machine first. - Always lower the attachment or tool to the ground before working on the machine. - If you must work on a lifted machine or attachment, securely the machine or attachment. - Do not the machine on cinder blocks, bollow tires, or props that may crumble under continuous load. - Do not work under a machine that is ed solely by a jack.

S0054

STAY CLEAR OF MOVING PARTS • Entanglements in moving parts can cause serious injury. • To prevent accidents, care should be taken to ensure that hands, feet, clothing, jewelry and hair do not become entangled when working near rotating parts.

S0056

S-18

EX255-EX285

SAFETY PRECAUTIONS DISPOSE OF WASTE IN THE APPROPRIATE MANNER • Waste improperly disposed of represents a danger for the envinronment. Potentially dangerous waste used on the FIAT KOBELCO excavators includes lubricants, fuel, coolant, brake fluid, filters and batteries. - Used sealed containers when discharging fluids. Do not use containers for food or beverages which may induce drinking. - Do not spill waste over the ground, into drains, or water beds. S0064

- Obtain information about the correct methods to recycle or dispose of waste from local Authorities, collection centres or your Dealer.

WORK IN A CLEAN AREA • Before starting an operation, clean the working area. Clear the area from all the objects that can be dangerous for mechanics or people in the working area.

S0166

PROPERLY LIGHT THE WORKING AREA • Properly and safely light the working area. - Use safe portable lamps in order to work inside and under the machine. - Make sure that the lamp is shielded by a cage; the incandescent filament of a lamp, accidentally broken, can cause fuel or oil fire.

F1480

S0167

EX255-EX285

S-19

SAFETY PRECAUTIONS REGULARLY WASH THE MACHINE • Remove all the traces of grease, oil and deposits, in order to avoid people accidents or damages to things. - Do not spray water or steam in the cab.

F1462

S0153

F1463

S0058

STORE ATTACHMENTS SAFELY • Stored attachments such as buckets, hydraulic breakers and blades can fall and cause serious injury or death. - Securely store attachments and implements to prevent falling. - Keep bystanders away from storage areas.

PREVENT ACID SCALDS • The sulphuric acid, contained in the battery, is poisonous. It is strong enough to scald the skin, corrode clothes and cause blindness, if it is sprayed into the eyes. To avoid dangers: - Fill the batteries in airy areas. - Wear eye protections and rubber gloves. - Avoid breathing the electrolyte vapours when topping up. - Avoid spilling or dripping the electrolyte. - Use proper emergency starting techniques. If you are touched with acid sprays: - Rinse your skin well with water. - Put on your skin sodium bicarbonate or clay to help the acid neutralization. - Rinse your eyes with water for 10-15 minutes. - Immediately see a doctor. If you have swallowed the acid: - Drink a big quantity of water or milk, swallow milk of magnesia, scrabbled eggs or vegetal oil. - Immediately see a doctor.

F1474

S0168

S-20

EX255-EX285

SAFETY PRECAUTIONS STARTING THE ENGINE WITH BOOSTER BATTERIES • Battery gas may explode causing serious damages and injuries. - If the engine is to be started using booster batteries, ensure to comply with all procedures detailed in the chapter “OPERATING INSTRUCTIONS” of the OPERATION AND MAINTENANCE INSTRUCTION MANUAL. - The operator should be sitting in the driver’s seat to keep the machine under control when the engine starts. Starting the engine with booster batteries is a two man operation.

S0001

- Do not use batteries that have been stored in the cold for a long time. - Mistakes in following procedures detailed for starting the engine with slave batteries may cause the batteries to explode or machine to move unexpectedly.

PREVENT BATTERY EXPLOSIONS • Battery gas can explode. - Keep sparks, lighted matches, and flames away from the top of battery. - Never check battery charge by placing a metal object across the posts. Use a voltmeter or hydrometer. - Do not charge a frozen battery; it may explode. Warm battery to 16 °C.

• Battery electrolyte is poisonous. If the battery should explode, battery electrolyte may be splashed into eyes, possibly resulting in blindness. - Be sure to wear eye protection when checking electrolyte specific gravity.

S0001

EX255-EX285

S-21

SAFETY PRECAUTIONS PREVENT BURNS Hot spraying fluids: • After operation, engine coolant is hot and under pressure. Hot water or steam is contained in the engine, radiator and heater lines. Skin with escaping hot water or steam can cause severe burns. - To prevent possible injury from hot spraying water. DO NOT remove the radiator cap until the engine is cool. When opening, turn the cap slowly to the stop. Allow all pressure to be released before removing the cap. - The hydraulic oil tank is pressurized. Again, be sure to release all pressure before removing the cap.

S0019

Hot fluids and surfaces: • Engine oil, reduction gear oil and hydraulic oil also become hot during operation. The engine, hoses, lines and other parts become hot as well. - Wait for the oil and components to cool down before starting any maintenance or inspection work. S0059

KEEP CLEAN THE MACHINE Keep clean the engine compartment, radiator, batteries, hydraulic pipes, fuel tank and operator's position. The engine compartment temperature can quickly rise, after stopping the engine. IN THESE CASES, BE CAREFUL TO POSSIBLE FIRES. Open the access doors in order to quicken the engine cooling process and clean the compartment.

S0177

S-22

EX255-EX285

SAFETY PRECAUTIONS AVOID HIGH-PRESSURE FLUIDS • Fluids such as diesel fuel or hydraulic oil under pressure can penetrate the skin or eyes causing serious injury, blindness or death. - Avoid this hazard by relieving pressure before disconnecting hydraulic or other lines. SA0016

- Tighten all connections before applying pressure. - Search for leaks with a piece of cardboard; take care to protect hands and body from highpressure fluids. Wear a face shield or goggles for eye protection. SA0017

- In an accident occurs, see a doctor familiar with this type of injury immediately. Any fluid injected into the skin must be surgically removed within a few hours or gangrene may result.

SA0018

PREVENT PARTS FROM FLYING OFF • Grease in the track adjuster is under high pressure. Failure to follow the precautions below may result in serious injury, blindness, or death. - NEVER attempt to remove GREASE FITTING or VALVE ASSEMBLY. - As pieces may fly off, be sure to keep body and face away from valve.

• Travel reduction gears are under pressure. - As pieces may fly off, be sure to keep body and face away from AIR RELEASE PLUG to avoid injury. REDUCTION GEAR OIL is hot. Wait for gear oil to cool down, then gradually loosen the air release plug to release pressure.

F3635

S0178

EX255-EX285

S-23

SAFETY PRECAUTIONS PROTECT AGAINST FLYING DEBRIS • If flying debris hit eyes or any other part of the body, serious injury may result. - Guard against injury from flying pieces of metal or debris; wear goggles or safety glasses. - Keep bystanderds away from the working area before striking any object.

S0046

HANDLE FLUIDS SAFELY - AVOID FIRES • Handle fuel with care: it is highly flammable. If fuel ignites, an explosion and/or a fire may occur, possibly resulting in serious injury or death. - Do not refuel the machine while smoking or when near open flame or sparks. - Always stop the engine before refuelling the machine. - Fill the tank outdoors.

S0050

• All fuels, most lubrificants, and some antifreeze fluids are flammable. - Store flammable fluids well away from fire hazards. - Do not burn or puncture pressurized containers. - Do not store oily rags; they can ignite and burn spontaneously.

S0051

S-24

EX255-EX285

SAFETY PRECAUTIONS PREVENT FIRES • Check for Oil Leaks: - Fuel, hydraulic oil and lubricant leaks can lead to fires. - Check for missing or loose clamps, kinked hoses, lines or hoses that rub against each other, damage to the oil-cooler, and loose oil-cooler flange bolts which may cause oil leaks. - Tighten, repair or replace any missing, loose or damaged clamps, lines, hoses, oil-cooler and oilcooler flange bolts. - Do not bend or strike high-pressure lines. - Never install bent or damaged lines, pipes, or hoses. • Check for Shorts circuits which could cause fires: - Clean and tighten all electrical connections. - Check before each shift or after about ten (10) hour operation for loose, kinked, hardened or frayed electrical cables and wires. - Check before each shift or after about ten (10) hour operation for missing or damaged terminal caps. - DO NOT OPERATE MACHINE if cable or wires are loose, kinked, etc.. • Clean up Flammables: - Spilled fuel and lubricans, and trash, grease, debris, accumulated coal dust, and other flammables may cause fires. - Prevent fires by inspecting and cleaning the machine daily and by removing spilled or accumulated flammables immediately. • Check Key-start Switch: - If a fire breaks out, failure to stop the engine will escalate the fire, hampering fire fighting. - Always check key-start switch function before operating the machine every day: 1. Start the engine and run it at slow idle. 2. Turn the key-start switch to the OFF position to confirm that the engine stops. - If any abnormalities are found, be sure to repair them before operating the machine. • Check Heat Shields: - Damaged or missing heat shields may lead to fires. - Damaged or missing heat shields must be repaired or replaced before operating the machine.

S0051

EX255-EX285

S-25

SAFETY PRECAUTIONS EVACUATING IN CASE OF FIRE • If a fire breaks out, evacuate the machine in the following way: - Stop the engine by turning the key-start switch to the OFF position if there is time. - Use a fire extinguisher if there is time. - Exit the machine.

S0060

BEWARE OF EXHAUST FUMES • Prevent asphyxiation. Engine exhaust fumes can cause sickness or death. - If you must operate in a building, be sure there is adequate ventilation. Either use an exhaust pipe extension to remove the exhaust fumes or open doors and windows to bring enough outside air into the area.

S0061

USE APPROPRIATE TOOLS • Use tools appropriate for the job to be performed. - Inappropriate tools, parts and procedures might generate dangerous conditions. - Use tools of correct size to tighten or loosening securing elements, in order to avoid injuries caused by a wrench getting out of control. - Do not use U.S. Standard or British Standard tools on metric fasteners and vice versa. • Use only FIAT KOBELCO genuine spare parts (please refer to the PARTS CATALOG).

S0120

S-26

EX255-EX285

SAFETY PRECAUTIONS AVOID HEATING NEAR PRESSURIZED FLUID LINES Flammable spray can be generated by heating near pressurized fluid lines, resulting in severe burns to yourself and bystanders. Do not heat by welding, soldering, or using a torch near pressurized fluid lines or other flammable materials. Pressurized lines can be accidentally cut when heat goes beyond the immediate flame area. Install temporary fire resistant guards to protect hoses or other materials when welding, soldering, etc. S0062

AVOID APPLYING HEAT TO LINES CONTAINING FLAMMABLE FLUIDS - Do not weld or flame cut pipes or tubes that contain flammable fluids. - Clean them thoroughly with non-flammable solvent before welding or flame cutting them.

REMOVE PAINT BEFORE WELDING OR HEATING • Hazardous fumes can be generated when paints is heated by weiding, soldering, or using a torch. If inhaled, these fumes may cause sickness. - Avoid breathing potentially toxic fumes and dust. - Do all such work outside or in a well-ventilated area. - Dispose of paint and solvents properly. - Remove paint before welding or heating: 1. If you sand or grind paint, avoid breathing the dust. Wear an approved respirator. 2. If you use solvent or paint stripper, remove stripper with soap and water before welding. Remove solvent or paint stripper containers and other flammable material from area. Allow fumes to disperse at least 15 minutes before welding or heating.

S0063

WORKSHOP MANUAL

EX255-EX285

ESCAVATOR


Section 1 - GENERAL INFORMATION Group 1 Group 2

- Precautions for Disassembly and Assembly - Tightening Torque

Section 2 - UPPERSTRUCTURE Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Group 7 Group 8 Group 9 Group 10 Group 11

-

Cab Counterweight Main Frame Pump Device Control Valve Swing Device Pilot Valve Pilot Shut-Off Valve Shockless Valve Solenoid Valve Unit Pilot Relief Valve Unit

Section 3 - UNDERCARRIAGE Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Group 7

-

Swing Bearing Travel Device Center t Track Adjuster Front Idler Upper and Lower Roller Tracks

Section 4 - FRONT ATTACHMENT Group 1 Group 2

- Front Attachment - Cylinders

Section 5 - ENGINE AND ACCESSORY Group 01 Group 02 Group 03 Group 04 Group 05 Group 06 Group 07 Group 08 Group 09 Group 10 Group 11 Group 12

-

General Information Maintenance Engine Disassembly Engine Inspection and Repair Engine Reassembly Lubricating System Cooling System Fuel System Turbocharger Starting and Charging Troubleshooting Repair Standards

SECTION 1

EX255-EX285

GENERAL INFORMATION

CONTENTS Group 1 - Precautions for Disassembly and Assembly Precautions for Disassembly and Assembly ............................................. W1-1-1

Group 2 - Tightening Torque Tightening Torque Specification .............. W1-2-1 Torque Chart .......................................... W1-2-2 Piping t ............................................ W1-2-5

EX255-EX285

W1-1-1

PRECAUTIONS FOR DISASSEMBLY AND ASSEMBLY PRECAUTIONS FOR DISASSEMBLY AND ASSEMBLY Preparations for Disassembly

Precautions for Disassembly and Assembly

•

•

Clean the Machine

- To prevent dirt from entering, cap or plug the removed pipes. - Before disassembling, clean the exterior of the components and place it on a work bench. - Before disassembling, drain gear oil from the reduction gear. - Be sure to provide appropriate containers for draining fluids. - Use matching marks for easier reassembling. - Be sure to use the specified special tools, when instructed. - If a part or component cannot be removed after removing its securing nuts and bolts, do not attempt to remove it forcibly. Find the cause(s), then take the appropriate measures to remove it. - Orderly arrange disassembled parts. Mark and tag them as necessary. - Store common parts, such as bolts and nuts with reference to where they are to be used and in a manner that will prevent loss. - Inspect the or sliding surfaces of disassembled parts for abnormal wear, sticking, or other damage. - Measure and record the degree of wear and clearances.

Thoroughly wash the machine before bringing it into the shop. Bringing a dirty machine into the shop may cause machine components to be contaminated during disassembling/assembling, resulting in damage to machine components, as well as decreased efficiency in service work.

•

Inspect the Machine Be sure to thoroughly understand all disassembling/assembling procedures beforehand, to help avoid incorrect disassembling of components as well as personal injury. Check and record the items listed below to prevent problems from occurring in the future. - The machine model, machine serial number, and hour meter reading. - Reason for disassembly (symptoms, failed parts, and causes). - Clogging of filters and oil, water or air leaks, if any. - Capacities and condition of lubricants. - Loose or damaged parts.

•

Prepare and Clean Tools and Disassembly Area Prepare the necessary tools to be used and the area for disassembling work.

Precautions for Disassembly

•

Precautions for Assembly - Be sure to clean all parts and inspect them for any damage. If any damage is found, repair or replace it. - Dirt or debris on the or sliding surfaces may shorten the service life of the machine. Take care not to contaminate any or sliding surfaces. - Be sure to replace O-rings, backup rings, and oil seals with new ones once they are disassembled. Apply a film of grease before installing. - Be sure that liquid-gasket-applied surfaces are clean and dry. - If an anti-corrosive agent has been used on a new part, be sure to thoroughly clean the part to remove the agent. - Utilize matching marks when assembling. - Be sure to use the designated tools to assemble bearings, bushings and oil seals. - Keep a record of the number of tools used for disassembly/assembly. After assembling is complete, count the number of tools, so as to make sure that no tools are missing.

W1-1-2

EX255-EX285

PRECAUTIONS FOR DISASSEMBLY AND ASSEMBLY Bleeding Air from Hydraulic System When hydraulic oil is drained, the suction filter or the suction lines are replaced, or the removal and installation of the pump, swing motor, travel motor or cylinder is done, bleed air from the hydraulic system in the following procedures:

•

Bleeding Air from Hydraulic Pump

IMPORTANT - If the engine is started with air trapped in the hydraulic pump housing, damage to the pump may result. Be sure to bleed air before starting the engine.

- Remove the air bleeding plug from the top of the pump and fill the pump housing with hydraulic oil. - After the pump housing is filled with hydraulic oil, temporarily tighten the plug. Then, start the engine and run at slow idle speed. - Slightly loosen the plug to bleed air from the pump housing until hydraulic oil oozes out. - After bleeding all the air, securely tighten the plug.

•

Bleeding Air from Travel Motor / Swing Motor - With the drain plug / hose on travel motor / swing motor removed, fill the motor case with hydraulic oil.

•

Bleeding Air from Hydraulic Circuit - After refilling hydraulic oil, start the engine. While operating each cylinder, swing motor and travel motor evenly, operate the machine under light loads for 10 to 15 minutes. Slowly start each operation (never fully stroke the cylinders during initial operation stage). As the pilot oil circuit has an air bleed device, air trapped in the pilot oil circuit will be bled while performing the above operation for approx. 5 minutes. - Reposition the front attachment to check hydraulic oil level. - Stop the engine. Recheck hydraulic oil level. Replenish oil as necessary. SM1000

EX255-EX285

W1-1-3

PRECAUTIONS FOR DISASSEMBLY AND ASSEMBLY Floating Seal Precautions

A

1. In general, replace the floating seal with a new one. If the floating is to be reused, follow these procedures: (1) Keep seal rings together as a matched set with seal ring faces together. Insert a piece of cardboard to protect surfaces. B

(2) Check the seal ring face (A) for scuffing, scoring, corrosion, deformation or uneven wear.

SM1001

(3) Check O-ring (B) for tears, breaks, deformation or hardening.

2. If incorrectly assembled, oil leakage or damage will occur. Be sure to do the following, to prevent trouble. (1) Clean the floating seal and seal mounting bores with cleaning solvent. Use a wire brush to remove mud, rust or dirt. After cleaning, thoroughly dry parts with compressed air.

CORRECTLY

INCORRECTLY

(2) Clean the floating seal and seal mounting bores, as dust on them tends to enter the floating seal when installing it. (3) Check that the O-ring is not twisted, and that it is installed correctly on the seal ring. (4) After installing the floating seal, check that seal ring surface (C) is parallel with mating face (A) by measuring the distances (a) and (b), as illustrated. If these distances differ, correct the O-ring seating.

SM1002

CORRECTLY

INCORRECTLY

A a

a

C B

b a=b

b a≠b SM1003

W1-1-4

EX255-EX285

PRECAUTIONS FOR DISASSEMBLY AND ASSEMBLY NOTES:

EX255-EX285

W1-2-1

TIGHTENING TORQUE TIGHTENING TORQUE SPECIFICATIONS No. Descriptions

Bolt Diam. mm

Wrench Size mm

Torque Nm

kgf m

lbf ft

1

Engine cushion rubber mounting bolt

18

27

392

40

290

2

Engine bracket mounting bolt

10 12

17 19

64 108

6.5 11

47 80

3

Hydraulic oil tank mounting bolt

20

30

390

40

290

4

Fuel tank mounting bolt

16

24

205

21

152

5

ORS fittings for hydraulic hoses and piping

* 1-3/16"-12 * 1-7/16"-12 * 1-11/16"-12

36 41 50

175 205 324

18 21 33

130 152 239

6

Pump device mounting bolt

10

17

49

5

36

7

Control valve mounting bolt

16

24

205

21

152

8

Control valve bracket mounting bolt

16

24

205

21

152

9

Swing device mounting bolt

22

32

665

68

490

10

Battery mounting bolt

10

17

9.8

1

7

11

Cab mounting nut

16

24

205

21

152

12

Swing bearing mounting bolt to upperst. Swing bearing mounting bolt to undercar.

27 27

41 41

1230 1205

125 123

900 890

13

Travel device mounting bolt

20

30

620

63

456

14

Sprocket mounting bolt

20

30

490

50

362

15

Upper roller mounting bolt

16

24

265

27

195

16

Lower roller mounting bolt

20

30

500

51

369

17

Track shoe mounting bolt

22

32

940

96

694

18

Low pressure coupling and clamp

8 5 6

13 8 10

10.3to12.4 2.90 4.40

1.05to1.26 0.30 0.45

8 to 16 2 3

*: UNF thread

NOTE - (1) Apply lubricant (e.g. white zinc B dissolved into spindle oil) to bolts and nuts to stabilize friction coefficient of them. (2) Make sure bolt and nut threads are clean before installing. (3) Apply Loctite to threads before installing and tightening swing bearing mounting bolts.

W1-2-2

EX255-EX285

TIGHTENING TORQUE TORQUE CHART WARNING Use tools appropriate for the work to be done. Makeshift tools and procedures can create safety hazards. For loosening and tightening nuts and bolts, use the correct tools. Avoid bodily injury caused by slipping wrenches.

Bolt Types Tighten nuts or bolts correctly to torque specifications. Four kinds of bolts, hexagon bolts T, H, M and socket bolt, each made of different material, are used. Make sure to employ the correct bolts and tighten them to specification when assembling the machine or components.

Hexagon T Bolt

Hexagon H Bolt

SM1004

Hexagon M Bolt

Socket Bolt

SM1005

Specified Tightening Torque Chart Bolt Dia.

M8 M10 M12 M14 M16 M18 M20 M22 M24 M27 M30 M33 M36

Wrench Hexagon Size Wrench

13 17 19 22 24 27 30 32 36 41 46 50 55

T Bolt, Socket bolt

H Bolt

M Bolt

Size

Nm

kgf m

lbf ft

Nm

kgf m

lbf ft

Nm

kgf m

lbf ft

6 8 10 12 14 14 17 17 19 19 22 24 27

29.5 64 108 175 265 390 540 740 930 1 370 1 910 2 550 3 140

3 6.5 11 18 27 40 55 75 95 140 195 260 320

22 47 80 130 195 290 400 540 690 1 010 1 410 1 880 2 310

19.5 49 88 137 205 295 390 540 690 1 030 1 420 1 910 2 400

2 5 9 14 21 30 40 55 70 105 145 195 245

14.5 36 65 101 152 220 290 400 505 760 1 050 1 410 1 770

9.8 19.5 34 54 78 118 167 215 275 390 540 740 930

1 2 3.5 5.5 8 12 17 22 28 40 55 75 95

7.2 14.5 25.5 40 58 87 123 159 205 290 400 540 690

EX255-EX285

W1-2-3

TIGHTENING TORQUE IMPORTANT (1) Apply lubricant (i. e. white zinc B dissolved into spindle oil) to nuts and bolts to stabilize their friction coefficients. (2) Torque tolerance is ±10 %. (3) Be sure to use bolts of correct length. Bolts that are too long cannot be tightened, as the bolt tip comes into with the bottom of the bolt hole. Bolts that are too short cannot develop sufficient tightening force. (4) The torques given in the chart are for general use only. Do not use these torques if a different torque is given for a specific application. (5) Make sure that the nut and bolt threads are clean before installing. Remove dirt or corrosion, if any.

Bolt Tightening Order When tightening two or more bolts, tighten them alternately, as shown, to ensure even tightening.

Equally tighten upper and lower alternately

Tighten diagonally

1 1,4

6

2,3

4

Tighten from center and diagonally

12

9

4

1

6

7

14

13

8

5

2

3

10

11

3 5 2

SM1006

W1-2-4

EX255-EX285

TIGHTENING TORQUE Service Recommendations for Split Flange

IMPORTANT (1) Be sure to clean and inspect sealing surfaces. Scratches / roughness cause leaks and seal wear. Unevenness causes seal extrusion. If defects cannot be polished out, replace the component. (2) Be sure to use only specified O-rings. Inspect Orings for any damage. Take care not to file O-ring surfaces. When installing an O-ring into a groove, use grease to hold it in place. (3) Loosely assemble split flange halves. Make sure that the split is centrally located and perpendicular to the port. Hand-tighten the bolts to hold the parts in place. Take care not to pinch the O-ring. (4) Tighten bolts alternately and diagonally, as shown, to ensure even tightening. (5) Do not use air wrenches. Using an air wrench often causes tightening of one bolt fully before tighten the others, resulting in damage to O-rings or uneven tightening of bolts.

SM1007

WRONG

SM1008

Nut and Bolt Lockings •

Lock Plate SM1009

IMPORTANT- Do not reuse lock plates. Do not try to bend the same point twice. RIGHT

•

Cotter Pin

IMPORTANT- Do not reuse cotter pins. Match the holes in the bolt and nut while tightening, not while loosening.

Bend along edge sharply

RIGHT

•

WRONG

RIGHT

Do not bend it round

WRONG

Lock Wire

IMPORTANT - Apply wire to bolts in the bolt-tightening direction, not in the bolt-loosening direction.

Bend along edge sharply SM1010

RIGHT

RIGHT

RIGHT

WRONG

WRONG Loosen

Tighten

SM1011

EX255-EX285

W1-2-5

TIGHTENING TORQUE PIPING T Pipe Thread Connection / Union t Tightening Torque Specifications

1

4

3

5

2

Union t Metal sealing faces (4) and (5) of adaptor (1) and hose (2) fit together to seal pressure oil. Union ts are used to small-diameter lines. t Body

IMPORTANT (1) Do not over-tighten union nut (3). Excessive force will be applied to metal sealing surfaces (4) and (5), possibly cracking adaptor (1). Be sure to tighten union nut (3) to specifications.

SM1012

37°

(2) Scratches or other damage to sealing surfaces (4) or (5) will cause oil leakage at the t. Take care not to damage them when connecting /disconnecting.

37°

Male Union t

Female Union t SM1013

Wrench Size

Type

37° Union t

Tightening Torque

Union Nut

t Body

Nm

kgf m

lbf ft

19 22 27 36 41 50

17 19 22 30, 32 36 46

29 39 78.5 157 205 255

3 4 8 16 21 26

22 29 69 116 152.5 188

NOTE - Tightening torque for the non-union type 37° male t is the same as the 37° female union t.

W1-2-6

EX255-EX285

TIGHTENING TORQUE O-ring Seal t O-ring (6) seats against the end face of adaptor (7) to seal pressure oil. 7

6

9

IMPORTANT (1) Be sure to replace O-ring (6) with a new one when reconnecting. (2) Before tightening union nut (9), confirm that Oring (6) is seated correctly in O-ring groove (8). Tightening union nut (9) with O-ring (6) displaced will damage O-ring (6), resulting in oil leakage.

8

10

t body SM1014

(3) Take care not to damage O-ring groove (8) or sealing face (10). Damage to O-ring (6) will cause oil leakage. (4) If union nut (9) is found to be loose, causing oil leakage, do not tighten it to stop the leak. Instead, replace O-ring (6) with a new one, then tighten union nut (9) after confirming that O-ring (6) is securely seated in place.

Wrench Size

Tightening Torque

Union Nut

t Body

Nm

kgf m

lbf ft

27

22 30, 32 36 46

93 175 205 320

9.5 18 21 33

69 130 152 240

36 41 50

EX255-EX285

W1-2-7

TIGHTENING TORQUE Screwed-In Connection

PT

PF 30°

IMPORTANT - Many types of screwed-in connections are used for hose connections. Be sure to confirm that the thread pitch and thread type (tapered or straight) are the correct type before using any screw-in connection. Male Tapered Thread

Male Straight Thread SM1015

Male Tapered Thread Wrench

Tightening Torque

t Body

Nm

kgf m

lbf ft

17, 19 19, 22 27, 22 36, 32 41 50 60

34 49 93 157 205 320 410

3.5 5 9.5 16 21 33 42

25 36 69 116 152.5 240 300

Internal Thread

Seal Tape Application Seal tape is used to seal clearances between male and female threads, so as to prevent any leakage between threads. Be sure to apply just enough seal tape to fill up thread clearances. Do not overwrap.

Clearance

External Thread

SM1016

Leave one to two pitch threads uncovered

•

Application Procedure Confirm that the thread surface is clean, free of dirt or damage. Apply seal tape around threads as shown. Wrap seal tape in the same direction as the threads.

SM1017

Low-Pressure-Hose Clamp Tightening Torque

T-Bolt Type

Worm Gear Type

Low-pressure-hose clamp tightening torque differs depending on the type of clamp. See below for correct tightening torque of each type of low-pressure-hose clamp. T-Bolt Type Band Clamp: 4.4 N m (0.45 kgf m, 3.25 lbf ft ) Worm Gear Type Band Clamp: 5.9 to 6.9 N m (0.6 to 0.7 kgf m, 4.3 to 5.1 lbf ft ) SM1018

SM1019

W1-2-8

EX255-EX285

TIGHTENING TORQUE WRONG

Connecting Hose

RIGHT

WARNING 1) When replacing hoses, be sure to use only genuine parts. Using hoses other than genuine hoses may cause oil leakage, hose rupture or separation of fitting, possibly resulting in a fire on the machine. (2) Do not install hoses kinked. Application of high oil pressure, vibration, or an impact to a kinked hose may result in oil leakage, hose rupture or separation of fitting. Utilize print marks on hoses when installing hoses to prevent hose from being installed kinked. (3) If hoses rub against each other, wear to the hoses will result, leading to hose rupture. Take necessary measures to protect hoses from rubbing against each other. Take care that hoses do not come into with moving parts or sharp objects.

SM1020

WRONG

RIGHT

Rubbing Against Each Other

SM1021

WRONG Clamp

RIGHT Clamp

Rubbing SM1022

WRONG

RIGHT

Rubbing Clamp SM1023

SECTION 2

EX255-EX285

UPPERSTRUCTURE

CONTENTS Group 1 -

Cab

Remove and Install Cab ....................... W2-1-1

Group 2 -

Counterweight

Remove and Install Counterweight ....... W2-2-1

Group 3 -

Main Frame

Remove and Install Main frame ............ W2-3-1

Group 4 -

Pump Device

Remove and Install Pump Device ........ W2-4-1 Disassemble Pump Device .................. W2-4-2 Assemble Pump Device ..................... W2-4-10 Disassemble Regulator ...................... W2-4-22 Assemble Regulator ........................... W2-4-24 Disassemble and Assemble Pilot Pump ......................................... W2-4-26 Maintenance Standard ....................... W2-4-28

Group 5 -

Control Valve

Remove and Install Control Valve ......... W2-5-1 Disassemble Control Valve 1 ................ W2-5-2 Assemble Control Valve 1-1 ................. W2-5-6 Assemble Control Valve 1-2 ................. W2-5-8 Disassemble Control Valve 2 .............. W2-5-10 Assemble Control Valve 2-1 ............... W2-5-14 Assemble Control Valve 2-2 ............... W2-5-16 Disassemble Control Valve 3 .............. W2-5-18 Assemble Control Valve 3-1 ............... W2-5-22 Assemble Control Valve 3-2 ............... W2-5-26 Disassemble Control Valve 4 .............. W2-5-28 Assemble Control Valve 4-1 ............... W2-5-32 Assemble Control Valve 4-2 ............... W2-5-34 Disassemble Control Valve 5 .............. W2-5-38 Assemble Control Valve 5 .................. W2-5-40

Group 6 -

Swing Device

Remove and Install Swing Device ........ W2-6-1 Disassemble Swing Device (EX255) .... W2-6-2 Assemble Swing Device (EX255) ......... W2-6-6 Disassemble Swing Device (EX285) .. W2-6-12 Assemble Swing Device (EX285) ....... W2-6-16 Disassemble Swing Motor (EX255) .... W2-6-22 Assemble Swing Motor (EX255) ......... W2-6-26 Disassemble Swing Motor (EX285) .... W2-6-30 Assemble Swing Motor (EX285) ......... W2-6-34 Disassemble and Assemble Parking Brake Release Valve (EX285) W2-6-38 Maintenance Standard ....................... W2-6-39

Group 7 -

Pilot Valve

Remove and Install Right Pilot Valve .... W2-7-1 Remove and Install Left Pilot Valve ...... W2-7-4 Remove and Install Travel Pilot Valve ............................................ W2-7-7 Disassemble Right and Left Pilot Valve ............................................ W2-7-8 Assemble Right and Left Pilot Valve .......................................... W2-7-10 Disassemble Travel Pilot Valve ........... W2-7-14 Assemble Travel Pilot Valve ............... W2-7-16 Positioning Pilot Valve (Triple Articulation Version) ................. W2-7-20 Special Tools ...................................... W2-7-31

Group 8 -

Pilot Shut-off Valve

Remove and Install Pilot Shut-off Valve ...................................... W2-8-1 Disassemble Pilot Shut-off Valve ......... W2-8-2 Assemble Pilot Shut-off Valve .............. W2-8-4

Group 9 -

Shockless Valve

Remove and Install Shockless Valve ... W2-9-1 Disassemble and Assemble Shockless Valve .................................. W2-9-2

Group 10 -

Solenoid Valve Unit

Remove and Install Solenoid Valve Unit .......................................... W2-10-1 Disassemble Proportional Solenoid Valve ................................... W2-10-2 Assemble Proportional Solenoid Valve ................................... W2-10-4

Group 11 -

Pilot Relief Valve Unit

Remove and Install Pilot Relief Valve Unit .......................................... W2-11-1 Disassemble Pilot Relief Valve ........... W2-11-2 Assemble Pilot Relief Valve ............... W2-11-4

EX255-EX285

W2-1-1

CAB REMOVE AND INSTALL CAB Remove Cab 1. Remove nuts (2) and seat (1). : 13 mm

1 2 SM1125

8

2. Loosen bolts (6) (3 used) and bolts (4) (4 used) behind the cab and remove rear cover (5).

7

8

: 13 mm 4

5

3. Loosen bolts (8) to remove rear under cover (7). : 13 mm

6 SM1126

4. Remove filter (20). Loosen screws (9) to remove duct (10) from the cab.

20 9 10 SM1127

W2-1-2

EX255-EX285

CAB 5. Disconnect cable connectors (11, relais), (12, antenna, ceiling lamp and windshield wiper), (13, loudspeaker) behind the cab and ground (14) inside the cab.

12 13

11

SM5526

6. Remove washer vinyl hose (15) behind the cab.

SM5509

7. Remove cap (21) from duct cover (16). Loosen screws (17) to remove duct cover (16).

21

17

16

SM1130

8. While pushing the mating surface of duct (18) toward the rear side of the cab, remove duct (18).

Mating surface of duct

18

SM1131

EX255-EX285

W2-1-3

CAB 9. Attaccare la cabina al paranco utilizzando cinghie di sollevamento.

WARNING The approximate weight of cab: 250 kg (551 lb)

SM1132

10. Remove bolts (19) and nuts (22). : 17 mm 19

: 24 mm : 8 mm 22

SM1133

11. Carefully remove cab.

SM1134

W2-1-4

EX255-EX285

CAB Installation

WARNING The approximate weight of cab: 250 kg (551 lb)

1. Attach cab to hoist using straps. Install cab onto frame. SM1134

2. Tighten bolts (19) and nuts (22). : 17 mm

19

: 49 N m (5 kgfm, 36 lbf ft) 22 : 24 mm : 205 N m (21 kgf m, 152 lbf ft) : 8 mm SM1133

: 64 N m (6.5 kgf m, 47 lbf ft)

3. Install duct (10) to the cab with screws (9). Install filter (20) into duct (10).

: 4.9 N m (0.5 kgf m, 3.6 lbf ft)

20 9 10

4. Install harness connectors (11, relais), (12, antenna, ceiling lamp and windshield wiper), (13, loudspeaker) behind the cab and ground (14) inside the cab.

SM1127

12 13

: 19.5 N m (2 kgf m, 14.5 lbf ft)

11

SM5526

EX255-EX285

W2-1-5

CAB 5. Connect washer vinyl hose (15) at the rear of the cab inside.

SM5509

8

6. Install rear under cover (7) with bolts (8).

7

8

: 13 mm : 19.5 N m (2 kgf m, 14.5 lbf ft) 4

5

7. Install rear cover (5) with bolts (6) (3 used) and bolts (4) (4 used). : 13 mm : 19.5 N m (2 kgf m, 14.5 lbf ft) 6 SM1126

8. Push duct (18) toward the front of the cab to insert it into the front duct.

Mating surface of duct

18

SM1131

W2-1-6

EX255-EX285

CAB 9. Install duct cover (16) with screws (17). Install caps (21) onto duct cover (16).

21

17

16

SM1130

10. Secure seat (1) with nuts (2). : 13 mm : 19.5 N m (2 kgf m, 14.5 lbf ft)

1 2 SM1125

EX255-EX285

W2-2-1

COUNTERWEIGHT REMOVE AND INSTALL COUNTERWEIGHT 1

Removal

WARNING Approximate weight of counterweight: 5 700 kg (12 566 lb)

1. Remove caps (1) from counterweight. Install eye-bolts to the counterweight.

SM1135

Eye-bolts: M36, Pitch 4.0

2. Attach wire rope (2) to eye-bolts using shackles. Take out slack of wire rope by applying tension slowly with a crane or hoist.

2

SM1136

3. Remove bolts (3). Lift counterweight using a crane or hoist. : 46 mm

3

SM1137

4. Lower the counterweight on proper stand.

SM1138

W2-2-2

EX255-EX285

COUNTERWEIGHT Installation

WARNING Approx. weight of counterweight: 5 700 kg (12 566 lb)

1. Attach lifting tools to counterweight. Lift counterweight (4) and install it onto the frame. Install bolts (3) and washers to counterweight and tighten temporarily.

4 3

: 46 mm

SM1137

2. Remove wire rope. Tighten the bolts with a power wrench (6) and torque wrench (7). : 46 mm : 1 570 N m (160 kgf m, 1 157 lbf ft)

6

3. Remove the eye-bolts. Install caps (1) to counterweight.

7

SM1139

1

SM1135

EX255-EX285

W2-3-1

MAIN FRAME REMOVE AND INSTALL MAIN FRAME WARNING Escaping fluid under pressure can penetrate the skin, causing serious injury. Avoid the hazard by relieving pressure before disconnecting hydraulic or other lines. Hydraulic oil may be hot just after operation. Hot hydraulic oil may spout, possibly causing severe burns. Be sure to wait for oil and components to cool before starting work. The hydraulic oil tank cap may fly off if removed without releasing internal pressure first. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. Preparation 1. Park the machine on a firm, level surface. 2. Stop the engine. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. Refer to "Hydraulic Circuit Pressure Release Procedure" on page W4-2-12.

3. Remove hydraulic oil tank cap. Connect a vacuum pump to maintain negative pressure in the hydraulic oil tank.

NOTE - Be sure to run the vacuum pump continuously while working.

Removal WARNING Approximate weight of cab: 250 kg (551 lb)

1. Remove cab assembly. (See Cab section)

: 24 mm, 17 mm, 13 mm : 8 mm SM1134

WARNING Approximate weight of counterweight: 5 700 kg (12 566 lb)

2. Remove the counterweight. (See Counterweight section) : 46 mm SM1136

W2-3-2

EX255-EX285

MAIN FRAME

WARNING Approx. weight of front attachment assembly: • EX255 monobloc: 4550 kg (10 031 lb) • EX255 triple articulation: 4890 kg (10 780 lb) • EX285 monobloc: 5600 kg (12 346 lb) • EX285 triple articulation: 5900 kg (13 007 lb)

3. Remove front attachment assembly from the upperstructure. (See Front Attachment section) : 19 mm, 30 mm, 36 mm, 41 mm

SM1140

4. Drain hydraulic oil from the hydraulic oil tank, and disconnect hydraulic lines from the control valve to the center t on top of the center t. Disconnect drain hose, and remove the fitting and stopper from the center t. : 19 mm, 22 mm, 27 mm, 36 mm SM1141

EX255-EX285

W2-3-3

MAIN FRAME

WARNING Approximate weight of main frame: EX255: 4000 kg (8818 lb) EX285: 4500 kg (9921 lb)

5. Attach wire ropes to the front and rear of main frame. See wire ropes taut using a crane. Use chain blocks for easy adjustment of wire rope lengths and to level the frame.

Rear SM1142

IMPORTANT - Make sure rear slings do not touch engine.

Front

SM1143

SM1144

6. Put matching marks on swing bearing and main frame. Remove bolts (14) from the swing bearing. : 32 mm

14 SM1380

W2-3-4

EX255-EX285

MAIN FRAME 7. Lift main frame slightly from undercarriage. Level main frame by adjusting the chain blocks. Remove main frame.

SM1146

EX255-EX285

W2-3-5

MAIN FRAME Installation 13

WARNING Approximate weight of main frame: EX255: 4000 kg (8818 lb) EX285: 4500 kg (9921 lb)

1. Fasten hoist to front and rear of main frame. Level main frame by adjusting chain blocks (13) and lower main frame onto undercarriage. Align the matching mark on the swing bearing with that on the main frame. SM1146

2. Install bolts (14) on the swing bearing and tighten temporary. Install main frame and tighten bolts to specification. : 32 mm Upperstructure side : 640 N m (65 kgf m, 470 lbf ft)

14 SM1380

3. Install fitting (10) and connect hose (8) to the center t.

4

: 19 mm

5

: 34 N m (3.5 kgf m, 25 lbf ft)

Connect lines (4 to 7). : 22 mm, 27 mm, 36 mm : 39 N m (4 kgf m, 29 lbf ft)

9

: 93 N m (9.5 kgf m, 69 lbf ft)

8

Install stopper (9). : 36 mm : 175 N m (18 kgf m, 130 lbf ft)

7

6

10 SM1141

W2-3-6

EX255-EX285

MAIN FRAME

WARNING Approx. weight of front attachment assembly: • EX255 monobloc: 4550 kg (10 031 lb) • EX255 triple articulation: 4890 kg (10 780 lb) • EX285 monobloc: 5600 kg (12 346 lb) • EX285 triple articulation: 5900 kg (13 007 lb)

4. Install front attachment assembly (3). (See Front Attachment section) : 19 mm : 29.5 N m (3 kgf m, 21.5 lbf ft) : 30 mm : 540 N m (55 kgf m, 400 lbf ft) : 36 mm : 137 N m (14 kgf m, 101 lbf ft) 3

: 41 mm

SM1140

: 205 N m (21 kgf m, 152 lbf ft)

WARNING Approximate weight of counterweight: 5 700 kg (12 566 lb) 1 5. Install counterweight (1). (See Counterweight in this section) : 46 mm : 1 570 N m (160 kgf m, 1 157 lbf ft)

SM1136

WARNING Approximate weight of cab: 250 kg (551 lb)

6. Install cab (2). (See Cab in this section) 2 : 24 mm : 205 N m (21 kgf m, 159 lbf ft) : 17 mm : 49 N m (5 kgf m, 36 lbf ft) : 13 mm : 20 N m (2 kgf m, 14 lbf ft) : 8 mm : 64 N m (6.5 kgf m, 47 lbf ft)

SM1134

EX255-EX285

W2-3-7

MAIN FRAME 7. Fill the hydraulic oil tank with hydraulic oil to the specified level. Run the engine at slow idle. Check hose connections for any oil leakage.

SM1147

W2-3-8

EX255-EX285

MAIN FRAME NOTES:

EX255-EX285

W2-4-1

PUMP DEVICE REMOVE AND INSTALL PUMP DEVICE WARNING Escaping fluid under pressure can penetrate the skin, causing serious injury. Avoid the hazard by relieving pressure before disconnecting hydraulic or other lines. Hydraulic oil may be hot just after operation. Hot hydraulic oil may spout, possibly causing severe burns. Be sure to wait for oil to cool before starting work. The hydraulic oil tank cap may fly off if removed without releasing internal pressure first. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. Preparation 1. Park the machine on a firm, level surface. 2. Stop the engine. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure.

3. Remove hydraulic oil tank cap. Connect a vacuum pump to maintain negative pressure in the hydraulic oil tank. NOTE - Be sure to run the vacuum pump continuously while working.

Removal

1

2

Air bleed plug

1. Disconnect connectors. WARNING Pump device weight: 170 kg (375 lb)

10 3

9 2. Disconnect hoses (1 to 4, 6 to 10) and pipe (5) from the pump device. : 19 mm, 22 mm, 27 mm, 36 mm : 8 mm, 10 mm

4 8

7 3. Attach eyebolts (M12, Pitch 1.75, Length 22) to the pump device, then connect to a hoist. 4. Remove pump device mounting bolts to remove pump device.

6

Installation 1. Install the pump device with pump device mounting bolts. 2. Connect hoses (1 to 4, 6 to 10) and pipes (5). 3. Connect connectors. IMPORTANT - Be sure to check hydraulic oil level and oil leakage, after assembling. Bleed the air from the pump. (Refer to W1-1-2) : 41 mm

SM1044

5

: 17 mm Wrench Size (mm)

Tightening Torque Nm

Remark

kgf m lbf ft

: 27

93

9.5

69

Hose

: 36

69

7

51

Hose

: 10

108

11

80

Bolt

: 17

49

5

36

Bolt

:8

49

5

36

Bolt

: 19

29

3

22

Hose

: 22

49

5

36

Pipe

: 78 N m (8 kgf m, 58 lbf ft)

W2-4-2

EX255-EX285

PUMP DEVICE DISASSEMBLE PUMP DEVICE 69

97

79

81

97 70

98

98

68 65 66 17

24

21 22

87 20 74 8 87 9

67 73 38 72

66 68

74 19

83

11 24 84

12

62 82 2

20 8 9

13

38 67

38 49

18 12

38 49

61

13

55

SM1045

52

36 47

23

48 15 34

45

37

46 1

32 16

31

30

40 14

39

41

28

43

5

6

7

3 54 53 55

26 25

SM1046

5 4

19

EX255-EX285

W2-4-3

PUMP DEVICE 88 51

96

50

74

74

85

75

86

64

60

93 38

38

71 89 44 92

35 75

35

64

75

35 33

57

58

42

29 33 27 77 76

91 56 59

33

78

96

35 77 76

35 90

29

88 33 75

78 SM1047

1 2 3 4 5 6 7 8 9 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

-

Gear Casing Pump Casing Pilot Gear Gear Shaft Bearing (2 Used) Retaining Ring Retaining Ring Bearing (2 Used) Bearing Nut (2 Used) Drive Disc Oil Seal (2 Used) Retaining Ring (2 Used) Gear Gear Retaining Ring (2 Used) Drive Disc Spring Pin (2 Used) Plunger (14 Used) Spacer Ring (2 Used) Bolt (6 Used) Spring Washer (6 Used) Packing Bearing (2 Used) Oil Seal Retaining Ring Valve Plate Pilot Pump Pin (4 Used) Socket Bolt (2 Used) Spring Washer (2 Used) Washer (2 Used) Pin (4 Used)

34 35 36 37 38 39 40 41 42 43 44 45

-

46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 64

-

Adapter (2 Used) Retaining Ring (12 Used) Plug Level Gauge O-Ring (6 Used) Pipe Gauge Socket Bolt (2 Used) Packing Servo Piston (2 Used) Plug Set Screw (2 Used) N sensor (Engine Speed Sensor) O-Ring Washer Socket Bolt Plug (2 Used) O-Ring (2 Used) Stopper (2 Used) Plug (2 Used) Adapter Plug Fitting plug (2 Used) Servo Pipe Clamp (2 Used) Bolt Spring Washer Socket Bolt (12 Used) O-Ring (2 Used) Thrust Ring Pump Pressure Sensor (2 Used)

65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 81 82 83 84 85 86 87 88 89 90 91 92 93 96 97 98

-

Pin (2 Used) Center Shaft (2 Used) Plug (2 Used) Spring (2 Used) Regulator (2 Used) Cylinder Block (2 Used) Valve Plate Spring Pin (4 Used) O-Ring (2 Used) O-Ring (20 Used) Lever (4 Used) Pin (2 Used) Link (2 Used) Pin (2 Used) Pipe Adapter (2 Used) Clamp Socket Bolt Spring Washer Backup Ring O-Ring O-Ring (4 Used) Socket Bolt (16 Used) Spring Pin (2 Used) Stopper (2 Used) O-Ring (2 Used) Pin (2 Used) Selector Head Spring Washer(16 Used) Socket Bolt (8 Used) Spring Washer(8 Used)

W2-4-4

EX255-EX285

PUMP DEVICE 69

79

81

97

SM1045

83

84

82 2 88 51

96

50

74

74

60

93 64

44 92

64

36 47

57

58

42

48 91 56 59 96

34 45

90 88

46 1

43 53 55 SM1046

SM1048

EX255-EX285

W2-4-5

PUMP DEVICE Disassemble Pump Device 1. Remove plug (43) to drain oil. Drain oil: Approx. 1.0 L (1.06 US qt)

8. Remove socket bolts (88), spring washers (96), stoppers (90), (51) and O-rings (91), (50), (74) from selector head (93). : 6 mm

: 8 mm

2. Remove plug (36) and adapters (34).

IMPORTANT - Be sure to heat set screw (44) to remove it. LOCTITE 829 was applied to set screw (44) when installed.

: 17 mm, 36 mm 9. Remove set screws (44), pins (92) and servo pistons (42) from selector head (93). 3. Loosen socket bolt (83) and then remove spring washer (84), clamp (82) and N sensor (45) connectors from pump casing (2). : 5 mm

: 6 mm

10. Remove socket bolt (48), spring washer (47), N sensor (45) and O-ring (46) from gear casing (1). : 5 mm

WARNING Pump device weight: 170 kg (375 lb)

4. Place the pump device with the transmission side positioned to the bottom side and secure it.

5. Remove bolt (58), adapter (53) and fitting plug (55). Remove spring washer (59), clamp (57) and servo pipe (56) from selector head (93). : 13, 17, 19 mm

WARNING Selector head weight: 30 kg (66 lb)

6. Remove socket bolts (60) from selector head (93). Remove selector head (93) assembly from pump casing (2). : 10 mm

7. Remove pump pressure sensors (64) from selector head (93). : 27 mm

11.Remove pipe (79) and adapters (81) from regulators (69). : 22 mm

W2-4-6

EX255-EX285

PUMP DEVICE

85

75

86

71

35

89 75

35 75

35 33 29 33

27 77 76

33

78

35 77

35

29

SM1047

76

33

75

78

69

97

81

97 70

98

98

68 65 66

74 21 22

73 87

66 68

74 19

2

SM1045

19

EX255-EX285

W2-4-7

PUMP DEVICE 12. Loosen socket bolts (97) and remove spring washers (98), regulators (69) and O-rings (73), (74), (87) from pump casing (2). : 8 mm

13. Remove backup ring (85), O-ring (86) and spring pins (89).

IMPORTANT - Valve plates (27) and (71) are exclusively used in the right and left pumps respectively. Take care not to mistake the up and down positions.

14. Remove retaining rings (35) and pins (29) to remove valve plates (27), (71). : 7 mm

15. Remove cylinder blocks (70), center shafts (66), springs (68) and plungers (19) from pump casing (2).

16. Remove links assemblies (77) from pump casing (2).

17. Remove retaining rings (35), pins (78), (33), (76) and levers (75) from links (77).

WARNING Pump casing weight: 43 kg (95 lb)

18. Attach the pump casing to crane or hoist using wire ropes. Loosen bolts (21) and remove pump casing (2) from gear casing (1). : 24 mm

W2-4-8

EX255-EX285

PUMP DEVICE

17 24 20 8

9

SM1045

11 24 62 12

20 2

8 9

13

18 12 61

13

52

23 15

32

31

30

16 1 14 28 5

6

7

3

26 25

SM1046

5 4

EX255-EX285

W2-4-9

PUMP DEVICE 19. Remove spring pins (18) from pump casing (2). Remove packing (23) from gear casing (1).

15

Aligning Mark

14

IMPORTANT - If aligning marks are not made, it is very hard to align pump timing when reassembling. 17 20. Put three aligning marks on each mashed parts: between gear (14) and drive disc (11) spline, gear (15) and drive disc (17) spline, gears (14) and (15), as illustrated.

11 16

16

SM1049

21. Remove retaining rings (16) and gears (14) and (15) from to drive discs (11) and (17).

22. Remove retaining rings (13) and oil seals (12) from drive discs (11) and (17). 75301492 23. Loosen plugs (52) to remove O-rings (61). Using a press, pull drive discs (11) and (17) assembly out of pump casing (2). Then, remove thrust ring (62).

24. Using special tool (75301492), remove bearing nuts (9) from drive discs (11) and (17). SM1050

25. Using a press, remove bearings (8), (24) and spacer rings (20) from drive discs (11) and (17).

26. Loosen bolts (30) to remove pilot pump (28) from gear casing (1). : 6 mm 75301488 27. Remove retaining rings (6) and (7) from gear casing (1). Pull off upper side bearing (5) and gear shaft (4) using special tool (75301488).

28. Remove pilot gear (3) from gear casing (1). Then, pull off the other side bearing (5).

29. Remove retaining ring (26) and oil seal (25) from gear casing (1).

4

3

5

SM1051

W2-4-10

EX255-EX285

PUMP DEVICE ASSEMBLE PUMP DEVICE 34

36

59

2

58 10

57

56

55

SM3017

53

37

39 40

41

43

64

28

60

30

31

32

1 3 4 5 6 7 16 14 15 18 23 45-46 47-48

98

97

82

83

84

SM1053

EX255-EX285

W2-4-11

PUMP DEVICE

74 51

50 88 79

86 35 81 85 87 74 69 73 76 78 77 65 66 2 8 9 12

13 16 17

68

11

75

72

44 92 25 26 62 29 35 42 93

38 49 71 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

-

Gear Casing Pump Casing Pilot Gear Gear Shaft Bearing (2 Used) Retaining Ring Retaining Ring Bearing (2 Used) Bearing Nut (2 Used) Main pump Drive Disc Oil Seal (2 Used) Retaining Ring (2 Used) Gear Gear Retaining Ring (2 Used) Drive Disc Spring Pin (2 Used) Plunger (14 Used) Spacer Ring (2 Used) Bolt (6 Used) Spring Washer (6 Used) Packing Bearing (2 Used) Oil Seal Retaining Ring Valve Plate Pilot Pump Pin (4 Used) Socket Bolt (2 Used) Spring Washer (2 Used) Washer (2 Used)

91 96 90 89 33 70 19 52 24 20 61 35

33 34 35 36 37 38 39 40 41 42 43 44 45

-

46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 64

-

Pin (4 Used) Adapter (2 Used) Retaining Ring (12 Used) Plug Level Gauge O-Ring (6 Used) Pipe Gauge Socket Bolt (2 Used) Packing Servo Piston (2 Used) Plug Set Screw (2 Used) N sensor (Engine Speed Sensor) O-Ring Washer Socket Bolt Plug (2 Used) O-Ring (2 Used) Stopper (2 Used) Plug (2 Used) Adapter Plug Fitting plug (2 Used) Servo Pipe Clamp (2 Used) Bolt Spring Washer Socket Bolt (12 Used) O-Ring (2 Used) Thrust Ring Pump Pressure Sensor (2 Used)

SM1054

22-21

65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 81 82 83 84 85 86 87 88 89 90 91 92 93 96 97 98

-

Pin (2 Used) Center Shaft (2 Used) Plug (2 Used) Spring (2 Used) Regulator (2 Used) Cylinder Block (2 Used) Valve Plate Spring Pin (2 Used) O-Ring (2 Used) O-Ring (20 Used) Lever (4 Used) Pin (2 Used) Link (2 Used) Pin (2 Used) Pipe Adapter (2 Used) Clamp Socket Bolt Spring Washer Backup Ring O-Ring O-Ring (4 Used) Socket Bolt (16 Used) Spring Pin (2 Used) Stopper (2 Used) O-Ring (2 Used) Pin (2 Used) Selector Head Spring Washer(16 Used) Socket Bolt (8 Used) Spring Washer(8 Used)

W2-4-12

EX255-EX285

PUMP DEVICE 34

6

1 3

SM3017

4 5

43

7

SM1053

8 17 11

SM1055

24

20

9

EX255-EX285

W2-4-13

PUMP DEVICE Assemble Pump Device

7

6

4

5

1. Drive bearing (5) into gear casing (1). Install pilot gear (3). Drive in gear shaft (4) so that the spline aligns with that of pilot gear (3).

1 3

2. Drive the other bearing (5) onto gear shaft (4). 5 3. Install retaining ring (7) to gear casing (1) and retaining ring (6) to gear shaft (4).

4. Wind seal tape around adapters (34) (2 used) and tighten them to gear casing (1). : 36 mm

SM1056

8

8

20

20

: 69 N m (7 kgf m, 51 Ibf ft) 24

24

5. Tighten plug (43). : 8 mm

11

17

: 49 N m (5 kgf m, 36 Ibf ft) SM1057

6. Heat inner race of bearings (24) and (8) to 50 to 80 °C (122 to 176 °F). Apply a film of hydraulic oil to inner race of bearings (24), then install bearings (24) onto drive discs (11) and (17) using a press. 75301492

9

7. Apply a film of hydraulic oil to inner race of bearings (8), then install spacer rings (20) and bearings (8) onto drive discs (11) and (17) using a press.

8. Apply a film of hydraulic oil to bearing nuts (9) (2 used) thread. Tighten bearing nuts (9) until they come in with bearings (8), using special tool (75301492).

SM1050

9. Rotate bearings (8) 2 to 3 turns for break-in, using special tool (75301491). 10. Follow the above three steps to adjust starting torque to specification. Starting torque specification: 2.16±0.49 N m (0.22±0.05 kgf m, 1.59±0.36 Ibf ft)

75301491 9 8

20 IMPORTANT - If starting torque is increased over the specification, loosen bearing nut (9) then tap drive discs (11) and (17) shaft end to release load. Retry steps 8. to 10. to adjust the starting torque.

24 11-17 SM1058

W2-4-14

EX255-EX285

PUMP DEVICE 2

62

8

11

17

SM1059

24

16

14 15

SM1053

12

13

SM1055

52-61

EX255-EX285

W2-4-15

PUMP DEVICE 11. Install thrust ring (62) into pump casing (2). (Drive disc (11) side only.) 12. Heat pump casing (2) to 50 to 80 °C (122 to 176 °F). Apply a film of hydraulic oil to the outer circumference of roller bearings (8) and (24). Install drive disc (11) and (17) assemblies into pump casing (2).

75301490 12

13. Apply a film of grease to O-rings (61) (2 used) then install them onto plugs (52) (2 used). Tighten plugs (52) to pump casing (2). : 19 mm : 34 N m (3.5 kgf m, 25 Ibf ft) 14. Install special tools (75301489 and 75301490) over the spline parts of drive discs (11) and (17) to protect oil seals (12) from being damaged. If the special tools are not available, wind adhesive tapes over the spline parts. IMPORTANT - Apply a film of grease to oil seal (12) (2 used) lip.

Shaft side Long Shaft Side

15. Drive oil seal (12) (2 used) as illustrated. Remove the special tools. 16. Install retaining rings (13) (2 used).

SM1060

75301489

Short Shaft Side

75301493

When replacing drive discs (11), (17) and / or transmission gears (14), (15) IMPORTANT - Install special tool with the D mark facing toward long drive disc (11) side. M8x1,25

SM1061

17. Install special tool (75301493) to drive discs (11), (17). 18. Rotate drive discs (11), (17) clockwise, as viewed from the shaft end side to remove circumferential play between the special tool and drive discs (11), (17). 15

19. Install gear (15) and retaining ring (16) onto drive disc (17). 20. Install gear (14) so that both splines on drive disc (11) and gear (15) teeth, can correctly engage with those of gear (14). Install retaining ring (16) onto drive disc (11). IMPORTANT - Although drive disc (11) is held unrotable with special tool (75301493), it may be necessary to jolt drive disc (11) in order to install gear (14). When not replacing drive discs (11), (17) and/or transmission gears (14),(15) 21. Align the marks for drive disc (11) and gear (14). Also, align the marks for drive disc (17) and gear (15).

Aligning Mark

14

17 11 16

16

SM1049

W2-4-16

EX255-EX285

PUMP DEVICE

28

30

31

32

1

53 39 40 55

41

3

28

SM3017

14

23 18

22-21 35 76 78 77

2

17 11

75

33-35

SM1054

SM1053

EX255-EX285

W2-4-17

PUMP DEVICE 22. Install spring pins (18) (2 used) and packing (23) to gear casing (1).

WARNING Pump casing weight: 43 kg (95 Ib)

23. Sling pump casing (2) with a crane and install it to gear casing (1) so that pilot gear (3) engages gear (14).

24. Tighten bolts (21) (6 used) with spring washers (22) (6 used). : 24 mm : 147 N m (15 kgf m, 109 Ibf ft)

25. Apply THREEBOND 1215 to gear casing (1) surface. Install pilot pump (28) to gear casing (1), then tighten socket bolts (30) (2 used) with spring washers (31) (2 used) and washers (32) (2 used). : 8 mm : 49 N m (5 kgf m, 36 Ibf ft)

26. Install adapter (53) and fitting plug (55) onto pilot pump (28). : 27 mm : 93 N m (9.5 kgf m, 69 Ibf ft) : 6 mm : 34 N m (2 kgf m, 15 Ibf ft)

27. Install packing (41) and pipe gauge (39) to gear casing (1). Then tighten with socket bolts (40) (2 used). : 6 mm : 19.5 N m (2 kgf m, 15 Ibf ft)

28. With retaining rings (35) (2 used) installed to the one side of pins (76) (2 used), drive pins (76) (2 used) into links (77) (2 used). Then, install retaining rings (35) (2 used) to the other side of pins (76) (2 used).

29. Install levers (75) (4 used), pins (33) (4 used), and retaining rings (35) (4 used) to the U type end of links (77) (2 used). 30. Install pins (78) (2 used) to links (77) (2 used).

W2-4-18

EX255-EX285

PUMP DEVICE

74

86 85 87 74 69 73

78 77 65 66

68

17

75

11

44 92

35- 29 42 93

SM1054

89

70 19

2

45-46

47-48

98

97

SM1053

EX255-EX285

W2-4-19

PUMP DEVICE 31. Apply a film of hydraulic oil to the spherical surface of drive discs (11) and (17) and insert plungers (19) (7 used).

32. After applying grease to the hole of center shaft (66) (2 used), install pins (65). Install center shafts (66) into the center spherical surface section of drive discs (11) and (17). Then, install springs (68) (2 used).

33. Assemble plungers (19) (14 used) and center shafts (66) (2 used) into cylinder blocks (70) (2 used).

34. Pinch the tip of center shafts (66) with pliers to rotate the center shaft and install pins (65) (2 used) into the groove on cylinder blocks (70) (2 used).

38. Install O-rings (73) (2 used), (74) (10 used), and (87) (4 used) onto pump casing (2). Install regulators (69) (2 used) onto pump casing (2) using socket bolts (97) (8 used) and spring washers (98) (8 used). (Refer to "Assemble Regulator" on page W2-4-24.) : 8 mm : 49 N m (5 kgf m, 36 lbf ft)

39. Install backup ring (85), spring pins (89) (2 used) and O-ring (86) into pump casing (2). Install O-rings (74) (4 used) to selector head (93).

40. Apply a film of grease to O-ring (46). Install N sensor (45) to gear casing (1) then tighten with socket bolt (48) and washer (47). : 5 mm : 9.8 N m (1 kgf m, 7.2 lbf ft)

IMPORTANT - Take care not to damage the O-ring (73) groove when driving in pins (78).

41. Assemble servo pistons (42) (2 used) and pins (92) (2 used) to selector head (93).

35. After installing links (77) (2 used) assembly into pump casing (2), drive pins (78) (2 used) into the groove on the mounting surface of regulators (69) so that the pin end is flush with the mounting surface.

IMPORTANT - Apply LOCTITE LI829 to set screws (44).

36. Apply a film of LOCTITE LI829 to the threads of pins (29) (4 used). Then, tighten the pins (2 used) into valve plates (27) and (71). : 7 mm : 9.8 N m (1 kgf m, 7.2 lbf ft)

37. Install pins (29) into the hole of levers (75). Install retaining rings (35) (4 used).

IMPORTANT - Valve plates (27) and (71) are exclusively used in the right and left pumps respectively. Replacing the right with the left or up-side-down is not applicable. Install the valve plates so that the suction port is positioned to the upper side of the center when viewed from the front.

42. Tighten set screws (44) (2 used) to the smaller diameter side of servo pistons (42) (2 used) to secure pins (92) (2 used). : 6 mm : 34 N m (3.5 kgf m, 25 lbf ft)

W2-4-20

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PUMP DEVICE 96 88 51

50

74

2

11

93

25 26

SM1054

91 88 90 89 96

34

56 59 58 57

36

1

2

82 83 84

93

55 64 60 SM3017

EX255-EX285

W2-4-21

PUMP DEVICE 43. Apply a film of grease to stoppers (51) (2 used), (90) (2 used) and O-rings (50) (2 used), (91) (2 used). Assemble O-rings (50) (2 used), (91) (2 used) to stoppers (51) (2 used), (90) (2 used). Install stoppers (51) (2 used), (90) (2 used) to selector head (93), then tighten with spring washers (96) (16 used) and socket bolts (88) (16 used). : 6 mm : 19.5 N m (2 kgf m, 15 lbf ft)

50. Connect servo pipe (56) then clamp it using bolt (58) and clamp (57). : 13 mm : 2.9 N m (0.3 kgf m, 25 lbf ft)

51. Fix the N sensor connector on pump casing (2) using clamp (82), spring washer (84), and socket bolt (83). : 5 mm : 10 N m (1 kgf m, 7.2 lbf ft)

WARNING Selector head weight: 30 kg (66 lb)

44. Sling selector head (93) assembly with a crane. Install O-ring (74) (6 used) to pump casing (2). Install the selector head onto pump casing (2) so that spring pins (89) (2 used) align with the pin holes on the selector head. Then tighten socket bolts (60) (12 used).

52. Install special tool (75301490) to drive disc (11). Apply a film of grease to oil seal (25) and install the oil seal to drive disc (11). Remove special tool (75301490) and drive in oil seal (25). Install retaining ring (26). If special tool (75301490) is not available, wind tape around the spline of drive disc (11) to protect the oil seal from being damaged when installing.

: 10 mm : 108 N m (11 kgf m, 80 lbf ft)

45. Tighten pump pressure sensors (64) (2 used) to selector head (93). : 27 mm : 98 N m (10 kgf m, 72 lbf ft)

53. Supply oil into gear casing (1) through adapter (34) about 1.0 liters (1.06 US qt). Tighten plug (36) to adapter (34). : 17 mm : 69 N m (7 kgf m, 51 lbf ft)

54. Install level gauge to pipe gauge (39).

46. Temporarily tighten fitting plug (55) onto pump casing (2).

47. Temporarily tighten clamps (57) (2 used) to selector head (93) with washer (59) and bolt (58).

75301490

25

48. Insert servo pipe (56) between clamps (57) (2 used) and tighten the nut for fitting plug (55). : 19 mm : 34 N m (3.5 kgf m, 25 lbf ft) 49. Tighten servo pipe (56). : 17 mm : 34 N m (3.5 kgf m, 25 lbf ft)

SM1062

W2-4-22

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PUMP DEVICE DISASSEMBLE REGULATOR

49

24

27

28

20

21

14

34

15 29

17

17 12 16

16 14 SM1063

9

35

8

7

6

5

3

97-98

2

1

40

47 48

41

14

15

13

37-38

12

36

SM1064

1 2 3 5 6 7 8 9 12 13 14

-

Regulator Casing Sleeve A Spool A Load Cylinder Load Piston O-Ring Backup Ring O-Ring Stopper (2 Used) Stopper O-Ring (3 Used)

15 16 17 20 21 24 27 28 29 34 35

-

O-Ring (2 Used) Nut (2 Used) Nut (2 Used) Piston Cylinder Inner Stopper Sleeve B Spool B Set Screw Nut Cover

36 37 38 40 41 47 48 49 97 98

-

Cover Socket Bolt (8 Used) Spring Washer (8 Used) Plug O-Ring Spring Spring Spring Socket Bolt (4 Used) Spring Washer(4 Used)

EX255-EX285

W2-4-23

PUMP DEVICE Disassemble Regulator IMPORTANT - When disassembling the regulator, do not disassemble adjusting parts (12), (16), (17), (29), (34) unless necessary. If disassembled the performance curve of the regulator is changed. To adjust the regulator, refer to the Operational Perform-ance Test. Section in the Technical Manual (Troubleshooting).

1. Hold regulator casing (1) of regulator with a vice and remove plug (40). : 41 mm

2. Loosen socket bolts (37) to remove covers (36), (35) assembly. : 6 mm

3. Remove springs (47), (48) from regulator casing (1).

4. Remove load cylinder (5) from regulator casing (1) by pushing spool A (3).

5. Remove load piston (6), O-ring (7), (9) and backup ring (8) from load cylinder (5).

6. Remove sleeve A (2) with spool A (3) from regulator casing (1).

7. Remove spool A (3) from sleeve A (2).

8. Remove sleeve B (27), spool B (28) and spring (49) from regulator casing (1).

9. Remove piston (20), O-ring (14) and cylinder (21) from regulator casing (1).

W2-4-24

EX255-EX285

PUMP DEVICE ASSEMBLE REGULATOR 49

24

27

28

20

21

14

34

15 29

17

17 12 16

16 14 SM1063

9

8

7

6

5

3

2

1

47 48

14

15

13

12

76 SM1066

79

35

97-98

40

41

37-38

36

SM1065

87

1 2 3 5 6 7 8 9 12 13 14 15 16

-

Regulator Casing Sleeve A Spool A Load Cylinder Load Piston O-Ring Backup Ring O-Ring Stopper (2 Used) Stopper O-Ring (3 Used) O-Ring (2 Used) Nut (2 Used)

17 20 21 24 27 28 29 34 35 36 37 38 40

-

Nut (2 Used) Piston Cylinder Inner Stopper Sleeve B Spool B Set Screw Nut Cover Cover Socket Bolt (8 Used) Spring Washer (8 Used) Plug

74

73

41 47 48 49 73 74 76 79 81 87 97 98

-

O-Ring Spring Spring Spring O-Ring O-Ring (5 Used) Pin Pipe Adapter O-Ring (2 Used) Socket Bolt (4 Used) Spring Washer (4 Used)

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W2-4-25

PUMP DEVICE Assemble Regulator IMPORTANT - Take care not to mistake the combination and direction of spool B (28) and sleeve B (27). 1. Apply a film of hydraulic oil to spool B (28) and sleeve B (27). Install spool B (28) into sleeve B (27) and install into regulator casing (1).

2. Apply a film of hydraulic oil to spool A (3) and sleeve A (2), install into regulator casing (1).

10. Install regulator casing assembly to pump casing, then tighten with socket bolts (97) (4 used) and spring washers (98) (4 used). : 8 mm : 49 N m (5 kgf m, 36 lbf ft)

IMPORTANT - Install the pin for the link in the groove for sleeve B (27) and sleeve A (2) in regulator casing (1). Using tape, hold the grooves for sleeve B (27) and sleeve A (2) so that both grooves are aligned. Then, after installing, be sure to remove the tape. Check through the hole of plug (40) that pin (76) is surely installed into sleeve B (27) and sleeve A (2).

3. Apply a film of grease to O-ring (7), (9) then install O-rings (7), (9) and backup ring (8) to load cylinder (5).

Before operating the pump, bleed air trapped in the pump casing and fill the pump casing with hydraulic oil.

4. Install load piston (6) into load cylinder (5) and install into regulator casing (1).

11. Tighten adapter (81) and pipe (79) onto regulator casing (1). : 19 mm

5. Apply a film of grease to O-rings (14) (2 used) then install on stoppers (12) (2 used). IMPORTANT - Stopper (13) length is different from that of inner stopper (24). Inner stopper (24) is the shortest.

6. Install cover (35) with spring (49) onto regulator casing (1). Install and tighten socket bolts (37) (4 used) and spring washers (38) (4 used).

: 34 N m (3.5 kgf m, 25 lbf ft) : 22 mm : 49 N m (5 kgf m, 36 lbf ft)

12. Install O-ring (41) onto plug (40), tighten it onto regulator casing (1). : 41 mm : 78 N m (8 kgf m, 58 lbf ft)

: 6 mm : 19.8 N m (2 kgf m, 15 lbf ft)

7. Install O-ring (14), piston (20) in cylinder (21), and install into regulator casing (1).

8. Install cover (36) with springs (48), (47) onto regulator casing (1) Install and tighten socket bolts (37) (4 used) and spring washers (38) (4 used). : 6 mm : 19.8 N m (2 kgf m, 15 lbf ft)

9. Apply a film of grease to O-rings (73), (74) (5 used), (87) (2 used) and install them onto the pump casing (2).

IMPORTANT - Be sure to fill the casing with hydraulic oil before operating the pump.

W2-4-26

EX255-EX285

PUMP DEVICE DISASSEMBLE AND ASSEMBLE PILOT PUMP

27 13 26

10

10

12

1 9

6

26 14

27 6 9 2 3

5

16 15

SM1066

7 12

EX255-EX285

W2-4-27

PUMP DEVICE Item

Part Name

Q.ty Wrench Size mm

Tightening Torque lbf ft kgf m Nm

Remarks

1

Housing

1

2

Flange

1

3

Oil Seal

1

5

Retaining Ring

1

6

Seal

2

7

Cover

1

9

Backup Ring

2

10

Key

2

12

O-ring

2

13

Gear

1

14

Gear

1

15

Washer

4

16

Bolt

4

26

Bushing

2

Apply a film of hydraulic oil to bushing when installing

27

Bushing

2

Apply a film of hydraulic oil to bushing when installing

Apply grease to oil seal lip when installing

Apply grease to seal when installing

Apply grease to backup ring when installing

Apply grease to O-ring when installing

:17

39 to 44 4 to 4.5 29 to 33

W2-4-28

EX255-EX285

PUMP DEVICE MAINTENANCE STANDARD Pump device Unit: mm (in)

Gear Backlash

Standard

Allowable Limit

Rimedy

0.68 (0.03)

1.5 (0.06)

Replace

Main Pump 1. Tooth thickness (Driving disc splines). Unit: mm (in) Standard

Allowable Limit

5.4 (0.21)

3.8 (0.15)

2. Sleeve diameter (Driving disc). Unit: mm (in) Standard

Allowable Limit

1

45 (1.77)

44.8 (1.76)

2

55 (2.17)

54.8 (2.16)

3

55 (2.17)

54.8 (2.16)

SM1068

3. Clearance between plunger and driving disc (b). Unit: mm (in) Standard

Allowable Limit

0.058 (0.002)

0.4 (0.016)

b

SM1069

4. Clearance between plunger (a) and cylinder block (D). (D - a) Unit: mm (in) Standard

Allowable Limit

0.043 (0.002)

0.08 (0.003)

D a SM1070

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W2-4-29

PUMP DEVICE 5. Clearance between plunger and connecting rod. Unit: mm (in) Standard

Allowable Limit

0.15 (0.006)

0.4 (0.016)

Plunger

Connecting rod

SM1071

6. Clearance between small chamber (D) and servo piston (a). D-a Unit: mm (in) Standard

Allowable Limit

0.083 (0.003)

0.2 (0.008)

Small Chamber Side

D a

7. Clearance between large chamber (D) and servo piston (a). D-a Unit: mm (in) Standard

Allowable Limit a

0.079 (0.003)

0.2 (0.008)

8. Clearance between valve plate (D) and servo piston (a). D-a Unit: mm (in) Standard

Allowable Limit

0.051 (0.002)

0.3 (0.011)

Large Chamber Side

D

D

SM1072

a

SM1073

W2-4-30

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PUMP DEVICE NOTES

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W2-5-1

CONTROL VALVE REMOVE AND INSTALL CONTROL VALVE WARNING Escaping fluid under pressure can penetrate the skin, causing serious injury. Avoid the hazard by relieving pressure before disconnecting hydraulic or other lines. Hydraulic oil may be hot just after operation. Hot hydraulic oil may spout, possibly causing severe burns. Be sure to wait for oil to cool before starting work. The hydraulic oil tank cap may fly off if removed without releasing internal pressure first. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. Preparation 1. Park the machine on a firm, level surface. 2. Stop the engine. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. Refer to “Hydraulic Circuit Pressure Release Procedure” on page W4-2-12.


Removal

1. Install control valve to frame and tighten the bolts.

NOTE - Attach caps to hoses and pipes. Attach labels or tags to hoses and pipes, to aid in assembly.

2. Connect all hoses, pipes and connectors to the control valve.

1. Disconnect all hoses, pipes and connectors from the control valve. : 17 mm : 9.8 N m (1 kgf m, 7 lbf ft) : 19 mm : 34 N m (3.5 kgf m, 25 lbf ft) : 22 mm : 49 N m (5 kgf m, 36 lbf ft) : 36 mm : 175 N m (18 kgf m, 130 lbf ft) : 8 mm : 64 N m (6.5 kgf m, 147 lbf ft) : 10 mm : 108 N m (11 kgf m, 80 lbf ft)


IMPORTANT - After completing installation: Check hydraulic oil level. Add oil if necessary. Run the engine. Check the engine components for any oil leakage. A B

C

D E

SM1191

E D

C

B

A

WARNING Control valve assembly weight: 240 kg (530 lb) 2. Remove control valve mounting bolts. : 24 mm : 205 N m (21 kgf m, 150 lbf ft)

Installation SM1192

NOTE - Refer to “Removal” section above for wrench sizes and tightening torques.

A = Swing B = Arm I C = Boom II

D = Auxiliary E = Travel left

W2-5-2

EX255-EX285

CONTROL VALVE DISASSEMBLE CONTROL VALVE 1

E = Travel Flow Control Valve F = Pump Control Valve

1

2

E 3

4 5

6

7

8

17 17 18

12

19 20 F 21 55

22 39

40

40

51

41

39

39 35 38

38

23

37

24 25 26 27 28 35 29

42

30 43 31 44 34

39 36

32

33 SM1193

1 2 3 4 5 6 7 8 12 17 18 19 20 21

-

Plug (Restriction) O-Ring Plug Spool Seat Spring O-Ring Plug Pilot Plate Socket Bolt Lock Nut Screw Washer O-Ring

22 23 24 25 26 27 28 29 30 31 32 33 34 35

-

Plug O-Ring Spring Seat Spool Sleeve O-Ring Spool Sleeve O-Ring Seat Retaining Ring Spring O-Ring

36 37 38 39 40 41 42 43 44 51 55

-

Housing (5-Spool Side) O-Ring O-Ring O-Ring Spring Check Valve Spring Poppet Sleeve Check Valve Pilot Plate

EX255-EX285

W2-5-3

CONTROL VALVE Disassemble Control Valve 1 •

Be sure to thoroughly read “Precautions for Disassembly and Assembly” on page W1-1-1 before starting the disassembly work.

•

Travel Flow Control Valve 1. Loosen and remove plug (8) from pilot plate (12). : 36 mm

2. Remove spring (6), seat (5), and spool (4) from pilot plate (12).

3. Loosen and remove plug (3) from pilot plate (12).

4. Loosen and remove plug (1) from pilot plate (12). : 5 mm

5. Loosen socket bolts (17) to remove pilot plate (12) from housing (36). : 10 mm

6. Loosen socket bolts (17) to remove pilot plate (55) from housing (36). : 10 mm

W2-5-4

EX255-EX285

CONTROL VALVE

17 18 19 X 55

40 51

22 40

24

41

25 26 27

Y 29

42

30 43 44 34 36

Z

X = Pump Control Valve Y = Load Check Valve Z = Load Check Valve

32

33 SM1193

EX255-EX285

W2-5-5

CONTROL VALVE •

Load Check Valve 7. Remove springs (40) and (42), check valves (41) and (51), poppet (43), and sleeve (44) from housing (36).

•

Pump Control Valve 8. Remove plug (22) from housing (36). Take care not to drop spring (24), seat (25), and spool (26) at this time. : 38 mm

NOTE - Do not remove lock nut (18) and screw (19).

9. Attach the nut (M8 Pitch 1.25) to spool (29). Remove spool (29) together with sleeve (30) from housing (36).

10. Remove retaining ring (33), seat (32), and spring (34).

11. Pull out spool (29) and sleeve (27) from sleeve (30).

W2-5-6

EX255-EX285

CONTROL VALVE ASSEMBLE CONTROL VALVE 1-1

C

B A

36

36

51

51

39

39

40

40

55

55

38

40

36 17

17

12

55

39

SM1194

51

SM1195

SM1196

18 21 25 26

28 27 29

32 34 32 33 A= B= C= D= E= F=

D SM1197

19 20 22 23 24

31

Side View of 5 - Spool Control Valve Swing Arm I Pump Control Valve Boom II Travel (left)

30 F

E

36 44 36 43 51 39 39 42 40 12 12 40 38 39 41 SM1199 SM1198

12 17 18 19 20 21 22 23

-

Pilot Plate Socket Bolt Lock Nut Screw Washer O-Ring Plug O-Ring

24 25 26 27 28 29 30 31

-

Spring Seat Spool Sleeve O-Ring Spool Sleeve O-Ring

32 33 34 36 38 39 40 41

-

Seat Retaining Ring Spring Housing (5-Spool Side) O-Ring O-Ring Spring Check Valve

42 43 44 51 55

-

Spring Poppet Sleeve Check Valve Pilot Plate

EX255-EX285

W2-5-7

CONTROL VALVE Assemble Control Valve 1-1 •

Pump Control Valve 1. Insert spool (29) onto sleeve (30). 2. Install seat (32), spring (34), and seat (32) on spool (29), in that order. Secure with retaining ring (33).

3. Install O-rings (28) (2 used) on sleeve (27). Insert sleeve (27) into sleeve (30). 4. Install O-rings (31) (3 used) on sleeve (30). Install sleeve (30) into housing (36). 5. Install spool (26) onto spool (29). 6. Install spring (24), seat (25), and O-ring (23) onto plug (22). Install plug (22) onto housing (36). : 38 mm : 84 N m (8.6 kgf m, 62 lbf ft)

•

Load Check Valve (5-spool side) 7. Install poppet (43) and spring (42) into sleeve (44). Install sleeve (44) into housing (36). 8. Install pairs of check valve (41) and spring (40), and check valves (51) and springs (40) (5 used each) into housing (36). 9. Install O-rings (39) and (38) onto housing (36). 10. Install pilot plate (55) on housing (36). : 10 mm : 78 N m (8 kgf m, 58 lbf ft)

W2-5-8

EX255-EX285


B

A

36 17

17

X

12

55

55

51 36 SM1194

1

3

SM1196

C

2

A = Side view of 5 Spool Control Valve B = Arm I C = Cross Section X D = Auxiliary E = Travel (left) F = Travel Flow Control Valve

SM1200

12

E

D

36 39

36 F

40

8

7

6

51

5

12

4

37

12

38

SM1199 SM1201

1 2 3 4 5

-

Plug (Restriction) O-Ring Plug Spool Seat

6 7 8 12 17

-

Spring O-Ring Plug Pilot Plate Socket Bolt

36 - Housing (5-Spool Side) 37 - O-Ring 38 - O-Ring 39 - O-Ring

40 - Spring 51 - Check Valve 55 - Pilot Plate

EX255-EX285

W2-5-9


Load Check Valve (5-spool side) 1. Install check valve (51) and spring (40) into housing (36). 2. Install O-rings (37), (38), and (39) on housing (36). 3. Install pilot plate (12) on housing (36). : 10 mm : 78 N m (8 kgf m, 58 lbf ft)

•

Travel Flow Control Valve 4. Install spool (4), seat (5), spring (6) into pilot plate (12). Install O-ring (7) on plug (8). Install plug (8) onto pilot plate (12). : 36 mm : 98 N m (10 kgf m, 72 lbf ft) 5. Install plug (1) onto pilot plate (12). 6. Install O-ring (2) onto plug (3). Install plug (3) onto pilot plate (12). : 5 mm : 15 N m (1.5 kgf m, 11 lbf ft)

W2-5-10

EX255-EX285

CONTROL VALVE DISASSEMBLE CONTROL VALVE 2

1 61

2

59

60 3

58

4

57

F

5 56

6

6

55

7

21

54

23

53

24

22 6

8

8

H G

52

6

6

51

9

20

50

30

49

29

31

47

48

46

45

26 25 32 27 33 34 28

10

8

11 12

30 38

13 L

37

14

39 36

35

15 16 19

17 18

19 F= G= H= L =

SM1202

1 2 3 4 5 6 7 8 9 10 11 12 13 14

-

Housing (4-Spool Side) Spool Spring O-Ring Plug O-Ring Check Valve Spring Poppet Poppet Spring Plug Spring Spacer

15 16 17 18 19 20 21 22 23 24 25 26 27 28

-

O-Ring O-Ring Plug Filter Socket Bolt Check Valve Check Valve O-Ring O-Ring O-Ring Plug Screw O-Ring Backup Ring

29 30 31 32 33 34 35 36 37 38 39 45 46 47

-

Load Check Valve Load Check Valve Bucket Flow Control (Restriction) Bucket Flow Control Valve (Switch Valves A and B)

Plug O-Ring Retaining Ring Seat Spring Spool Pilot Plate Spool Seat Spring Pilot Plate Screw Lock Nut Washer

48 49 50 51 52 53 54 55 56 57 58 59 60 61

-

O-Ring Plug O-Ring Spring Seat Spool Sleeve O-Ring Spool Sleeve O-Ring Seat Spring Retaining Ring

EX255-EX285

W2-5-11


Be sure to thoroughly read “Precautions for Disassembly and Assembly” on page W1-1-1 before starting the disassembly work. 1. Loosen socket bolts (19) to remove pilot plate (39) from housing (1). : 10 mm

•

Bucket Flow Control Valve (Switch Valve A) 2. Remove plug (29) from pilot plate (35). : 10 mm 3. Remove spool (34) from pilot plate (35). 4. Remove retaining ring (31), seat (32), and spring (33) from spool (34).

•

Bucket Flow Control Valve (Switch Valve B, Poppet Valve) 5. Remove plug (29) from pilot plate (35). 6. Remove spring (38), seat (37), and spool (36) from pilot plate (35). 7. Loosen socket bolts (19) to separate pilot plate (35) from housing (1).

NOTE - Take care not to drop spacer (14) and spring (13) at this time. :10 mm 8. Remove plug (12) from housing (1). Remove spring (11) and poppet (10) from poppet (9). : 8 mm

•

Load Check Valve 9. Remove springs (8) and check valves (7), (20), and (21) from housing (1).

W2-5-12

EX255-EX285

CONTROL VALVE

1

F 61

59

2

60

G 3

57 5 56

54 53 52 51

49 46 45

17

SM1202

F = Pump Control Valve G = Flow Combiner Valve

EX255-EX285

W2-5-13

CONTROL VALVE • Pump Control Valve 10. Remove plug (49) from housing (1). Take care not to drop spring (51), seat (52), and spool (53) at this time. : 38 mm

NOTE - Do not remove lock nut (46) and screw (45).

11. Attach the nut of bolt (M8 Pitch 1.25) to spool (56). Remove spool (56) together with sleeve (57) from housing (1).

12. Remove retaining ring (61), seat (59), and spring (60).

13. Pull out spool (56) and sleeve (54) from sleeve (57).

•

Flow Combiner Valve 14. Remove plug (5), spring (3) and spool (2) from housing (1). : 36 mm 15. Remove plug (17) from housing (1). : 19 mm

W2-5-14

EX255-EX285


B

A 1 21 1

39

6 8

35 39

8 SM1203

57 54

55 53 50 49

6 21

47 46 45

SM1204

A = Side View of 4 - Spool Valve B = Arm II C = Pump Control Valve D = Boom I E = Bucket

C SM1209

61 59 60 56

58

52 51 48

D

E

1

1

21

6

6 8 35 39

8

8

6

6

7

1 6 7 8 20 21 35

-

Housing (4-Spool Side) O-Ring Check Valve Spring Check Valve Check Valve Pilot Plate

39 45 46 47 48 49 50

-

Pilot Plate Screw Lock Nut Washer O-Ring Plug O-Ring

20

SM1206

SM1205

51 52 53 54 55 56 57

-

Spring Seat Spool Sleeve O-Ring Spool Sleeve

58 59 60 61

-

O-Ring Seat Spring Retaining Ring

EX255-EX285

W2-5-15


Pump control valve 1. Insert spool (56) onto sleeve (57). 2. Install seat (59), spring (60), and seat (59) on spool (56), in that order. Secure with retaining ring (61).

3. Install O-rings (55) (2 used) on sleeve (54). Insert sleeve (54) into sleeve (57). 4. Install O-rings (58) (3 used) on sleeve (57). Install sleeve (57) into housing (1). 5. Install spool (53) onto spool (56). 6. Install spring (51), seat (52), and O-ring (50) onto plug (49). Install plug (49) onto housing (1). : 38 mm : 84 N m (8.6 kgf m, 62 lbf ft)

•

Check Valve (4-spool side) 7. Install check valve (7), check valve(20), check valves (21) (3 used) and spring (8) (5 used) into housing (1). 8. Install O-rings (6) (5 used) on housing (1).

W2-5-16

EX255-EX285


B

A

1

1

39

17 19

19

39 35 5 SM1203

9

10 11

12

SM1204

A= B= C= D= E=

Side View of 4-Spool Control Valve Arm II Bucket Travel (Right) Bucket Flow Control Valve A (Switch Valve) F = Bucket Flow Control Valve B (Switch Valve Orifice) G = Flow Combiner Valve

C SM1210

D

1

6

1 15 16 18

13-14

E

36

35

6 26 25 34

37 38 30

6

22 29 30

Housing (4-Spool Side) Spool Spring O-Ring Plug O-Ring Poppet Poppet Spring

5

4

SM1207

F

-

3

35

SM1206

1 2 3 4 5 6 9 10 11

2

27-28 33 32 31

29

1

17

G

SM1208

12 13 14 15 16 17 18 19 22

-

Plug Spring Spacer O-Ring O-Ring Plug Filter Socket Bolt O-Ring

25 26 27 28 29 30 31 32 33

-

Plug Screw O-Ring Backup Ring Plug O-Ring Retaining Ring Seat Spring

34 35 36 37 38 39

-

Spool Pilot Plate Spool Seat Spring Pilot Plate

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W2-5-17


Bucket Flow Control Valve (Switch Valve B, Poppet Valve)

•

Flow Combiner Valve 10. Install spool (2) and spring (3) into housing (1). 11. Tighten plug (5) onto housing (1).

1. Attach poppet (10) and spring (11) to poppet (9). Tighten plug (12) onto poppet (9). : 8 mm : 39 N m (4 kgf m, 29 lbf ft) 2. Install poppet (9) into housing (1). 3. Install O-rings (6) and (22) onto housing (1). 4. Install spacer (14) and spring (13) into pilot plate (35). Install pilot plate (35) onto housing (1). 5. Tighten pilot plate (35) onto housing (1) using socket bolts (19). : 10 mm : 78 N m (8 kgf m, 58 lbf ft) 6. Install spool (36), seat (37), and spring (38) into pilot plate (35). Tighten plug (29) onto pilot plate (35). : 10 mm : 71 N m (7.2 kgf m, 52 lbf ft)

•

Bucket Flow Control Valve (Switch Valve A) 7. Attach seat (32) onto spool (34) and secure it using retaining ring (31).

8. Install spring (33) onto spool (34) and insert them into pilot plate (35). 9. Install O-ring (30) onto plug (29). Tighten plug (29) onto pilot plate (35). : 10 mm : 71 N m (7.2 kgf m, 52 lbf ft)

: 36 mm : 157 N m (16 kgf m, 116 lbf ft) 12. Install O-rings (15) and (16) onto plug (17). Tighten plug (17) onto housing (1). : 19 mm : 76 N m (7.7 kgf m, 56 lbf ft)

W2-5-18

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CONTROL VALVE DISASSEMBLE CONTROL VALVE 3 L = Anti-Drift Valve M = Travel/Boom Lower Selector Valve N = Arm Regenerative Valve

J

3

2

5

1 4

3

6 44

7 45

46

47 48

L

13 49

50

4 12

43

42

41

1 0 40

11

M 26

N 27 39

J 1 2 3 4 5 6 7 8 9 10 11 12 13

-

38

37

28

29

35

30

32

8

16 22

33

20 18

21

12

19

34

14 15 16 17 18 19 20 21 22 23 24 25 26 27

9

15

23

17 31

10

14

24

36

Plug Socket Bolt Pilot Plate Overload Relief Valve O-Ring Housing (5-Spool Side) Main Relief Valve Pilot Housing Bolt (5 Used) Seat (10 Used) Spring (5 Used) Spool (Travel Left) O-Ring O-Ring

25

9

-

Spool (Swing) Spool (Arm I) Spool (Boom II) Spool (Auxiliary) Spacer Backup Ring O-Ring Spring Check Valve Sleeve Spool Spring O-Ring Check Valve

28 29 30 31 32 33 34 35 36 37 38 39 40 41

-

Spring O-Ring Backup Ring O-Ring O-Ring Spacer Spring Spacer Backup Ring O-Ring Spool O-ring Socket Bolt Plug

SM1211

42 43 44 45 46 47 48 49 50

-

O-Ring Body Spacer O-Ring Spring Seat Spool O-Ring Plug

EX255-EX285

W2-5-19


•


Arm Regenerative Valve 9. Remove spring (34) and spool (38) from housing (5). 10. Heat spacer (35) mounting part on spool (38) using a hair dryer to melt adhesive.

•

5-Spool Side Main Spool 11. Put spool (38) in a vise. Remove spacer (35) from spool (38).

1. Loosen socket bolts (1), then remove pilot plate (2) and pilot housing (7) from housing (5). : 10 mm 2. Pull out five spools (11) , (14 to 17) from housing (5).

NOTE - Place protectors, such as wooden plates, between the vise and the spool so as not to damage the spool.

3. Put the chamfered end of spool (11) in a vise. Remove bolt (8).

: 14 mm

: 22 mm 4. Remove seat (9), spring (10) and seat (9) from bolt (8). 5. Disassemble spools (14), (15), (16) and (17), referring to the steps 3 and 4 above.

•

Arm Anti-Drift Valve 6. Loosen socket bolts (40) to remove body (43) from housing (5).

NOTE - Spacer (44) and spring (46) may fly off at this time. : 10 mm 7. Pull out spacer (18) from housing (5) using a bolt (M5, Pitch 0.8). 8. Pull out spring (21) and check valve (22) from housing (5) using a magnet.

•

Travel/Boom Lower Selector Valve 12. Remove sleeve (23), spool (24), and spring (25) from housing (5).

W2-5-20

EX255-EX285

CONTROL VALVE

J

3

5

6

0

27

28

33 SM1211

EX255-EX285

W2-5-21

CONTROL VALVE •

Check Valve 13. Pull out spacer (33) from housing (5) using a bolt (M6, Pitch 1.0). 14. Pull out spring (28) and check valve (27) from housing (5) using a magnet.

•

Overload Relief Valve 15. Remove overload relief valve (3) from housing (5). : 32 mm

•

Main Relief Valve 16. Loosen plug (J) to remove main relief valve (6) from housing (5). : 32 mm

W2-5-22

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CONTROL VALVE ASSEMBLE CONTROL VALVE 3-1 B

A 34

3

C

5

1

39

2

41-42 35 36 37

M M

38 SM1212 SM1214

SM1213

6

3 43 40

A= B= C= E= F= G= H= I =

Cross section M-M

5

H 26

Top View of Control Valve Arm Regenerative Valve Bottom View of Control Valve Arm I Anti-Drift Valve Boom II Travel/Boom Lower Selector Valve Main Relief Valve

24 23 25

G SM1215

I 6

E 43 48 50

F

49

47 46 45- 44 12 20-19 18 21 22

J 3

12 32 31 33 30 29 28 27

5

5

4

4

5 2 3

2

SM1198

SM1196

J 1 2 3 4 5 6 12 18 19 20

-

Plug Socket Bolt Pilot Plate Overload Relief Valve O-Ring Housing (5-Spool Side) Main Relief Valve O-Ring Spacer Backup Ring O-Ring

SM1216

21 22 23 24 25 26 27 28 29 30 31

-

Spring Check Valve Sleeve Spool Spring O-Ring Check Valve Spring O-Ring Backup Ring O-Ring

32 33 34 35 36 37 38 39 40 41 42

-

O-Ring Spacer Spring Spacer Backup Ring O-Ring Spool O-Ring Socket Bolt Plug O-Ring

43 44 45 46 47 48 49 50

-

Body Spacer O-Ring Spring Seat Spool O-Ring Plug

EX255-EX285

W2-5-23


Overload Relief Valve 1. Install two overload relief valves (3) to housing (5). : 32 mm : 83 N m (8.5 kgf m, 62 lbf ft) 2. Install five O-rings (4) onto housing (5). 3. Install pilot plate (2) onto housing (5) using socket bolts (1) (6 used). : 10 mm : 78 N m (8 kgf m, 58 lbf ft)

•

Check Valve 4. Install check valve (27) and spring (28) into housing (5). 5. Install O-rings (29), (31), and (32) and backup ring (30) onto spacer (33). Install spacer (33) into housing (5).

•

Arm Regenerative Valve 6. Install O-ring (37) and backup ring (36) onto spacer (35). 7. Apply LOCTITE 271 to the threads of spacer (35). Install spacer (35) onto spool (38). 8. Put spool (38) in a vise. Tighten spacer (35) onto spool (38).

NOTE - Place protectors, such as wooden plates, between the vise and the spool so as not to damage the spool. : 14 mm : 18.6 N m (1.9 kgf m, 14 lbf ft) 9. Install spool (38) and spring (34) into housing (5). 10. Install O-ring (39) onto housing (5).

W2-5-24

EX255-EX285

CONTROL VALVE

B

A

C

5

M M

SM1212 SM1214

SM1213

6

43 40

5

Cross section M-M

H 26

A= B= C= E= F = G= H= I =

Top View of Control Valve Arm Regenerative Valve Bottom View of Control Valve Arm I Arm Anti-Drift Boom II Travel/Boom Lower Selector Valve Main Relief Valve

24 23 25

G SM1215

I 6

E 43 48 50

49

F

47 46 45- 44 12 20-19 18 21 22

J 5

12 5

5 SM1196

SM1198 SM1216

EX255-EX285

W2-5-25

CONTROL VALVE •

Arm Anti-Drift Valve 11. Install check valve (22) and spring (21) into housing (5). 12. Install O-rings (12) and (20) and backup ring (19) on spacer (18). Install spacer (18) into housing (5). 13. Install spool (48), seat (47), and spring (46) into body (43). 14. Install O-ring (45) onto spacer (44). Install spacer (44) into body (43). 15. Install O-rings (12) (3 used) onto housing (5). 16. Install body (43) onto housing (5). : 10 mm : 78 N m (8 kgf m, 58 lbf ft) 17. Install O-ring (49) onto plug (50). Install plug (50) onto body (43). : 6 mm : 29 N m (3 kgf m, 22 lbf ft)

•

Travel/Boom Lower Selector Valve 18. Install spring (25), spool (24), and sleeve (23) into housing (5). 19. Install O-ring (26) onto housing (5).

•

Main Relief Valve 20. Install main relief valve (6) onto housing (5). 21. Tighten plug (J) of main relief valve (6). : 32 mm : 83 N m (8.5 kgf m, 62 lbf ft)

W2-5-26

EX255-EX285


A

5

A= B= C= D= E= F=

Top View of Control Valve Travel (left) Auxiliary Boom II Arm I Swing

A

A

SM1212

7

B

C

D

1

E

F 9 10 8 9 4

7 13 5 11

14 15 16

17

SM1217

Cross section A-A

1 4 5 7 8

-

Socket Bolt O-Ring Housing (5-Spool Side) Pilot Housing Bolt (5 Used)

9 10 11 13 14

-

Seat (10 Used) Spring (5 Used) Spool (Travel Left) O-Ring Spool (Swing)

15 - Spool (Arm I) 16 - Spool (Boom II) 17 - Spool (Auxiliary)

EX255-EX285

W2-5-27


5-Spool Side Main Spool 1. Put the chamfered end of spool (11) in a vise. 2. Install seat (9), spring (10), and seat (9) on spool (11) in that order. Install bolt (8). : 22 mm : 15 N m (1.5 kgf m, 11 lbf ft) 3. Assemble spools (14) to (17) referring to steps 1 and 2 above. 4. Install spools (11), (14), (15), (16), and (17) into housing (5). 5. Install O-rings (4) (5 used) and O-rings (13) (3 used) onto housing (5). 6. Install pilot housing (7) onto housing (5). 7. Tighten socket bolts (1) (6 used). :10 mm : 78 N m (8 kgf m, 58 lbf ft)

W2-5-28

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CONTROL VALVE DISASSEMBLE CONTROL VALVE 4 3

4

5

6

A = Boom Anti-Drift Valve

2

7

16

8

15 1

14

18

9

13

10 5 17

12 5

11

19

2

22

17

21

22 20 19

23 24 25

A

41

40

39

38

37 36

42

52

1 2 3 4 5 6 7 8 9 10 11 12 13

-

51

Pilot Plate Socket Bolt Body Socket Bolt O-Ring Plug Lock Nut Poppet O-Ring Plug Plug Spool Seat

43

50

44

49

26

34 35

45

48

46

34

20

33

29 32

31

28

30

47

14 15 16 17 18 19 20 21 22 23 24 25 26

-

27

SM1218

Spring O-Ring Spacer O-Ring Housing (4-Spool Side) O-Ring O-Ring Pilot Housing Overload Relief Valve Spool (Travel Right) Spool (Bucket) Spool (Boom I) Backup Ring

27 28 29 30 31 32 33 34 35 36 37 38 39

-

Plug O-Ring Spring Washer Sleeve Poppet Bolt (4 Used) Seat (8 Used) Spring (4 Used) Spool (Arm II) Poppet Spring O-Ring

40 41 42 43 44 45 46 47 48 49 50 51 52

-

Backup Ring Plug Check Valve Spring O-Ring Backup Ring Spacer Check Valve Spring O-Ring Backup Ring O-Ring Spacer

EX255-EX285

W2-5-29



•

Boom Anti-Drift Valve 10. Loosen socket bolts (4) to remove body (3) from housing (18).

NOTE - Spacer (16) and spring (14) may fly off at this time. •

4-Spool Side Main Spool : 10 mm 1. Loosen socket bolts (2), then remove pilot plate (1) and pilot housing (21) from housing (18). : 10 mm 2. Pull out four spools (36), (23 to 25) from housing (18).

11. Pull out spacer (46) from housing (18) using a bolt (M5 Pitch 0.8). 12. Pull out spring (43) and check valve (42) from housing (18) using a magnet.

3. Put the chamfered end of spool (36) in a vise. Remove bolt (33). : 22 mm 4. Remove seat (34), spring (35) and seat (34) from bolt (33). 5. Disassemble spools (23), (24), (25), referring to the steps 3 and 4 above.

•

Boom Regenerative Valve 6. Heat plug (27), (41) mounting part on spool (25) using a hair dryer to melt adhesive.

75301502

7. Put spool (25) in a vise. Remove plugs (27), (41) from spool (25) using special tool (75301502). NOTE - Place protectors, such as wooden plates, between the vise and the spool so as not to damage the spool. 8. Remove spring (29), washer (30), sleeve (31), and poppet (32) from one end of spool (25). 9. Remove spring (38) and poppet (37) from the other end of spool (25).

SM1219

W2-5-30

EX255-EX285

CONTROL VALVE

A = Emergency Boom Lower Mechanism

A 3

7 8 18 10

22

52 48

47 SM1218

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W2-5-31

CONTROL VALVE •

Check Valve 13. Pull out spacer (52) from housing (18) using a bolt (M6 Pitch 1.0). 14. Pull out spring (48) and check valve (47) from housing (18) using a magnet.

•

Overload Relief Valve 15. Remove overload relief valves (22) from housing (18). : 32 mm

•

Emergency Boom Lower Mechanism 16. Loosen lock nut (7) to remove poppet (8) from body (3). : 13 mm : 4 mm 17. Remove plug (10) from body (3). : 19 mm

W2-5-32

EX255-EX285

CONTROL VALVE ASSEMBLE CONTROL VALVE 4-1 A= B= C= D= E=

11

Top View of Control Valve Emergency Boom Lower Mechanism Bottom View of Control Valve Boom I Boom Anti-Drift Valve

22

3

5

9

5

B

3

7

12

8

13

10

14

6

22 16 4

A

15

5 SM1220

18

E

D

3 20 20 44-45 46

SM1212

43 C

42

18 22 18

SM1205

SM1214

22

3 4 5 6 7 8 9 10

-

Body Socket Bolt O-Ring Plug Lock Nut Poppet O-Ring Plug

11 12 13 14 15 16 18

-

Plug Spool Seat Spring O-Ring Spacer Housing (4-Spool Side)

20 22 42 43 44 45 46

-

O-Ring Overload Relief Valve Check Valve Spring O-Ring Backup Ring Spacer

EX255-EX285

W2-5-33


Overload relief valve 1. Install four overload relief valves (22) to housing (18). : 32 mm : 83 N m (8.5 kgf m, 62 lbf ft)

•

• Emergency Boom Lower Mechanism 9. Install O-ring (9) onto poppet (8). Install poppet (8) into plug (10). 10. Install O-ring (5) onto plug (10). Install plug (10) onto body (3). 11. Tighten poppet (8) until it comes in with body (3) inside. Then, install lock nut (7).

Boom Anti-Drift Valve 2. Install check valve (42) and spring (43) into housing (18). 3. Install O-rings (20) and (44) and backup ring (45) on spacer (46). Install spacer (46) into housing (18). 4. Install spool (12), seat (13), and spring (14) into body (3). 5. Install O-ring (15) onto spacer (16). Install spacer (16) into body (3). 6. Install O-rings (20) (3 used) onto housing (18) and tighten socket bolts (4). 7. Install body (3) onto housing (18). : 10 mm : 78 N m (8 kgf m, 58 lbf ft) 8. Install O-ring (5) onto plug (11). Install plug (11) onto body (3). : 6 mm : 29 N m (3 kgf m, 22 lb ft)

NOTE - Use an alien wrench so that poppet (8) does not turn when tightening lock nut (7). : 13 mm : 29 N m (3 kgf m, 22 lbf ft) : 4 mm

W2-5-34

EX255-EX285


A= B= C= D= E= G= H=

B

Top View of Control Valve Travel (right) Bucket Boom I Arm II Bottom View of Control Valve Boom Regenerative Valve

C

D

33

E

34

21

35 19

34

18 17

23

36

A

18

25

A

2

47

21

48 49-50 51

24

A

52

1 Cross Section A-A

17 SM1221

34 SM1212

35 33

G

34

27

29

26

30

28

32

31

H

25 37

38

39-40 1 41 18

1 2 17 18 19 21 23 24 25 26 27

-

2

Pilot Plate Socket Bolt O-Ring Housing (4-Spool Side) O-Ring Pilot Housing Spool (Travel Right) Spool (Bucket) Spool (Boom I) Backup Ring Plug

SM1214

SM1222

28 29 30 31 32 33 34 35 36 37 38

-

O-Ring Spring Washer Sleeve Poppet Bolt (4 Used) Seat (8 Used) Spring (4 Used) Spool (Arm II) Poppet Spring

39 40 41 47 48 49 50 51 52

-

O-Ring Backup Ring Plug Check Valve Spring O-Ring Backup Ring O-Ring Spacer

EX255-EX285

W2-5-35


Check Valve 1. Install check valve (47) and spring (48) into housing (18). 2. Install O-rings (49) and (51) and backup ring (50) on spacer (52). Install spacer (52) into housing (18). 3. Install O-rings (17) (4 used) onto housing (18). 4. Install pilot plate (1) onto housing (18) using socket bolts (2) (7 used). : 10 mm : 78 N m (8 kgf m, 58 lbf ft)

•

Boom Regenerative Valve 5. Attach poppet (32) and spring (29) to sleeve (31). 6. Install O-ring (28) and backup ring (26) onto plug (27). Apply LOCTITE 271 to the threads of plug (27).

75301502

7. Put spool (25) in a vise. Tighten plug (27) onto spool (25) using special tool (75301502). SM1219

NOTE - Place protectors, such as wooden plates, between the vise and the spool so as not to damage the spool. : 14 mm : 15 N m (1.5 kgf m, 11 lbf ft) 8. Attach poppet (37) and spring (38) to spool (25). 9. Install O-ring (39) and backup ring (40) onto plug (41). Apply LOCTITE 271 to the threads of plug (41).

75301502

10. Put spool (25) in a vise. Tighten plug (41) onto spool (25) using a special tool (75301502). NOTE - Place protectors, such as wooden plates, between the vise and the spool so as not to damage the spool. : 14 mm : 15 N m (1.5 kgf m, 11 lbf ft)

SM1219

W2-5-36

EX255-EX285

CONTROL VALVE

A= B= C= D= E= G=

Top View of Control Valve Travel (right) Bucket Boom I Arm II Bottom View of Control Valve

B

C

D

33

E

34

21

35 19

34

18 18

17

23

A

36

2

25

21 A

A

24

Cross Section A-A SM1221

SM1212

34 35 33

G

34

25

18

SM1214

SM1222

EX255-EX285

W2-5-37

CONTROL VALVE •

4 - Spool Side Main Spool 11. Install seat (34), spring (35), and seat (34) on spool (36) in that order. 12. Put the chamfered end of spool (36) in a vise. Install bolt (33). : 22 mm : 15 N m (1.5 kgf m, 111 lbf ft) 13. Assemble spools (23) to (25) referring to steps 11 and 12 above. 14. Install spools (36), (23), (24), and (25) into housing (18). 15. Install O-rings (17) (4 used) and O-rings (19) (3 used) onto housing (18). 16. Install pilot housing (21) onto housing (18). 17. Tighten socket bolts (2) (7 used). : 10 mm : 78 N m (8 kgf m, 58 lbf ft)

W2-5-38

EX255-EX285

CONTROL VALVE DISASSEMBLE CONTROL VALVE 5 A=

Hydraulic Timer

2

3

1 8 7

6

8 7 6 4

5

9

15 13

14

12 10

11

A

2 3 SM1223

1 2 3 4

-

Housing (5-Spool Side) O-Ring Plug Check Valve

5 6 7 8

-

Spring O-Ring Cover Socket Bolt

9 10 11 12

-

Housing (4-Spool Side) Spring Filter Restriction

13 - Poppet 14 - O-Ring 15 - Plug

EX255-EX285

W2-5-39



•

Hydraulic Timer 1. Remove plug (15) from housing (9). : 22 mm 2. Remove poppet (13) and spring (10) from housing (9). Note that filter (11) cannot be removed as it is fixed to poppet (13).

•

Check Valve 3. Loosen socket bolts (8) to remove covers (7) from housings (1) and (9). : 8 mm 4. Remove springs (5) and check valves (4) from housings (1) and (9). 5. Remove plugs (3) from housings (1) and (9). : 19 mm

W2-5-40

EX255-EX285

CONTROL VALVE ASSEMBLE CONTROL VALVE 5 A = Hydraulic Timer

5

9

4

1 7

7

8 6 7 6

6

5 4

4

5

SM1217 SM1221

A 15 2

3

14

12 11 13 10

SM1227

SM1224

8 8

7 9 1

9

1

SM1226

SM1225

1 2 3 4

-

Housing (5-Spool Side) O-Ring Plug Check Valve

5 6 7 8

-

Spring O-Ring Cover Socket Bolt

9 - Housing (4-Spool Side) 10 - Spring 11 - Filter

12 13 14 15

-

Restriction Poppet O-Ring Plug

EX255-EX285

W2-5-41

CONTROL VALVE Assemble Control Valve 5 •

Check Valve 1. Install check valves (4) (3 used) and springs (5) (3 used) into housings (1) and (9). 2. Install O-rings (6) (3 used) onto housings (1) and (9). Install cover (7) onto housing (1) and tighten socket bolt (8). : 8 mm : 61 N m (6.2 kgf m, 45 lbf ft)

•

Hydraulic Timer 3. Attach poppet (13) and spring (10) to plug (15). 4. Install O-ring (14) onto plug (15). Install plug (15) onto housing (9). : 22 mm : 76 N m (7.7 kgf m, 56 lbf ft) 5. Install O-ring (2) on each plug (3) (2 used). Install plugs (3) on housings (1) and (9). : 19 mm : 34 N m (3.5 kgf m, 25 lbf ft)

W2-5-42

EX255-EX285

CONTROL VALVE NOTES

EX255-EX285

W2-6-1

SWING DEVICE REMOVE AND INSTALL SWING DEVICE WARNING Escaping fluid under pressure can penetrate the skin, causing serious injury. Avoid the hazard by relieving pressure before disconnecting hydraulic or other lines. Hydraulic oil may be hot just after operation. Hot hydraulic oil may spout, possibly causing severe burns. Be sure to wait for oil to cool before starting work. The hydraulic oil tank cap may fly off if removed without releasing internal pressure first. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. Preparation 1. Park the machine on a firm, level surface. 2. Stop the engine. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure.


Removal 1. Disconnect hoses (1, 3, 5 to 8). : 41 mm : 205 N m (21 kgf m, 152 lbf ft) : 36 mm : 175 N m (18 kgf m, 130 lbf ft) : 22 mm : 39 N m (4 kgf m, 29 lbf ft) : 19 mm : 29.5 N m (3 kgf m, 22 lbf ft) : 8 mm : 64 N m (6.5 kgf m, 147 lbf ft)

1

2 3

NOTE - Attach caps to hoses and pipes.

8

2. Remove adapter (2) and install an eyebolt to the swing device assembly to sling it with a wire rope. Eyebolts: (M27 Pitch 2.0) : 36 mm : 108 N m (11 kgf m, 80 lbf ft)

7 6 5 4

WARNING Swing device assembly weight: 330 kg (730 lb) 3. Remove swing device mounting bolts (4). 4. Sling the swing device assembly with a crane or hoist. : 32 mm : 640 N m (65 kgf m, 470 lbf ft)

SM1024

Installation 1. Install the swing device assembly to frame and tighten bolts (4). IMPORTANT - Before installing the swing device assembly, apply liquid packing to both mounting surfaces on the swing reduction gears and frame.

2. Install adapter (2). Connect hoses (1, 3, 5 to 8). IMPORTANT - Be sure to fill the swing motor with hydraulic oil after installing it. Check hydraulic oil level. Add oil if necessary. Run the engine. Check the components for any oil leakage.

W2-6-2

EX255-EX285 EX255

SWING DEVICE DISASSEMBLE SWING DEVICE (EX255)

1

31 2 3 4 5 30 29

22

28

23

27

21

6

20

7

4

8

19

9 7

26

18

10

17

11

16

12

15

13

24

25

14 13 SM3501

1 2 3 4 5 6 7 8 9 10 11

-

Swing Motor Socket Bolt (8 Used) First Stage Sun Gear Thrust Plate (2 Used) Pin (3 Used) Spring Pin (3 Used) Thrust Plate (6 Used) Needle Bearing (3 Used) First Stage Planetary Gear (3 Used) Socket Bolt (12 Used) Pin (3 Used)

12 13 14 15 16 17 18 19 20 21 22

-

Spring Pin (3 Used) Thrust Plate (6 Used) Second Stage Planetary Gear (3 Used) Bearing Retaining Ring Second Stage Carrier O-Ring Ring Gear Second Stage Sun Gear First Stage Carrier Drain Pipe

23 24 25 26 27 28 29 30 31

-

Drain Plug Bolt (10 Used) Oil Seal Cover Shaft O-Ring Sleeve Bearing Housing

EX255-EX285 EX255

W2-6-3

SWING DEVICE Disassemble Swing Device •


1. Remove plug (23) to drain oil and disconnect drain pipe (22). Drain oil: 13.2 L (13.95 US qt) : 27 mm WARNING Swing motor weight: 60 kg (132 Ib) 2. Put matching marks on swing motor, ring gear (19), and housing (31). Remove socket bolts (2). Remove motor (1) using a crane. : 10 mm NOTE - Insert a screwdriver between the motor and ring gear (19) to pry the motor up for easy separation. 3. Remove first stage sun gear (3). Remove first stage carrier (21) assembly from ring gear (19). WARNING Ring gear weight: 29 kg (64 lb) 4. Remove socket bolts (10). Remove ring gear (19) using a crane. : 14 mm

NOTE - Insert a screwdriver to the notches on housing (31) to pry ring gear (19) up for easy separation. 5. Remove O-ring (18) from housing (31).

WARNING Second stage carrier assembly weight: 30 kg (66 lb)

6. Remove second stage sun gear (20) and second stage carrier (17) assembly. 7. Remove retaining ring (16) from shaft (27).

WARNING Remaining component weight (Housing, shaft,etc.): Approx. 160 kg (350 lb)

8. Turn over housing (31). Loosen bolts (24). Remove cover (26). : 19 mm 9. Remove oil seal (25) from cover (26). 10. Push shaft (27) out of housing (31) using a press.

W2-6-4

EX255-EX285 EX255

SWING DEVICE

1

31 2 3 4 5 30 29

22

28

23

27

21

6

20

7

4

8

19

9 7

26

25

18

10

17

11

16

12

15

13

24

14 13 SM3501

EX255-EX285 EX255

W2-6-5

SWING DEVICE 11. Pull bearing (30) out of shaft (27) using a press. 12. Remove sleeve (29) from shaft (27). Remove O-ring (28) from sleeve (29). 13. Remove bearing (15) from housing (31). 14. Drive spring pins (6) (3 used) out of first stage carrier (21) using a round bar and a hammer. 15. Remove pins (5) (3 used), first stage planetary gears (9) (3 used), thrust plates (7) (6 used), and needle bearings (8) (3 used) from first stage carrier (21). 16. Remove thrust plate (4) from first stage carrier (21). 17. Disassemble second stage carrier (17) assembly referring to steps 14 to 16 above. (Note that no needle bearings are used on the second stage planetary gears).

EX255 EX255-EX285

W2-6-6

SWING DEVICE ASSEMBLE SWING DEVICE (EX255)

3

6

5

1

2

21

8 9 7

4

12 19

14

20 10 18 13 17 11 16 4 15

22

30 31

24 26

25

23

29

1 2 3 4 5 6 7 8 9 10 11

-


SM3518

27

28

12 13 14 15 16 17 18 19 20 21 22

-


23 24 25 26 27 28 29 30 31

-


EX255-EX285 EX255

W2-6-7

SWING DEVICE Assemble Swing Device 1. Install needle bearing (8) in each of first stage planetary gears (9) (3 used).

WARNING Housing weight: 92 kg (203 lb)

IMPORTANT - Set thrust plate (4) with the grooved side upwards.

9. Attach housing (31) to a crane using eye bolts. Lift and mount housing (31) onto shaft (27).

2. Install thrust plate (4) in first stage carrier (21).

IMPORTANT - Set thrust plates (7) with the grooved sides facing toward the planetary gear end. Also, set the thrust plates so that the bent parts fit along the periphery of the carrier flange.

3. Install first stage planetary gears (9) (3 used) and thrust plates (7) (6 used) into first stage carrier (21).

4. Aligning the hole on pin (5) with spring pin hole on first stage carrier (21), drive pins (5) (3 used) into first stage carrier (21).

5. Tap spring pins (6) (3 used) into first stage carrier (21) and pin (5).

NOTE - Be sure that the slit part of spring pin (6) faces upwards as shown.when driving it into the first stage carrier and the pin.

5 6

Slit

6. Assemble second stage carrier (17), referring to steps 2 to 5 above.

NOTE - Thrust plates (13) do not have any bent parts.

7. Install O-ring (28) on sleeve (29). Install sleeve (29) onto shaft (27).

8. Install bearing (30) onto shaft (27) using a press.

10. Install bearing (15) into housing (31) using a press.

11. Install retaining ring (16) onto shaft (27).

EX255 EX255-EX285

W2-6-8

SWING DEVICE

3

21

10 19 20 18 17

31

24 26

25

27

SM3518

EX255-EX285 EX255

W2-6-9

SWING DEVICE 12. Apply THREEBOND 1215 to oil seal (25) mounting part of cover (26). Install oil seal (25) onto cover (26).

18. Install first stage carrier (21) into ring gear (19).

IMPORTANT - Be sure to position the sun gear with the stepped end facing downward. 13. Apply THREEBOND 1215 on cover (26) mounting part of housing (31). 19. Install first stage sun gear (3) into first stage carrier (21). WARNING Total weight assembled so far (housing, shaft, etc.): Approx. 145 kg (320 lb)

IMPORTANT - Be sure that the lip part of oil seal (25) does not come into with the tooth end of shaft (27) when installing the cover.

14. Turn over housing (31). Install cover (26) using bolts (24). : 19 mm : 88 N m (9 kgf m, 65 lbf ft)

WARNING Second stage carrier weight: 30 kg (66 lb)

15. Turn over housing (31). Install second stage carrier (17) assembly into housing (31). Install Oring (18) on housing (31).

16. Install second stage sun gear (20) into second stage carrier (17).

WARNING Ring gear weight: 29 kg (65 lb)

17. Attach ring gear (19) to a crane using eye bolts (M12 Pitch 1.75). Lift and install ring gear (19) into housing (31). Tighten socket bolts (10). NOTE - Be sure to align the matching mark on ring gear (19) with that on housing (31). : 14 mm : 205 N m (21 kgf m, 152 lbf ft)

W2-6-10

EX255-EX285 EX255

SWING DEVICE

1

2

19

22 31

23

SM3518

EX255-EX285 EX255

W2-6-11

SWING DEVICE 20. Install drain plug (23) on drain pipe (22). Install drain pipe (22) onto housing (31). : 10 mm : 49 N m (5 kgf m, 36 Ibf ft) : 27 mm : 93 N m (9.5 kgf m, 69 Ibf ft)

21. Fill the swing reduction gear with proper oil. Proper Oil: 13.2 L (13.95 US qt)

22. Apply THREEBOND 1102 to the swing motor mounting surface of ring gear (19).

WARNING Swing motor weight: Approx. 60 kg (132 lb)

23. Lift and mount motor (1) onto ring gear (19). Tighten socket bolts (2).

NOTE - Be sure to align the matching mark on motor (1) with that on ring gear (19). : 10 mm : 88 N m (9 kgf m, 65 Ibf ft)

W2-6-12

EX255-EX285 EX285

SWING DEVICE DISASSEMBLE SWING DEVICE (EX285)

1 2 16 15

3 4

5 6

21 31 7 8 9 7

20 12 11 22

30 33

4

23

17

26 24 29

25

13

28

14 13

32

10 19

27

18 SM5102

1 2 3 4 5 6 7 8 9 10 11

-


12 13 14 15 16 17 18 19 20 21 22

-


23 24 25 26 27 28 29 30 31 32 33

-

Drain Plug Bolt (10 Used) Oil Seal Cover Shaft O-Ring Sleeve Bearing Housing O-Ring O-Ring

EX255-EX285 EX285

W2-6-13

SWING DEVICE Disassemble Swing Device •


1. Remove plug (23) to drain oil and disconnect drain pipe (22). Drain oil: 17 L (17.96 US qt) : 27 mm WARNING Swing motor weight: 70 kg (154 Ib) 2. Put matching marks on the swing motor, ring gear (19), and housing (31). Remove socket bolts (2). Remove motor (1) using a crane. : 10 mm NOTE - Insert a screwdriver between the motor and ring gear (19) to pry the motor up for easy separation. 3. Remove first stage sun gear (3). Remove first stage carrier (21) assembly from ring gear (19). Remove O-ring (32) from ring gear (19).

WARNING Ring gear weight: 35 kg (77 lb) 4. Remove socket bolts (10). Remove ring gear (19) using a crane. : 17 mm NOTE - Insert a screwdriver to the notches on housing (31) to pry ring gear (19) up for easy separation. 5. Remove O-ring (18) from housing (31).

WARNING Second stage carrier assembly weight: 35 kg (77 lb)

6. Remove second stage sun gear (20) and second stage carrier (17) assembly. 7. Remove retaining ring (16) from shaft (27).

WARNING Remaining component weight (housing, shaft,etc.): approx. 210 kg (463 lb)

8. Turn over housing (31). Loosen bolts (24). Remove cover (26). : 19 mm 9. Remove oil seal (25) and O-Ring (33) from cover (26). 10. Push shaft (27) out of housing (31) using a press.

W2-6-14

EX255-EX285 EX285

SWING DEVICE

1 2 16 15

3 4

5 6

21 31 20 12 11 30 33

22 23

4

7 8 9 7 17

26 24 29

25

13

28

14 13

32

10

27

19 18 SM5102

EX255-EX285 EX285

W2-6-15

SWING DEVICE 11. Pull bearing (30) out of shaft (27) using a press. 12. Remove sleeve (29) from shaft (27). Remove O-ring (28) from sleeve (29). 13. Remove bearing (15) from housing (31). 14. Drive spring pins (6) (3 used) out of first stage carrier (21) using a round bar and a hammer. 15. Remove pins (5) (3 used), first stage planetary gears (9) (3 used), thrust plates (7) (6 used), and needle bearings (8) (3 used) from first stage carrier (21). 16. Remove thrust plate (4) from first stage carrier (21). 17. Disassemble second stage carrier (17) assembly referring to steps 14 to 16 above. (Note that no needle bearings are used on the second stage planetary gears).

W2-6-16

EX255-EX285 EX285

SWING DEVICE ASSEMBLE SWING DEVICE (EX285)

3

6 5

1 2 4 19

32

8 9 7 12 14

21

20

10

17

13 18 11

16

4 15 22

30 31 33

26 25

24 29

23

28

27 SM5103

1 2 3 4 5 6 7 8 9 10 11

-


12 13 14 15 16 17 18 19 20 21 22

-


23 24 25 26 27 28 29 30 31

-


EX255-EX285 EX285

W2-6-17

SWING DEVICE Assemble Swing Device 1. Install needle bearing (8) in each of first stage planetary gears (9) (3 used).


IMPORTANT - Set thrust plate (4) with the grooved side upwards.

9. Attach housing (31) to a crane using eye bolts. Lift and mount housing (31) onto shaft (27).

2. Install thrust plate (4) in first stage carrier (21).

IMPORTANT - Set thrust plates (7) with the grooved sides facing toward the planetary gear end. Also, set the thrust plates so that the bent parts fit along the periphery of the carrier flange.

3. Install first stage planetary gears (9) (3 used) and thrust plates (7) (6 used) into first stage carrier (21).

4. Aligning the hole on pin (5) with spring pin hole on first stage carrier (21), drive pins (5) (3 used) into first stage carrier (21).

5. Tap spring pins (6) (3 used) into first stage carrier (21) and pin (5).

NOTE - Be sure that the slit part of spring pin (6) faces upwards as shown.when driving it into the first stage carrier and the pin.

5 6

Slit

6. Assemble second stage carrier (17), referring to steps 2 to 5 above.

NOTE - Thrust plates (13) do not have any bent parts.

7. Install O-ring (28) on sleeve (29). Install sleeve (29) onto shaft (27).

8. Install bearing (30) onto shaft (27) using a press.

10. Install bearing (15) into housing (31) using a press.

11. Install retaining ring (16) onto shaft (27).

W2-6-18

EX255-EX285 EX285

SWING DEVICE

3

32 21 19 20 10

17 18

31 33 24

26 25

27 SM5103

EX255-EX285 EX285

W2-6-19

SWING DEVICE 12. Apply THREEBOND 1215 to oil seal (25) mounting part of cover (26). Install oil seal (25) and Oring (33) onto cover (26).

18. Install first stage carrier (21) and O-ring (32) into ring gear (19). 19. Install first stage sun gear (3) into first stage carrier (21).

13. Apply THREEBOND 1215 on cover (26) mounting part of housing (31).

WARNING Total weight assembled so far (Housing, shaft, etc.): Approx. 190 kg (420 lb)

IMPORTANT - Be sure that the lip part of oil seal (25) does not come into with the tooth end of shaft (27) when installing the cover.

14. Turn over housing (31). Install cover (26) using bolts (24). : 19 mm : 88 N m (9 kgf m, 65 lbf ft)

WARNING Second stage carrier weight: 35 kg (77 lb)

15. Turn over housing (31). Install second stage carrier (17) assembly into housing (31). Install Oring (18) on housing (31).

16. Install second stage sun gear (20) into second stage carrier (17).

WARNING Ring gear weight: 35 kg (77 lb)

17. Attach ring gear (19) to a crane using eye bolts (M12 Pitch 1.75). Lift and install ring gear (19) into housing (31). Tighten socket bolts (10). NOTE - Be sure to align the matching mark on ring gear (19) with that on housing (31). : 14 mm : 205 N m (21 kgf m, 152 lbf ft)

IMPORTANT - Be sure to position the sun gear with the stepped end facing downward.

EX285 EX255-EX285

W2-6-20

SWING DEVICE

1 2 19

22

31

23

SM5103

EX255-EX285 EX285

W2-6-21

SWING DEVICE 20. Install drain plug (23) on drain pipe (22). Install drain pipe (22) onto housing (31). : 10 mm : 49 N m (5 kgf m, 36 Ibf ft) : 27 mm : 93 N m (9.5 kgf m, 69 Ibf ft)

21. Fill the swing reduction gear with proper oil. Proper Oil: 17.0 L (18 US qt)

22. Apply THREEBOND 1102 to the swing motor mounting surface of ring gear (19).

WARNING Swing motor weight: Approx. 70 kg (154 lb)

23. Lift and mount motor (1) onto ring gear (19). Tighten socket bolts (2).

NOTE - Be sure to align the matching mark on motor (1) with that on ring gear (19). : 10 mm : 88 N m (9 kgf m, 65 Ibf ft)

W2-6-22

EX255-EX285 EX255

SWING DEVICE DISASSEMBLE SWING MOTOR (EX255)

4

5

6

3

7 8

2

9 10 11

1

12 13

14 15

33 16

32 31

17

34

17

18

30 17 27

19 20

24

25

26

28

35

29 36 37

21 38

22 39

23 40 41 42

SM1027

43

1 - Roller Bearing 2 - O-Ring 3 - Valve Casing (Brake Valve) 4 - Socket Bolt (4 Used) 5 - Poppet (2 Used) 6 - Spring (2 Used) 7 - O-Ring (2 Used) 8 - Plug (2 Used) 9 - Valve Plate 10 - Spring (18 Used)

11 12 13 14 15 16 17 18 19 20 21

-

Brake Piston O-Ring Friction Plate (3 Used) Relief Valve (2 Used) Pin (2 Used) Push Rod (12 Used) Spacer (3 Used) Holder Socket Bolt (2 Used) Cover O-Ring

22 23 24 25 26 27 28 29 30 31 32

-

Spring Spool Plug (3 Used) Spool Spring Rotor O-Ring Plug Spring Retaining Ring Plate (4 Used)

33 34 35 36 37 38 39 40 41 42 43

-

O-Ring Plunger (9 Used) Retainer Plate Thrust Plate Shaft (Output Shaft) Spacer Roller Bearing Oil Seal Seal Cover Retaining Ring Casing

EX255-EX285 EX255

W2-6-23

SWING DEVICE Disassemble Swing Motor •


WARNING Weight of swing motor assembly: approx. 60 kg (130 Ib)

5. Remove valve casing (3) from casing (43).

NOTE - Valve plate (9) may be stuck on the bottom of valve casing (3). Take care not to drop valve plate (9) when removing valve casing (3). 6. If valve plate (9) has not been removed in the previous step, remove it. Then, remove springs (10) (18 used ).

1. Remove relief valves (14) (2 used) from valve casing (3). NOTE - Never attempt to disassemble relief valves (14). : 36 mm

2. Remove plugs (8) (2 used).

IMPORTANT - If a screwdriver or similar tool is used to separate (pry) valve plate (9) from the rotor side, take care not to damage the sealing surfaces. (Note that the top surface of the valve plate differs from the bottom surface.)

7. Apply two hooks to the notch A and pull the hooks to remove brake piston (11).

: 14 mm 8. Remove O-rings (12), (33) from casing (43). 3. Remove springs (6) (2 used) and poppets (5) (2 used).

4. Put align marks on valve casing (3) and casing (43). Loosen and remove socket bolts (4) (4 used). : 17 mm

A

11 43

NOTE - Note that valve casing (3) will be raised by springs (10) as socket bolts (4) are loosened. SM1028

W2-6-24

EX255-EX285 EX255

SWING DEVICE

13

16

32 31

17

34

17

18

30 17 27 35

29 19 20

25

36

26 37

21 38

22 39

23 40 41 42

SM1027

43

EX255-EX285 EX255

W2-6-25

SWING DEVICE 9. Lay casing (43) on its side. Pull out rotor (27) from shaft (37).

10. Remove plates (32) (4 used) and friction plates (13) (3 used) from casing (43).

WARNING Be sure to press and hold spacer (17) using a press when removing retaining ring (31). Attempting to remove retaining ring (31) without pressing the spacer down may cause the spacer and/or retaining ring (31) to spring up, possibly resulting in personal injury.

11. Remove thrust plate (36).

12. Lay casing (43) on its side. Drive shaft (37) out of casing (43) using a plastic hammer.

18. Press and hold spacer (17) using a press, and remove retaining ring (31).

19. Remove spacer (17), spring (30), and spacer (17). 13. Remove retaining ring (42) and seal cover (41) from casing (43).

20. Remove plug (29), spring (26), and spool (25) from casing (43). : 6 mm

14. Remove oil seal (40) from casing (43). 21. Remove socket bolts (19), cover (20) and O-ring (21). 15. Remove the outer race of roller bearing (39) from casing (43) using a metal bar and a plastic hammer.

: 4 mm

22. Remove spring (22) and spool (23) from casing (43). 16. Remove the inner race of roller bearing (39), from shaft (37) using a press. Remove spacer (38) from shaft (37).

17. Remove plungers (34) (9 used), retainer plate (35), holder (18), spacer (17), push rods (16) (12 used) from rotor (27).

NOTE - Although a filter and an orifice are install in spool (23), do not attempt to remove them unless restriction or deformation is found.

W2-6-26

EX255-EX285 EX255

SWING DEVICE ASSEMBLE SWING MOTOR (EX255)

3

4

8

7

6

5

14 Y

Y

29 28

30

17

31

1

9

15

10

2 Cross Section Y-Y

26

11

24

12

19

33

20

13

21

22 23

25

32

35

27

36

16

17

34 18 38 40


11 12 13 14 15 16 17 18 19 20 21

-

41

Brake Piston O-Ring Friction Plate (3 Used) Relief Valve (2 Used) Pin (2 Used) Push Rod (12 Used) Spacer (3 Used) Holder Socket Bolt (2 Used) Cover O-Ring

37

42

22 23 24 25 26 27 28 29 30 31 32

-

39

43

Spring Spool Plug (3 Used) Spool Spring Rotor O-Ring Plug Spring Retaining Ring Plate (4 Used)

SM1029

33 34 35 36 37 38 39 40 41 42 43

- O-Ring - Plunger (9 Used) - Retainer Plate - Thrust Plate - Shaft (Output Shaft) - Spacer - Roller Bearing - Oil Seal - Seal Cover - Retaining Ring - Casing

EX255-EX285 EX255

W2-6-27

SWING DEVICE Assemble Swing Motor 1. Install spacer (38) onto shaft (37). Install the inner race of roller bearing (39) onto shaft (37) using a press.

10. Attach plungers (34) (9 used) on retainer plate (35). Insert plungers (34) into rotor (27).

2. Install retaining ring (42) onto casing (43). Install the inner race of roller bearing (1) onto shaft (37) using a press.

IMPORTANT - Be sure to apply a film of hydraulic oil on the rotor bore surface before inserting plungers (43).

IMPORTANT - Be sure that the lip part of oil seal (40) faces upwards when installing it.

3. Turnover casing (43). Install seal cover (41) into casing (43). Install oil seal (40) into casing (43) using a protection plate and a press.

11. Lay casing (43) on its side. Install rotor (27) assembly onto shaft (37).

IMPORTANT - On each of plate (32) periphery is a series of tab-like protrusions with four of the protrusions missing at an interval. Likewise, four teeth are missing on each friction plate. When installing plates (32) and friction plates (13), be sure to align these missing parts.

4. Install the outer race of roller bearing (39) onto casing (43) a metal bar and a hammer. 12. Stand casing (43) upright. Install plates (32) (4 used) and friction plates (13) (3 used) one by one alternately. 5. Lay casing (43) on its side. Install shaft (37) into casing (43). 13. Install O-rings (12) and (33) on casing (43). 6. Stand casing (43) upright. Install thrust plate (36) into casing (43).

7. Install spacer (17), spring (30), and spacer (17) into rotor (27), in that order.

8. Press down spacer (17) to give enough clearance for retaining ring (31) installation. Install retaining ring (31).

9. Insert push rods (16) (12 used) into rotor (27). Install spacer (17) and holder (18) onto rotor (27), in that order.

14. Install brake piston (11) into casing (43). If brake piston (11) does not enter the casing smoothly due to the installation of the O-rings above, tap the periphery of the brake piston evenly with a plastic hammer.

15. Install spring (10) (18 used ) on brake piston (11).

EX255 EX255-EX285

W2-6-28

SWING DEVICE

3

4

8

7

6

5

14 Y

Y

29 28

1

9

2 Cross Section Y-Y

26

19 20 21

25

22 23

43

SM1029

EX255-EX285 EX255

W2-6-29

SWING DEVICE IMPORTANT - Be sure that the model stamped end of roller bearing faces upwards when installing.

21. Install spool (25) and spring (26) into casing (43). Tighten attached plug (29), O-ring (28). : 6 mm : 36 N m (3.7 kgf m, 27 lbf ft)

16. Install roller bearing (1) into valve casing (3) using a plastic hammer. 22. Install spool (23) and spring (22) into casing (43). 17. Install O-ring (2) and valve plate (9) on valve casing (3). NOTE - Be sure to apply grease to the surface of valve plate (9) so as to prevent it from dropping when installing valve casing (3) onto the casing.

IMPORTANT - Take care not to drop valve plate (9). Also, be sure to align the matching marks on valve casing (3) and casing (43).

18. Install valve casing (3) onto casing (43). Tighten valve casing (3) onto casing (43) using socket bolts (4)(4 used). : 17 mm : 430 N m (44 kgf m, 320 lbf ft)

19. Insert poppets (5) (2 used) and springs (6) (2 used) into valve casing (3). Tighten attached plugs (8), O-ring (7). : 14 mm : 330 N m (34 kgf m, 245 lbf ft)

20. Install relief valves (14) (2 used) into valve casing (3). : 36 mm : 175 Nm (18 kgf m, 130 lbf ft)

23. Install O-ring (21) and cover (20) onto casing (43). Tighten socket bolts (19). : 4 mm : 7 N m (0.7 kgf m, 5 lbf ft)

IMPORTANT - Be sure to fill the swing motor with hydraulic oil after installing it.

W2-6-30

EX255-EX285 EX285

SWING DEVICE DISASSEMBLE SWING MOTOR (EX285) 1

2

3

4

9 10 11 12 13 5

6 7 8

14 44 15 33

16 34 18

17

30

45

19

31 32

38 46

27

35

43

36 37

39

40 41 42 47

SM5507

45 47 48

1 - Roller Bearing 2 - O-Ring 3 - Valve Casing (Brake Valve) 4 - Socket Bolt (4 Used) 5 - Poppet (2 Used) 6 - Spring (2 Used) 7 - O-Ring (2 Used) 8 - Plug (2 Used) 9 - Valve Plate

10 11 12 13 14 15 16 17 18 19

-

Spring (24 Used) Brake Piston O-Ring Friction Plate (2 Used) Relief Valve (2 Used) Pin (2 Used) Push Rod (12 Used) Spacer Holder Socket Bolt (3 Used)

30 31 32 33 34 35 36 37 38 39

-

Spring Retaining Ring Plate (3 Used) O-Ring Plunger (9 Used) Retainer Plate Thrust Plate Shaft (Output Shaft) Spacer Roller Bearing

40 41 42 43 44 45 46

-

Oil Seal Seal Cover Retaining Ring Casing Retaining Ring Spacer (3 Used) Parking Brake Release Valve 47 - Retaining Ring (2 Used) 48 - O-Ring

EX255-EX285 EX285

W2-6-31

SWING DEVICE Disassemble Swing Motor •


WARNING Weight of swing motor assembly: Approx. 70 kg (155 Ib)

1. Remove relief valves (14) (2 used) from valve casing (3). NOTE - Never attempt to disassemble relief valves (14). : 36 mm

2. Remove plugs (8) (2 used). : 14 mm

3. Remove springs (6) (2 used) and poppets (5) (2 used).

6. Remove valve casing (3) from casing (43).

NOTE - Valve plate (9) may be stuck on the bottom of valve casing (3). Take care not to drop valve plate (9) when removing valve casing (3).

7. If valve plate (9) has not been removed in the previous step, remove it. Then, remove springs (10) (24 used ).

IMPORTANT - If a screwdriver or similar tool is used to separate (pry) valve plate (9) from the rotor side, take care not to damage the sealing surfaces. (Note that the top surface of the valve plate differs from the bottom surface.)

8. Apply two hooks to the notch A and pull the hooks to remove brake piston (11).

9. Remove O-rings (12), (33) from casing (43).

4. Loosen socket bolts (19) to remove parking brake release valve (46) from casing (43). : 10 mm

A

11 43

5. Put align marks on valve casing (3) and casing (43). Loosen and remove socket bolts (4) (4 used). : 17 mm

NOTE - Note that valve casing (3) will be raised by springs (10) as socket bolts (4) are loosened.

SM1028

EX285 EX255-EX285

W2-6-32

SWING DEVICE

1

2

3

4

9 10 11 12 13 5

6 7 8

14 44 15 33

16 34 18

17

30

45

19

31 32

38 46

27

35

43

36 37

39

40 41 42 47 45 47 48

SM5507

EX255-EX285 EX285

W2-6-33

SWING DEVICE 10. Lay casing (43) on its side. Pull out rotor (27) from shaft (37).

11. Remove plates (32) (3 used) and friction plates (13) (2 used) from casing (43).

12. Remove thrust plate (36).

13. Remove retaining ring (42) and seal cover (41) from casing (43).

WARNING Be sure to press and hold spacer (45) using a press when removing retaining ring (31). Attempting to remove retaining ring (31) without pressing the spacer down may cause the spacer and/or retaining ring (31) to spring up, possibly resulting in personal injury.

19. Press and hold spacer (45) using a press, and remove retaining ring (31).

20. Remove spacer (45), spring (30), and spacer (38).

14. Remove oil seal (40) from seal cover (41).

15. Lay casing (43) on its side. Drive shaft (37) out of casing (43) using a plastic hammer.

16. Remove retaining rings (44) and (47) (2 used). Remove the outer race of roller bearing (39) from casing (43) using a metal bar and a plastic hammer.

17. Remove the inner races of roller bearings (39) and (1), from shaft (37) using a press. Remove spacer (45) from shaft (37).

18. Remove plungers (34) (9 used), retainer plate (35), holder (18), spacer (17), push rods (16) (12 used) from rotor (27).

21. Remove the outer race of roller bearing (1), from valve casing (3), using a bearing puller.

W2-6-34

EX255-EX285 EX285

SWING DEVICE ASSEMBLE SWING MOTOR (EX285) 44

3 1

9

31

15

45

11

2

12

10

33

30

13

38

32 19

27

46

18

34

35

16 17

36

47

43

45 39 48 41 37

40

42

6

4

5 14 7

SM5508

8


11 12 13 14 15 16 17 18 19 27 30

-

Brake Piston O-Ring Friction Plate (2 Used) Relief Valve (2 Used) Pin (2 Used) Push Rod (12 Used) Spacer Holder Socket Bolt (3 Used) Rotor Spring

31 32 33 34 35 36 37 38 39 40 41

- Retaining Ring - Plate (4 Used) - O-Ring - Plunger (9 Used) - Retainer Plate - Thrust Plate - Shaft (Output Shaft) - Spacer - Roller Bearing - Oil Seal - Seal Cover

42 43 44 45 46

-

Retaining Ring Casing Retaining Ring Spacer (3 Used) Parking Brake Release Valve 47 - Retaining Ring (2 Used) 48 - O-Ring

EX255-EX285 EX285

W2-6-35

SWING DEVICE Assemble Swing Motor 1. Install retaining ring (47) and spacer (45) onto shaft (37). Install the inner race of roller bearing (39) onto shaft (37) using a press. Install spacer (45) and retaining ring (47) onto shaft (37). 2. Install the inner race of roller bearing (1) onto shaft (37) using a press. Install retaining ring (44) onto shaft (37).

IMPORTANT - Be sure that the lip part of oil seal (40) faces upwards when installing it.

3. Install oil seal (40) onto seal cover (41) using a protection plate and a press.

4. Install the outer race of roller bearing (39) onto casing (43) a metal bar and a hammer.

5. Lay casing (43) on its side. Install shaft (37) into casing (43).

6. Stand casing (43) upright. Install O-ring (48) into casing (43).

7. Install seal cover (41) into casing (43). Secure with retaining ring (42).

8. Install spacer (38), spring (30), and spacer (45) into rotor (27), in that order.

9. Press down spacer (45) to give enough clearance for retaining ring (31) installation. Install retaining ring (31).

10. Insert push rods (16) (12 used) into rotor (27). Install spacer (17) and holder (18) onto rotor (27), in that order.

11. Attach plungers (34) (9 used) on retainer plate (35). Insert plungers (34) into rotor (27).

IMPORTANT - Be sure to apply a film of hydraulic oil on the rotor bore surface before inserting plungers (34).

12. Lay casing (43) on its side. Install thrust plate (36) onto rotor (27). Install them onto shaft (37).

IMPORTANT - On each of plate (32) periphery is a series of tab-like protrusions with four of the protrusions missing at an interval. Likewise, four teeth are missing on each friction plate. When installing plates (32) and friction plates (13), be sure to align these missing parts.

13. Stand casing (43) upright. Install plates (32) (3 used) and friction plates (13) (2 used) one by one alternately.

14. Install O-rings (12) and (33) on casing (43).

15. Install brake piston (11) into casing (43). If brake piston (11) does not enter the casing smoothly due to the installation of the O-rings above, tap the periphery of the brake piston evenly with a plastic hammer.

16. Install spring (10) (24 used ) on brake piston (11).

EX285 EX255-EX285

W2-6-36

SWING DEVICE

44

3 1

9

31

15

45

11

2

12

10

33

30

13

38

32 19

27

46

18

34

35

16 17

36

47

43

45 39 48 41 37

6

40

42

4

5 14 7

SM5508

8

EX255-EX285 EX285

W2-6-37

SWING DEVICE IMPORTANT - Be sure that the model stamped end of roller bearing faces upwards when installing.

22. Install parking brake release valve (46) onto casing (43) using socket bolts (19) (3 used). : 10 mm

17. Install the outer race of roller bearing (1) into valve casing (3) using a plastic hammer.

18. Install O-ring (2) and valve plate (9) on valve casing (3). NOTE - Be sure to apply grease to the surface of valve plate (9) so as to prevent it from dropping when installing valve casing (3) onto the casing.

IMPORTANT - Take care not to drop valve plate (9). Also, be sure to align the matching marks on valve casing (3) and casing (43).

19. Install valve casing (3) onto casing (43). Tighten valve casing (3) onto casing (43) using socket bolts (4)(4 used). : 17 mm : 430 N m (44 kgf m, 320 lbf ft)

20. Insert poppets (5) (2 used) and springs (6) (2 used) into valve casing (3). Tighten attached plug (8) O-ring (7). : 14 mm : 330 N m (34 kgf m, 245 lbf ft)

21. Install relief valves (14) (2 used) into valve casing (3). : 36 mm : 175 Nm (18 kgf m, 130 lbf ft)

: 9.8 N m (1 kgf m, 2 lbf ft)

IMPORTANT - Be sure to fill the swing motor with hydraulic oil after installing it.

EX285 EX255-EX285

W2-6-38

SWING DEVICE DISASSEMBLE AND ASSEMBLE PARKING BRAKE RELEASE VALVE (EX285)

40

34

39

41

38

33

37

42

36

32

35

31

43 SM5106

31 32 33 34 35

-

Housing Spool Spring Plunger Bushing

36 37 38 39 40

-

Filter Spacer Orifice Spring O-Ring

41 - O-Ring (2 Used) 42 - Steel Ball 43 - Bolt (3 Used)

EX255-EX285

W2-6-39

SWING DEVICE MAINTENANCE STANDARD Swing motor d

1. Plunger and rotor bore clearance (d, D) Unit: mm (in) Standard Clearance

Allowable Limit

EX255

0.027 (0.00106)

0.052 (0.00205)

EX285

0.032 (0.00126)

0.062 (0.00244)

SM1030

D

D

SM1031

2. Plunger and shoe clearance (a) Unit: mm (in) Standard Clearance

Allowable Limit

0

0.3 (0.012)

a

SM1032

a

SM1033

W2-6-40

EX255-EX285

SWING DEVICE 3. Thickness of shoe (t) Unit: mm (in) Standard Clearance

Allowable Limit

EX255

5.5 (0.216)

5.3 (0.209)

EX285

6.0 (0.236)

5.8 (0.228) t SM1034

4. Thickness of friction plate Unit: mm (in) Standard Clearance

Allowable Limit

EX255

1.8 (0.071)

1.6 (0.063)

EX285

4 (0.157)

3.6 (0.142)

5. Total clearance of retainer plate (1) and holder (2): (H - h)

SM1035

2 1

Unit: mm (in) Standard Clearance

Allowable Limit

EX255

5.5 (0.216)

5.0 (0.197)

EX285

7.0 (0.276)

6.5 (0.256) h H

If the dimension is reduced to below allowable limit, replace retainer plate (1) and holder (2).

SM1036

EX255-EX285

W2-7-1

PILOT VALVE REMOVE AND INSTALL RIGHT PILOT VALVE WARNING Escaping fluid under pressure can penetrate the skin, causing serious injury. Avoid the hazard by relieving pressure before disconnecting hydraulic or other lines. Hydraulic oil may be hot just after operation. Hot hydraulic oil may spout, possibly causing severe burns. Be sure to wait for oil to cool before starting work. The hydraulic oil tank cap may fly off if removed without releasing internal pressure first. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. Preparation 1. Park the machine on a firm, level surface.

Removal

2. Stop the engine. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure.

1

2

3

1. Loosen screws (6) (2 used), (1) (2 used) and (5) (2 used) to remove cover (7) and frame (2). Loosen screws (4) (4 used) to dislocate boot (3).

4 5

6 7 SM1105

2. Confirm that the console is in the forefront position. If not, position the console in the forefront position. Loosen bolts (8) (2 used) to disconnect the ts. Raise stand (9). : 17 mm

8

9

SM1106

3. Remove screws (10) and (12). Dislocate cover (11) to the right. 10 11

12

SM1107

W2-7-2

EX255-EX285

PILOT VALVE 4. Loosen screw t (13) to remove the lever. : 24 mm

13

IMPORTANT - Attach an identification tag on each hose to aid in reassembly.

14

5. Disconnect hoses (15) to (20). : 22 mm 15 NOTE - Attach a cap on each of disconnected hose ends.

16 17

6. Loosen bolts (14) to remove the pilot valve. : 13 mm 15 - Hose H : (To the bucket roll-out section in the control valve) 16 - Hose P3 : (From the pilot control shut-off valve) 17 - Hose A : (To the boom raise section in the control valve) 18 - Hose G : (To the bucket roll-in section in the control valve) 19 - Hose T6 : (To the hydraulic oil tank) 20 - Hose B : (To the boom lower section in the control valve)

20

19

18

SM1108

Installation 1. Mount the pilot valve using bolts (14).

13

14

: 13 mm : 9.8 N m (1.0 kgf m, 7.2 lbf ft)

2. Connect hoses (15) to (20). : 22 mm

15

: 39 N m (4.0 kgf m, 29 lbf ft)

16 17

3. Attach the lever. Tighten screw t (13) to secure the lever. : 24 mm : 88 N m (9.0 kgf m, 65 lbf ft)

15 - Hose H : (To the bucket roll-out section in the control valve) 16 - Hose P3 : (From the pilot control shut-off valve) 17 - Hose A : (To the boom raise section in the control valve) 18 - Hose G : (To the bucket roll-in section in the control valve) 19 - Hose T6 : (To the hydraulic oil tank) 20 - Hose B : (To the boom lower section in the control valve)

20

19

18

SM1108

EX255-EX285

W2-7-3

PILOT VALVE 4. Install cover (11) using screws (10) and (12).

10 11

12

SM1107

5. Secure stand (9) using bolts (8) (2 used). : 17 mm : 49 N m (5.0 kgf m, 36 lbf ft)

8

1 6. Install frame (2) using screws (1) (2 used) and screws (5) (2 used). Install cover (7) using screws (6) (2 used). Set the boot in position, and secure it using screws (4) (4 used).

2

9

SM1106

3 4 5

6 IMPORTANT - After completing installation: Check hydraulic oil level. Add oil if necessary. Run the engine. Check the components for any oil leakage.

7 SM1105

W2-7-4

EX255-EX285

PILOT VALVE REMOVE AND INSTALL LEFT PILOT VALVE

WARNING Escaping fluid under pressure can penetrate the skin, causing serious injury. Avoid the hazard by relieving pressure before disconnecting hydraulic or other lines. Hydraulic oil may be hot just after operation. Hot hydraulic oil may spout, possibly causing severe burns. Be sure to wait for oil to cool before starting work. The hydraulic oil tank cap may fly off if removed without releasing internal pressure first. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. Preparation 1. Park the machine on a firm, level surface.


Removal 3 1. Loosen screw (2) (2 used), to remove cover (1). Loosen screws (4) (4 used) to dislocate boot (3).

4

2 1 SM5515

2. Remove pad (13).To remove pad, disengage the two latches while pressing and pushing pad (13) in the direction indicated by arrow. Then, slide the pad to the opposite of the direction indicated by arrow to remove it. 3. Loosen screws (15) (2 used) and screws (16) (2 used) to remove cover (14).

13

14

15

➡

16 16

SM1109

4. Confirm that the console is in the forefront position. If not, position the console in the forefront position. Loosen bolts (8) (2 used) to disconnect the ts. Raise stand (9). : 17 mm

8

9

SM1106

EX255-EX285

W2-7-5

PILOT VALVE 5. Loosen screws (10) and (12) to dislocate cover (11) to the right. 10 11

12

SM1107

6. Loosen screw t (17) to remove the lever.

17

18

: 24 mm IMPORTANT - Attach an identification tag on each hose to aid in reassembly.

19

7. Disconnect hoses (19) to (24).

20

: 22 mm 21 NOTE - Attach a cap on each of the disconnected hose ends. 8. Loosen bolts (18) to remove the pilot valve. : 13 mm 19 20 21 22 23 24

- Hose D : - Hose P2 : - Hose E : - Hose C : - Hose T5 : - Hose F :

(To the right swing section in the control valve) (From the pilot control shut-off valve) (To the arm roll-in section in the control valve) (To the left swing section in the control valve) (To the hydraulic oil tank) (To the arm roll-out section in the control valve)

SM1110

24

Installation

23

17

22

18

1. Mount the pilot valve using bolts (18). : 13 mm : 9.8 N m (1.0 kgf m, 7 lbf ft)

19 20

2. Connect hoses (19) to (24). : 22 mm : 39 N m (4.0 kgf m, 29 lbf ft)

21

3. Attach the lever. Tighten screw t (17) to secure the lever. : 24 mm : 88 N m (9.0 kgf m, 65 lbf ft) 19 - Hose D 20 - Hose P2 21 - Hose E 22 - Hose C 23 - Hose T5 24 - Hose F

: : : : : :

(To the right swing section in the control valve) (From the pilot control shut-off valve) (To the arm roll-in section in the control valve) (To the left swing section in the control valve) (To the hydraulic oil tank) (To the arm roll-out section in the control valve)

SM1110

24

23

22

W2-7-6

EX255-EX285

PILOT VALVE 4. Install cover (11) using screws (10) and (12). 10 11

12

SM1107

5. Secure stand (9) using bolts (8) (2 used). : 17 mm : 49 N m (5.0 kgf m, 36 lbf ft)

8

9

6. Install cover (14) using screws (15) (2 used) and screws (16) (2 used).

13

7. Install pad (13) on cover (14).

SM1106

14

15

16 16

SM1109

8. Set boot (3) in position, and secure it using screws (4) (4 used).

3 4

9. Install cover (1) using screws (2) (2 used).

IMPORTANT - After completing installation: Check hydraulic oil level. Add oil if necessary. Run the engine. Check the components for any oil leakage.

2 1 SM5515

EX255-EX285

W2-7-7

PILOT VALVE REMOVE AND INSTALL TRAVEL PILOT VALVE


Removal 1. Loosen bolt (2) to remove pedal (1).



: 17 mm IMPORTANT - Attach an identification tag on each hose to aid in reassembly. 2. Disconnect hoses (3) to (8). : 22 mm NOTE - Attach a cap on each of disconnected hose ends.

1

3. Loosen bolts (9) to remove the pilot valve. : 17 mm

2

Installation 1. Mount the pilot valve using bolts (9). : 17 mm : 49 Nm (5.0 kgf m, 36 lbf ft)


3. Mount pedal (1) using bolts (2). : 17 mm : 49 N m (5.0 kgf m, 36 lbf ft)

3 8 9 7 6

4

5 SM1111

3 - Hose 12: (To the right reverse travel section in the control valve) 4 - Hose 10: (To the left reverse travel section in the control valve) 5 - Hose P1: (From the pilot control shut-off valve) 6 - Hose 9 : (To the left forward section in the control valve) 7 - Hose 11: (To the right forw. section in the control valve) 8 - Hose T4 : To the hydraulic oil tank

W2-7-8

EX255-EX285

PILOT VALVE DISASSEMBLE RIGHT AND LEFT PILOT VALVE

1 25 23 24

2 22

21 21

3

20 20 19 19

4 18

18

17

5

5

6

6 7

12

16

15

11

8

10

9

14

13 SM1112

1 2 3 4 5 6 7 8 9

-

Screw t Cam Universal t Plate Oil Seal (4 Used) O-Ring (4 Used) Bushing A (2 Used) Pusher A (2 Used) Spring Guide A (2 Used)

10 11 12 13 14 15 16 17 18

-

Spring Guide B (2 Used) Pusher B (2 Used) Bushing B (2 Used) Socket Bolt Plate O-Ring Seal Washer Casing Piston (4 Used)

19 20 21 22 23 24 25

-

Spool (4 Used) Spacer (4 Used) Shim (20 Used) Return Spring A (2 Used) Balance Spring A (2 Used) Return Spring B (2 Used) Balance Spring B (2 Used)

EX255-EX285

W2-7-9

PILOT VALVE Disassemble Right and Left Pilot Valve •

•

•

•

Be sure to thoroughly read “Precautions for Disassembly and Assembly” on page W1-1-1 before starting the disassembly work. As casing (17) and spools (19) are precision parts specially made to fit each other, they must be replaced as a set. Do not attempt to replace these parts individually. Note that return spring A (22) and balance spring A (23), which are used in ports 1 and 3, differ from return spring B (24) and balance spring B (25), which are used in ports 2 and 4. For this reason, be sure to indicate the port number from which it is removed. Port numbers are stamped on casing (17).

10. Remove spools (19) (4 used) from casing (17). 11. Compress balance spring A (23) or B (25) to remove spacers (20) from each spool (19). Remove balance spring A (23) or B (25) and shims (21) from each spool (19). 12. Remove spring guide A (9) or B (10), and return spring A (22) or B (24) from each seat.

1. Remove screw t (1) and cam (2). : 19 mm, 32 mm 2. Temporarily tighten plate (4) using two bolts (M8, Pitch 1.25). Loosen universal t (3) to remove it from casing (17). 3. Turn over casing (17) and place it in a vise. Remove socket bolt (13). : 10 mm 4. Pull out plate (14) using a pulling bolt (M16, Pitch 2). Remove O-ring (15) from the plate. Remove seal washer (16) from casing (17). 5. Remove piston (18) from spool (19) in each port. (Four pistons in total) 6. Turn over casing (17). Attach special tool (75301512) to the universal t connecting hole. Tighten plate (4) using the special tool.

75301512

4 17

7. Remove the bolts (2 used) temporarily installed in the step 2. Gradually loosen the special tool until pushers A (8), B (11) and plate (4) are fully raised, unloading spring compresssion. 8. Remove plate (4) and pushers A (8), B (11) from casing (17). 9. Remove pusher A (8), O-ring (6), and oil seal (5) from each bushing A (7). Remove pusher B (11), O-ring (6), and oil seal (5) from each bushing B (12).

SM1113

W2-7-10

EX255-EX285

PILOT VALVE ASSEMBLE RIGHT AND LEFT PILOT VALVE

1

11

2 3 8

12

5 4

7

20

6

10 9

25

23

24

22

21 19 17 18

13

14

16

15 SM5516

1 2 3 4 5 6 7 8 9

-

Screw t Cam Universal t Plate Oil Seal (4 Used) O-Ring (4 Used) Bushing A (2 Used) Pusher A (2 Used) Spring Guide A (2 Used)

10 11 12 13 14 15 16 17 18

-

Spring Guide B (2 Used) Pusher B (2 Used) Bushing B (2 Used) Socket Bolt Plate O-Ring Seal Washer Casing Piston (4 Used)

19 20 21 22 23 24 25

-

Spool (4 Used) Spacer (4 Used) Shim (20 Used) Return Spring A (2 Used) Balance Spring A (2 Used) Return Spring B (2 Used) Balance Spring B (2 Used)

EX255-EX285

W2-7-11

PILOT VALVE Assemble Right and Left Pilot Valve 1. Insert special tool (75301504) into each port on casing (17). Be sure to insert the smaller end of the special tool first.

IMPORTANT - The number of shims (21) has been determined during the perfomance test at the factory. Take care not lose them. Install spacer (20) with its concave side facing the spring.

2. Install shims (21) (20 used) and balance spring A (23) (2 used) or B (25) (2 used) onto each spool (19) (4 used). While compressing balance spring A (23) (2 used) or B (25) (2 used), insert spacer (20) (4 used) onto the neck part of each spool (19) (4 used).

SM1115

75301504

IMPORTANT - Install spring guide A (9) or B (10) with its concave side facing the spring.

3. Install spring guide A (9) (2 used) or B (10) (2 used) and return spring A (22) (2 used) or B (24) (2 used) onto each spool (19) (4 used).

IMPORTANT - Be sure to confirm the applicable port number for each spool (19) before inserting.

4. Insert spools (19) into casing (17). 5. Install oil seal (5) (4 used) and O-ring (6) (4 used) onto each bushing A (7) (2 used) or B (12) (2 used). Insert pusher A (8) (2 used) or B (11) (2 used) into each bushing A (7) or B (12), respectively. Oil Seal Driving Tool: 75301503

75301512

6. Put each of the pusher assemblies onto the respective spool assembly. 7. Install plate (4) on bushings A (7) and B (12). Install special tool (75301512) into the universal t connecting hole on casing (17). 8. Gradually tighten the special tool until the bottom of bushings A (7) and B (12) is flush with the top surface of casing (17). Remove special tool (75301504) from each casing port. SM1116

9. Temporarily secure plate (4) using two bolts (M8, Pitch 1.25). Remove special tool (75301512).

W2-7-12

EX255-EX285

PILOT VALVE

1

11

2 3 8

19 17 18

13

14

16

15 SM1114

EX255-EX285

W2-7-13

PILOT VALVE 10. Insert piston (18) into each spool (19), with the smaller end first. 11. Install seal washer (16) on casing (17). Install O-ring (15) onto plate (14). 12. Secure plate (4) onto casing (17) using socket bolt (13). : 10 mm : 49 N m (5 kgf m, 36 lbf ft) 13. Turn over casing (17). Apply LOCTITE 262 to universal t (3). Install universal t (3) into casing (17). : 17 mm : 24.5 N m (2.5 kg m, 18.1 lbf ft) 14. Sufficiently apply grease to the t part of universal t without giving any air gaps. Apply grease to the top of pushers A (8) (2 used) and B (11) (2 used). 15. Install cam (2) onto universal t (3). 16. Tighten screw t (1) while keeping the clearance between pushers A (8) and B (11) and cam (2) to 0 to 0.2 mm (0 to 0.008 in). Remove the two temporarily installed bolts. Filler Gauge : 17 mm, 32 mm : 69 to 88 N m (7 to 9 kgf m, 50 to 65 lbf ft)

W2-7-14

EX255-EX285

PILOT VALVE DISASSEMBLE TRAVEL PILOT VALVE

1

2

3 4 5

10 11

24

8

10

23 22 21

8

6

20

7

19 17 16

9 18 15

14 25

13 12 SM1117

1 2 3 4 5 6 7 8 9

-

Cover Sems Bolt (2 Used) Spring Pin (2 Used) Spring Pin (2 Used) Cam (2 Used) Socket Bolt (2 Used) Spring Washer (2 Used) Pin (2 Used) Holder

10 11 12 13 14 15 16 17 18

-

Bushing (2 Used) Bushing (2 Used) Plug O-Ring Casing Spool (4 Used) Spacer (4 Used) Shim Return Spring (4 Used)

19 20 21 22 23 24 25

-

Balance Spring (4 Used) Spring Guide (4 Used) Pusher (4 Used) Bushing (4 Used) O-Ring (4 Used) Oil seal (4 Used) Plate

EX255-EX285

W2-7-15

PILOT VALVE Disassemble Travel Pilot Valve •

•

Be sure to thoroughly read “Precautions for Disassembly and Assembly” on page W1-1-1 before starting the disassembly work. As casing (14) and spools (15) are precision parts specially made to fit each other, they must be replaced as a set. Do not attempt to replace these parts individually. 1. Remove sems bolts (2) (2 used) to remove cover (1) from holder (9). : 10 mm 2. Turn over casing (14), and put it in a vise. Remove plug (12) from casing (14). Remove O-ring (13) from plug (12).

75301513

3. Turn over casing (16), and put it in a vise. Remove one of two socket bolts (6). Install special tool (75301513) into the bolt hole. : 8 mm 4. Remove the other socket bolt (6). Install special tool (75301513) into the bolt hole. : 8 mm 5. Loosen (operate) both special tools (75301513) evenly at the same time. Remove holder (9) from casing (14). 6. Put holder (9) in a vise. Remove spring pins (3) (2 Used) and (4) (2 Used) using special tool (75301487). 7. Remove pin (8) (2 Used) and cam (5) (2 Used) from holder (9). Do not remove bushings (10) and (11) unless they are damaged. 8. Remove the pusher assemblies (4 Used). Remove pusher (21), O-ring (23), oil seal (24), from each bushing (22). 9. Remove spools (15) (4 used) from casing (14).

10. Compress balance spring (19) to remove spring guide (20) from each spool (15). Remove balance spring (19), shims (17) and spacers (16) from each spool (15). Remove return spring (18) from each port.

SM1118

W2-7-16

EX255-EX285

PILOT VALVE ASSEMBLE TRAVEL PILOT VALVE

8

10

11

6-7

1

3-4

5

9

21

2 24 22

23 25 20 14 19 18 17 16 15

SM1119

12-13

1 2 3 4 5 6 7 8 9

-

Cover (2 Used) Sems Bolt (2 Used) Spring Pin (2 Used) Spring Pin (2 Used) Cam (2 Used) Socket Bolt (2 Used) Spring Washer (2 Used) Pin (2 Used) Holder

10 11 12 13 14 15 16 17 18

-

Bushing (2 Used) Bushing (2 Used) Plug O-ring Casing Spool (4 Used) Spacer (4 Used) Shim Return Spring (4 Used)

19 20 21 22 23 24 25

-

Balance Spring (4 Used) Spring Guide (4 Used) Pusher (4 Used) Bushing (4 Used) O-ring (4 Used) Oil seal (4 Used) Plate

EX255-EX285

W2-7-17

PILOT VALVE Assemble Travel Pilot Valve

IMPORTANT - The number of shims (17) has been determined during the perfomance test at the factory. Take care not lose them. Install spring guide (20) with its concave side facing the spring.

1. Attach shims (17) spacer (16) (4 used) and balance spring (19) (4 used) onto each spool (15) (4 used). While compressing balance spring (19), insert spring guide (20) (4 used) onto the neck part of each spool (15). 2. Turn over casing (14), and clamp with a vise. 3. Install O-ring (13) onto plug (12), and install plugs (12) onto casing (14). : 8 mm : 34 N m (3,5 kgf m, 25 lbf ft) 4. Turn over casing (14) and clamp with a vise. Insert return springs (18) (4 used) into casing (14).

IMPORTANT - Be sure to confirm the applicable port number for each spool (15) before inserting.

5. Insert spool (15) (4 used) assemblies into casing (14). 6. Install oil seal (24) and O-ring (23) onto each bushing (22). Insert pusher (21) into of each bushing (22) (4 used). 7. Put each of the pusher (21) assemblies onto the respective spool (15) (4 used) assembly. 75301513 8. Install holder (9) on the pusher (21) (4 used) assembly. Install special tools (75301513) (2 used) into the bolt holes on casing (14). 9. Gradually tighten the special tools until the bottom of bushings (22) is flush with the top surface of casing (14).

SM1120

W2-7-18

EX255-EX285

PILOT VALVE

8

1

6-7

3-4

5

9

21

2

SM1119

EX255-EX285

W2-7-19

PILOT VALVE 10. Remove one of special tools (75301513). Temporarily tighten spring washer (7) and socket bolt (6).

75301513

11. Remove the other special tool (75301513). Temporarily tighten the other spring washer (7) and socket bolt (6). Tighten both socket bolts (6) (2 used) to specification. : 8 mm : 49 N m (5 kgf m, 36 lbf ft)

IMPORTANT - When inserting pin (8), the spring pin hole nearer to the pin end must be facing outerwards.

12. Apply grease to the top of pushers (21) (4 used). Place cam (5) (2 used) on holder (9), aligning the pin holes. Insert pin (8) (2 used) into the pin hole.

IMPORTANT - Be sure to drive spring pins (3) and (4) until they extrude approx. 3 mm (0.12 in) down from the bottom of cam (5). Then, mushroom the spring pin ends at the top of the cam to prevent them from coming out.

13. Insert spring pins (3) and (4) using special tool (75301487). 14. Install cover (1) onto holder (9) using sems bolts (2) (2 used). : 10 mm : 2 N m (0.2 kgf m, 1.5 lbf ft)

SM1121

W2-7-20

EX255-EX285

PILOT VALVE POSITIONING PILOT VALVE (triple articulation version) WARNING Escaping fluid under pressure can penetrate the skin, causing serious injury. Avoid the hazard by relieving pressure before disconnecting hydraulic or other lines. Hydraulic oil may be hot just after operation. Hot hydraulic oil may spout, possibly causing severe burns. Be sure to wait for oil to cool before starting work. The hydraulic oil tank cap may fly off if removed without releasing internal pressure first. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. Preparation 1. Park the machine on a firm, level surface.


Removal 1. Loosen bolts (2) to remove pedal (1). : 17 mm IMPORTANT - Attach an identification tag on each hose to aid in reassembly.


2. Disconnect hoses (4) to (7). : 22 mm NOTE - Attach a cap on each of disconnected hose ends.

3. Loosen bolts to remove the pilot valve (3). : 17 mm

Installation 1. Mount the pilot valve (3) using bolts. : 17 mm : 44 N m (5.0 kgf m, 36 lbf ft)

SM3520


3. Mount pedal (1) using bolts (2). : 17 mm : 49 N m (5.0 kgf m, 36 lbf ft)

4 5 6 7

(Hose (Hose (Hose (Hose

T7) H) I) R4) -

To hydraulic oil tank To connection upper extra control valve To connection lower extra control valve From hydraulic oil tank

EX255-EX285

W2-7-21

PILOT VALVE

11B 11C 11

35

11A 11E 31

11D 13

30

2

29 27

1 39

6

28

5

25 38 15 24 40

37 36 16 17

1 2 5 6 11 11A11B-

Return spring Balance spring Spacer Shim Tappet Bushing Dust seal

11C11D11E 13 15 16 17 -

O-Ring Piston Oil seal Spring guide Plunger O-Ring Plug

SM3521

24 25 27 28 29 30 31

-

Plate Socket Bolt Cam Pin Spring pin Spring pin Cover

35 36 37 38 39 40

-

Screw Plug O-Ring Spool Bushing Body

W2-7-22

EX255-EX285

PILOT VALVE Disassemble positioning pilot valve

1. Remove the two screw (35) and cover (31). 35

31

SM3523

2. Remove plug (17) and (36) and extract O-rings (16) and (37).

37 36 16 17

SM3524

3. Remove plunger (15).

15 SM5518

EX255-EX285

W2-7-23

PILOT VALVE 4. Pull-out the two spring pins (29) and (30), pin (28) and remove cam (27), bushings (39) and plate (24).

30 29 27 39

28

24 5. Remove one of the socket bolt (25) from the valve body, and install tool 75298319 in the valve body.

SM3526

6. Remove the other socket bolt (25) and install another tool 75298319 in the valve body. 25 7. Loosen progressively the two tools 75298319 until the force of the springs is neutralized.

24 SM3527

8. Remove the two tools 75298319 from the valve body.

75298319

SM3528

W2-7-24

EX255-EX285

PILOT VALVE 9. Extract the two tappet assemblies (11). Separate piston (11D) from bushing (11A). 11A

11D

SM3529

10. Remove O-ring (11C) from bushing (11A).

11C

11A SM3530

11. Remove dust seal (11B).

11B

11A

SM3531

12. Remove oil seal (11E). 11A

11E SM3532

EX255-EX285

W2-7-25

PILOT VALVE 13. Remove the two spool assemblies. Remove spacer (5) from spool (38) pushing on balance spring (2).

5

2 38

SM3533

14. Pull-out balance spring (2) and shims (6) from spool (38). 2 6

38

SM3534

15. Remove spring guide (13) and return spring (1) from seat.

13 1 40

SM3537

W2-7-26

EX255-EX285

PILOT VALVE Assemble positioning pilot valve

1. Clean all components and lubricate with clean hydraulic oil all inner parts.

SM3535

2. Insert shims (6) and balance spring (2) into spool (38). 2 6

NOTE - The quantity of shims is established during the performance test.

38

SM3534

3. Will pressing spring (2) insert spacer (5). 5

2

NOTE - Make sure that the spacer is positioned with the spring seat toward the spring.

SM5517

4. Mount tool 75298321 in the two lower holes of the valve body.

75298321 SM3536

EX255-EX285

W2-7-27

PILOT VALVE 5. Insert return spring (1) and spring guide (13) into body (40).

13

NOTE - Make sure that the spring seat is positioned toward the spring.

1 40

SM3537

6. Insert the spool assemblies into spring guide (13). NOTE - Insert the single assemblies making reference to the cylinder number. 13

SM3538

7. Position dust seal (11B) in bushing (11A) with some grease, using tool 75298322.

75298322

11B 11A

SM3539

8. Position oil seal (11E) in bushing (11A). 11A

11E SM3532

W2-7-28

EX255-EX285

PILOT VALVE 9. Mount O-ring (11C) in bushing (11A). 11C

11A SM3530

10. Insert piston (11D) into bushing (11A) from the oil seal side (11E). 11A

NOTE - Smear some grease inside the bushing.

11D

SM3529

11. Position the two tappet assemblies into their seats, install plate (24) and mount the two tools 75298319 in the valve body.

75298319 24

Tighten the two tools until the lower surface of the bush is in line with the upper surface of the valve body.

SM3528

EX255-EX285

W2-7-29

PILOT VALVE 75298319

12. Remove tool 75298319 from the left side and temporary tighten socket bolt (25). 25

SM3541

13. Remove other tool 75298319 and temporary tighten other socket bolt (25). Tightening both socket bolts (25).

25

Tightening torque: 39 N m (4 kgf m, 29 lbf ft).

SM3542

14. Remove the two tools 75298321 from the bottom of the valve body.

75298321

SM3540

W2-7-30

EX255-EX285

PILOT VALVE 15. Lock the valve body into a vise and insert plunger (15).

15 SM5518

16. Position O-rings (37) and (16) on plugs (36) and (17).

37 36 16 17. Install plugs (36) and (17).

17

SM3524

Tightening torque: 49 N m (5 kgf m, 36 lbf ft)

35 18. Install cover (31) using screw (35).

31

SM3523

EX255-EX285

W2-7-31

PILOT VALVE SPECIAL TOOLS Special Tools for Right and Left Pilot Valve

2

1

SM5519

ITEM

Tools No.

Tool Name

Remarks

2

75301504

Guide for assembling plate

For assembling spools and holder

1

75301512

Valve holder

For disassembling and assembling plate

Special Tools for Travel Pilot Valve

SM1124

SM1123

ITEM

Tools No.

Tool Name

Remarks

1

75301513

Valve holder assembly

For disassembling and assembling valve

2

75301487

Spring pin driving guide

For tapping in/out spring pin

Special tools for Positioning Pilot Valve (Triple articulation version): ITEM

Tools No.

Tool Name

Remarks

1

75298319

Valve holder assembly

For disassembling and assembling valve

2

75298321

Spring pin driving guide (q.ty 4)

For tapping in/out spring pin

3

75298322

Inserting tool

For inserting dust seal

W2-7-32

EX255-EX285

PILOT VALVE NOTES:

EX255-EX285

W2-8-1

PILOT SHUT-OFF VALVE REMOVE AND INSTALL PILOT SHUT-OFF VALVE

WARNING Escaping fluid under pressure can penetrate the skin, causing serious injury. Avoid the hazard by relieving pressure before disconnecting hydraulic or other lines. Hydraulic oil may be hot just after operation. Hot hydraulic oil may spout, possibly causing severe burns. Be sure to wait for oil to cool before starting work. The hydraulic oil tank cap may fly off if removed without releasing internal pressure first. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. Preparation 1. Park the machine on a firm, level surface. 2. Stop the engine. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure.


Removal 1. Remove the outer located under the driver's compartment, by removing the six securing screws. : 17 mm

1

2

3 5

2. Remove ball t (10). : 13 mm NOTE - Attach labels or tags to hoses and pipes, to aid in assembly.

11

3. Disconnect pilot hoses (1 to 9). : 17, 19, 22 mm 4. Remove bolts (11) to remove the pilot shut-off valve.

4

: 8 mm Installation SM1311

1. Install the pilot shut-off valve using bolts (11).

10

9

8

7

6

2. Connect pilot hoses (1 to 9). 3. Install ball t (10). 4. Install the outer . Wrench size (mm)

Tightening Torque N m kgf m lbf ft

Remark

: 13

10

1

7

Nut

: 22

39

4

29

Hoses

:8

20

2

15

Bolt

: 17

49

5

36

Bolt

: 19

29

3

22

Hoses

1 2 3 4 5 6 7 8 9 10 11

-

Hose P2 : Hose P1 : Hose P3 : Hose T6 : Hose DP : Hose PF : Hose T5 : Hose T4 : Hose A4 : Ball t Bolt

(To Swing and Arm Pilot Valve) (To Travel Left and Right Pilot Valve) (To Boom and Bucket Pilot Valve) (From Bucket and Boom Pilot Valve) (To Solenoid Valve Unit) (From Pilot Relief Valve) (From Swing and Arm Pilot Valve) (From Travel Left and Right Pilot Valve) (To Shockless Valve)

W2-8-2

EX255-EX285

PILOT SHUT-OFF VALVE DISASSEMBLE PILOT SHUT-OFF VALVE

1 2 3 4

5 6 7 8

14 13 12

9

11 10 SM1312

1 2 3 4

-

Retaining Ring Washer Backup Ring O-Ring

5 6 7 8

-

O-Ring Backup Ring Washer Retaining Ring

9 10 11 12

-

Spring Pin Lever Spool Socket Bolt

13 - Steel Ball 14 - Body

EX255-EX285

W2-8-3

PILOT SHUT-OFF VALVE Disassemble Pilot Shut-Off Valve •

Before disassembling, be sure to read and understand all the "Precautions for Disassembly and Assembly" on page W1-1-1. 1. Remove retaining ring (1) and washer (2) and pull out spool (11).

NOTE - Mark spool (11) and lever (10) for alignment when installing.

2. Pull out spring pin (9) from spool (11), and remove lever (10). 3. Remove washer (7) and retaining ring (8) from spool (11). 4. Remove backup ring (3), (6) and O-ring (4), (5) from body (14). 5. Loosen socket bolt (12) from body (14). : 6 mm

W2-8-4

EX255-EX285

PILOT SHUT-OFF VALVE ASSEMBLE PILOT SHUT-OFF VALVE

SM1313

1 2 3 4

-

Retaining Ring Washer Backup Ring O-Ring

5 6 7 8

-

O-Ring Backup Ring Washer Retaining Ring

9 10 11 12

-

Spring Pin Lever Spool Socket Bolt

13 - Steel Ball 14 - Body

EX255-EX285

W2-8-5

PILOT SHUT-OFF VALVE Assemble Pilot Shut-Off Valve

IMPORTANT - Apply a film of grease to O-rings (4) and (5), and backup rings (3) and (6).

1. Install O-rings (4) and (5), backup rings (3) and (6) to body (14). 2. Install washer (7) and retaining ring (8) to spool (11). 3. Drive spring pin (9) alignmenting spool (11) and lever (10). (Alignment marks made when disassembling.)

IMPORTANT - Be sure to apply a film of hydraulic oil to spool (11).

4. Install spool (11) to body (14). 5. Install washer (2) and retaining ring (1) to spool (11). 6. Install and tighten socket bolt (12). : 6 mm : 44 N m (4.5 kgf m, 33 lbf ft)

W2-8-6

EX255-EX285

PILOT SHUT-OFF VALVE NOTES:

EX255-EX285

W2-9-1

SHOCKLESS VALVE REMOVE AND INSTALL SHOCKLESS VALVE





Removal

Installation

IMPORTANT - Attach labels or tags to hoses to aid in assembly.

1. Apply LOCTITE to bolts (10), then install shockless valve with bolts (10).

1. Disconnect hoses (1 to 9, 13 to 20).

2. Install pressure switch (11) and pressure sensor (12).

: 19, 22 mm

3. Connect hoses (1 to 9, 13 to 20).

2. Remove pressure switch (11) and pressure sensor (12).

Wrench Size

: 24 mm

Tightening Torque

(mm)

3. Remove bolts (10) to remove shockless valve. : 17 mm

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

-

Hose (To left swing control valve) Hose (To right swing control valve) Hose (To bucket roll-out control valve) Hose (To bucket roll-in control valve) Hose (To boom raise control valve) Hose (To boom lower control valve) Hose (To arm roll-in control valve) Hose (To arm roll-out control valve) Hose (From pilot shut-off valve) Bolt Pressure switch (for boom raise) Pressure sensor (for arm roll-in) Hose (From arm roll-in pilot valve) Hose (From arm roll-out pilot valve) Hose (From boom lower pilot valve) Hose (From boom raise pilot valve) Hose (From bucket roll-in pilot valve) Hose (From bucket roll-out pilot valve) Hose (From right swing pilot valve) Hose (From left swing pilot valve)

16

17

Nm

Remark

kgf m lbf ft

: 17

20

2

14.5

Bolt

: 19

29

3

21.7

Hose

: 22

39

4

29

Hose

: 24

78

8

58

Pressure sensor and Switch

18

19

20 11

15

1

14

13

2

12

3 4

10

5 9

8

7

6 SM1314

W2-9-2

EX255-EX285

SHOCKLESS VALVE DISASSEMBLE AND ASSEMBLE SHOCKLESS VALVE

1

14

2 11

3 4

10

5

6

13

7 15 9

7 4 8 3 2

9

1 10 10 11

11 12

12 SM1315

EX255-EX285

W2-9-3

SHOCKLESS VALVE

Section V

5

Section X

6

1 1 2

2 4

6

3

10

4

6

3

11 10 9 15 7 10

11 12 14

Z

1 A4 X

V

Z

W

2

3

6

Y

4

Section W

11 10 9

8

7 10

11 12 14

13 1 Section Z-Z

2

3

6

4

Section Y SM1316

W2-9-4

EX255-EX285

SHOCKLESS VALVE Item

Part Name

Q.ty

Wrench Size (mm)

Torque Specification

Remark

Nm

kgf m

lbf ft

:5

10

1

7.2

PF 1/8

1

Plug

4

2

O-ring

4

3

Spring

4

4

Steel Ball

4

5

Body

1

6

Steel Ball

5

7

Ring

2

8

Orfice

1

9

Plunger

2

10

Spring

4

11

O-ring

4

12

Plug

2

:8

49

5

36

PF 3/8

13

Orifice

1

:5

10

1

7.2

PF 1/8

14

Plug

2

:8

49

5

36

PF 3/8

15

Orifice

1

EX255-EX285

W2-10-1

SOLENOID VALVE UNIT REMOVE AND INSTALL SOLENOID VALVE UNIT WARNING Escaping fluid under pressure can penetrate the skin, causing serious injury. Avoid the hazard by relieving pressure before disconnecting hydraulic or other lines. Hydraulic oil may be hot just after operation. Hot hydraulic oil may spout, possibly causing severe burns. Be sure to wait for oil to cool before starting work. The hydraulic oil tank cap may fly off if removed without releasing internal pressure first. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. Preparation 1. Park the machine on a firm, level surface. 2. Stop the engine. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure.


Removal 1 2

1. Remove all wire harnesses for solenoid valves from connectors. 2. Disconnect pilot lines (1 to 6, 8 to 11, 16).

3 4 5

16

: 17, 19, 22 mm

6

15 3. Remove bolts (7) to remove solenoid valve unit. 14

: 8 mm

11 10

Installation

13 1. Install solenoid valve unit with bolts (7).

12

9

8

7 SM1037

2. Connect pilot lines (1 to 6, 9, to 11, 16). 3. Connect all wire harnesses for solenoid valves to connectors.

Wrench Size (mm)

Tightening Torque

Remark

Nm

kgf m

lbf ft

: 17

44

4,5

32.5

Hose

: 19

29

3

22

Pipe

: 22

59

6

43

Hose

:8

20

2

16

Bolt

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

-

Hose PE: (To pump control valve (4-spool)) Pipe DE: (From bucket flow control valve) Pipe PH: (To pump control valve (5-spool)) Hose PG: (To swing parking brake) Pipe DP: (From pilot shut-off valve) Hose DS: (To hydraulic oil tank) Socket Bolt Hose SG: (To main relief valve) Hose SI: (To travel speed change) Pipe SD: (To pump regulator valve (Pump 1 and 2)) Pipe SC: (To arm regenerative valve) Solenoid Valve (SG) Solenoid Valve (SI) Solenoid Valve (SD) Solenoid Valve (SC) Hose F: (From pilot shut-off valve)

W2-10-2

EX255-EX285

SOLENOID VALVE UNIT DISASSEMBLE PROPORTIONAL SOLENOID VALVE

1 2

3

4 5 6 7 8 9 10

13

11

14 12

15

16 17 18 SM1038

1 2 3 4 5

-

Socket Bolt (2 Used) Lock Nut O-Ring Adjusting Screw Spring

6 7 8 9 10

-

Solenoid Spring O-Ring Diaphragm Spool

11 12 13 14 15

-

Washer Spring O-Ring O-Ring O-Ring

16 - Sleeve 17 - Plate 18 - Washer

EX255-EX285

W2-10-3

SOLENOID VALVE UNIT Disassemble Proportional Solenoid Valve 1. Loosen socket bolts (1) and remove solenoid (6).

IMPORTANT - Take care not to lose spring (7) provided in the groove of solenoid (6) when removing solenoid (6). Do not remove pressure control lock nut (2) and adjusting screw (4). : 3 mm

2. Pull out spool (10) and remove washer (11), spring (12) and diaphragm (9) from spool (10). 3. Pull sleeve (16) out of the housing and remove O-rings (13), (14) and (15) from sleeve (16), and then take washer (18), plate (17) out of the housing.

W2-10-4

EX255-EX285

SOLENOID VALVE UNIT ASSEMBLE PROPORTIONAL SOLENOID VALVE

4

2

6

1

8

16

13

14

9

7

11

12

10

15

18

17 SM1039

1 2 3 4 5

-

Socket Bolt (2 Used) Lock Nut O-Ring Adjusting Screw Spring

6 7 8 9 10

-

Solenoid Spring O-Ring Diaphragm Spool

11 12 13 14 15

-

Washer Spring O-Ring O-Ring O-Ring

16 - Sleeve 17 - Plate 18 - Washer

EX255-EX285

W2-10-5

SOLENOID VALVE UNIT Assemble Proportional Solenoid Valve 16 IMPORTANT - Apply a film of grease to O-rings (13), (14) and (15). Install sleeve (16) together with plate (17) and washer (18). Apply a film of hydraulic oil to sleeve (16). When inserting sleeve (16), be sure to align the ports of the sleeve with the ports of the housing.

15 14 13

1. Install washer (18) and plate (17) into the housing. Install O-rings (13), (14) and (15) onto sleeve (16) and insert into the housing.

IMPORTANT - Take care not to damage the bore edges of sleeve (16) when inserting the spool assembly. After inserting spool (10) to check that spool (10) slides in and out smoothly without any restriction about 3 to 5 mm (0.12 to 0.20 in).

SM1040

10

9

16

2. Install diaphragm (9), washer (11) and spring (12) to spool (10). Apply a film of hydraulic oil to the spool

12 SM1041

11

10

SM1042

3. Install solenoid (6) with tightening socket bolts (1). 6 IMPORTANT - Lock nut (2) and adjusting screw (4) should not be removed during disassembly, so they are not required to be reassembled.

IMPORTANT - Be careful not to allow spring (7) to fall out when installing solenoid (6).

7

: 3 mm : 3 N m (0.3 kgf m, 2.2 lbf ft)

1

SM1043

W2-10-6

EX255-EX285

SOLENOID VALVE UNIT NOTES

EX255-EX285

W2-11-1

PILOT RELIEF VALVE UNIT REMOVE AND INSTALL PILOT RELIEF VALVE UNIT WARNING Escaping fluid under pressure can penetrate the skin, causing serious injury. Avoid the hazard by relieving pressure before disconnecting hydraulic or other lines. Hydraulic oil may be hot just after operation. Hot hydraulic oil may spout, possibly causing severe burns. Be sure to wait for oil to cool before starting work. The hydraulic oil tank cap may fly off if removed without releasing internal pressure first. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure.

Preparation 1. Park the machine on a firm, level surface. 2. Stop the engine. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure.


Removal 1 1. Disconnect hoses (1, 2, 3 and 6). : 22 mm, 27 mm 2 2. Remove bolts (4) to remove relief valve unit. 6

: 17 mm

5 3 Installation 1. Install relief valve unit with bolts (4).

4

2. Connect hoses (1, 2, 3 and 6).

SM4225

Wrench Size Tightening Torque mm

Remark

Nm

kgf m

lbf ft

: 17

49

5

36

Bolt

: 22

39

4

29

Hose

: 27

70

7

50

Hose

: 19

39

4

29

Hose

1 2 3 4 5 6

-

Hose TA: (To hydraulic oil tank) Hose PI: (To control valve (4-Spool) Hose PD:(To Pilot shut-off valve) Bolt Pilot Relief Valve Hose PA:(From pilot pump)

W2-11-2

EX255-EX285

PILOT RELIEF VALVE UNIT DISASSEMBLE PILOT RELIEF VALVE

1

2 Port A

Port P

3

Port PI

4 Port T

5

6

7

8

SM4226

1 - Plug 2 - O-Ring

3 - Body 4 - Poppet

5 - Spring 6 - Shim

7 - O-Ring 8 - Plug

EX255-EX285

W2-11-3

PILOT RELIEF VALVE UNIT Disassemble Pilot Relief Valve 1. Loosen plug (1) and remove O-ring (2) from body (3). : 8 mm

2. Loosen plug (8) and remove O-ring (7), shim (6), spring (5), and poppet (4) from body (3). : 36 mm

W2-11-4

EX255-EX285

PILOT RELIEF VALVE UNIT ASSEMBLE PILOT RELIEF VALVE

B

A

T

A

B

1

2 3

4 PI

P

5

A

7 T

8 6 Section A-A

Section B-B SM4277

1 - Plug 2 - O-Ring

3 - Body 4 - Poppet

5 - Spring 6 - Shim

7 - O-Ring 8 - Plug

EX255-EX285

W2-11-5

PILOT RELIEF VALVE UNIT Assemble Pilot Relief Valve 1. Install poppet (4) and spring (5) into body (3).

IMPORTANT - Be sure to check if poppet (4) moves smoothly.

2. Install shim (6) and O-ring (7) to plug (8) and tighten plug (8) to body (3). : 36 mm : 49 N m (5 kgf m, 36 lbf ft)

3. Install O-ring (2) to plug (1) and tighten plug (1) to body (3). : 8 mm : 49 N m (5 kgf m, 36 lbf ft)

W2-11-6

EX255-EX285

PILOT RELIEF VALVE UNIT IMPORTANT - When pilot filter (3) for pilot relief valve unit (1) is replaced or disassembled, correctly tighten socket bolt (2). : 6 mm : 20±2 N m (2±0.2 kgf m, 14.5±1.5 lbf ft)

1

2

3

SM4225

1 - Pilot Relief Valve Unit 2 - Socket Bolt 3 - Pilot Filter

SECTION 3

EX255-EX285

UNDERCARRIAGE

CONTENTS Group 1 -

Swing Bearing

Remove and Install Swing Bearing ...................................... W3-1-1

Group 2 -

Travel Device

Remove and Install Travel Device ......... W3-2-1 Travel Device Components (EX255) ...... W3-2-2 Travel Motor Removal (EX255) .............. W3-2-3 Disassemble Travel Reduction Gear (EX255) ....................... W3-2-4 Reassembly (EX255) ............................ W3-2-9 Assemble Travel Reduction Gear (EX255) ..................... W3-2-10 Travel Motor Installation (EX255) ........ W3-2-16 Disassemble Travel Device (EX285) ... W3-2-18 AssembleTravel Device (EX285) ......... W3-2-24 Disassemble Travel Motor (EX255) ..... W3-2-30 Assemble Travel Motor (EX255) .......... W3-2-34 Disassemble Brake Valve (EX255) ..... W3-2-42 Assemble Brake Valve (EX255) .......... W3-2-44 Disassemble Travel Motor (EX285) ..... W3-2-46 Assemble Travel Motor (EX285) .......... W3-2-50 Disassemble Brake Valve (EX285) ...... W3-2-58 Assemble Brake Valve (EX285) .......... W3-2-60 Maintenance Standard ........................ W3-2-62

Group 3 -

Center t

Remove and Install Center t .......... W3-3-1 Disassemble Center t .................... W3-3-2 Assemble Center t ......................... W3-3-4 Maintenance Standard ......................... W3-3-7

Group 4 -

Track Adjuster

Remove and Install Track Adjuster ...................................... W3-4-1 Disassemble Track Adjuster ................. W3-4-2 Assemble Track Adjuster ................... W3-4-10

Group 5 -

Front Idler

Remove and Install Front Idler ............. W3-5-1 Disassemble Front Idler (EX255) .......... W3-5-2 Assemble Front Idler (EX255) .............. W3-5-6 Disassemble Front Idler (EX285) .......... W3-5-8 Assemble Front Idler (EX285) ............ W3-5-12 Maintenance Standard ....................... W3-5-14

Group 6 -

Upper and Lower Roller

Remove and Install Upper Roller .......... W3-6-1 Remove and Install Lower Roller .......... W3-6-4 Disassemble Upper Roller .................... W3-6-7 Disassemble Lower Roller .................... W3-6-8 Assemble Lower Roller ...................... W3-6-10 Maintenance Standard ....................... W3-6-12

Gruppo 7 -

Tracks

Remove and Install Tracks ................... W3-7-1 Maintenance Standard ......................... W3-7-7

EX255-EX285

W3-1-1

SWING BEARING REMOVE AND INSTALL SWING BEARING Before removing the swing bearing, the upperstructure must be removed first. For removal and installation of the upperstructure, refer to “Remove and Install Main Frame” section. In this section, the procedure starts on the premise that the upperstructure has already been removed. Mark

Removal 1. Put alignment marks on swing bearing (1) and track frame (2).

1

2 SM1307

2. Remove bolts (3) (36 used). : 32 mm

3

SM1308

WARNING Swing bearing weight: 331 kg (730 lb)

3. Attach lifting tools (75298793), hoist swing bearing (4) and remove it.

4

SM1309

W3-1-2

EX255-EX285

SWING BEARING Installation Clean the matching surfaces of swing bearing and the frame. 1. Apply THREEBOND 1102 to the matching surfaces of swing bearing and track frame.

WARNING Swing bearing weight: 331 kg (730 lb) SM1309

Front Frontside Side

IMPORTANT - Inner race soft zone (S) and the ball filler port should be placed on the same position (right side of the frame).

“S” ÒSÓ Soft Zone Soft Zone Marking MarkingPosition Position

10.5°

2. Hoist the swing bearing. Align the swing bearing with the alignment mark on the track frame and install the swing bearing.

PositionofofPlug Plug Position

SM3517

3. Install bolts (3) (36 used) and tighten to specification. : 32 mm : 700 N m (71 kgf m, 514 lbf ft)

3

SM1308

EX255-EX285

W3-2-1

TRAVEL DEVICE REMOVE AND INSTALL TRAVEL DEVICE WARNING Escaping fluid under pressure can penetrate the skin, causing serious injury. Avoid the hazard by relieving pressure before disconnecting hydraulic or other lines. Hydraulic oil may be hot just after operation. Hot hydraulic oil may spout, possibly causing severe burns. Be sure to wait for oil to cool before starting work. The hydraulic oil tank cap may fly off if removed without releasing internal pressure first. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure.

Preparation 1. Park the machine on a firm, level surface. 2. Stop the engine. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure.


Installation

Removal The procedure starts on the premise that the track link has already been removed. 1. Loosen bolts (7) to remove cover (6). Disconnect hoses (2) to (5). : 19 mm : 34 N m (3.5 kgf m, 25 lbf ft) : 22 mm : 177 N m (18 kgf m, 130 lbf ft) : 27 mm : 93 N m (9.5 kgf m, 69 lbf ft) : 36 mm : 157 N m (16 kgf m, 116 lbf ft) NOTE - Install caps on all disconnected hose and line ends.

1. Install the travel device using bolts (1). 2. Connect hoses (2) to (5). 3. Install cover (6) using bolts (7).

IMPORTANT - After completing travel motor installation, be sure to fill the travel motor with hydraulic oil. After completing installation of the travel motor or the travel device, be sure to perform test driving to prevent motor seizure. Test drive as follows: 1. Run the engine with the engine control dial in the slow idle position. 2. Turn the travel speed mode switch to the slow speed position. 3. Test drive the machine back-and-forth for 0.5 m to 1 m (19.7 to 39.37 in) in each direction five times or more.

2. Attach the travel device to a crane using a wire rope. Remove any slack from the wire rope so as to secure the travel device when the mounting bolts are removed.

5

1

4 3

WARNING Travel device weight: EX255: Approx. 315 kg (694 Ib) EX285: Approx. 441 kg (972 lb)

3. Remove bolts (1). Remove the travel device using the crane. : 30 mm : 590 N m (60 kgf m, 434 lbf ft)

2

7 6

SM5500

W3-2-2

EX255-EX285 EX255

TRAVEL DEVICE TRAVEL DEVICE COMPONENTS (EX255)

SM3022

EX255-EX285 EX255

W3-2-3

TRAVEL DEVICE TRAVEL MOTOR REMOVAL •

Oil draining Unscrew the plugs (2) and let the oil flow.

2

SM1270

1. Unscrew the 4 socket head screws M16x80 (22) grade 12.9, which fix the hydraulic motor to the gearbox.

22

SM1271

2. Remove the hydraulic motor from the gearbox.

SM1272

3. Remove the O-ring (21) from the hydraulic motor seat.

21

SM1273

EX255 EX255-EX285

W3-2-4

TRAVEL DEVICE DISASSEMBLE TRAVEL REDUCTION GEAR (EX255)

1 7 W3-2-20PGS˜

10

9

8

14 15 16 3

2

5 6 17 18

4 11

19 20

12

21

13

SM3515

22

1 2 3 4 5 6

-

Screw (10 used) Plug (2 used) Washer (2 used) Cover O-ring Plug

7 8 9 10 11 12

-

1st stage sun gear 1st reduction assembly 2nd reduction assembly Circlip Planetary gear (5 used) Spacer (5 used)

13 - Ring nut 14 - Screw (18 used) 15 - Spring washer (18 used) 16 - Sprocket 17 - Gearbox housing

18 19 20 21 22

-

Half seal Centering ring Hub O-ring Screw (4 used)

EX255-EX285 EX255

W3-2-5

TRAVEL DEVICE 1. Loosen screws (14). Remove sprocket (16) from gearbox housing (17) using a craine. : 30 mm

WARNING Sprocket weight: approx. 47 kg (104 lb)

2. Turn the gearbox upside down, unscrew and remove the 2 plugs M22x1,5 (2) and the 2 washers (3) from the end cover (4).

SM1275

3. Unscrew and remove the 10 socket head screws M10x25 (1), grade 12.9, from the end cover (4).

1 SM1276

4. Remove the end cover (4) using 2 screws M22x1.5 tightened to the oil plugs holes. 4

SM1277

W3-2-6

EX255-EX285 EX255

TRAVEL DEVICE 5. Remove the O-ring (5) from its seat in the end cover (4). 5

SM1278

6. Remove the 1st stage sun gear (7).

7

SM1279

8 7. Remove the 1st reduction assembly (8).

SM1280

8. Remove the 2nd reduction assembly (9).

9

SM1281

EX255-EX285 EX255

W3-2-7

TRAVEL DEVICE 9. Using pliers remove the 5 circlips (10) from their seats placed in the pins of the flanged hub (20).

10

SM1282

10. Use a puller to remove the 5 planet assemblies of the 3rd reduction (11) from the flanged hub (20).

11

SM1283

11. Remove the 5 spacer (12).

12

SM1284

12. By means of a punch, remove the riveting in the edge of the ring nut (13). Using the tool 75301526, unscrew the nut M230x2 (13).

13

SM1285

EX255 EX255-EX285

W3-2-8

TRAVEL DEVICE 13. Remove the centering ring from (19) from the flanged hub (20).

NOTE - The above operation must be executed only in case the hub must be replaced.

19

SM1286

14. Using a press and a metal stopper, remove the flanged hub (20) from the gearbox housing (17). 17

WARNING In case of oil leakages, it might be necessary to check and eventually replace the lifetime seal (18), which means both the metal rings parts and the O-rings.

20 SM1287

15. Use a screwdriver to remove the 1st half-seal (18) from the flanged hub (20).

18 SM1288

16. Use a screwdriver to remove the 2nd half-seal (18) from the gearbox housing (17).

18

SM1289

EX255 EX255-EX285

W3-2-9

TRAVEL DEVICE REASSEMBLY (EX255) 1. Important notes before reassembly When proceeding with the gearbox reassembly, it is necessary to follow the rules listed below: a) In case of damaged gears, for example a planet, do not replace the single gear, but the whole reduction stage. b) Replace always the O-rings of the part to be reassembled after having carefully cleaned the seats and having butterd some grease on the seats themselves and on the O-rings to make easier the reassembly.

2. Instructions for the installation of the half seals To follow these instructions at the time of fitting, in order to obtain the correct seal: a) Carefully clean the seats (1) and (2) using, if necessary, metal brushes or solvent (surfaces in with or (3) must be perfectly clean and dry).

1

2

b) Make sure that sealing surface (4) of metal rings (5) are free from scratches, dinges or foreign substances; metal ring surfaces (6) must be perfectly clean and dry.

6

6

3

3

c) Carefully clean the lapped surface (4) of metal rings (5) and remove dust or fingersprints. Then lubrificate them with a thin oil film, taking care not to oil the other components.

5

5

4

4 SM1290

EX255 EX255-EX285

W3-2-10

TRAVEL DEVICE ASSEMBLE TRAVEL REDUCTION GEAR (EX255)

W3-2-25PGS 16

13 15

12 11

19 21

14

10 9

18

20

1

22 23 4

8 7 6

3 2 5 17

SM3023

1 2 3 4 5 6

-

Screw (10 used) Plug (2 used) Washer (2 used) Cover O-ring Plug

7 8 9 10 11 12

-

1st stage sun gear 1st reduction assembly 2nd reduction assembly Circlip Planetary gear (5 used) Spacer (5 used)

13 - Ring nut 14 - Screw (18 used) 15 - Spring washer (18 used) 16 - Sprocket 17 - Gearbox housing

18 19 20 21 22 23

-

Half seal Centering ring Hub O-ring Screw (4 used) Travel motor

EX255-EX285 EX255

W3-2-11

TRAVEL DEVICE 1. Assemble the 1st half seal (18) on the tool 75301527.

75301527

18 SM1291

2. Assemble the 1st half seal (18) on the gearbox housing (17).

SM1292

3. Assemble, by using the same tool 75301527, the 2nd half seal (18) on the flanged hub (20). Clean carefully the metal faces of the half-seals.

SM1293

4. Lube the metallic face of the half seal (18) with a thin oil film.

SM1294

W3-2-12

EX255-EX285 EX255

TRAVEL DEVICE 5. Fit the lower ball row (d) into the gearbox housing (17), holding the inner ring (c) with spacers (a, b).

d

c a b

SM1295

g

6. Remove the spacer (b). Place the bearing spacer (e). Drop the upper ball row (f). Assemble the inner raceway (g).

f e

a b SM1296

7. Place the flanged hub (20) inside the gearbox housing (17). Using a press and a metallic stopper, push the flanged hub (20) against the shoulder of the gearbox housing (17) until assembly of the unit is complete.

20

17

SM1297

8. Turn the gearbox upside down. Place the centering ring (19) on the flanged hub (20) and using a press and a metal stopper push it against the shoulder until assembly is complete.

SM1298

EX255-EX285 EX255

W3-2-13

TRAVEL DEVICE 9. Using the tool 75301526 screw-in a new ring nut M230x2 (13) at a torque of 375-425 da N m.

13

SM1285

10. Deform the ring nut (13) next to a space on the flanged hub (20).

SM1311 SM1299

11. Assemble correctly the 5 spacers (12) on the pins of the flanged hub (20).

12

SM1312

SM1284

WARNING 12.Place correctly the 5 planet assemblies of the 3rd reduction (11) on the pins of the flanged hub (20), checking that the groove side is turned to the end cover (see figure).

SM1313

W3-2-14

EX255-EX285 EX255

TRAVEL DEVICE 13. Use a press and the metal stopper 75301528, to push the 5 planet assemblies of the 3rd reduction (11) against the flanged hub shoulder (20) until assembly is complete.

SM1304

14. Use pliers to assemble the 5 circlips (10) in the flanged hub pin seats (20).

10

SM1282

9 15. Assemble the 2nd reduction assembly (9).

SM1281

8 16. Assemble the 1st reduction assembly (8).

SM1280

EX255-EX285 EX255

W3-2-15

TRAVEL DEVICE 17. Insert the 1st stage sun gear (7).

7

SM1279

18. Mount the O-ring (5) into its seat in the end cover (4).

5

SM1278

4 19. Place the end cover (4) on the gearbox housing (17).

SM1305

20. Fix the end cover (4) to the gearbox housing (17) throught 10 socket head screws M10x25 (1), grade 12.9, tightened by a torque wrench at 7.5 daN m torque.

21. Install sprocket (16) onto gearbox housing (17). Tighten screws (14) with spring washer (15). : 30 mm : 470 N m (48 kgf m, 346 lbf ft) SM1276

EX255 EX255-EX285

W3-2-16

TRAVEL DEVICE TRAVEL MOTOR INSTALLATION (EX255) IMPORTANT - Before mounting the hydraulic motor, , use a depth slide gauge to measure the axial distance from the input side of the flanged hub (20) to the 1st stage sun gear (7). Axial dimension = 115 ± 2 mm.

SM1306

1. Fit the O-ring (21) into the seat of the hydraulic motor.

21

SM1273

2. Place the hydraulic motor on the gearbox.

SM1272

3. Fix the hydraulic motor to the gearbox through 4 socket head screws M16x80 (22), grade 12.9, tightened by a torque wrench at 27 da N m torque.

22

SM1271

EX255-EX285 EX255

W3-2-17

TRAVEL DEVICE 4. Fill the gearbox with the lubricant oil. Loosen the filling oil plug and put fill with proper oil. Approximate oil capacity 4,5 liters ± 10 %. Insert the washers (3) and the plugs M22x1.5 (2) into the oil draing-filling holes of the end cover (4). Tighten the plugs by a torque wrench at 3-4 daNm torque.

SM1276

EX285 EX255-EX285

W3-2-18

TRAVEL DEVICE DISASSEMBLE TRAVEL DEVICE (EX285) 36 31 32 31 30 45

44 29

46

42

35 37 43

10 9 8 23

18

2 8 1 7 33

34 19 24

3 25 26 28 26

27

4

5

3

22 19 20 21

6 17

41 40 14

12

27 16

11 15 38

SM5107

13 1 2 3 4

-

5 6 7 8 9 10 11 12 13 14 15 16

-

Third Stage Carrier Third Stage Sun Gear Thrust Plate (6 Used) Second Stage Planetary Gear (3 Used) Needle Bearing (3 Used) Pin (3 Used) Spring Pin (3 Used) Spacer (2 Used) Second Stage Sun Gear First Stage Carrier Propeller Shaft Ring Gear Bolt (24 Used) Stopper Pin Cover Bolt (12 Used)

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

- Plug (3 Used) - Spring Pin (3 Used) - Thrust Plate (6 Used) - Needle Bearing (3 Used) - First Stage Planetary Gear (3 Used) - Pin (3 Used) - Second Stage Carrier - Spring Pin (3 Used) - Pin (3 Used) - Thrust Plate (6 Used) - Needle Bearing (6 Used) - Third Stage Planetary Gear (3 Used) - Motor - Floating Seal - Roller Bearing (2 Used)

32 33 34 35 36 37 38 40 41 42 43 44 45 46

-

Drum Spring Washer (20 Used) Bolt (20 Used) Spring Washer (4 Used) Bearing Nut Bolt (4 Used) Sprocket Retaining Ring Bearing O-Ring Spacer Housing Lock Plate Bolt (2 Used)

EX285 EX255-EX285

W3-2-19

TRAVEL DEVICE Disassemble Travel Device •

Be sure to thoroughly read “Precautions for Disassembly and Assembly” on page W1-1-1 before starting the disassembly work. WARNING Pressure may remain in the travel device. Slowly loosen the air bleed plug to completely release the residual pressure. Then, remove the drain plug to drain gear oil into a container. If the air bleed plug is loosened quickly, the plug may fly off and/or gear oil may spout. Position your face and body away from the plug. 29

1. Stand the travel device upright with the motor on the top. Install spacer (75301498) on the frame mounting surface on motor (29) using two bolts (M20, Pitch 2.5). : 30 mm 75301498 WARNING Travel device weight: 441 kg (972 lb)

SM1079

2. Turn over the travel device. (Stand the travel device upright with the spacer (75301498) side on a work bench.) NOTE - If the spacer (75301498) is not available, use a device to stand the travel device securely so that the brake valve does not come into with the work bench. 3. Remove bolts (16) to remove cover (15). : 19 mm NOTE- For easy separation of cover (15), apply a chisel between cover (15) and ring gear (12) and lightly tap on the end of the chisel. Do not remove stopper pin (14) unless it is damaged or excessively worn. 4. Remove propeller shaft (11) and first stage carrier (10) assembly. 5. Remove second stage sun gear (9) and second stage carrier (23) as an assembly. Remove third stage sun gear (2).

75301485

13

WARNING Ring gear weight: 50 kg (110 Ib) 6. Remove bolts (13). Attach eye bolt (75301485) to ring gear (12). Remove ring gear (12) using a crane. : 24 mm

SM1080

W3-2-20

EX255-EX285 EX285

TRAVEL DEVICE

36 31 32 31 30 45

44 29

46

42

35 37 10

18 1

17

SM5107

EX255-EX285 EX285

W3-2-21

TRAVEL DEVICE

WARNING Weight of third stage carrier assembly: Approx. 45 kg (99 lb)

46 45

7. Remove third stage carrier (1) assembly.

36

8. Remove lock bolt (46), and lock plate (45), from bearing nut (36).

9. Remove bearing nut (36) using special tools. Special Tools: 75301495, 75301496, 75301497 Bolt: M16 (60 to 90 mm in length): 2 pieces

SM5109

WARNING Weight of drum and sprocket combined: 130 kg (290 lb)

75301496 75301497 75301495

10. Attach eye bolt (75301486) to drum (32). Remove drum (32) from housing (44) using a crane. 11. Remove the inner race of roller bearing (31) from drum (32).

36 SM1082

12. Remove the half of floating seal (30) from drum (32). 13. Remove the other half of floating seal (30) from housing (44). 75301486 NOTE - Do not attempt to remove the inner race of roller bearing (31) which remained in housing (44) side unless it is to be replaced.

14. Apply a metal bar to the outer race of roller bearing on drum (32) side, and tap the bar end with a hammer to drive the outer race out. SM1083

15. Apply a round bar to spring pin (18), and tap the end of the bar to drive spring pin (18) out of first stage carrier (10) assembly.

EX285 EX255-EX285

W3-2-22

TRAVEL DEVICE

32

44

10

43

8 23 18 8 1 33

34 19

21

22 19 20

38 SM5107

EX255-EX285 EX285

W3-2-23

TRAVEL DEVICE 16. Remove pin (22). Remove first stage planetary gears (21), needle bearings (20), and thrust plates (19). 17. Remove spacer (43) from first stage carrier (10) assembly. 18. Disassemble second stage carrier (23) assembly following steps 16 to 18 above. 19. Disassemble third stage carrier (1) assembly following steps 16 to 18 above.

WARNING Sprocket weight: Approx. 65 kg (143 lb)

20. Loosen bolts (34). Remove sprocket (38) from drum (32) using a crane. : 30 mm

EX285 EX255-EX285

W3-2-24

TRAVEL DEVICE ASSEMBLE TRAVEL DEVICE (EX285) 29

42

44

8 13 12 1 2 23 8 9 10

43

17

11 15 14

41 40 21 20 22 18 19 16

30 31 32

45 46 28 27 25 26 24

36

38

3 4

5

6

7

33-34 SM5108

1 2 3 4

-

5 6 7 8 9 10 11 12 13 14 15

-

Third Stage Carrier Third Stage Sun Gear Thrust Plate (6 Used) Second Stage Planetary Gear (3 Used) Needle Bearing (3 Used) Pin (3 Used) Spring Pin (3 Used) Spacer (2 Used) Second Stage Sun Gear First Stage Carrier Propeller Shaft Ring Gear Bolt (24 Used) Stopper Pin Cover

16 17 18 19 20 21 22 23 24 25 26 27 28 29

- Bolt (12 Used) - Plug (3 Used) - Spring Pin (3 Used) - Thrust Plate (6 Used) - Needle Bearing (3 Used) - First Stage Planetary Gear (3 Used) - Pin (3 Used) - Second Stage Carrier - Spring Pin (3 Used) - Pin (3 Used) - Thrust Plate (6 Used) - Needle Bearing (6 Used) - Third Stage Planetary Gear (3 Used) - Motor

30 31 32 33 34 35 36 37 38 40 41 42 43 44 45 46

-

Floating Seal Roller Bearing (2 Used) Drum Spring Washer (20 Used) Bolt (20 Used) Spring Washer (4 Used) Bearing Nut Bolt (4 Used) Sprocket Retaining Ring Bearing O-Ring Spacer Housing Lock Plate Bolt (2 Used)

EX255-EX285 EX285

W3-2-25

TRAVEL DEVICE Assemble Travel Device 1. If replacing roller bearing (31), warm the inner race 50 to 70 °C (122 to 158 °F) using a heater, then install it into housing (44). Wait for the inner race to cool. Then, drive it in position completely using a metal bar and a hammer.

7. Install bearing nut (36) to housing (44), with the uneven surface side towards the hub and tighten manually. 8. Secure the travel device immovable. Attach the special tools to bearing nut (36). Then, tighten it using a torque wrench. Special Tools: 75301495, 75301496, 75301497

2. Install one half of floating seal (30) on housing (29). Bolt:

M16 (60 to 90 mm in length): 2 pieces : 785 N m (80 kgf m, 580 lbf ft)

NOTE - For easier insertion of floating seal O-ring, use wooden spatula to guide it along the periphery.

3. Install the outer race of roller bearing (31) on drum (32) in position completely using a metal bar and a hammer. Install the halt floating seal (30) into drum (32). 75301496 75301497 75301495

WARNING Sprocket weight: Approx. 65 kg (143 lb) 36 4. Mount sprocket (38) on drum (32). Apply LOCTITE 262 to bolts (34). Tighten bolts (34) and spring washer (33). : 30 mm : 470 N m (48 kgf m, 350 lbf ft)

WARNING Weight of drum and sprocket combined: Approx. 130 kg (290 lb)

5. Attach eyebolt (75301486) to drum (32) then install drum (32) onto housing (44) with motor (29), using a hoist. 6. Warm the inner race of roller bearing (31) 50 to 70 °C (122 to 158 °F) using a heater. Install it between drum (32) and housing (44). Wait for the inner race to cool. Then, drive it into position completely using a metal bar and a hammer.

SM1082

EX285 EX255-EX285

W3-2-26

TRAVEL DEVICE

44

8 13 12 1

30 31 32

45 46 28 27 25 26 24

36

38 SM5108

EX255-EX285 EX285

W3-2-27

TRAVEL DEVICE 9. Tap on drum (32) using a plastic hammer to secure appropriate play. Then, rotate sprocket (38) three turns clockwise and then counterclockwise. 10. Repeat step 9 above. Then, tighten bearing nut (36) to specification.

75301496 75301497

Special Tools: 75301495, 75301496, 75301497 Bolt: M16 (60 to 90 mm in length): 2 pieces

75301495

: 785 N m (80 kgf m, 580 lbf ft) 36 11. Install lock plate (45). Apply LOCTITE 262 to the thread of bolts (46) (2 used), then tighten them to specification.

SM1082

: 19 mm : 88 N m (9 kgf m, 65 lbf ft) 12. Install two needle bearings (27) into each third stage planetary gear (28). 46

13. Putting thrust plates (26) on both ends of each third stage planetary gears (28), install them into third stage carrier (1). Install thrust plates (8) into third stage carrier (1).

45 36

14. Drive pin (25) into third stage carrier (1), aligning the spring pin holes.

15. Drive spring pin (24) into the spring pin hole on third stage carrier (1) and pin (25).

NOTE - Be sure that the slit part of spring pin (24) faces upwards in relation to the end of pin (25), as shown.

WARNING Third stage carrier assembly weight: Approx. 45 kg (99 lb)

SM5109

25 24

Spaccatura

SM1085

16. Install third stage carrier (1) assembly, aligning splines with housing (44). 17. Install third stage sun gear (2) into third stage carrier (1). Be sure that the lower tooth end faces upwards. 18. Clean (decrease) ring gear mounting surface of drum (32). Apply THREEBOND 1215 to the mounting surface.

W3-2-28

EX255-EX285 EX285

TRAVEL DEVICE

29

42

44

8 13 12 1 2 23 8 9 10

43

17

11 15 14

41 40 21 20 22 18 19 16

30 31 32

SM5108

EX255-EX285 EX285

W3-2-29

TRAVEL DEVICE

WARNING Ring gear weight: Approx. 50 kg (110 lb) 18. Install ring gear (12) onto drum (32) using a crane. Tighten bolts (13).

WARNING Travel device weight: Approx. 441 kg (972 lb)

30. Turn over the travel device. Remove spacer (75301498).

: 24 mm : 265 N m ( 27 kgf m, 195 lbf ft) 19. Install spacer (8) into second stage carrier (23). 20. Assemble second stage carrier (23) referring to steps 12 to 15. 21. Install second stage carrier (23) assembly into ring gear (12). 22. Install second stage sun gear (9) into second stage carrier (23). 23. Install spacer (43) into first stage carrier (10). 24. Assemble first stage carrier (10) referring to steps 12 to 15. 25. Install first stage carrier (10) assembly into ring gear (12), aligning splines between first stage carrier (10) and second stage sun gear (9). 26. Add lubricant oil to gear box. (Refer to the Operator’s Manual for the type of lubricant oil to be used.) Oil capacity:

7.8 L (2.1 US gal)

27. Insert propeller shaft (11). Be sure that the propeller shaft correctly meshes with first stage planetary gears (21) and the shaft of motor (29). 28. Clean (degrease) the cover mounting surface of ring gear (12). Apply THREEBOND 1215 to the mounting surface. Install cover (15). Tighten bolts (16). : 19 mm : 108 N m (11 kgf m, 80 lbf ft) 29. Wrap seal tape around plugs (17). Install plugs (17) into cover (15). : 10 mm : 49 N m (5 kgf m, 36 lbf ft)

IMPORTANT - Be sure to fill the travel device with the specified amount of gear oil after installing it on the machine.

EX255 EX255-EX285

W3-2-30

TRAVEL DEVICE DISASSEMBLE TRAVEL MOTOR (EX255)

13

14

12 11 10 9 8 7 6 5 4 3 2 1

15 16 17 18 19 20 21

25

22

26 27 23

28

24 29 30

31 32 40 39

38 37

33

36

SM3513

34 35

1 2 3 4 5 6 7 8 9 10 11 12 13 14

-

O-Ring Disc Spring D-Ring Piston D-Ring Plate (5 Used) Spacer Drive Disc Bearing Spacer Bearing Housing Oil Seal Retaining Ring

15 16 17 18 19 20 21 22 23 24 25 26 27 28

-

O-Ring Baring Nut Plunger (7 Used) Rotor Plug (2 Used) Friction Plate (4 Used) Link Reamer Bolt Plug O-Ring Pin Center Shaft Center Spring Bushing

29 30 31 32 33 34 35 36 37 38 39 40

-

Valve Plate Plate Knock Pin (2 Used) Socket Bolt (8 Used) Brake Valve O-Ring Plug Servo Piston Piston Ring (2 Used) O-Ring Cover Socket Bolt (4 Used)

EX255-EX285 EX255

W3-2-31

TRAVEL DEVICE Disassemble Travel Motor •


WARNING Brake valve weight: 30 kg (66 lb)

1. Loosen socket bolts (32), and remove brake valve (33) using hoist from the motor. : 14 mm

2. Loosen socket bolts (40) and remove cover (39) and O-ring (38).

22

: 10 mm

3. Turn over brake valve (33). Remove drain plug (23). Insert a hexagon wrench from drain plug hole to remove reamer bolt (22).

SM1087

: 8, 10 mm

4. Remove servo piston (36) to remove valve plate (29) and link (21).

IMPORTANT - Remove plug (19), only necessary. 19 5. Remove O-rings (1, 15) from housing (12). SM1088

6. Remove rotor (18) from housing (12). Make matching mark on rotor (18) and plungers (17).

7. Remove center spring (27) and center shaft (26).

8. Remove plungers (17) one by one. First, grab plunger (17) upright against drive disc (8). Then, turn it at an angle against the drive disc while slightly raising the bottom of the plunger to remove the plunger. (to disconnect the t).

IMPORTANT - Make matching mark on the plungers (17) and drive disc (8).

9. Remove disc spring (2).

W3-2-32

EX255-EX285 EX255

TRAVEL DEVICE

13

14

12

11 10 9 8 7 6 5 4 3

16

20

SM3513

EX255-EX285 EX255

W3-2-33

TRAVEL DEVICE

WARNING Be sure to reduce air pressure to 98 to 196 kPa (1 to 2 kgf/cm2, 14 to 28 psi) when using compressed air. Cover piston (4) with cloths when removing the piston using compressed air to avoid sudden flying off.

12

4

10. Remove piston (4) from housing while supplying 98 to 196 kPa (1 to 2 kgf/cm2, 14 to 28 psi) air pressure to the brake releasing hydraulic circuit using an air pump. 11. Remove D-rings (3, 5) from piston (4). 12. Remove plates (6), friction plates (20) and spacer (7) from housing (12).

SM1089

WARNING Housing+drive disc+etc weight: 50 kg (110 lb)

13. Turn over housing (12), then tap with plastic hammer to remove drive disc (8) assembly.

75301492 75301499

14. Remove retaining ring (14) from housing (12). Pull out oil seal (13).

8

15. Attach drive disc (8) assembly to special tool (75301492 and 75301499). Remove bearing nut (16). 16. Place wooden blocks under the outer race, as illustrated. Press drive disc (8) using a press to pull out bearing (11) and spacer (10). 17. Remove the outer race of bearing (11) from spacer (10).

SM1090

10

9

11 Pista

18. Place wooden blocks under the inner race of bearing (9). Push drive disc (8) out using a press. IMPORTANT - If the inner race of bearing (9) is removed, do not reuse it.

SM1091

W3-2-34

EX255-EX285 EX255

TRAVEL DEVICE ASSEMBLE TRAVEL MOTOR (EX255)

35

30

28

29

15

2

18

27

25

26 Cross Section A-A

A 33 22

21

19

A 14

B C

8

12 A 23 13 37 16

39 40

11

38

1 2 3 4 5 6 7 8 9 10 11 12 13 14

-


36

32 17

1

4

15 16 17 18 19 20 21 22 23 24 25 26 27 28

-

3

5

20

O-Ring Baring Nut Plunger (7 Used) Rotor Plug (2 Used) Friction Plate (4 Used) Link Reamer Bolt Plug O-Ring Pin Center Shaft Center Spring Bushing

6

7

9 10

SM3519

29 30 31 32 33 34 35 36 37 38 39 40

-


EX255-EX285 EX255

W3-2-35

TRAVEL DEVICE Assemble Travel Motor 1. Warm the inner race of bearing (9) to 70 to 90 °C (160 to 194 °F) in an oil bath or using a dryer. Then, install it onto drive disc (8) using special tool 75298960 and a press.

10 9

2. Put the outer race on the inner race of bearing (9). 3. Install the outer race of bearing (11) onto spacer (10) by tapping with a plastic hammer. 4. Put spacer (10) on the outer race of bearing (9). Confirm that the oil groove side of the spacer faces bearing (9).

Oil groove

SM1093

5. Warm the inner race of bearing (11) to 70 to 90 °C (160 to 194 °F) in an oil bath or using a dryer. Then, install it onto drive disc (8) using special tool and a press. Apply a metal bar to the inner race. Tap the end of the bar to completely install it in position (or to confirm that it has been completely installed in position). 6. Fix drive disc (8) in special tool (75301499). Tighten bearing nut (16) while applying lubricants until the specified shaft starting torque is obtained.

7. Measure shaft starting torque.

16 75301499 8

: 2 ± 0.5 N m (0.2 ± 0.05 kgf m, 1.5 ± 0.4 lbf ft) SM1090

IMPORTANT - Take care not to damage oil seal (13).

8. Install oil seal (13) into housing (12) using a press. Install retaining ring (14).


9. Turn over housing (12). Install drive disc (8) assembly into housing (12) by tapping with a plastic hammer. SM1094

EX255 EX255-EX285

W3-2-36

TRAVEL DEVICE

30

15

2

18

27

25


A

33

8

A

23

17

1

4

3

5

20

6

7

10

SM3519

EX255-EX285 EX255

W3-2-37

TRAVEL DEVICE 10. Install spacer (7) into housing (12) with the oil groove side facing downward, aligning the oil groove and the hole on housing (12). 11. Install plates (6) (5 used) and friction plates (20) (4 used) one by one alternately, aligning notches of each plate and friction plate. Be sure to install plates (6) to housing (12) side and friction plates (20) to drive disc (8) side. 12. Attach D-rings (3) and (5) onto piston (4). Install piston (4) into housing (12).

NOTE - Tap the end of piston (4) with a plastic hammer for easy insertion. 17

8

13. Install disc spring (2) onto housing (12) with the larger diameter side facing upward. 14. Aligning matching marks, install plungers (17) into the spherical ts on drive disc one by one. Confirm that plungers (17) move smoothly in the ts. SM1095

15. Install center shaft (26) onto drive disc (8). Attach center spring (27) onto center shaft (26). 16. Insert the top part of center shaft (26) into the center hole on rotor (18), aligning pin (25) on center shaft (26) with the groove on rotor (18).

18

17. Insert plungers (17) into rotor (18) one by one, aligning the matching marks. Be sure that the groove on rotor (18) comes over pin (25) on shaft (26). 18. Install O-rings (1) and (15) onto housing (12). 19. Add hydraulic oil into housing (12). Hydraulic oil:1.2 L (1.27 US qt) 20. Remove plug (23) from brake valve (33). 21. Install plate (30) on brake valve (33).

26

25 SM1096

EX255 EX255-EX285

W3-2-38

TRAVEL DEVICE

35

30

28


A 33 22

21

19

A 23

37 39 40

38

36

SM3519

EX255-EX285 EX255

W3-2-39

TRAVEL DEVICE 22. Attach piston rings (37) onto servo piston (36). Then, attach them to special tool (75301530).

36

23. Insert servo piston (36) into brake valve (33). 24. If replacing bushing (28), drive it into valve plate (29) using special tool (75301494).

NOTE - Note the facing direction of the oil groove side when removing the bushing.

25. Apply LOCTITE 262 to plugs (19). Install link (21) on valve plate (29) using plugs (19).

75301530

SM1097

: 6 mm : 49 N m (5 kgf m, 36 lbf ft)

29

21

26. Install link (21) and valve plate (29) to fit into the groove on plate (30). Align the groove of link (21) with servo piston (36). 27. Align the holes on link (21) and on servo piston (36) by inerting the aligning tool (75301500) through plug (23) hole. 28. Apply extreme-pressure grease to the tip of reamer bolt (22) to prevent seizure between parts. Install reamer bolt (22) into link (21) and servo piston (36) through the other plug (23) hole on the opposite side.

19

SM1098

: 8 mm 36

: 49 N m (5 kgf m, 36 lbf ft)

75301500

21

29. Remove plug (35) from brake valve (33). Secure valve plate (29) using a fastening device. 30. Install O-ring (38) on cover (39). Install cover (39) on brake valve (33) using socket bolts (40). : 10 mm : 88 N m (9 kgf m, 65 lbf ft)

22

SM1099

EX255 EX255-EX285

W3-2-40

TRAVEL DEVICE

35


A 33

A B C

12 A 23

32

SM3519

EX255-EX285 EX255

W3-2-41

TRAVEL DEVICE 31. Attach special tool (75301501) to the top of center shaft (26). 32. Remove plug (A) from brake valve (33). Remove spool (B) and spring (C). : 8 mm

75301501 26

WARNING Brake valve weight: 30 kg (66 Ib)

33. Attach brake valve (33) to a crane. Lift brake valve (33) and align special tool (75301501) with plug (A) hole. Then, install brake valve (33) onto housing (12). 34. Remove special tool (75301501) and the fastening device from brake valve (33). 35. Install plugs (23) and (35), spool (B), spring (C), and plug (A) to brake valve (33). : 5 mm : 15 N m (1.5 kgf m, 11 lbf ft) : 8 mm : 34 N m (3.5 kgf m, 25 lbf ft) : 10 mm : 118 N m (12 kgf m, 90 lbf ft) 36. Install socket bolts (32). : 12 mm : 215 N m (22 kgf m, 160 lbf ft)

SM1092

12

W3-2-42

EX255-EX285 EX255

TRAVEL DEVICE DISASSEMBLE BRAKE VALVE (EX255)

4 8

5

9

6

1- 2

7

10 11 12

3

21 20 19

13 7

18 12

6

14 15

5

11

16 17

1- 2

4 10

9

SM1101

8

1 2 3 4 5 6 7

-

O-Ring (2 Used) Overload Relief Valve (2 Used) Casing Plug (2 Used) O-Ring (2 Used) Spring (2 Used) Poppet (2 Used)

8 9 10 11 12 13 14

-

Plug (2 Used) O-Ring (2 Used) Spring (2 Used) Spring (2 Used) Stopper (2 Used) Spool Ball (2 Used)

15 16 17 18 19 20 21

-

Seat (2 Used) O-Ring (2 Used) Plug (2 Used) Plug O-Ring Spool Spring

EX255-EX285 EX255

W3-2-43

TRAVEL DEVICE Disassemble Brake Valve •

•

•


Parking Brake Release Valve 9. Remove plug (17) and O-ring (16) from casing (3). : 6 mm

10. Remove seat (15) and tilt casing (3) to remove ball (14).

Counterbalance Valve

: 5 mm

1. Remove plug (8) and O-ring (9) from casing (3). : 36 mm 2. Remove springs (10), (11) and stopper (12). 3. Remove spool (13) from casing (3).

•

Reducing Valve 11. Remove plug (18) and O-ring (19) from casing (3). : 8 mm

•

Overload Relief Valve 12. Remove spool (20) and spring (21). 4. Remove overload relief valve (2) from casing (3). : 27 mm

•

Check Valve 5. Remove plug (4) and O-ring (5) from casing (3). : 12 mm 6. Remove spring (6) and poppet (7).

•

Servo Piston Operating Shuttle Valve 7. Remove plug (17) and O-ring (16) from casing (3). : 6 mm 8. Remove seat (15) and tilt casing (3) to remove ball (14). : 5 mm

W3-2-44

EX255-EX285 EX255

TRAVEL DEVICE ASSEMBLE BRAKE VALVE (EX255)

Cross Section C-C

6

7

1

2 14 19

A

20

21

15

5 18 16

4

17 C

10 11 8 9 12 3 B

13 A

Cross Section A-A

14

15

Cross Section B-B

17

1 2 3 4 5 6 7

-


8 9 10 11 12 13 14

-

SM1102

16

Plug (2 Used) O-Ring (2 Used) Spring (2 Used) Spring (2 Used) Stopper (2 Used) Spool Ball (2 Used)

15 16 17 18 19 20 21

-

Seat (2 Used) O-Ring (2 Used) Plug (2 Used) Plug O-Ring Spool Spring

EX255-EX285 EX255

W3-2-45

TRAVEL DEVICE Assemble Brake Valve •

5. Install O-ring (16) to plug (17), then install it to casing (3).

Reducing Valve

: 6 mm : 34 N m (3.5 kgf m, 25 lbf ft)

1. Insert spring (21) and spool (20) into casing (3), and tighten plug (18) with O-ring (19) to casing (3). : 8 mm

•

: 69 N m (7 kgf m, 51 lbf ft)

•

Check Valve 6. Insert poppet (7) with spring (6) into casing (3), and tighten plug (4) with O-ring (5) to casing (3).

Parking Brake Relief Valve (Cross Section C-C)

: 12 mm : 235 N m (24 kgf m, 175 lbf ft)

2. Tilt casing (3) and insert ball (14). Apply LOCTITE 262 to seat (15) and tighten it to casing (3).

•

: 5 mm

Overload Relief Valve 7. Install overload relief valve (2) to casing (3).

: 14.5 N m (1.5 kgf m, 11 lbf ft)

: 27 mm : 540 N m (55 kgf m, 400 lbf ft)

IMPORTANT - Before inserting ball (14), put ball (14) on seat (15) and tap on the ball with a hammer to obtain tight fitting between ball (14) and seat (15). Also, after inserting ball (14) and before tightening seat (15), insert a metal bar into the plug hole to apply its end to ball (14), then tap the other end of the bar to obtain tight fitting between ball (14) and the casing.

3. Install O-ring (16) to plug (17), then install it to casing (3). : 6 mm : 34 N m (3.5 kgf m, 25 lbf ft)

•

Servo Piston Operating Shuttle Valve (Cross Section B-B) 4. Tilt casing (3) and insert ball (14). Apply LOCTITE 262 to seat (15) and tighten it to casing (3). : 5 mm : 14.5 N m (1.5 kgf m, 11 lbf ft)


•

Counterbalance Valve 8. Insert spool (13) into casing (3).

IMPORTANT - Apply film of hydraulic oil to spool (13). 9. Install springs (10), (11) to stopper (12), then insert it into casing (3). 10. Install O-ring (9) to plug (8), then install to casing (3). : 36 mm : 215 N m (22 kgf m, 160 lbf ft)

IMPORTANT - Be sure to fill the travel device with hydraulic oil after installing it.

EX285 EX255-EX285

W3-2-46

TRAVEL DEVICE DISASSEMBLE TRAVEL MOTOR (EX285) 12 10

9 8 7

13 14

20 4

5

3 1

2

11 16

15

25 26

6

27 17 18

19

28

21

29

22 19 23 32 24

30

31

40

39 38 37

33 36

SM5110

34 35

1 2 3 4 5 6 7 8 9 10 11 12 13 14

-


15 16 17 18 19 20 21 22 23 24 25 26 27 28

-

O-Ring Bearing Nut Plunger (7 Used) Rotor Plug (2 Used) Friction Plate (4 Used) Link Reamer Bolt Plug O-Ring Pin Center Shaft Center Spring Bushing

29 30 31 32 33 34 35 36 37 38 39 40

-


EX255-EX285 EX285

W3-2-47

TRAVEL DEVICE Disassemble Travel Motor •


WARNING Brake valve weight: 43 kg (95 lb)

1. Loosen socket bolts (32), and remove brake valve (33) using hoist from the motor. : 14 mm

2. Loosen socket bolts (40) and remove cover (39) and O-ring (38).

22

: 10 mm

3. Turn over brake valve (33). Remove drain plug (23). Insert a hexagon wrench from drain plug hole to remove reamer bolt (22).

SM1087

: 8, 10 mm

4. Remove servo piston (36) to remove valve plate (29) and link (21).

IMPORTANT - Remove plug (19), only necessary. 19 5. Remove O-rings (1), (15) from housing (12). SM1088

6. Remove rotor (18) from housing (12). Make matching mark on rotor (18) and plungers (17).

7. Remove center spring (27) and center shaft (26).

IMPORTANT - Make matching mark on the plungers (17) and drive disc (8).

8. Remove plungers (17) one by one. First, grab plunger (17) upright against drive disc (8). Then, turn it at an angle against the drive disc while slightly raising the bottom of the plunger to remove the plunger. (to disconnect the t)

9. Remove disc spring (2).

EX285 EX255-EX285

W3-2-48

TRAVEL DEVICE

12

9

10

8 7 13 14

20 4

5

3 11 16

6

SM5110

EX285 EX255-EX285

W3-2-49

TRAVEL DEVICE

WARNING Be sure to reduce air pressure to 98 to 196 kPa (1 to 2 kgf/cm2, 14 to 28 psi) when using compressed air. Cover piston (4) with cloths when removing the piston using compressed air to avoid sudden flying off.

12

4

10. Remove piston (4) from housing while supplying 98 to 196 kPa (1 to 2 kgf/cm2, 14 to 28 psi) air pressure to the brake releasing hydraulic circuit using an air pump. 11. Remove D-rings (3, 5) from piston (4). 12. Remove plates (6), friction plates (20) and spacer (7) from housing (12).

SM1089

WARNING Housing+drive disc+etc weight: 50 kg (110 lb)

13. Turn over housing (12), then tap with plastic hammer to remove drive disc (8) assembly. 14. Remove retaining ring (14) from housing (12). Pull out oil seal (13).

75301492 75301499 8

15. Attach drive disc (8) assembly to special tool 75301492 and 75301499. Remove bearing nut (16). 16. Place wooden blocks under the outer race, as illustrated. Press drive disc (8) using a press to pull out bearing (11) and spacer (10). 17. Remove the outer race of bearing (11) from spacer (10).

SM1090

10

9

11 Pista

18. Place wooden blocks under the inner race of bearing (9). Push drive disc (8) out using a press. IMPORTANT - If the inner race of bearing (9) is removed, do not reuse it.

SM1091

W3-2-50

EX255-EX285 EX285

TRAVEL DEVICE ASSEMBLE TRAVEL MOTOR (EX285)

34,35 28

1

15

2

3

4

5

6

7

8

9

Cross Section A

30 29 31

10

33 11 12 13

22 21 19

14

18 25 16 17

37

20

39

SM5111

36 38 40

1 2 3 4 5 6 7 8 9 10 11 12 13 14

-


24,23 32

27

26

15 16 17 18 19 20 21 22 23 24 25 26 27 28

-

O-Ring Bearing Nut Plunger (7 Used) Rotor Plug (2 Used) Friction Plate (4 Used) Link Reamer Bolt Plug O-Ring Pin Center Shaft Center Spring Bushing

29 30 31 32 33 34 35 36 37 38 39 40

-


EX285 EX255-EX285

W3-2-51

TRAVEL DEVICE Assemble Travel Motor 1. Warm the inner race of bearing (9) to 70 to 90 °C (160 to 194 °F) in an oil bath or using a dryer. Then, install it onto drive disc (8) using special tool 75298960 and a press.

10 9

2. Put the outer race on the inner race of bearing (9). 3. Install the outer race of bearing (11) onto spacer (10) by tapping with a plastic hammer. 4. Put spacer (10) on the outer race of bearing (9). Confirm that the oil groove side of the spacer faces bearing (9).

Oil groove

SM1093

5. Warm the inner race of bearing (11) to 70 to 90 °C (160 to 194 °F) in an oil bath or using a dryer. Then, install it onto drive disc (8) using special tool and a press. Apply a metal bar to the inner race. Tap the end of the bar to completely install it in position (or to confirm that it has been completely installed in position). 6. Fix drive disc (8) in special tool (75301499). Tighten bearing nut (16) while applying lubricants until the specified shaft starting torque is obtained.

7. Measure shaft starting torque.

16 75301499 8

: 3 ± 0.5 N m (0.3 ± 0.05 kgf m, 2.2 ± 0.4 lbf ft) SM1090

IMPORTANT - Take care not to damage oil seal (13).

8. Install oil seal (13) into housing (12) using a press. Install retaining ring (14).


9. Turn over housing (12). Install drive disc (8) assembly into housing (12) by tapping with a plastic hammer. SM1094

W3-2-52

EX255-EX285 EX285

TRAVEL DEVICE

34,35 28

1

15

2

3

4

5

6

7

8

9

Cross Section A

30 29 31

10

33 11 12 13 14

18 25 16 17 20

SM5111

36 38 40

24,23 32

27

26

EX285 EX255-EX285

W3-2-53

TRAVEL DEVICE 10. Install spacer (7) into housing (12) with the oil groove side facing downward, aligning the oil groove and the hole on housing (12). 11. Install plates (6) (5 used) and friction plates (20) (4 used) one by one alternately, aligning notches of each plate and friction plate. Be sure to install plates (6) to housing (12) side and friction plates (20) to drive disc (8) side. 12. Attach D-rings (3) and (5) onto piston (4). Install piston (4) into housing (12).

NOTE - Tap the end of piston (4) with a plastic hammer for easy insertion. 17

8

13. Install disc spring (2) onto housing (12) with the larger diameter side facing upward. 14. Aligning matching marks, install plungers (17) into the spherical ts on drive disc one by one. Confirm that plungers (17) move smoothly in the ts. SM1095

15. Install center shaft (26) onto drive disc (8). Attach center spring (27) onto center shaft (26). 16. Insert the top part of center shaft (26) into the center hole on rotor (18), aligning pin (25) on center shaft (26) with the groove on rotor (18).

18

17. Insert plungers (17) into rotor (18) one by one, aligning the matching marks. Be sure that the groove on rotor (18) comes over pin (25) on shaft (26). 18. Install O-rings (1) and (15) onto housing (12). 19. Add hydraulic oil into housing (12). Hydraulic oil:1.3 L (1.37 US qt) 20. Remove plug (23) from brake valve (33). : 10 mm

21. Install plate (30) on brake valve (33).

26

25 SM1096

EX285 EX255-EX285

W3-2-54

TRAVEL DEVICE

34,35 28

Cross Section A

30 29 31 33

22 21 19

37

39

SM5111

36 38 40

24,23

EX255-EX285 EX285

W3-2-55

TRAVEL DEVICE 22. Attach piston rings (37) onto servo piston (36). Then, attach them to special tool (75301530).

36

23. Insert servo piston (36) into brake valve (33). 24. If replacing bushing (28), drive it into valve plate (29) using special tool (75301494).

NOTE - Note the facing direction of the oil groove side when removing the bushing.

25. Apply LOCTITE 262 to plugs (19). Install link (21) on valve plate (29) using plugs (19).

75301530

SM1097

: 6 mm : 49 N m (5 kgf m, 36 lbf ft)

29

21

26. Install link (21) and valve plate (29) to fit into the groove on plate (30). Align the groove of link (21) with servo piston (36). 27. Align the holes on link (21) and on servo piston (36) by inerting the aligning tool (75301500) through plug (23) hole. 28. Apply extreme-pressure grease to the tip of reamer bolt (22) to prevent seizure between parts. Install reamer bolt (22) into link (21) and servo piston (36) through the other plug (23) hole on the opposite side.

19

SM1098

: 8 mm 36

: 49 N m (5 kgf m, 36 lbf ft)

75301500

21

29. Remove plug (35) from brake valve (33). Secure valve plate (29) using a fastening device. 30. Install O-ring (38) on cover (39). Install cover (39) on brake valve (33) using socket bolts (40). : 10 mm : 88 N m (9 kgf m, 65 lbf ft)

22

SM1099

W3-2-56

EX255-EX285 EX285

TRAVEL DEVICE

34,35 28

1

15

2

3

4

5

6

7

8

9

Cross Section A

30 29 31

10

33 11 12 13 14

18 25 16 17 20

SM5111

36 38 40

24,23 32

27

26

EX255-EX285 EX285

W3-2-57

TRAVEL DEVICE 31. Attach special tool (75301501) to the top of center shaft (26). 32. Remove plug (A) from brake valve (33). Remove spool (B) and spring (C). : 8 mm

75301501 26

WARNING Brake valve weight: 43 kg (95 Ib)

33. Attach brake valve (33) to a crane. Lift brake valve (33) and align special tool (75301501) with plug (A) hole. Then, install brake valve (33) onto housing (12). 34. Remove special tool (75301501) and the fastening device from brake valve (33). 35. Install plugs (23) and (35), spool (B), spring (C), and plug (A) to brake valve (33). : 5 mm : 15 N m (1.5 kgf m, 11 lbf ft) : 8 mm : 34 N m (3.5 kgf m, 25 lbf ft) : 10 mm : 118 N m (12 kgf m, 90 lbf ft) 36. Install socket bolts (32). : 14 mm : 390 N m (40 kgf m, 290 lbf ft)

SM1092

12

EX285 EX255-EX285

W3-2-58

TRAVEL DEVICE DISASSEMBLE BRAKE VALVE (EX285)

8 9 A

10

4

12

5

17 16 15 14

13

6 1,2

4

3

12

21

10 20

6

14 15 16 17

19 18

7

9

5 1,2

8 4

SM5112

B

A B 1 2 3 4 5 6

-

Parking Brake Shuttle Valve Servo Piston Shuttle Valve O-Ring (2 Used) Overload Relief Valve (2 Used) Casing Plug (2 Used) O-Ring (2 Used) Spring (2 Used)

7 8 9 10 12 13 14 15

-

Poppet (2 Used) Plug (2 Used) O-Ring (2 Used) Spring (2 Used) Stopper (2 Used) Spool Ball (2 Used) Seat (2 Used)

16 17 18 19 20 21

-

O-Ring (2 Used) Plug (2 Used) Plug O-Ring Spool Spring

EX285 EX255-EX285

W3-2-59

TRAVEL DEVICE Disassemble Brake Valve •

•


Counterbalance Valve 1. Remove plug (8) and O-ring (9) from casing (3). : 41 mm 2. Remove spring (10) and stopper (12). 3. Remove spool (13) from casing (3).

•

Overload Relief Valve 4. Remove overload relief valve (2) from cas ing (3). : 27 mm

•

Check Valve 5. Remove plug (4) and O-ring (5) from casing (3). : 12 mm 6. Remove spring (6) and poppet (7).

•

Servo Piston Operating Shuttle Valve 7. Remove plug (17) and O-ring (16) from casing (3). : 6 mm 8. Remove seat (15) and tilt casing (3) to remove ball (14). : 5 mm

•

Parking Brake Release Shuttle Valve 9. Remove plug (17) and O-ring (16) from casing (3). : 6 mm 10. Remove seat (15) and tilt casing (3) to remove ball (14). : 5 mm

•

Reducing Valve 11. Remove plug (18) and O-ring (19) from casing (3). : 8 mm 12. Remove spool (20) and spring (21).

W3-2-60

EX255-EX285 EX285

TRAVEL DEVICE ASSEMBLE BRAKE VALVE (EX285)

14 15

16

14

17

15 Section B

17

16 Section C

2

1

7

6

19

20

21

18

3 4 5

8 9

13

12

Section A-A

10

SM5113

1 2 3 4 5 6 7

-


8 9 10 12 13 14 15

-

Plug (2 Used) O-Ring (2 Used) Spring (2 Used) Stopper (2 Used) Spool Ball (2 Used) Seat (2 Used)

16 17 18 19 20 21

-

O-Ring (2 Used) Plug (2 Used) Plug O-Ring Spool Spring

EX285 EX255-EX285

W3-2-61

TRAVEL DEVICE Assemble Brake Valve •

5. Install O-ring (16) to plug (17), then install it to casing (3).

Reducing Valve

: 6 mm : 34 N m (3.5 kgf m, 25 lbf ft)

1. Insert spring (21) and spool (20) into casing (3), and tighten plug (18) with O-ring (19) to casing (3). : 8 mm

•

: 69 N m (7 kgf m, 51 lbf ft)

•

Check Valve 6. Insert poppet (7) with spring (6) into casing (3), and tighten plug (4) with O-ring (5) to casing (3).

Parking Brake Relief Valve (Cross Section C-C)

: 12 mm : 235 N m (24 kgf m, 175 lbf ft)

2. Tilt casing (3) and insert ball (14). Apply LOCTITE 262 to seat (15) and tighten it to casing (3).

•

: 5 mm

Overload Relief Valve 7. Install overload relief valve (2) to casing (3).

: 14.5 N m (1.5 kgf m, 11 lbf ft)

: 27 mm : 540 N m (55 kgf m, 400 lbf ft)


•

Counterbalance Valve 8. Insert spool (13) into casing (3).

IMPORTANT - Apply film of hydraulic oil to spool (13). 3. install O-ring (16) to plug (17), then install it to casing (3). : 6 mm

9. Install spring (10) to stopper (12), then insert it into casing (3).

: 34 N m (3.5 kgf m, 25 lbf ft)

•

Servo Piston Operating Shuttle Valve (Cross Section B-B) 4. Tilt casing (3) and insert ball (14). Apply LOCTITE 262 to seat (15) and tighten it to casing (3). : 5 mm : 14.5 N m (1.5 kgf m, 11 lbf ft)


10. Install O-ring (9) to plug (8), then install to casing (3). : 41 mm : 340 N m (35 kgf m, 250 lbf ft)

IMPORTANT - Be sure to fill the travel device with hydraulic oil after installing it.

W3-2-62

EX255-EX285

TRAVEL DEVICE MAINTENANCE STANDARD Sprocket

B C D

E

A

SM1103

IMPORTANT - Consult FIAT-HITACHI for any inqueries concerning welding procedures.

Standard (mm) mm (in) EX255 A B

72.0 (2.83)

Allowable Limit mm (in)

EX285

EX255

EX285

93.0 (3.66)

64 (2.52)

75 (2.95)

579.6 (22.82) 616.5 (24.27) 570 (22.42)

C

PCD644.6 (25.38)

D

658.4 (25.92)

E

190.0 (7.48)

PCD689.4 (27.50) 704.0 (27.72) 203.2 (8.0)

602 (23.70)

–

–

648 (25.51)

694 (27.32)

–

–

Remedy

Build up and finishing

EX255-EX285

W3-2-63

TRAVEL DEVICE Parking Brake

E

C

Part Name

A

B

D

SM1104

Standard (Thickness) of Height mm (in) EX255

Allowable Limit (Thickness) mm (in)

EX285

A

Friction Plate

B

Spacer

8.5 (0.33)

9.0 (0.35)

-

C

Disk Spring

6.2 (0.24)

6.5 (0.26)

6.10 (0.24)

D

Piston

*41.5 (1.63)

*46.0 (1.81)

-

E

Plate Remark

Remedy

3.3 (3.25)

1.8 (0.070)

3.25

1.75 (0.069)

The spacer and piston do not wear down. New friction plates are made with a marginal tolerance of plus (+) 0.1 mm in thickness.

NOTA - * Piston thickness (D) is the distance (width) between the disc spring (C) ing left end of the piston and the brake plate (E) ing right end of the piston.

W3-2-64

EX255-EX285

TRAVEL DEVICE NOTES

EX255-EX285

W3-3-1

CENTER T REMOVE AND INSTALL CENTER T WARNING Escaping fluid under pressure can penetrate the skin, causing serious injury. Avoid the hazard by relieving pressure before disconnecting hydraulic or other lines. Hydraulic oil may be hot just after operation. Hot hydraulic oil may spout, possibly causing severe burns. Be sure to wait for oil to cool before starting work. The hydraulic oil tank cap may fly off if removed without releasing internal pressure first. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. Preparation 1. Park the machine on a firm, level surface.




Removal

Installation

NOTE - Attach labels or tags to hoses and adapters, to aid in assembly.

NOTE - Refer to “Removal” section above for wrench sizes and tightening torque.

1. Disconnect hoses (1), (2), and (5) to (16). Remove the adapters. Loosen bolts (3) and remove lock plate (4). : 19 mm : 34 N m (3.5 kgf m, 25 lbf ft)

1. Install the center t and lift it, then tighten bolts (17). 2. Install adapters and hoses (1), (2), (5) to (16). 3. Install lock plate (4) and tighten bolts (3). 1

: 22 mm : 39 N m (4.0 kgf m, 29 lbf ft) : 27 mm : 93 N m (9.5 kgf m, 69 lbf ft)

2

3

4

8

: 36 mm : 175 N m (18 kgf m, 130 lbf ft)

5

SM1141

NOTE - Plug all disconnected ends.

7

6 9

2. Attach the center t to a hoist. 17 3. Remove bolts (17) and lower the hoist to remove the center t. : 19 mm : 34 N m (3.5 kgf m, 25 lbf ft)

WARNING Weight of center t: 26.5 kg (58.5 lb)

10 16 11 15 14

12

13 SM1148

W3-3-2

EX255-EX285

CENTER T DISASSEMBLE CENTER T 1

2

3

4

5

7

6

12 10

11

9

8

SM1149

1 2 3 4

-

Plug Spindle Dust Seal O-Ring

5 6 7 8

-

Bushing Body Oil Seal (6 Used) Bolt (4 Used)

9 10 11 12

-

Cover Retaining Ring O-Ring Ring

EX255-EX285

W3-3-3

CENTER T Disassemble Center t IMPORTANT - Put a matching mark on body (6) and spindle (2).

WARNING

75301505

Weight of center t: 26.5 kg (58.5 Ib) 8 1. Remove two bolts (8) and install two eyebolts (M10, Pitch1.5, Length18 mm). Attach hoist to the center t, then secure it on workbench (75298324).

6

2. Remove eyebolts and bolts (8) to remove cover (9) from body (6). SM1150

: 17 mm 3. Remove O-ring (11), retaining ring (10) and ring (12) from body (6). 4. Attach the special tool (75301505) to body (6), using bolts (8) (2 Used) and remove body (6) from spindle (2). : 17 mm

IMPORTANT - Take care not to damage the spindle. 5. Remove oil seals (7) from body (6). 6 IMPORTANT - Use two picks to pry out oil seals (7), for easy removal, as illustrated. Take care not to damage the seal groove with the pick. 7 6. Remove dust seal (3) and O-ring (4) from body (6). SM1151

W3-3-4

EX255-EX285

CENTER T ASSEMBLE CENTER T

1

2

3 4

5 6

7

12

SM1152

11

1 2 3 4

-

Plug Spindle Dust Seal O-Ring

10

5 6 7 8

-

9

Bushing Body Oil Seal (6 Used) Bolt (4 Used)

8

9 10 11 12

-

Cover Retaining Ring O-Ring Ring

EX255-EX285

W3-3-5

CENTER T Assemble Center t 1. Install O-ring (4) and dust seal (3) into body (6).

NOTE - If bushing is removed, be sure to reinstall bushing (5) before installing dust seal (3).

2. Install oil seals (7) (6 Used) into body (6). 3. Secure spindle (2) to workbench (75298324). Mount body (6) on spindle (2).

NOTE - Align with the matching mark on the spindle and body.

IMPORTANT - Take care not to damage the seals when installing. Clearance between body (6) and spindle (2) is about 0.1 mm (0.004 in), so that body (6) must be straight to spindle (2).

0,1 mm

4. Tap body (6) with a soft hammer until it touches the edge of spindle (2).

IMPORTANT - Be sure to install ring (12) with the chamfered side down.

5. Install ring (12) and O-ring (11) to body (6).

IMPORTANT - Be sure to install retaining ring (10) with the chamfered side down.

6. Install retaining ring (10) to spindle (2). 7. Install cover (9) and tighten bolts (8) (4 Used). : 17 mm : 49 N m (5 kgf m, 36 lbf ft)

SM1153

W3-3-6

EX255-EX285

CENTER T When replacing the body or spindle with new one, the following procedures are required.

75301507

Replacing Body (6) 1. Clean body (6) and bushing (5).

6

2. Press bushing (5) into body (6), using pressing tool (75301507).

5

Pressing force: 4.9 to 14.7 kN (500 to 1500 kgf, 1100 to 3300 lbf)

SM1154

Replacing Spindle (2)

1

2

1. Clean spindle (2). 2. Insert plugs (1) into spindle (2) using pressing tools (75301506) so that the top of the plug sleeve is lower than the top surface of spindle (2).

A

3. Insert the balls into the plug sleeves so that the top of each ball (A) is 0.4 mm ( 0.016 in ) or more lower than the respective sleeve edge, as illustrated in the detail D.

Sleeve

Detail D

SM1155

75301506

Balls

SM1156

EX255-EX285

W3-3-7

CENTER T MAINTENANCE STANDARD Item Bushing

Allowable Limit (basis of judgment) Remedy 1. Wear more than 0.2 mm (0.008 in)

Replace

2. Scored, abnormal wear.

Replace

3. Uneven wear. (wear range is less than 180°).

Replace

Wear area

Body, Spindle

Sliding Surface and Sealed Part

Scored or something hurt it

Replace

1. Scored more than 0.1 mm (0.004 in). Replace Sliding Surface Except Sealed Part

Sliding Surface Ring

Cover

Sliding Surface Ring

2. Scored less than 0.1 mm (0.004 in) deep.

Repair with oil stone

1. Wear more than 0.5 mm (0.02 in) deep. Abnormal wear.

Replace

2. Wear less than 0.5 mm (0.02 in) deep.

Repair

3. Scored less than 0.5 mm (0.02 in) deep and able to repair.

Repair

1. Wear more than 0.5 mm (0.02 in).

Replace

2. Wear less than 0.5 mm (0.02 in).

Repair

3. Scored less than 0.5 mm (0.02 in) deep and able to repair.

Repair

W3-3-8

EX255-EX285

CENTER T NOTES:

EX255-EX285

W3-4-1

TRACK ADJUSTER REMOVE AND INSTALL TRACK ADJUSTER Before removing the track adjuster, the tracks and the front idler must be removed first. For removal and installation of the tracks and the front idler, refer to applicable removal/installation sections. In this section, the procedure starts on the premise that the tracks and the front idler have already been removed. Removal WARNING Track adjuster weight: EX255: 118 kg (260 lb) EX285: 161 kg (355 lb)

1

2

1. After removing the front idler and yoke, remove track adjuster (1) from track frame (2) by prying it out, using a pry bar.

Installation

SM1157

1. As illustrated, install track adjuster (1) into spring guide (3) on track frame (2). Check that the end face of track adjuster (1) comes into with the face of plate (4).

2

3

SM1175

3

4

SM1158

W3-4-2

EX255-EX285

TRACK ADJUSTER DISASSEMBLE TRACK ADJUSTER

3 4 6

8

9 10

11 17

12

16 15 14 13 SM1159

3 4 6 8 9

-

Wiper Ring Piston Rod U-Ring Rod O-Ring

10 11 12 13 14

-

Cylinder Plug Valve Nut Washer

15 - Spacer 16 - Spring 17 - Seal

EX255-EX285

W3-4-3

TRACK ADJUSTER Disassemble Track Adjuster •

Be sure to thoroughly read “Precautions for Disassembly and Assembly” on page W1-1-1 before starting the disassembly work. Be sure to use special tool (75301508) for assembly / disassembly of the track adjuster.

75301508

WARNING Prevent personal injury. The spring force of the track adjuster is extremely large.Thoroughly inspect the special tool for any damage. Carefully perform assembly work referring to the procedure below.

SM1160

WARNING Approximate weight of the track spring holder assembly: 225 kg (496 lb) Plate

1. Place a jack on the bottom of the track spring holder assembly (75301508). 2. Loosen four nuts to remove the plate. : 46 mm

WARNING Track adjuster weight: EX255: 118 kg (260 lb) EX285: 161 kg (355 lb)

SM1161

3. Connect the track adjuster to a hoist using a lifting strap. Put the track adjuster in the track spring holder assembly (75301508), using the hoist. Remove the lifting strap.

SM1162

W3-4-4

EX255-EX285

TRACK ADJUSTER

8

11 17

12

14 13 SM1159

EX255-EX285

W3-4-5

TRACK ADJUSTER 4. Install the plate on the spring holder. Remove valve (12) with grease fitting.

Plate

SM1163

5. Set an oil jack as illustrated. Jack up the specified amount below to compress the spring.

NOTE EX255 - Specified Amount: A - B = 112 mm (4.41 in). A = Free length: 689 mm (27.13 in); B = Set length: 577 mm (22.72 in). EX285 - Specified Amount: A - B = 120 mm (4.72 in). A = Free length: 677 mm (26.65 in); B = Set length: 557 mm (21.93 in).

SM1164

13

8

6. Tighten nuts to secure the track adjuster. : 46 mm Operate the oil jack to compress the track adjuster approximately 10 mm (0.4 in) until a clearance is observed between washer (14) and nut (13).

SM1165

13

8

11

7. Remove plug (11) and nut (13). : 5 mm : 75 mm

SM1166

W3-4-6

EX255-EX285

TRACK ADJUSTER

3 4

8

10

16 15 14 SM1159

EX255-EX285

W3-4-7

TRACK ADJUSTER 8. Lower jack to release the spring force.

SM1167

9. Loosen the nuts to remove the plate. Remove washer (14).

Plate

14 WARNING Spring assembly weight: EX255: 110 kg (242 lb) EX285: 148 kg (326 lb)

SM1168

10. Remove the track adjuster, using an eyebolt (M16, Pitch1.5) and hoist. Remove the hoist and eyebolt.

WARNING Spring weight: EX255: 70 kg (154 lb) EX285: 87 kg (192 lb)

11. Remove spring (16) from rod (8). 12. Remove spacer (15) from rod (8). SM1169

13. Pull out piston rod (4) from cylinder (10).

W3-4-8

EX255-EX285

TRACK ADJUSTER

4 6

8

9 10

SM1159

EX255-EX285

W3-4-9

TRACK ADJUSTER 14. Remove rod (8) and O-ring (9) from cylinder (10).

3 6

15. Remove wear ring (3), and U-ring (6) from cylinder (10).

10

SM1170

W3-4-10

EX255-EX285

TRACK ADJUSTER ASSEMBLE TRACK ADJUSTER

EX255 12 11 13

2

14

8

15

16

9

B

10

4

6

3

1

577 mm (free length, 689 mm) 718 mm

SM1171

EX285 12 11 13

2

14

8

15

16

9

B

10

4

6

3

1


SM1171

1 2 3 4

-

Idler Flange Wiper Ring Piston Rod

6 8 9 10

-

U-Ring Rod O-Ring Cylinder

11 12 13 14

-

Plug Valve Nut Washer

15 - Spacer 16 - Spring

EX255-EX285

W3-4-11

TRACK ADJUSTER Assemble Track Adjuster 1. Clean all parts. Install U-ring (6), and wiper ring (3) to cylinder (10). 2. Apply a film of grease to O-ring (9) and install it into cylinder (10). Install rod (8) into cylinder (10).

3 6 10

3. Apply grease to U-ring (6), wiper ring (3), cylinder (10), and to piston rod (4). Install piston rod (4) into cylinder (10).

IMPORTANT - Fill part (B) on cylinder (10) and insert piston rod (4) to completely bleed air from part (B) and from the inside of rod (8).

4. Install spacer (15) on rod (8).

SM1170

8

WARNING Spring weight: EX255: 70 kg (154 lb) EX285: 87 kg (192 lb)

5. Install spring (16) on rod (8).

WARNING Spring assembly weight: EX255: 110 kg (242 lb) EX285: 148 kg (326 lb)

6. Put the track adjuster in the spring holder, using an eyebolt (M16, Pitch1.5) and hoist. Remove the hoist and eyebolt.

SM1169

W3-4-12

EX255-EX285

TRACK ADJUSTER EX255

11

13

14

8

16


SM1171

EX285

11

13

14

8

16


SM1171

EX255-EX285

W3-4-13

TRACK ADJUSTER 7. Install washer (14) on spring (16). Install the plate.

Plate

14 16

SM1168

8. Align the jack and track adjuster with the hole in plate. Tighten the nuts to secure the track adjuster. : 46 mm

SM1165

9. Operate the jack to compress spring (16) to specification. Compressed Length: 577 mm (1 ft 10.7 in)

16

SM1172

13

8

11

10. Apply LOCTITE 242 to plug (11). Install nut (13) and plug (11) to rod (8). : 75 mm : 5 mm : 14.5 N m (1.5 kgf m, 11 lbf m)

SM1166

W3-4-14

EX255-EX285

TRACK ADJUSTER EX255

12

8


SM1171

EX285

12

8


SM1171

EX255-EX285

W3-4-15

TRACK ADJUSTER 11. Install valve (12) to rod (8). : 24 mm : 147 N m (15 kgf m, 110 lbf ft)

12. Lower the jack.

SM1164

13. Remove the nuts and plate.

Plate

: 46 mm

SM1163

WARNING Track adjuster weight: EX255: 118 kg (260 lb) EX285: 161 kg (355 lb)

14. Remove the track adjuster from the spring holder, using a lifting strap and a hoist.

SM1173

15. If only the spring assembly is to be transported, be sure to use a special tool, such as the one illustrated, to carry the spring assembly safely. : 24 mm

SM1174

W3-4-16

EX255-EX285

TRACK ADJUSTER NOTES

EX255-EX285

W3-5-1

FRONT IDLER REMOVE AND INSTALL FRONT IDLER Before removing the front idler, the tracks must be removed first. For removal and installation of the tracks, refer to “Remove and Install Tracks” section. In this section, the procedure starts on the premise that the tracks has already been removed.

SM1176

Removal WARNING Front idler weight: EX255: 123 kg (271 lb) EX285: 203 kg (448 lb)

1

3 1. Slide the front idler forward, using a pry bar. 2. Attach the front idler to a hoist, then remove front idler (1) from track frame (3). 2 SM1177

3. To keep the front idler (1) for a time, place it on blocks as shown.

SM1178

1 Installation 1. Attach front idle (1) to a hoist, then install it to track frame (3). Apply a film of grease to the sliding surface between track frame (3) and yoke bearing (2).

3

2 SM1190

W3-5-2

EX255-EX285 EX255

FRONT IDLER DISASSEMBLE FRONT IDLER (EX255)

2 1 3 4

7 6

6

8

5 4 3 2 1

9 10 8

SM1179

1 2 3 4

-

Bearing (2 Used) Elastic pin (2 Used) O-Ring (2 Used) Floating Seal (2 Used)

5 6 7 8

-

Axle Bushing (2 Used) Idler Plug (2 Used)

9 - Yoke 10 - Bolt (4 Used)

EX255-EX285 EX255

W3-5-3

FRONT IDLER Disassemble Front Idler •


1. Loosen bolts (10) to remove yoke (9). Remove plug (8) from bearing (1) to drain oil into a container. : 24 mm : 6 mm

2. Remove elastic pin (2).

: 16 mm

1

5

7

WARNING Total weight including idler: Approx. 107 kg (236 lb)

3. Set the idler assembly in a press as illustrated. Apply the press on the axle end. Push axle (5) out of bearing (1) using the press. Axle (5) will come off idler (7), and the upper side bearing (1) will also be separated from idler (7).

SM1180

1 4

4. Remove floating seal (4) from bearing (1) and idler (7).

IMPORTANT - For handling of floating seal (4), refer to the section “Floating seal precautions” on page W1-1-3.

7

4 3

5 1 SM1181

W3-5-4

EX255-EX285 EX255

FRONT IDLER

6 5

3

1

SM1179

EX255-EX285 EX255

W3-5-5

FRONT IDLER 5. Press out axle (5) to remove bearing (1) and O-ring (3).

3 1

5

SM1182

6. Remove bushings (6), using special tool. Special Tool: 75301510

75301510

6

SM1183

EX255 EX255-EX285

W3-5-6

FRONT IDLER ASSEMBLE FRONT IDLER (EX255)

1

2

4

5

6

10

3

8

9

SM1184

7

1 2 3 4

-


5 6 7 8

-

Axle Bushing (2 Used) Idler Plug (2 Used)

9 - Yoke 10 - Bolt (4 Used)

EX255-EX285 EX255

W3-5-7

FRONT IDLER Assemble Front Idler 2

1. Install bushing (6) into idler (7) using a press.

5

2. Install O-ring (3) (1 piece) onto axle (5). Aligning the pin holes, install axle (5) into bearing (1) and secure using elastic pin (2). Take care not to damage O-ring (3).

1

IMPORTANT - The elastic pin (2) has to be fitted with the slit oriented to the internal side of the idler. 3

3. Install floating seal (4) (one pair) into idler (7) and into bearing (1).

7

SM1185

4

1


4. Insert axle (5) into idler (7) from the floating seal installed side. Install O-ring (3) onto axle (5).

5 SM1186

5. Install the other floating seal (4) (one pair) into idler (7) and into the other bearing (1). 6. Install bearing (1) onto axle (5), aligning the pin holes. Secure them using elastic pin (2). 1

4

3

7 1

IMPORTANT - The elastic pin (2) has to be fitted with the slit oriented to the internal side of the idler.

7. Add engine oil via plug (8) hole on bearing (1). Apply sealant (LOCTITE 503 or equivalent) to plug (8). Tighten plug (8). SM1187

: 6 mm : 20 N m (2 kgf m, 15 lbf ft) SAE 30 oil quantity: 265 cm3 (0.28 US qt) 2 8. Install yoke (9) and tighten bolts (10). : 24 mm : 206 N m (21 kgf m, 152 lbf ft)

5 1 SM1188

EX285 EX255-EX285

W3-5-8

FRONT IDLER DISASSEMBLE FRONT IDLER (EX285)

2

6

3

4

1

7 12 6

8

5 4 1

3

2

9

11 10

SM5115

1 2 3 4

-


5 6 7 8

-

Axle Bushing (2 Used) Idler Plug

9 -Yoke 10 - Bolt (4 Used) 11 - Washer (4 Used) 12 - O-Ring

EX285 EX255-EX285

W3-5-9

FRONT IDLER Disassemble Front Idler •


1. Loosen bolts (10) to remove yoke (9). Remove plug (8) from bearing (1) to drain oil into a container. : 24 mm : 6 mm

2. Remove elastic pin (2).

: 16 mm

1

5

CAUTION Total weight including idler: Approx. 177 kg (390 lb)

7

3. Set the idler assembly in a press as illustrated. Apply the press on the axle end. Push axle (5) out of bearing (1) using the press. Axle (5) will come off idler (7), and the upper side bearing (1) will also be separated from idler (7).

SM1180

1 4

4. Remove floating seal (4) from bearing (1) and idler (7).


7

4 3

5 1 SM1181

EX285 EX255-EX285

W3-5-10

FRONT IDLER

1 6

3

6 5 3 1

SM5115

EX285 EX255-EX285

W3-5-11

FRONT IDLER 5. Press out axle (5) to remove bearing (1) and O-ring (3).

3 1

5

SM1182

6. Remove bushings (6), using special tool. Special Tool: 75301509

75301509

6

SM1183

W3-5-12

EX255-EX285 EX285

FRONT IDLER ASSEMBLE FRONT IDLER (EX285)

1

2

4

5

8-12

10-11

9

SM5116

7

1 2 3 4

-


6

3

5 6 7 8

-

Axle Bushing (2 Used) Idler Plug

9 10 11 12

-

Yoke Bolt (4 Used) Washer (4 Used) O-Ring

EX255-EX285 EX285

W3-5-13

FRONT IDLER Assemble Front Idler 2

1. Install bushing (6) into idler (7) using a press.

5

2. Install O-ring (3) (1 piece) onto axle (5). Aligning the pin holes, install axle (5) into bearing (1) and secure using elastic pin (2). Take care not to damage O-ring (3).

1

IMPORTANT - The elastic pin (2) has to be fitted with the slit oriented to the internal side of the idler. 3

3. Install floating seal (4) (one pair) into idler (7) and into bearing (1).

7

SM1185

4

1


4. Insert axle (5) into idler (7) from the floating seal installed side. Install O-ring (3) onto axle (5).

5

5. Install the other floating seal (4) (one pair) into idler (7) and into the other bearing (1).

SM1186

6. Install bearing (1) onto axle (5), aligning the pin holes. Secure them using elastic pin (2). 1

4

3

7 1

IMPORTANT - The elastic pin (2) has to be fitted with the slit oriented to the internal side of the idler.

7. Add engine oil via plug (8) hole on bearing (1). Apply sealant (LOCTITE 503 or equivalent) to plug (8). Tighten plug (8). : 6 mm

SM1187

: 20 N m (2 kgf m, 15 lbf ft) SAE 30 oil quantity: 380 cm3 (0.41 US qt) 2 8. Install yoke (9) and tighten bolts (10). : 24 mm : 225 N m (23 kgf m, 166 lbf ft)

5 1 SM1188

W3-5-14

EX255-EX285

FRONT IDLER MAINTENANCE STANDARD Front Idler

C D

E A B

Standard (mm) (in)

SM1189

Allowable Limit (mm) (in)

Remedy

EX255

EX285

EX255

EX285

A

84 (3.31)

101 (3.98)

66 (2.60)

92 (3.62)

B

159 (6.26)

203 (7.99)

–

Buildup weld and

C

500 (19.69)

530 (20.87)

482 (18.98)

520 (20.47)

D

540 (21.26)

574 (22.60)

–

E

20 (0.79)

22 (0.87)

–

finishing


Axle and Bushing Standard

Allowable Limit

(mm) (in)

(mm) (in)

EX255

EX285

EX255

Remedy

EX285

Axle

Outside Dia.

75 (2.95)

85 (3.35) 74.2 (2.92) 84.2 (3.31)

Bushing

Inside Dia.

75 (2.95)

85 (3.35) 76 (2.99) 86 (3.39)

Bushing

Flange Thickness

Replace 2 (0.08)

1.2 (0.05)

EX255-EX285

W3-6-1

UPPER AND LOWER ROLLER REMOVE AND INSTALL UPPER ROLLER Removal

WARNING Do not loosen valve (1) quickly or loosen it too much as high-pressure grease in the adjusting cylinder may spout out. Loosen carefully, keeping body parts and face away from valve (1). Never loosen grease fitting (2). SM1228

IMPORTANT - When gravel or mud is packed between sprockets and tracks, remove it before loosening.

1

1. Loosen valve (1) to drain grease. : 24 mm

2 Grease Outlet

SM0100

3

WARNING Use a nonskid cloth between track frame (5) and oil jack to prevent slipping.

2. Jack up tracks (3) heigh enough to permit upper roller (4) removal.

5 3. Insert a wooden block between tracks (3) and track frame (5).

SM1230

4

3

5 SM1231

W3-6-2

EX255-EX285

UPPER AND LOWER ROLLER 4. Remove bolts (2) from upper roller (1). : 24 mm

1 2

SM1233

WARNING Upper roller weight: EX255: 14 kg (31 lb) EX285: 16 kg (35 lb) 1 5. Remove upper roller (1) from track frame (3).

3

SM1233

Installation WARNING Upper roller weight: EX255: 14 kg (31 lb) EX285: 16 kg (35 lb) 1 1. Install upper roller (1) and bolts (2).

2

: 24 mm : 265 N m (27 kgf m, 195 lbf ft)

3 SM1233

2. Remove the wooden block and jack.

SM1230

EX255-EX285

W3-6-3

UPPER AND LOWER ROLLER 3. Supply grease to valve (1) to adjust tracks tension.

1

Grease Outlet

SM0100

Check the track tension measuring the track sag (A) as indicated in the TRACKS section. Track sag specifications (A): EX255: 300 to 335 mm (11.8 to 13.2 in) EX285: 340 to 380 mm (13.4 to 15.0 in) : 24 mm : 147 N m (15 kgf m, 108 lbf ft)

NOTE - Check track sag after thoroughly removing soil stuck on the track area by washing.

SM1234

4. Add engine oil via plug (4) hole on cover (5). Apply sealant (LOCTITE 503 or equivalent) to plug (4). Tighten plug (4). 5 SAE 30 oil quantity: EX255: 85 cm3 (0.09 US qt) EX285: 75 cm3 (0.08 US qt)

4

: 6 mm : 9.8 to 19.6 N m (1 to 2 kgf m, 7.5 to 15 lbf ft)

SM1235

W3-6-4

EX255-EX285

UPPER AND LOWER ROLLER REMOVE AND INSTALL LOWER ROLLER Removal 1. Remove the roller guard and loosen bolts (5). 5

EX255 : 27 mm EX285 : 30 mm SM1236

2. Lift the one side of the track frame high enough to remove the lower roller. Insert wooden blocks under track frame (2).

2 SM1237

WARNING Do not loosen valve (3) quickly or loosen it too much as high-pressure grease in the adjusting cylinder may spout out. Loosen carefully, keeping body parts and face away from valve (3). Never loosen grease fitting (4).

SM1228

3 3. Loosen valve (3) to drain grease enough to permit the roller removal. : 24 mm

4 Grease Outlet

SM0100

EX255-EX285

W3-6-5

UPPER AND LOWER ROLLER

WARNING Lower roller weight: EX255: 35 kg (77 lb) EX285: 56 kg (123 lb)

4. Securely hold the lower roller using a fork lift. Remove lower roller (1). 1

Installation

2

SM1238

1

1. Securely hold the lower roller using a fork lift. Put lower rollers (1) on the tracks as illustration.

SM1239

2. Lower track frame (2) enough to allow bolts (4) to be installed into track frame (2).

2

4

SM1240

3. Align tapped holes in track frame (2). Tighten bolt (4).

EX255 : 27 mm

4

: 400 N m (41 kgf m, 295 lbf ft) EX285 : 30 mm : 500 N m (51 kgf m, 369 lbf ft)

SM1236

W3-6-6

EX255-EX285

UPPER AND LOWER ROLLER 4. Supply grease to valve (3) to adjust tracks tension. 3

Grease Outlet

SM0100

Check the track tension measuring the track sag (A) as indicated in the TRACKS section. Track sag specifications (A): EX255: 300 to 335 mm (11.8 to 13.2 in) EX285: 340 to 380 mm (13.4 to 15.0 in) : 24 mm : 147 N m (15 kgf m, 108 lbf ft) SM1234

NOTE - Check track sag after thoroughly removing soil stuck on the track area by washing.

EX255-EX285

W3-6-7

UPPER AND LOWER ROLLER DISASSEMBLE UPPER ROLLER NOTE - Replace the upper roller as an assembly.

SM1241

W3-6-8

EX255-EX285

UPPER AND LOWER ROLLER DISASSEMBLE LOWER ROLLER

5

4

2

3

8 6 5

6

7

4 3 2 1

SM1242

1 - Plug (2 Used) 2 - Collar ( 2 Used) 3 - Elastic pin (2 Used)

4 - O-ring (2 Used) 5 - Floating Seal (2 Used) 6 - Bushing (2 Used)

7 - Roller 8 - Axle

EX255-EX285

W3-6-9

UPPER AND LOWER ROLLER Disassemble Lower Roller •

2

5

7

5

Be sure to thoroughly read “Precautions for Disassembly and Assembly” on page W1-1-1 before starting the disassembly work. 5

1. Remove plug (1) and elastic pins (3) from collars (2), and drain oil.

2

: 6 mm : 14 mm

2. Press down axle (8) until O-ring (4) comes out of collar (2). Remove collar (2) from axle (8).

SM1243

4

2

3. Remove O-ring (4) from axle (8). Remove axle (8) from roller (7). 8 4. Remove floating seal (5) from roller (7) and collar (2).

5. Press out axle (8), and remove collar (2) and O-ring (4) from axle (8)

SM1244

6. In case of replacing bushings (6), remove the bushings using a press and the special tool. Special Tool: 75301509

75301509

6

SM1245

W3-6-10

EX255-EX285

UPPER AND LOWER ROLLER ASSEMBLE LOWER ROLLER

2

7

6

5

4

3

1

8 SM1246

1 - Plug (2 Used) 2 - Collar ( 2 Used) 3 - Elastic pin (2 Used)

4 - O-ring (2 Used) 5 - Floating Seal (2 Used) 6 - Bushing (2 Used)

7 - Roller 8 - Axle

EX255-EX285

W3-6-11

UPPER AND LOWER ROLLER Assemble Lower Roller 3

8 1. Install bushings (6) (2 used) onto roller (7) using a press. Take care not to dent the flange surface of bushings (6). Apply a coat of grease to O-ring (4) and install onto axle (8).

2. Install collar (2) onto axle (8), aligning the pin holes. Secure them using elastic pin (3). Take care not to damage O-ring (4).

2

7

4

SM1247

5

IMPORTANT - The elastic pin has to be fitted with the slit oriented to the internal side of the roller.

5

IMPORTANT - For handling of floating seal (5), refer to the section "Floating seal precautions” on page W1-1-3.

2

3. Install floating seal (5) to roller (7) and to collar (2). SM1248

4. Insert axle (8) into roller (7). Install the other floating seal (5) to roller (7) and to collar (2). Install O-ring (4) the other collar (2). Secure them using elastic pin (3).

2

5

8

7

IMPORTANT - The elastic pin has to be fitted with the slit oriented to the internal side of the roller.

5. Add oil via plug (1) hole on collar (2). Apply sealant (LOCTITE 503 or equivalent) to plug (1). Tighten plug (1).

SM1249

4

SAE 30 oil quantity: 3 EX255: 278 cm (0.29 US qt) 3 EX285: 555 cm (0.59 US qt) : 6 mm

3

7

1

: 9.8 to 19.6 N m (1 to 2 kgf m, 7.5 to 15 lbf ft)

SM1250

2

W3-6-12

EX255-EX285

UPPER AND LOWER ROLLER MAINTENANCE STANDARD Upper Roller

SM1251

Standard

Allowable Limit

(mm) (in)

(mm) (in)

EX255

EX285

EX255

A

84 (3.31)

98 (3.86)

–

B

150 (5.91)

165 (6.50)

–

Remedy

EX285 Replace

C

120 (4.72)

110 (4.33)

Lower Roller

SM1252

Standard

Allowable Limit

(mm) (in)

(mm) (in)

EX255

EX285

EX255

Remedy

EX285

A

172 (6.77)

203 (7.99) 181.5 (7.15) 213 (8.39)

B

218 (8.58) 256 (10.08)

C

23 (0.91)

26.5 (1.04) 11.5 (0.45) 18.5 (0.73)

D

155 (6.10)

175 (6.89)

–

Buildup weld and finishing

139 (5.47) 165 (6.50)

IMPORTANT - Consult FIAT-HITACHI for any inqueries concerning welding procedure.

EX255-EX285

W3-6-13

UPPER AND LOWER ROLLER Axle and Bushing Standard

Allowable Limit

(mm)

(mm)

EX255

EX285

EX255

Remedy

EX285

Axle

Outside Dia.

65 (2.56) 75 (2.95) 64.2 (2.53) 74.2 (2.92)

Bushing

Inside Dia.

65 (2.56) 75 (2.95)

Bushing

Flange Thickness

Replace 2 (0.08)

66 (2.60)

76 (2.99)

1.2 (0.047)

W3-6-14

EX255-EX285

UPPER AND LOWER ROLLER NOTES:

EX255-EX285

W3-7-1

TRACKS REMOVE AND INSTALL TRACKS

5

Removal 1. Move the tracks so that master pin (3) is positioned over front idler (4). Put a wooden block under track shoes (5), as shown.

4

3

SM1254

WARNING Do not loosen valve (1) quickly on loosen too much since high-pressure grease in the adjusting cylinder may spout out. Loosen carefully, keeping body parts and face away from valve (1). Never loosen grease fitting (2).

SM1253

2. To loosen the track tension, slowly turn valve (1) counterclockwise one turn; grease will escape from grease outlet.

1

: 24 mm SM1255

1

Grease outlet SM0100

W3-7-2

EX255-EX285

TRACKS

WARNING The front idler may jump out of position due to strong spring force when the tracks is disconnected. Especially, the strong spring force is always applied to the bolt part of the rod. If the rod and/or the bolt are damaged, metal fragments may fly off when the tracks is disconnected. Take the necessary precautions to prevent personal injuries. SM1256

Spacer

3. Remove master pin (3) by using a special tool.

Bushing

3

SM1257

EX255

EX285

A

75294946

75294946

B

75294947

75295630

C

75294964

75298429

D

75294963

75298430

E

75295757

75298428

G

75297580

75297580

D

G

B

C

3

E

A SM1258

4. Slowly drive the machine in reverse until the whole length of the removing track comes on the ground.

SM1259

5. Rotate the upperstructure 90 degrees toward the removing track side, perpendicular to the tracks. Operate the boom and arm so that the angle between them is 90 to 110 degrees. Lower the boom with the bucket rolled-in to jack up the machine as illustrated.

90° ÷ 110°

SM1260

EX255-EX285

W3-7-3

TRACKS Installation 1. Jack up the machine and put the track under the lower roller. Be sure to position the track in correct direction, as illustrated.

Idler side

Sprocket side

SM1261

2. Lift the track, and place it on sprocket (1).

1

SM1262

3. Slowly turn the sprocket in forward direction.

SM1263

3

4. Turn sprocket (1) until end of track (4) comes on front idler (3). Lower the machine and put a wooden block as illustrated.

4 SM1264

W3-7-4

EX255-EX285

TRACKS IMPORTANT - Hole surfaces, link holes and counterbore surfaces, bushing ends, shall be free from dust and rust. 5. Install master pin (5), using a hammer and special tool.

EX255

EX285

A

75294946

75294946

B

75294947

75295630

C

75294964

75298429

D

75294963

75298430

E

75295757

75298428

G

75297580

75297580

Spacer

Bushing

5

SM1257

D

G

B

C

5

E

A SM1258

IMPORTANT - Inject rust preventive protective (ex. TECTYL165 G) between pin and bushing clearance.

IMPORTANT - If any links have been removed from the track, be sure to charge the grease (es. AMBRA MG2) into the clearance between the pin and bushing when reconnecting the links. Also, apply a coat of grease to the ends of the bushing. Grease Charging Method: - Stand the bushing on a flat plate. - Fill the bushing bore with the grease. - Insert the pin into the bushing while pushing the bushing onto the plate (so that the bushing end stays on the plate). - Wipe off excess grease.

6. Supply grease to the cylinder through the grease fitting to adjust the track tension. : 24 mm Check the track tension measuring the track sag (A) as indicated in the pages to follow.

SM1265

EX255-EX285

W3-7-5

TRACKS Checking track sag • Turn the upperstructure 90° and lower the bucket to raise one track off the ground as shown. • Keep the angle between boom and arm 90° to 110° and rest the bucket round side (outer) onto the ground.

90° ÷ 110°

• Place blocks under the frame to the machine. • Rotate the raised track in reverse two full rotations, then forward two full rotations.

S0012

• Measure track sag (A) at the middle of the frame and from the bottom of the track frame to the back face of the track shoe. Distance (A) should be: EX255: 300 to 335 mm (11.8 to 13.2 in) EX285: 340 to 380 mm (13.4 to 15.0 in)

NOTE: Check track sag after thoroughly removing dirt stuck on the track by pressure-washing.

Precautions for adjusting track sag • If track sag is not within specification, loosen or tighten the track following the procedures detailed below. • When adjusting track sag, lower the bucket to the ground to raise one track off the ground. Repeat this procedure to raise the other track. Place blocks under the frame on the side of the raised track to the machine. • After adjusting track sag of both tracks, move the machine back and forth several times. Check track sag again. If, after settling, this is not within specifications repeat the above procedures until correct sag is obtained.

SM1234

W3-7-6

EX255-EX285

TRACKS Loosening the track 2 WARNING - Do not loosen the valve (1) quickly or too much as grease pressure inside the cylinder might dangerously eject it off its seat. - Loosen the valve with care, keeping the body parts and face away from the valve (1). - Never loosen the grease fitting (2).

IMPORTANT: remove any matter such as mud or gravel possibly stuck between sprockets and track links before loosening.

• To loosen the track, slowly turn valve (1) anticlockwise using a 24 mm long socket. The grease will escape from the valve base. • 1 to 1.5 turns of the valve (1) are sufficient to loosen the track. • If grease does not come out evenly, slowly rotate the raised track. • When proper track sag is obtained, turn valve (1) clockwise and tigthen to 14 daNm.

Tightening the track

WARNING It is abnormal if the trac remains tight after turning valve (1) anticlockwise or if the track is still loose after charging grease through the grease fitting (2). In such cases NEVER ATTEMPT TO DISASSEMBLE the track or the track adjuster due to dangerous high-pressure grease inside the track adjuster. your authorised FIAT-HITACHI Dealer immediately.

• To tighten the track, inject grease from a grease gun into fitting (2) until sag is within specification.

1 OM0142

EX255-EX285

W3-7-7

TRACKS MAINTENANCE STANDARD Link Pin and Track Bushing • •

Measure the length of four links, as illustrated, with the tension on the track. Do not measure the master-pin included part of the track.

SM1266

A

Standard (mm) (in) EX255 A


EX285

EX255

760.6 (29.95) 812 (31.97) 785.8(30.94)

EX285 830 (32.68)

Remedy Buildup weld and finishing or replace


Master Pin

SM1269

Standard (mm) (in)


EX255

EX285

EX255

A

212 (8.35)

251 (9.88)

B

37.72 (1.48) 44.2 (1.74) 35.5 (1.39) 41.5 (1.63)

Remedy

EX285 –

Replace Replace

W3-7-8

EX255-EX285

TRACKS Master Bushing

SM1267

Standard (mm) (in)

A

EX255

EX285

129.2 (5.09)

154 (6.06)

Allowable Limit (mm) (in) EX255

Remedy

EX285 – Replace

B

38.7 (1.52)

44.45 (1.75)

41.5 (1.63)

47,3 (1.86)

C

59 (2.32)

66.675 (2.625)

54 (2.13)

63 (2.48)

Suola

SM1268

Standard (mm) (in) EX255 A

EX285

217.5 (8.56) 240 (9.45)

Allowable Limit (mm) (in) EX255

Remedy

EX285 – Replace

B

10 (0.39)

13 (0.51)

–

C

26 (1.02)

26.5 (1.04)

15 (0.59)

SECTION 4

EX255-EX285

FRONT ATTACHMENT

CONTENTS Group 1 -

Front attachment

Remove and install front attachment (monobloc version) ................................ W4-1-1 Maintenance Standard (monobloc version) ................................ W4-1-6 Bucket teeth ......................................... W4-1-8 Standard dimensions for arm and bucket connection ................................. W4-1-9 Remove and install front attachment (triple articulation version) ................... W4-1-11 Maintenance Standard (triple articulation version) ................... W4-1-16

Group 2 -

Cylinders

Remove and install cylinders ................. W4-2-1 Hydraulic circuit pressure release procedure ................................ W4-2-12 Cylinder air bleeding procedure ............ W4-2-13 Disassemble cylinders ......................... W4-2-14 Assemble cylinders ............................. W4-2-20 Maintenance Standard ........................ W4-2-26 Special Tools (EX255) ......................... W4-2-27 Special Tools (EX285) ......................... W4-2-28

EX255-EX285

W4-1-1

FRONT ATTACHMENT REMOVE AND INSTALL FRONT ATTACHMENT (monobloc version) WARNING Escaping fluid under pressure can penetrate the skin, causing serious injury. Avoid this hazard by relieving pressure before disconnecting hydraulic or other lines. Hydraulic oil may be hot just after operation. Hot hydraulic oil may spout, possibly causing severe burns. Be sure to wait for oil to cool before starting work. The hydraulic oil tank cap may fly off if removed without releasing internal pressure first. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure.

Preparation 1. Park the machine on firm, level ground. Position the front attachment as illustated and lower the bucket to the ground. SM1317

Removal 12

1. Disconnect lubrication pipes (12) from both boom cylinder rod ends. : 19 mm

2. Loosen lock nuts (1), remove bolt (2) and stoppers (3) from both boom cylinder rod ends. : 30 mm SM1318

WARNING Boom cylinder weight: EX255: 203 kg (448 lb) EX285: 233 kg (514 lb)

4 4 2

WARNING Prevent personal injury. Metal fragments may fly off when a hammer is used to remove pins. Be sure to wear necessary protection, such as goggles, hardhat, etc.

3. Attach each boom cylinder to a crane. Remove cylinder rod end pin (5) and thrust plate (4) using a hammer and bar.

3

5

1

SM3502

W4-1-2

EX255-EX285

FRONT ATTACHMENT IMPORTANT - Avoid boom cylinder damage. A grease fitting is located on the boom cylinder. Be sure to position a wooden block so that the grease fitting does not come in with the wooden block when the boom cylinder is lowered.

4. Position a wooden block between the main frame and the boom cylinder bottom, as illustrated. Slowly lower the boom cylinder using the crane onto the wooden block.

5. Stop the engine. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. Completely release the residual pressure from the hydraulic circuit by performing the “Hydraulic Circuit Pressure Release Procedure” Refer to page W4-2-12.

SM1320

Wooden Block

6. Disconnect hoses (8) and (7) of arm cylinder and bucket cylinder. Close all openings with plugs to keep clean. : 36, 41 mm 8

7

SM3504

7. Remove bolts (10) and lock plate (9) from main frame. : 30 mm

10

9 11 SM3503

EX255-EX285

W4-1-3

FRONT ATTACHMENT

WARNING Approx. weight of front attachment assembly: EX255: 4550 kg (10 031 lb) EX285: 5600 kg (12 346 lb)

8. Attach the boom to a crane. Slighty hoist the boom to take out any wire rope slack. SM1323

9. Pull the boom foot pin with special tool (75301511).

75301511

SM1350

10. Lift the front attachment. Drive the base machine away from the front attachment and the crane.

SM1325

W4-1-4

EX255-EX285

FRONT ATTACHMENT Installation WARNING Approx. weight of front attachment assembly: EX255: 4550 kg (10 031 lb) EX285: 5600 kg (12 346 lb)

1. Install the front attachment Install dust seals to boom foot. Align the boom foot boss with the main frame boss. Insert a thrust plate to both right and left sides of the boom foot boss to take out clearance between the boom foot boss and the main frame boss the remaining clearance should be less than 1 mm.

SM1325

2. Install boom foot pin (11) using a hammer and bar. Install bolt (10) (2 used) and lock plate (9).

10

: 30 mm 9

: 540 N m (55 kgf m, 398 lbf ft) 11

SM3503

3 Remove the plugs from the pipes or hoses. Connect the arm and bucket hoses (7), (8) to the pipes. : 41 mm

7

8

: 295 N m (30 kg m, 218 lbf ft) : 36 mm : 235 N m (24 kgf m, 173 lbf ft)


SM3504

4. Attach the boom cylinder to a crane. Lift the boom cylinder and align the boom cylinder rod with the pin hole on the boom.

NOTE - For easy alignment, start the engine and use the boom control lever.

SM1326

EX255-EX285

W4-1-5

FRONT ATTACHMENT NOTE - Fill the hydraulic oil tank with hydraulic oil to the specified level. Run the engine at idle. Check hose connections for any oil leakage

IMPORTANT - Bleed air from hydraulic circuit.

WARNING Prevent personal injury. Metal fragments may fly off when a hammer is used to insert pins. Be sure to wear necessary protection, such as goggles, hardhat, etc.

4 4 2 5

3 5. Install thrust plate (4). Drive pin (5) into the pin hole. 1 6. Install thrust plate (4), stopper (3), tighten bolt (2) and lock nuts (1).

SM3502

: 30 mm : 540 N m (55 kgf m, 398 lbf ft) Install the other boom cylinder following the same procedures.

12

7. Connect lubrication pipes (12) to each boom cylinder rod. Tighten the connection to specification. : 19 mm : 29 N m (3 kgf m, 22 lbf ft) SM1318

8. Remove the pipes, with pipe fittings located in the holes (14), from the boom foot boss.

9. Remove plug (13) and install an adeguate grease fitting into plug (13) removed hole. Plug tapered thread: 3/8 GAS - UNI339

10. Fill grease via grease fitting. Remove grease fitting and re-install the plug (13) in the original position.

11. Connect the pipes, with pipe fittings, on the boom foot boss.

SM5521

W4-1-6

EX255-EX285

FRONT ATTACHMENT MAINTENANCE STANDARD (monobloc version) E

F

G C H J

D A I

K B

SM1328

Unit: mm (in) Parts Name

Standard EX255

A

B

C

D

E

F

EX285

Allowable Limit EX255

Remedy

EX285

Pin

100 (3.94)

99,0 (3.90)

Bushing

100 (3.94)

101,5 (4.00)

Pin

90 (3.54)

100 (3.94)

89.0 (3.50)

99.0 (3.90)

Boss (Main Frame)

90 (3.54)

100 (3.94)

91.5 (3.60)

101.5 (4.00)

Bushing (Boom Cylinder)

90 (3.54)

100 (3.94)

91.5 (3.60)

101.5 (4.00)

Pin

90 (3.54)

100 (3.94)

89.0 (3.50)

99.0 (3.90)


90 (3.54)

100 (3.94)

91.5 (3.60)

101.5 (4.00)

Boss (Boom)

90 (3.54)

100 (3.94)

91.5 (3.60)

101.5 (4.00)

Pin

90 (3.54)

100 (3.94)

89.0 (3.50)

99.0 (3.90)

Bushing

90 (3.54)

100 (3.94)

91.5 (3.60)

101.5 (4.00)

Pin

80 (3.15)

90 (3.54)

79.0 (3.11)

89.0 (3.50)

Boss (Arm)

80 (3.15)

90 (3.54)

81.5 (3.21)

91.5 (3.60)

Bushing (Arm Cylinder)

80 (3.15)

90 (3.54)

81.5 (3.21)

91.5 (3.60)

Pin

80 (3.15)

90 (3.54)

79.0 (3.11)

89.0 (3.50)

Boss (Boom)

80 (3.15)

90 (3.54)

81.5 (3.21)

91.5 (3.60)


80 (3.15)

90 (3.54)

81.5 (3.21)

91.5 (3.60)

Replace

EX255-EX285

W4-1-7

FRONT ATTACHMENT Unit: mm (in) Parts Name

Standard EX255

G

H

EX285


Remedy

EX285

Pin

80 (3.15)

79.0 (3.11)

Boss (Arm)

80 (3.15)

81.5 (3.21)

Bushing (Bucket Cylinder)

80 (3.15)

81.5 (3.21)

Pin

90 (3.54)

89.0 (3.50)

Bushing

90 (3.54)

91.5 (3.60)


90 (3.54)

91.5 (3.60) Replace

I

J

K

Pin

80 (3.15)

79.0 (3.11)

Bushing

80 (3.15)

81.5 (3.21)

Pin

90 (3.54)

89.0 (3.50)

Bushing

90 (3.54)

91.5 (3.60)

Pin

90 (3.54)

89.0 (3.50)

Bushing

90 (3.54)

91.5 (3.60)

IMPORTANT - Be sure to install front attachment bushings using a press.

W4-1-8

EX255-EX285

FRONT ATTACHMENT BUCKET TEETH Replacement

WARNING Keep people not involved in the maintenance work outside the working area. Wear adequate personal clothes and glasses with side shields as a protection against flying debris.

• Ensure the machine is parked on a level surface. 5

1

2

3

• Rest the bucket to the ground. • Switch off the auto-idle, fully turn the engine speed manual control anticlockwise, stop the engine, remove the ignition key and move the safety lever in the locked position (LOCK).

• Using a hammer (3) and a drift (2), as shown, drive the lock pin (1) from its seat and remove the tooth. 4 NOTE: Hit the lock pin (1) with the drift (2) on the pin tapered portion to drive it out of its seat.

• Clean shank (5) surface and install a new tooth (4) onto the shank.

• Install the lock pin (1) into its seat and drive it in using a drift (2) and a hammer (3) until it is fully seated.

SM1329

EX255-EX285

W4-1-9

FRONT ATTACHMENT STANDARD DIMENSIONS FOR ARM AND BUCKET CONNECTION

d e c

f

b a j p

o

k

i

n h g q

m l

Cross-section A

Cross-section B SM1330

Unit: mm (in) EX255

EX285

a (*)

460 (181.1)

475 (187)

b (*)

5 (2)

0 (0)

c

620 (244.1)

622 (244.9)

d

580 (228.3)

600 (236.2)

e

475 (187)

475 (187)

f

1547 (609)

1588 (625.7)

g

549 (216.1)

555 (218.5)

h

430 (169.3)

430 (169.3)

i

90 (35.4)

90 (35.4)

j

470 (185)

470 (185)

k

69 (27.1)

69 (27.1)

l

549 (216.1)

555 (218.5)

m

410 (161.4)

410 (161.4)

n

90 (35.4)

90 (35.4)

o

90°

90°

p

20°

45°

q

565 (222.4)

571 (224.8)

(*) Arm: 2 950 mm (1161.4 in) (EX255), 3 750 mm (1476.4 in) (EX285)

W4-1-10

EX255-EX285

FRONT ATTACHMENT NOTES:

EX255-EX285

W4-1-11

FRONT ATTACHMENT REMOVE AND INSTALL FRONT ATTACHMENT (triple articulation version) WARNING Escaping fluid under pressure can penetrate the skin, causing serious injury. Avoid this hazard by relieving pressure before disconnecting hydraulic or other lines. Hydraulic oil may be hot just after operation. Hot hydraulic oil may spout, possibly causing severe burns. Be sure to wait for oil to cool before starting work. The hydraulic oil tank cap may fly off if removed without releasing internal pressure first. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure.

Preparation 1. Park the machine on firm, level ground. Position the front attachment as illustated and lower the bucket to the ground.

SM1357

Removal 12

1. Disconnect lubrication pipes (12) from both boom cylinder rod ends. : 19 mm

2. Loosen lock nuts (1), remove bolt (2) and stoppers (3) from both boom cylinder rod ends. : 30 mm SM1318

WARNING

4

Boom cylinder weight: EX255: 203 kg (448 lb) EX285: 233 kg (514 lb)

4 2 3

5

WARNING Prevent personal injury. Metal fragments may fly off when a hammer is used to remove pins. Be sure to wear necessary protection, such as goggles, hardhat, etc.

1

SM3502

3. Attach each boom cylinder to a crane. Remove cylinder rod end pin (5) and thrust plate (4) using a hammer and bar.

W4-1-12

EX255-EX285

FRONT ATTACHMENT IMPORTANT - Avoid boom cylinder damage. A grease fitting is located on the boom cylinder. Be sure to position a wooden block so that the grease fitting does not come in with the wooden block when the boom cylinder is lowered.

4. Position a wooden block between the main frame and the boom cylinder bottom, as illustrated. Slowly lower the boom cylinder using the crane onto the wooden block. SM1320

5. Stop the engine. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. Completely release the residual pressure from the hydraulic circuit by performing the “Hydraulic Circuit Pressure Release Procedure”. Refer to page W4-2-12.

Wooden Block

7

8

6. Disconnect hoses (8), (7) and (31) of arm cylinder and bucket cylinder and positioning cylinder. Close all openings with plugs to keep clean. : 36, 41 mm : 12 mm 31

SM1358

7. Remove bolts (10) and lock plate (9) from main frame. : 30 mm 10

9 11 SM3503

EX255-EX285

W4-1-13

FRONT ATTACHMENT

WARNING Front assembly weight: EX255: 4890 kg (10 781 lb) EX285: 5900 kg (13 007 lb)

WARNING Avoid wire rope damage. Be sure to position a necessary protection between the wire rope and boom pin hole surfaces.

8. Attach the boom to a crane. Using the boom pin hole for front attachment sling.

WARNING To secure the top arm with an other crane, when remove the front attachment.

9. Slighty hoist the boom to take out any wire rope slack.

10. Pull the boom foot pin with special tool (75301511).

75301511

SM1350

11. Lift the front attachment. Drive the base machine away from the front attachment and the crane.

SM1325

W4-1-14

EX255-EX285

FRONT ATTACHMENT Installation WARNING Front assembly weight: EX255: 4890 kg (10 781 lb) EX285: 5900 kg (13 007 lb)

WARNING To secure the top arm with an other crane, when remove the front attachment.

SM1325

1. Install the front attachment. Install dust seals to boom foot. Align the boom foot boss with the main frame boss. Insert a thrust plate to both right and left sides of the boom foot boss to take out clearance between the boom foot boss and the main frame boss the remaining clearance should be less than 1 mm.

10

9 11 SM3503

2. Install boom foot pin (11) using a hammer and bar. Install bolt (10) (2 used) and lock plate (9). 7

: 30 mm : 540 N m (55 kgf m, 398 lbf ft)

8 3 Remove the plugs from the pipes or hoses. Connect positioning arm and bucket hoses (31) (7), and (8) to the pipes. : 41 mm : 295 N m (30 kg m, 218 lbf ft)

31

: 36 mm : 235 N m (24 kgf m, 173 lbf ft) SM1358

WARNING Boom cylinder weight: EX255: 203 kg (448 lb) EX285: 233 kg (514 lb) 4. Attach the boom cylinder to a crane. Lift the boom cylinder and align the boom cylinder rod with the pin hole on the boom.


SM1326

EX255-EX285

W4-1-15

FRONT ATTACHMENT NOTE - Fill the hydraulic oil tank with hydraulic oil to the specified level. Run the engine at idle. Check hose connections for any oil leakage



4 4 2 5

3 5. Install thrust plate (4). Drive pin (5) into the pin hole.

1

6. Install thrust plate (4), stopper (3), tighten bolt (2) and lock nuts (1).

SM3502

: 30 mm : 540 N m (55 kgf m, 398 lbf ft) 12 7. Connect lubrication pipes (12) to each boom cylinder rod. Tighten the connection to specification. : 19 mm : 29 N m (3 kgf m, 22 lbf ft)

8. Remove the pipes, with pipe fittings located in the holes (14), from the boom foot boss.

SM1318

9. Remove plug (13) and install an adeguate grease fitting into plug (13) removed hole. Plug tapered thread: 3/8 GAS - UNI339

10. Fill grease via grease fitting. Remove grease fitting and re-install the plug (13) in the original position.

11. Connect the pipes, with pipe fittings, on the boom foot boss. SM5521

W4-1-16

EX255-EX285

FRONT ATTACHMENT MAINTENANCE STANDARD (triple articulation version)

L

E

M G

D F

C

A N H

B I

J

K SM1357

Unit: mm (in) Parts Name

Standard EX255

A

B

C

D

E

F

EX285


Remedy

EX285

Pin

100 (3.94)

99.0 (3.90)

Bushing

100 (3.94)

101.5 (4.00)

Pin

90 (3.54)

100 (3.94) 89.0 (3.50) 99.0 (3.90)

Boss (Main Frame)

90 (3.54)

100 (3.94) 91.5 (3.60) 101.5 (4.00)


90 (3.54)

100 (3.94) 91.5 (3.60) 101.5 (4.00)

Pin

90 (3.54)

100 (3.94) 89.0 (3.50) 99.0 (3.90)


90 (3.54)

100 (3.94) 91.5 (3.60) 101.5 (4.00)

Boss (Boom)

90 (3.54)

100 (3.94) 91.5 (3.60) 101.5 (4.00)

Pin

100 (3.94)

99.0 (3.90)

Bushing

100 (3.94)

101.5 (4.00)

Pin

90 (3.54)

89.0 (3.50)

Boss (Arm)

90 (3.54)

91.5 (3.60)

Bushing (Positioning Cylinder)

90 (3.54)

91.5 (3.60)

Pin

90 (3.54)

89.0 (3.50)

Boss (Boom)

90 (3.54)

91.5 (3.60)

Bushing (Positioning Cylinder)

90 (3.54)

91.5 (3.60)

Replace

EX255-EX285

W4-1-17

FRONT ATTACHMENT Unit: mm (in) Parts Name

Standard EX255

G

H

I

J

EX285


Remedy

EX285

Pin

80 (3.15)

79.0 (3.11)

Boss (Arm)

80 (3.15)

81.5 (3.21)


80 (3.15)

81.5 (3.21)

Pin

90 (3.54)

89.0 (3.50)

Bushing

90 (3.54)

91.5 (3.60)


90 (3.54)

91.5 (3.60)

Pin

80 (3.15)

79.0 (3.11)

Bushing

80 (3.15)

81.5 (3.21)

Pin

90 (3.54)

89.0 (3.50)

Bushing

90 (3.54)

91.5 (3.60) Replace

K

L

M

N

Pin

90 (3.54)

89.0 (3.50)

Bushing

90 (3.54)

91.5 (3.60)

Pin

80 (3.15)

90 (3.54)

79.0 (3.11) 89.0 (3.50)

Boss (Positioning)

80 (3.15)

90 (3.54)

81.5 (3.21) 91.5 (3.60)


80 (3.15)

90 (3.54)

81.5 (3.21) 91.5 (3.60)

Pin

80 (3.15)

90 (3.54)

79.0 (3.11) 89.0 (3.50)

Boss (Arm)

80 (3.15)

90 (3.54)

81.5 (3.21) 91.5 (3.60)


80 (3.15)

90 (3.54)

81.5 (3.21) 91.5 (3.60)

Pin

90 (3.54)

100 (3.94)

89.0 (3.50) 99.0 (3.90)

Bushing

90 (3.54)

100 (3.94)

91.5 (3.60) 101.5 (4.00)

IMPORTANT - Be sure to Install front attachment bushings using a press.

W4-1-18

EX255-EX285

FRONT ATTACHMENT NOTES

EX255-EX285

W4-2-1

CYLINDERS REMOVE AND INSTALL CYLINDERS WARNING Escaping fluid under pressure can penetrate the skin, causing serious injury. Avoid this hazard by relieving pressure before disconnecting hydraulic or other lines. Hydraulic oil may be hot just after operation. Hot hydraulic oil may spout, possibly causing severe burns. Be sure to wait for oil to cool before starting work. The hydraulic oil tank cap may fly off if removed without releasing internal pressure first. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure.

Preparation 1. Park the machine on firm, level ground. Position the front attachment as illustrated and lower the bucket to the ground. 2. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. SM1317

Remove Bucket Cylinder 1. Insert wooden block (15) between bucket cylinder (1) and arm (8). 1 2. Completely release the residual pressure from the hydraulic circuit by performing the “Hydraulic Circuit Pressure Release Procedure”. Refer to page W4-2-12. 15 IMPORTANT - Pin (6) end of the link will drop when pin (6) is removed, possibly resulting in personal injury. Be sure to secure the link using a piece of wire before removing pin (6).

8 15 SM1331

3. Loosen nuts (4) and bolt (5), in that order. Pull out pin (6). Then, remove thrust plates (16).

16 5

: 30 mm

4

SM3506

6

W4-2-2

EX255-EX285

CYLINDERS 13

4. Use wire (14) to secure cylinder rod (13) as illustrated.

1

5. Disconnected hoses (9) (2 Used) from bucket cylinder (1). Put plugs on cylinder pipes and hoses. : 10 mm : 36 mm 14 WARNING Bucket cylinder weight: EX255: 172 kg (379 lb) EX285: 209 kg (461 lb)

SM1333

17 10

12 6. Use a crane to slightly hoist bucket cylinder (1). Loosen lock-nuts (11), remove screw (12) and stopper (18) then pull-out pin (10) using a hammer and a bar, so that the end of the cylinder gets free. Recover adjusting shims (17). : 30 mm

18 11

1 SM5522

7. Remove bucket cylinder (1). 9 9

EX255-EX285

W4-2-3

CYLINDERS Install Bucket Cylinder WARNING Bucket cylinder weight: EX255: 172 kg (379 lb) EX285: 209 kg (461 lb)

17 10

12 1. Connect bucket cylinder (1) to a crane using a sling belt. Align the hole on the bucket cylinder tube with the pin hole on the arm-tip bracket. 2. Install thrust plates (17). Insert pin (10). Then, install bolt (12) into stopper (18). Tighten lock nuts (11).

18 11

1 SM5522

: 30 mm : 540 N m (55 kgf m, 398 lbf ft) 9 3. Connect two hoses (9) to bucket cylinder (1). : 10 mm

9

: 88 N m (9.0 kgf m, 65 lbf ft) : 36 mm : 175 N m (18 kgf m, 130 lbf ft)

NOTE - Fill the hydraulic oil tank with hydraulic oil to the specified level. Run the engine at idle. Check hose connections for any oil leakage.

4. Align the bucket cylinder rod with bucket links (2), (3). Install thrust plates (16) and pin (6).

2

5

18

16

NOTE - For easy alignment, start the engine and use the arm control lever.

6 5. Install bolt (5), onto pin (6) and stopper (18); tighten lock nuts (4). : 30 mm : 540 N m (55 kgf m, 398 lbf ft)

IMPORTANT - If link (3) has been disconnected from the arm, be sure to insert thrust plate (16) when connecting it. Bleed air from hydraulic circuit.

3

4

SM3506

W4-2-4

EX255-EX285

CYLINDERS Remove Arm Cylinder 1

1. Insert a wooden block between arm cylinder (1) and boom (12).

2. Stop the engine. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. Completely release the residual pressure from the hydraulic circuit by performing the “Hydraulic Circuit Pressure Release Procedure”. Refer to page W4-2-12.

SM1347

12

13 3. Disconnect lubricant supply pipe from pin (9). Loosen lock nuts (10) and remove bolt (11).

11

: 30 mm

9 1

2

4. Remove pin (9) and thrust plate (13). 10

SM3508

5. Use wire to secure cylinder rod (2) as illustrated. 2

SM1337

1 6. Disconnect arm cylinder hoses (7), (16). Put plugs on the pipe on arm cylinder (1) and hoses.

8

7

: 36 mm

7. Disconnect Iubricant supply pipe (8). : 19 mm 16 SM3509

EX255-EX285

W4-2-5

CYLINDERS

WARNING

1

Arm cylinder weight: EX255: 300 kg (661 lb) EX285: 310 kg (683 lb)

8. Use a crane to slightly hoist arm cylinder (1). SM1335

1

5

15 3

9. Loosen lock nuts (4). Remove bolt (5) and pin (3). Then remove thrust plate (15) from arm cylinder (1). : 30 mm

4

SM3510

W4-2-6

EX255-EX285

CYLINDERS Install Arm Cylinder

WARNING Arm cylinder weight: EX255: 300 kg (661 lb) EX285: 310 kg (683 lb)

1. Use a crane to install arm cylinder (1) to the boom bracket. 2. Install thrust plates (15) stopper (18) and pin (3). Then, install bolts (5) and lock nuts (4) into stopper (18). : 30 mm

1

5

15

3 8

: 540 N m (55 kgf m, 398 lbf ft) 3. Attach lubricant supply pipe (8) and arm cylinder hoses (7) and (16). : 10 mm

7 18 4

: 88 N m (9 kgf m, 65 lbf ft) 16

: 19 mm

SM3509

: 29 N m (3 kgf m, 21 lbf ft) : 36 mm : 175 N m (18 kgf m, 129 lbf ft)

NOTE - Fill hydraulic oil tank with hydraulic oil to the specified level. Run the engine at idle. Check hose connections for any oil leakage.

4. Remove wire (6) from arm cylinder (1). Slightly hoist arm cylinder (1) and align the arm cylinder rod with arm (14).

6 2

SM1337

NOTE - For easy alignment, start the engine and use the arm control lever. 11

5. Install thrust plate (13), pin (9) and stopper (18). Then, install bolt (11) into stopper (18) and pin (9). Tighten lock nuts (10).

13

9

18

: 30 mm : 540 N m (55 kgf m, 398 lbf ft)


10

SM3508

EX255-EX285

W4-2-7

CYLINDERS Remove Boom Cylinder 1. Park the machine on firm, level surface and lower the bucket teeth and arm top to the ground with the arm and bucket cylinders fully retracted as illustrated. SM1317

2. Disconnect lubricant supply pipes (1). : 19 mm 1 WARNING Boom cylinder weight: EX255: 203 kg (448 lb) EX285: 233 kg (514 lb)

3

3. Use a crane to hoist the boom cylinder.

4. Loosen lock nuts (2), remove bolt (3) and stopper (4). Using bar and hammer, tap pin (5) until the boom cylinder is free. Remove thrust plate (6). : 30 mm

4 2 6

SM3511

5

5. Use a wire to secure the boom cylinder rod as illustrated. Lower cylinder on proper stand. 6. Stop the engine. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. Completely release the residual pressure from the hydraulic circuit by performing the “Hydraulic Circuit Pressure Release Procedure”. Refer to page W4-2-12. SM1342

7. Disconnect boom cylinder hoses (11) (4 used). Put plugs on cylinder pipes. : 36 mm 10 8. Loosen lock nuts (7), Remove bolt (8), pins (9), and thrust plates (10). : 30 mm

11 8


9 7

9. Hoist the boom cylinder with a crane. Remove the other boom cylinder following the same procedures.

9 SM3512

W4-2-8

EX255-EX285

CYLINDERS Install Boom Cylinder WARNING Boom cylinder weight: EX255: 203 kg (448 lb) EX285: 233 kg (514 lb) 1. Use a crane to install the boom cylinders to the main frame. 2. Install thrust plate (10) and pin (9). Then, install bolt (8) and lock nuts (7). Tighten lock nuts (7). : 30 mm : 540 N m (55 kgf m, 400 lbf ft)

SM1342

11

10

8

3. Install the other side boom cylinder. 4. Connect the boom cylinder hoses (11) (4 used). : 36 mm : 175 N m (18 kgf m, 130 lbf ft) 9 NOTE - Fill the hydraulic oil tank with hydraulic oil to the specified level. Run the engine at idle. Check hose connections for any oil leakage.

7 9 SM3512

5. Hoist the boom cylinder, and align the rod side with the boom.



3

4 2 6

6. Install pin (5) using a bar and hammer, then install thrust plates (6). 7. Install bolt (3), stopper (4), and lock nuts (2). Tighten lock nuts (2). : 30 mm

5

6 SM3511

1

: 540 N m (55 kgf m, 398 lbf ft) 8. Install lubricant supply pipes (1). : 19 mm : 29 N m (3 kgf m, 21 lbf ft) 9. Install other boom cylinder following the same procedure. SM1346


EX255-EX285

W4-2-9

CYLINDERS Remove positioning cylinder (triple articulation version) PREPARATION 1. Park the machine on firm, level ground. Position the front attachment as illustrated and lower the bucket to the ground. 2. Push the air release valve on top of the hydraulic oil tank to release any remaining pressure. SM1357

REMOVAL 6

5

1. Insert a wooden block between positioning cylinder and boom.

2. Completely release the residual pressure from the hydraulic circuit by performing the “Hydraulic Circuit Pressure Release Procedure”. Refer to page W4-2-12.

7

3. Disconnect lubrication pipe from positioning cylinder (rod side).

4 SM1360

4. Loosen lock nuts (4), remove bolt (5) and stopper (7). Using bar and hammer, tap pin (6) until the positioning cylinder is free and remove thrust plate.

14

: 30 mm

13

5. Use wire (14) to secure cylinder rod (13) as illustrated.

SM1337

6. Disconnected hoses (9) (2 used) from positioning cylinder. Put plugs on cylinder hoses. : 12 mm

9

7. Disconnect lubrication pipe (A) from positioning cylinder (bottom side). A

SM1358

W4-2-10

EX255-EX285

CYLINDERS

WARNING

1

Positioning cylinder weight: EX255-EX285: 242 kg (534 lb)

8. Use a crane to slightly hoist positioning cylinder (1). Loosen lock nuts (11), remove bolt (12), stopper (15) and pin (10). Remove thrust plate.

SM1361

12

1

10

9. Remove positioning cylinder (1).

15 11 SM1362

EX255-EX285

W4-2-11

CYLINDERS Install positioning cylinder 12

1

10

WARNING Positioning cylinder weight: EX255-EX285: 242 kg (534 lb)

1. Connect positioning cylinder (1) to a crane using a sling belt. Align the hole on the positioning cylinder tube with the pin hole on the boom-tip bracket.

15 11 SM1362

2. Install thrust plates and insert pin (10). Then install stopper pin (15) and bolt (12) into pin (10). Tighten lock nuts (11).

3. Connect lubrication pipe (A) to positioning cylinder (bottom side).

9

4. Connect two hoses (9) to positioning cylinder (1). A

: 12 mm

NOTE - Fill the hydraulic oil tank with hydraulic oil to the specified level. Run the engine at idle. Check hose connections for any oil leakage. SM1358

5. Remove wire (14) from positioning cylinder (13).

6. Slightly hoist positioning cylinder and align the positioning cylinder rod with positioner. Install thrust plate and insert pin (6).

14 13

NOTE - For easy alignment, start the engine and use the positioner control lever.

SM1337

6

5 7. Install stopper (7) and bolt (5) onto pin (6). Tighten lock nuts (4).

8. Connect lubrication pipe to positioning cylinder (rod side). 7

NOTE - Bleed air from hydraulic circuit. 4 SM1360

W4-2-12

EX255-EX285

CYLINDERS HYDRAULIC CIRCUIT PRESSURE RELEASE PROCEDURE

WARNING

4

6

Be sure to slowly loosen the overload relief valves. Quick loosening of the overload relief valves may cause pressurized oil to spout, possibly resulting in severe burns and/or oil penetration of skin.

Release the residual circuit pressure by slowly loosening the overload relief valve(s) for the line(s) or hose(s) to be disconnected. : 32 mm : 83±5N m (8.5±0.5 kgf m, 62±3.6 lbf ft)

IMPORTANT - Be sure to loosen the valve body, not the adjusting screw. Also, be sure to re-tighten the overload relief valve after releasing the residual circuit pressure.

SM1348

2 7

1 2 3 4 5 6 7 8

-

Boom Cylinder (Bottom Side) Boom Cylinder (Rod Side) Arm Cylinder (Bottom Side) Arm Cylinder (Rod Side) Bucket Cylinder (Bottom Side) Bucket Cylinder (Rod Side) Positioning Cylinder (Rod Side) Positioning Cylinder (Bottom Side)

1 8

3

5 SM1349

EX255-EX285

W4-2-13

CYLINDERS CYLINDER AIR BLEEDING PROCEDURE

WARNING After installing the cylinder, be sure to do the work air bleeding procedure. Move in the horizontal direction for boom cylinder and arm cylinder. Air bleeding procedure 1. Install cylinder. 2. Start engine and run at low speed (about low idle speed + 200 min-1). Extend and retract slowly 5 times. (Do not extend and retract to the stroke end dur-ing the first 4 times. On the last time extend and retract to the stroke end.) 3. Be sure that cylinder moves smoothly.

SM6293

Air Bleeding Figure

W4-2-14

EX255-EX285

CYLINDERS DISASSEMBLE CYLINDERS Boom Cylinder

11

1 2 3 4

7

5

6 9 10

8 13 20

15

16

21 23

14 19 16 17 18 20 19

22

12

SM1350A

24

Bucket Cylinder 11

1 2 3 4

7

5

6 9 10

8 13 20

15

16 20 21

22 12

19 16 17 18 19

24

23 SM1351

1 2 3 4 5 6

-

Wiper Ring Backup Ring U-Ring Buffer Ring Bushing Snap Ring

7 8 9 10 11 12

-

Cylinder Head Socket Bolt (12 Used) Backup Ring O-Ring Cylinder Rod Cylinder Tube

13 14 15 16 17 18

-

Cushion Bearing Cushion Seal Piston Backup Ring (2 Used) Seal Ring O-Ring

19 20 21 22 23 24

-

Slide Ring (2 Used) Slide Ring (2 Used) Shim Set Screw Steel Ball Nut

EX255-EX285

W4-2-15

CYLINDERS Disassemble Boom and Bucket Cylinders Be sure to thoroughly read all the “Precautions for Disassembly and Assembly” on page W1-1-1 before starting the disassembly procedure. The disassembly procedure below starts on the premise that the hydraulic lines and the line securing bands have been removed.

WARNING Boom cylinder: EX255: 203 kg (448 lb) EX285: 233 kg (514 lb) Bucket cylinder: EX255: 172 kg (379 lb) EX285: 209 kg (461 lb)

4. Pull-out cylinder rod (11) and secure it on special tool (75298623). Put matching marks between cylinder rod (11) and nut (24).

75298623

SM1365

5. Remove set screw (22) and steel ball (23). NOTE - Cut away its mushroomed portion using a drill first, as set screw (22) was mushroomed with a punch and hammer at two places after it had been screwed in.

1. Lift and securely place the cylinder on a workbench using a crane. Be sure that the cylinder is placed horizontally. Drain hydraulic oil from the cylinder.

: 6 mm

6. Loosen nut (24) using special tool (75298623). Remove shim (21), piston (15) and cushion bearing (13). For the boom cylinder, also remove and cushion seal (14).

SM1364

2. Fully extend cylinder rod (11). Secure the rod end using a crane. Remove socket bolts (8) from cylinder head (7).

Nut (24) turning special tool: EX255 - (bucket and boom cylinders): 95 mm (75294752) EX285 - (bucket and boom cylinders): 100 mm (75297716)

: 14 mm 3. Pull out cylinder head (7) from cylinder tube (12) by tapping with a plastic hammer.

IMPORTANT - Be sure to pull cylinder rod (11) straight so as not to damage the sliding surfaces.

SM1366

7. Remove slide rings (19), (20), backup rings (16), seal ring (17) and O-ring (18) from piston (15).

8. Remove cylinder head (7) from cylinder rod (11).

9. Remove O-rings (10), backup rings (9) and (2) from cylinder head (7). Then remove wiper ring (1), Uring (3), buffer ring (4), snap ring (6), and bushing (5).

W4-2-16

EX255-EX285

CYLINDERS Arm Cylinder

11

1 2 3 4

7

5

6 9 10

8 13 20

14 19 16

1 2 3 4 5 6 7 8 9 10

-

15

16

25 26

28 24 22

12

17 18 20 19 27 21 23

Wiper Ring Backup Ring U-Ring Buffer Ring Bushing Snap Ring Cylinder Head Socket Bolt (12 Used) Backup Ring O-Ring

11 12 13 14 15 16 17 18 19 20

-

Cylinder Rod Cylinder Tube Cushion Bearing (front) Cushion Seal (front) Piston Backup Ring (2 Used) Seal Ring O-Ring Slide Ring (2 Used) Slide Ring (2 Used)

SM1352

21 22 23 24 25 26 27

-

Shim Set Screw Steel Ball Nut Snap Ring Cushion Seal (rear) Cushion Bearing (rear) 28 - Stopper (2 Used)

EX255-EX285

W4-2-17

CYLINDERS Disassemble Arm Cylinder Be sure to thoroughly read all the “Precautions for Disassembly and Dissembly” on page W1-1-1 before starting the disassembly procedure. The disassembly procedure below starts on the premise that the hydraulic lines and the line securing bands have been removed.

WARNING

5. Remove set screw (22) and steel ball (23).

NOTE - Cut away its mushroomed portion using a drill first, as set screw (22) was mushroomed with a punch and hammer at two places after it had been screwed in.

: 6 mm

Arm cylinder weight: EX255: 300 kg (661 lb) EX285: 310 kg (683 lb)

1. Place the cylinder horizontally on a workbench using a crane and secure it. Drain hydraulic oil from the cylinder.

6. Loosen nut (24) using special tool (75298623). Remove shim (21), piston (15), cushion bearing (13) and cushion seal (14). Nut (24) Turning Special Tool: - EX255: 100 mm (75297716) - EX285: 115 mm (75297549)

SM1366 SM1364

2. Fully extend cylinder rod (11). Secure the rod end using a crane. Remove socket bolts (8) from cylinder head (7).

7. Remove slide ring (19), (20), backup ring (16), seal ring (17) and O-ring (18) from piston (15).


: 17 mm 3. Pull out cylinder head (7) from cylinder tube (12) by tapping with a plastic hammer.


4. Pull out cylinder rod (11) and secure it on special tool (75298623). Put matching marks between cylinder rod (11) and nut (24).

75298623

SM1365


10.Remove stopper (28) from cylinder rod (11) using a screw driver. Remove cushion bearing (27), cushion seal (26), and snap ring (25).

W4-2-18

EX255-EX285

CYLINDERS Positioning Cylinder (triple articulation version)

11

1 2 3 4

7

5

6 9 10

8 20

15

16

21 23

19 16 17 18 20 19

22

12

24 SM5523

1 2 3 4 5 6 7 8

-

Wiper Ring Backup Ring U-Ring Buffer Ring Bushing Snap Ring Cylinder Head Socket Bolt (12 Used)

9 10 11 12 15 16 17 18

-

Backup Ring O-Ring Cylinder Rod Cylinder Tube Piston Backup Ring (2 Used) Seal Ring O-Ring

19 20 21 22 23 24

-


EX255-EX285

W4-2-19

CYLINDERS Disassemble Positioning Cylinder Be sure to thoroughly read all the “Precautions for Disassembly and Assembly” on page W1-1-1 before starting the disassembly procedure. The disassembly procedure below starts on the premise that the hydraulic lines and the line securing bands have been removed.

5. Remove set screw (22) and steel ball (23).

NOTE - Cut away its mushroomed portion using a drill first, as set screw (22) was mushroomed with a punch and hammer at two places after it had been screwed in. : 6 mm

WARNING Positioning cylinder weight: EX255-EX285: 242 kg (534 lb)

1. Place the cylinder horizontally on a workbench using a crane and secure it. Drain hydraulic oil from the cylinder.

6. Loosen nut (24) using special tool (75298623). Remove shim (21) and piston (15). Nut (24) Turning Special Tool: EX255-EX285: 120 mm (75298684)

SM1366

SM1364

2. Fully extend cylinder rod (11). Secure the rod end using a crane. Remove socket bolts (8) from cylinder head (7). : 17 mm 3. Pull out cylinder head (7) from cylinder tube (12) by tapping with a plastic hammer.


4. Pull out cylinder rod (11) and secure it on special tool (75298623). Put matching marks between cylinder rod (11) and nut (24).

75298623

SM1365

7. Remove slide ring (19), (20), backup ring (16), seal ring (17) and O-ring (18) from piston (15).



W4-2-20

EX255-EX285

CYLINDERS ASSEMBLE CYLINDERS Boom Cylinder Face the slit toward the piston

Slit

Green Black

1 2

18 11 12 13 14 15 16 17 19 20 21

3 4 5 6 7 8 9-10

22-23 24

SM1353

Be sure that oil groove faces the correct direction when assembling

Bucket Cylinder

Slit

Green

1 2

3 4 5 6 7 8 9-10

11 12 13

18 15 16 17 19 20 21 22-23 24


1 2 3 4 5 6 7 8 9

-

Wiper Ring Backup Ring U-Ring Buffer Ring Bushing Snap Ring Cylinder Head Socket Bolt (12 Used) Backup Ring

10 11 12 13 14 15 16 17 18

-

O-Ring Cylinder Rod Cylinder Tube Cushion Bearing Cushion Seal Piston Backup Ring (2 Used) Seal Ring O-Ring

SM5524

19 20 21 22 23 24

-


EX255-EX285

W4-2-21

CYLINDERS Assemble Bucket and Boom Cylinder 1. Install bushing (5) to cylinder head (7) using a press. Special tools for bushing (5) installation: EX255 - boom cylinder: Ø 90 mm (75301684) - bucket cylinder: Ø 85 mm (75301685) EX285 - boom cylinder: Ø 95 mm (75301654) - bucket cylinder: Ø 90 mm (75301646)

IMPORTANT - Be sure that the cushion seal slit faces toward the piston and that the cushion bearing oil groove faces the correct direction.

7. Install cushion bearing (13) to cylinder rod (11). (For boom cylinder only, install cushion seal (14).) Install piston (15) to cylinder rod (11). 8. Install shim (21) to cylinder rod (11). Tighten nut (24) using special tool (75298623).

IMPORTANT - Be sure that the rings are installed correctly. 2. Install U-ring (3), backup ring (2), snap ring (6), and buffer ring (4) to cylinder head (7).

75298623

3. Install wiper ring (1) to cylinder head (7) using a plastic hammer. Special tools for wiper ring installing: EX255 - boom cylinder: (75301665) - bucket cylinder: (75301534) EX285 - boom cylinder: (75301533) - bucket cylinder: (75301665) 4. Install O-rings (10) and backup ring (9) to cylinder head (7). 5. Install O-ring (18), backup ring (16) (2 used), seal ring (17), slide ring (19) (2 used), (20) (2 used) to piston (15). Special tools for seals assembly: EX255: bucket and boom cylinder (75301670) EX285: bucket and boom cylinder (75301659)

SM1365

Be sure to align the machine mark on the rod with that on the nut. Nut (24) Turning Special Tools: EX255: 95 mm (75294752) : 5 440 N m (555 kgf m, 4012 lbf ft) (boom cylinder) 8 150 N m (831 kgf m, 6011 lbf ft) (bucket cylinder) EX285: 100 mm (75297716) : 6 800 N m (693 kgf m, 5015 lbf ft) (boom cylinder) 10 200 N m (1040 kgf m, 7523 lbf ft) (bucket cylinder) 9. Align the holes on cylinder rod (11) and nut (24). Insert steel ball (23) into the hole, and tighten set screw (22) into the hole. Mushroom the head of set screw (22) at two places using a punch and hammer. : 6 mm

15 SM1367

6. Install cylinder head (7) to cylinder rod (11). Special tools: EX255 - boom cylinder (75301688) - bucket cylinder (75301689) EX285 - boom cylinder: (75301537) - bucket cylinder: (75301693)

: 56.9±10.7 N m (5.8±1.09 kgf m, 42±7,9 lbf ft) IMPORTANT - Be sure to align cylinder rod (11) with the center of cylinder tube (12) when inserting, in order to avoid damaging the rings. 10. Secure cylinder tube (12) horizontally using a work bench. Insert cylinder rod (11) into cylinder tube (12). 11. Install cylinder head (7) to cylinder tube (12). Tighten socket bolts (8). : 14 mm : 267 N m (27.2 kgf m, 197 lbf ft) (EX255) 367 N m (37.4 kgf m, 271 lbf ft) (EX285)

W4-2-22

EX255-EX285

CYLINDERS Arm Cylinder

Face the slit toward the piston

Slit

Green Black

1 2

3 4 5 6 7 8 9-10

18 11 12 13 14 15 16 17 19 20 21 22-23 24 25 26 27 28


SM5525

1 2 3 4 5 6 7 8 9 10

-

Wiper Ring Backup Ring U-Ring Buffer Ring Bushing Snap Ring Cylinder Head Socket Bolt Backup Ring O-Ring

11 12 13 14 15 16 17 18 19 20

- Cylinder Rod - Cylinder Tube - Cushion Bearing (front) - Cushion Seal (front) - Piston - Backup Ring - Seal Ring - O-Ring - Slide Ring - Slide Ring

21 22 23 24 25 26 27 28

-

Shim Set Screw Steel Ball Nut Snap Ring Cushion Seal (rear) Cushion Bearing (rear) Stopper

EX255-EX285

W4-2-23

CYLINDERS Assemble Arm Cylinder

8. Install shim (21) to cylinder rod (11). Tighten nut (24) using special tool (75298623).

1. Install bushing (5) to cylinder head (7) using a press. Special tools for bushing installation (5): EX255: Ø 100 mm (75301686) EX285: Ø 100 mm (75301651)

75298623

IMPORTANT - Be sure that the rings are installed correctly. 2. Install U-ring (3), backup ring (2), buffer ring (4), and snap ring (6) to cylinder head (7). 3. Install wiper ring (1) to cylinder head (7) using a plastic hammer. Special tools for wiper ring installation: EX255-EX285: (75301676) 4. Install O-rings (10) and backup ring (9) to cylinder head (7). 5. Install O -ring (18) buckup ring (16) (2 used), seal ring (17), slide ring (19) (2 used), (20) (2 used), to piston (15). Special tool for seals assembly: EX255: (75301659) EX285: (75301170)

SM1365

Be sure to align the machine mark on the rod with that on the nut. Nut Turning Special Tools (24): EX255: 100 mm (75297716) : 10 200 N m (1040 kgf m, 7523 lbf ft) EX285: 115 mm (75297549) : 13 500 N m (1375 kgf m, 9957 lbf ft) 9. Align the holes on cylinder rod (11) and nut (24). Insert steel ball (23) into the hole, and tighten set screw (22) into the hole. Mushroom the head of set screw (22) at two places using a punch and hammer. : 6 mm : 56.9±10.7 N m (5.8±1.09 kgf m, 42±7,9 lbf ft) IMPORTANT - Be sure that the cushion seal slit faces toward the piston and that the cushion bearing oil groove faces the correct direction.

15 SM1367

6. Install cylinder head (7) to cylinder rod (11). Special tools for cylinder head installation: EX255: (75301690) EX285: (75301692)

IMPORTANT - Be sure that the cushion seal slit faces toward the piston and that the cushion bearing oil groove faces the correct direction.

7. Install cushion seal (14) to cylinder rod (11). Install cushion bearing (13) and piston (15) to cylinder rod (11).

10. Install snap ring (25) and cushion seal (26) to cylinder rod (11). Install cushion bearing (27) and stopper (28) to cylinder rod (11). IMPORTANT - Be sure to keep cylinder rod (11) aligned with the center of cylinder tube (12) when inserting, in order to avoid damaging the rings. 11. Secure cylinder tube (12) horizontally using a vise. Insert cylinder rod (11) into cylinder tube (12). 12. Install cylinder head (7) to cylinder tube (12). Tighten socket bolts (8). EX255: : 14 mm : 367 N m (37.4 kgf m, 271 lbf ft) EX285: : 17 mm : 520 N m (53 kgf m, 384 lbf ft)

W4-2-24

EX255-EX285

CYLINDERS Positioning Cylinder (triple articulation version)

Green

Slit

Black

1 2

3 4 5 6 7 8 9-10

18 15 16 17 19 20 21

11 12

22-23 24

SM1368

1 2 3 4 5 6

-

Wiper Ring Backup Ring U-Ring Buffer Ring Bushing Snap Ring

7 8 9 10 11 12

-

Cylinder Head Socket Bolt Backup Ring O-Ring Cylinder Rod Cylinder Tube

15 16 17 18 19 20

-

Piston Backup Ring Seal Ring O-Ring Slide Ring Slide Ring

21 22 23 24

-

Shim Set Screw Steel Ball Nut

EX255-EX285

W4-2-25

CYLINDERS Assemble Positioning Cylinder (triple articulation version) 1. Install bushing (5) to cylinder head (7) using a press. Special tools for bushing installation (5): EX255-EX285: Ø 90 mm (75301646)

IMPORTANT- Be sure that the rings are installed correctly.

8. Install shim (21) to cylinder rod (11). Tighten nut (24) using special tool (75298623).

75298623

2. Install U-ring (3), backup ring (2), buffer ring (4), and snap ring (6) to cylinder head (7).

3. Install wiper ring (1) to cylinder head (7) using a plastic hammer. Special tools for wiper ring installation: EX255-EX285: (75301665)

SM1365

Be sure to align the machine mark on the rod with that on the nut. Nut Turning Special Tools (24): EX255-EX285: 110 mm (75298684) : 8 460 N m (863 kgf m, 6240 lbf ft)

4. Install O-rings (10) and backup ring (9) to cylinder head (7).

5. Install O -ring (18) buckup ring (16) (2 used), seal ring (17), slide ring (19) (2 used), (20) (2 used) to piston (15). Special tool for seals assembly: EX255-EX285: (75301170)

9. Align the holes on cylinder rod (11) and nut (24). Insert steel ball (23) into the hole, and tighten set screw (22) into the hole. Mushroom the head of set screw (22) at two places using a punch and hammer. : 6 mm : 56.9 ± 10.7 N m (5.8 ± 10.9 kgf m, 42±7,9 lbf ft)

IMPORTANT - Be sure to keep cylinder rod (11) aligned with the center of cylinder tube (12) when inserting, in order to avoid damaging the rings.

10.Secure cylinder tube (12) horizontally using a vise. Insert cylinder rod (11) into cylinder tube (12).

15 SM1367

6. Install cylinder head (7) to cylinder rod (11). Special tools for cylinder head installation: EX255-EX285: (75301536)

11.Install cylinder head (7) to cylinder tube (12). Tighten socket bolts (8). : 17 mm : 520 N m (53 kgf m, 384 lbf ft)

7. Install piston (15) to cylinder rod (11).

W4-2-26

EX255-EX285

CYLINDERS MAINTENANCE STANDARD Rod

EX255 Cylinders

Unit: mm (in) STANDARD (A)

Boom

90 ± 0.03

Arm

100 ± 0.03

Bucket

85 ± 0.03

Positioning (*)

90 ± 0.03

Remedy Replace or plate with chromium


EX285 Cylinders

Unit: mm (in) STANDARD (A)

Boom

95 ± 0.03

Arm

100 ± 0.03

Bucket

90 ± 0.03

Positioning (*)

90 ± 0.03


Remedy

Replace or plate with chromium

EX255-EX285 EX255

W4-2-27

CYLINDERS SPECIAL TOOLS (EX255) Piston nut socket wrench: 75294752 for boom cylinders and bucket cylinder (95 mm) 75297716 for arm cylinder (100 mm) 75298684 for positioning cylinder (110 mm) (triple articulation version) Use nut loosening/tightening workbench: 75298623 SM1366

Tools kit seals installation:

75301679 for boom cylinders and bucket cylinder 75301659 for arm cylinder 75301170 for positioning cylinder (triple articulation version)

SM1369

Wiper installation tool: 75301665 for boom cylinders 75301534 for bucket cylinder 75601676 for arm cylinder 75301665 for positioning cylinder (triple articulation version)

SM1370

Bushing installation tool: 75301684 for boom cylinders (Ø 90 mm) 75301685 for bucket cylinder (Ø 85 mm) 75601686 for arm cylinder (Ø 100 mm) 75301646 for positioning cylinder (Ø 90 mm) (triple articulation version) SM1371

Head installation tool: 75301688 for boom cylinders 75301689 for bucket cylinder 75301690 for arm cylinder 75301536 for positioning cylinder (triple articulation version)

SM1372

W4-2-28

EX255-EX285 EX285

CYLINDERS SPECIAL TOOLS (EX285)

Piston nut socket wrench: 75297716 for boom cylinders and bucket cylinder (100 mm) 75297549 for arm cylinder (115 mm) 75298684 for positioning cylinder (110 mm) (triple articulation version)

Use nut loosening/tightening workbench: 75298623

SM1366

Tools kit seals installation:

75301659 for boom cylinders and bucket cylinder 75301170 for arm cylinder 75301170 for positioning cylinder (triple articulation version)

SM1369

Wiper installation tool: 75301533 75301665 75301676 75301665

for boom cylinders for bucket cylinder for arm cylinder for positioning cylinder (triple articulation version) SM1370

Bushing installation tool: 75301654 75301646 75301651 75301646

for boom cylinders (Ø 95 mm) for bucket cylinder (Ø 90 mm) for arm cylinder (Ø 100 mm) for positioning cylinder (Ø 90 mm) (triple articulation version) SM1371

Wiper installation tool: 75301537 for boom cylinders 75301693 for bucket cylinder 75301692 for arm cylinder 75301536 for positioning cylinder (triple articulation version)

SM1372

SECTION 5

EX255-EX285

ENGINE AND ACCESSORY

CONTENTS Group 1 -

General Information

Group 4 -

General Repair instructions ................... W5-1-1

Engine Inspection and Repair

Notes on the Format of this Manual ....... W5-1-1

Cylinder Head ...................................... W5-4-1

External View ....................................... W5-1-5

Valve Guide ......................................... W5-4-2

Main Data and Specifications ................ W5-1-6

Valve .................................................. W5-4-3

Angular Nut and Bolt Tightening Method ............................................. W5-1-7

Valve seat insert .................................. W5-4-4

Torque Specifications ............................ W5-1-9

Tappet ................................................. W5-4-7

Standard Bolt Torque Specifications ..... W5-1-20

Rocket Arm Shaft and Rocker Arm ........ W5-4-8

Special Tools List ............................... W5-1-22

Push Rod ............................................ W5-4-9

Identifications .................................... W5-1-24

Idler Gear and Idler Gear Shaft .............. W5-4-9

Valve Spring ........................................ W5-4-6

Camshaft .......................................... W5-4-10 Cylinder Body and Liner ...................... W5-4-11 Piston and Piston Ring ....................... W5-4-15 Piston Pin ......................................... W5-4-16

Group 2 -

Maintenance

Connecting Rod ................................. W5-4-17

Lubricating System ............................... W5-2-1

Crankshaft ......................................... W5-4-19

Fuel System ........................................ W5-2-2

Flywheel and Flywheel Housing ........... W5-4-25

Cooling System .................................... W5-2-6

Timing Gear Case Cover ..................... W5-4-25

Valve Clearance Adjustment .................. W5-2-7 Injection Timing .................................... W5-2-8 Compression Pressure Measurement ... W5-2-12 Turbocharger Inspection ...................... W5-2-13 Engine Repair Kit ............................... W5-2-14 Recommended Lubricants ................... W5-2-15 Engine Oil Viscosity Chart .................. W5-2-15

Group 5 -

Engine Reassembly

Piston and Connecting Rod ................... W5-5-1 Cylinder Head ...................................... W5-5-3 Rocket Arm and Rocker Arm Shaft ........ W5-5-6 Major Components ............................... W5-5-7 External Parts .................................... W5-5-16 Engine Tuning Operation ..................... W5-5-22

Group 3 -

Engine Disassembly

External Parts ...................................... W5-3-1 Major Components ............................... W5-3-5

Group 6 -

Lubricating System

Rocker Arm and Rocker Arm Shaft ...... W5-3-10

General Description .............................. W5-6-1

Cylinder Head .................................... W5-3-11

Oil Pump ............................................. W5-6-2

Piston and Connecting Rod ................. W5-3-12

Oil Cooler ............................................ W5-6-4

SECTION 5

Group 7 -

Cooling System

EX255-EX285

Group 11 - Troubleshooting


Hard Starting ..................................... W5-11-1

Thermostat .......................................... W5-7-2

1) Starter Inoperative .......................... W5-11-1 2) Starter Operates but Engine Does not Turn Over .............. W5-11-2

Group 8 -

Fuel System

General Description .............................. W5-8-1 Injection Nozzle ................................... W5-8-2 Inuection Pump Calibration Data ............ W5-8-6

3) Engine Turns Over but Does not Start (Fuel is Being Delivered to the Injection Pump) ...... W5-11-3 4) Engine Turns Over but Does not Start (Fuel is not Being Delivered to the Injection Pump) ..................... W5-11-4 Unstable Low Idling ............................ W5-11-5 Insufficient Power ............................... W5-11-7

Group 9 -

Turbocharger

Overheating ..................................... W5-11-10


White Exhaust Smoke ...................... W5-11-12

Turbocharger Identification .................... W5-9-2

Dark Exhaust Smoke ........................ W5-11-13

Inspection and Repair ........................... W5-9-3

Oil Pressure Does not Rise ............... W5-11-14 Excessive Fuel Consumption ............ W5-11-16 Excessive Oil Consumption .............. W5-11-18 Abnormal Engine Noise ..................... W5-11-19

Group 10 -

Starting and Charging

Starter motor ..................................... W5-10-1 Alternator .......................................... W5-10-4

1) Engine Knocking .......................... W5-11-19 2) Gas Leakage Noise ...................... W5-11-20 3) Continuous Noise ......................... W5-11-21 4) Slapping Noise ............................. W5-11-22

Group 12 - Repair Standards General Rules .................................... W5-12-1

EX255-EX285

W5-1-1

GENERAL INFORMATION GENERAL REPAIR INSTRUCTIONS 1. Before performing any service operation with the engine mounted, disconnect the grounding cable from the battery. This will reduce the chance of cable damage and burning due to short circuiting. 2. Always use the proper tool or tools ISUZU for the job at hand. Where specified, use the specially designed tool or tools. 3. Use genuine parts referring FIAT KOBELCO PARTS CATALOG. 4. Never reuse cotter pins, gaskets, O-rings, lock washers, and self locking nuts. Discard them as you remove them. Replace them with new ones. 5. Always keep disassembled parts neatly in groups. This will ensure a smooth reassembly operation. It is especially important to keep fastening parts separate. These parts vary in hardness and design, depending on their installation position. 6. All parts should be carefully cleaned before inspection or reassembly. Oil ports and other openings should be cleaned with compressed air to make sure that they are completely free of obstructions. 7. Rotating and sliding part surfaces should be lubricated with oil or grease before reassembly. 8. If necessary, use a sealer on gaskets to prevent leakage. 9. Nut and bolt torque specifications should be carefully followed. 10. Always release the air pressure from any machine-mounted air tank(s) before dismounting the engine or disconnecting pipes and hoses. To not do so is extremely dangerous. 11. Always check and recheck you work. No service operation is complete until you have done this. 12. Information contained in the "Main Data and Specifications" of the Workshop Manual and the Operation and Maintenance Instruction Manual may differ. In this case, the information contained in the Operation and Maintenance Instruction Manual should be considered applicable.

NOTES ON THE FORMAT OF THIS MANUAL This Workshop Manual is applicable to the 6BG1 and 6BG1T family of industrial diesel engines. Unless otherwise specified, these engines have common parts and components as well as data and specifications. Illustrations used in this Workshop Manual are based on the AA-6BG1 and BB-6BG1T engines. The BB-6BG1T engine is turbocharged with intercooler. 1. Find the applicable section by referring to the Table of Contents at the beginning of the Manual. 2. Common technical data such as general maintenance items, service specifications and tightening torques are included in the “General Information” section. 3. Each section is divided into sub-sections dealing with disassembly, inspection and repair, and reassembly. The section ENGINE ASSEMBLY is an exception. This part is divided into three sections to facilitates quick indexing. 4. When the same servicing operation is applicable to several different units, the manual will direct you to the appropriate page. 5. For the sake of brevity, self-explanatory removal and installation procedures are omitted. More complex procedures are covered in detail.

W5-1-2

EX255-EX285

GENERAL INFORMATION 6. Each service operation section in this Workshop Manual begins with an exploded view of the applicable area. A brief explanation of the notation used follows.

Parts marked with an asterisk (*) are included in the repair kit. Parts within a square frame are to be removed and installed as a single unit. All parts within an irregularly shaped frame form a single assembly. They are considered a "major component". Individual parts within the irregularly shaped frame are considered "minor components". The number tells you the service operation sequence. Removal of unnumbered parts is unnecessary unless replacement is required. The "*Repair Kit" indicates that a repair kit is available. Disassembly Steps - 2 1. Water by- hose 2. Thermostat housing 3. Water pump ▲ 4. Injection nozzle holder 5. Glow plug and glow plug connector 6. Cylinder head cover ▲ 7. Rocker arm shaft and rocker arm 8. Push rod ▲ 9. Cylinder head 10. Cylinder head gasket

▲ 11. Crankshaft damper pulley with dust seal 12. Timing gear case cover (Option) 13. Timing gear cover 14. Timing gear oil pipe 15. Idler gear ‘B’ and shaft 16. Idler gear “A” 17. Idler gear shaft

The parts listed under "Reassembly Steps" or "Installation Steps" are in the service operation sequence.

Inverted Engine

SM7400

The removal or installation of parts marked with a triangle (▲) is an important operation. Detailed information is given in the text.

EX255-EX285

W5-1-3

GENERAL INFORMATION 7.

Below is a sample of the text of the Workshop Manual.

This is the item shown in the illustration. It is marked with a triangle (▲) on the Major Components page.

Valve Guide Installation 1. Lubricate the valve guide outer face with engine oil. 2. Attach the installer to the valve guide. 3. Use a hammer to drive the valve guide into position from the cylinder head upper face. Valve Guide Installer: 1-85220-001-0 4. Measure the height of the valve guideuide upper end from the upper face of the cylinder head. Valve Guide Upper End Height (H)

Special tools are identified by the tool name and/or number. The illustration shows how the special tool is to be used.

14.1 (0.56)

Note: If the valve guide has en removed, both the Iva and the valve guide must be placed with new on as a set. Be absolutely sure to discard the used valves and valve guides.

Letters and numbers contained in a circle refer to the illustration.

SM7401

Symbols indicate the type of service operation or step to be performed. A detailed explanation of these symbols follows. Service data and specifications are given in this table.

8.

The following symbols appear throughout this Workshop Manual. They tell you the type of service operation or step to perform.

Removal

Adjustment

Installation

Cleaning

Disassembly

Important Operation Requiring Extra Care

Reassembly

Specified Torque (Tighten)

Alignment (Marks)

Special Tool Use Required or Recommended (Isuzu Tool or Tools)

Directional Indication

Commercially Available Tool Use Required or Recommended

Inspection Lubrication (Oil) Measurement

Sealant Application

Lubrication (Grease)

W5-1-4

EX255-EX285

GENERAL INFORMATION 9. Measurement criteria are defined by the “Standard” and “Limit”. A measurement falling within the “Standard” range indicates that the applicable part or parts are serviceable. “Limit” should be thought of as an absolute value. A measurement which is outside the “Limit” indicates that the applicable part or parts must be either repaired or replaced. 10. Components and parts are listed in the singular from throughout the Manual. 11. Directions used in this Manual are as follows: Front The cooling fan side of the engine viewed from the flywheel. Right The injection pump side of the engine. Left The exhaust manifold side of the engine. Rear The flywheel side of the engine. Cylinder numbers are counted from the front of the engine. The front most cylinder is No. 1 and rear most cylinder is No. 6. The engine’s direction of rotation is counterclockwise viewed from the flywheel. Right

Inj. pump

Rear

Front

Left

SM7402

12. Maintenance procedure call for use of Special or Commercial Tools, where necessary. The Special Tools required or recommended are identified by an ISUZU Part Number. Any Special Tools are available in Europe making a purchase order to the following: IED MAESA BOOMSESTENWEG 42B 2630 AARTSELAAR BELGIUM

EX255-EX285

W5-1-5

GENERAL INFORMATION EXTERNAL VIEW Turbocharger Oil filler cap

Turbocharger

Dipstick

Nozzle holder Air breather

Injection pump

Flywheel housing

Main oil filter Partial oil filter

Alternator Crank pulley Starter motor

Flywheel

Oil filler cap Fuel filter Nozzle holder

Fan pulley

Cooling fan

Fuel filter

Water pump

Water drain plug

Alternator pulley Injection pump Oil pan Flywheel housing

Oil pan

Main oil filter Partial oil filter Turbocharger

Partial oil filter

Crank pulley

Exhaust manifold Alternator

Oil drain plug

Flywheel housing

Cylinder head cover

Nozzle holder

NOTE: Engine details may vary depending on the specifications. Glow plug

Inlet manifold Air duct

SM7403

Oil filler cap

W5-1-6

EX255-EX285

GENERAL INFORMATION MAIN DATA AND SPECIFICATIONS ENGINE MODEL ITEM Engine type Combustion chamber type Cylinder liner type No. of cylinders - bore x stroke mm (in) Total piston displacement cm3 (cid) Compression ratio * Engine dimensions mm Length x width x height (in) * Engine weight (Dry) kg (Ib) Fuel injection order Specified fuel Injection pump * Governor Injection nozzle Injection starting pressure MPa (kgf/cm2/psi) Fuel filter type Water sedimentor Compression pressure MPa (kgf/cm2/psi) (At warm) Valve clearances (At cold) Intake mm (in) Exhaust mm (in) Lubrication method Oil pump Main oil filter type * Lubricating oil volume L (US gal) Oil cooler Cooling method Coolant volume (engine only) L (US gal) Water pump Thermostat type * Generator V-A * Starter V-kW * Turbocharger manufacturer * Turbocharger model

CC-6BG1T Water cooled, four cycle, vertical in-line overhead valve Direct injection Dry 6 - 105.0 x 125.0 (4.13 x 4.92) 6,494 (396) 18.0 to 1 1204 x 762 x 961 (47.4 x 30.0 x 37.8) 484 (1067) 1-5-3-6-2-4 Diesel fuel (ASTM D975 No. 2D) In-line plunger, Bosch AD type Mechanical, RSV type Multi hole 18.1 (185/2,630) Cartridge (spin-on) Sedimenter/water level indicating type 3.0 (31/441) at 200 min-1, at sea level 0.40 (0.016) 0.40 (0.016) Pressurized circulation Gear type Cartridge (spin-on) 21.5 (5.68) Water cooled integral type Pressurized forced circulation 12 (3.2) Belt driven impeller type Wax pellet type 24-40 24-4.5 IHI RHG6

NOTE: 1. These specifications are based on the standard engine. 2. Specifications for items marked with an asterisk (*) will vary according to the type of equipment on which the engine is installed. If you are unable to locate the data applicable to these specifications, please Isuzu Motors LTD through your FIAT KOBELCO Dealer.

EX255-EX285

W5-1-7

GENERAL INFORMATION ANGULAR NUT AND BOLT TIGHTENING METHOD 1. Carefully wash the nuts and bolts to remove all oil and grease.

2. Apply a coat of molybdenum disulfide grease to the threads and setting faces of the nuts and bolts. m nu d e ide b y lf o l u se M d i s rea g

SM7404

3. Tighten the nuts and bolts to the specified torque (snug torque) with a torque wrench. NUT OR BOLT

Snug torque

SM7405

4. Draw a line (A-B) across the center of each bolt.

Center line

SM7406

W5-1-8

EX255-EX285

GENERAL INFORMATION 5. Draw another line (C-D) on the face of each of the parts to be clamped. This line should be an extension of the line (A-B). Line

SM7407

6. Draw another line (F-G) on the face of each of the parts to be clamped. This line will be in the direction of the specified angle (Q) across the center (E) of the nut or bolt.

Specified angle (Q)

Coinciding line

SM7408

7. Use a socket wrench to tighten each nut or bolt to the point where the line (A-B) is aligned with the line (F-G). Tighten

SM7409

Example: Specified Angle and Tightening Rotation

A

30°

1/12 of a turn

B

60°

1/6 of a turn

C

90°

1/4 of a turn

D

180°

1 /2 of a torn

E

360°

One full turn

SM7410

EX255-EX285

W5-1-9

GENERAL INFORMATION TORQUE SPECIFICATIONS Cylinder Head and Cover N•m (kgf•m/lb.ft)

7.8–9.8 (0.8–1.0/5.8–7.2)

69→ → 88 →90°–120° →(9.0/65) (7.0/5.1)→

42–62 (4.3–6.3/31–46)

Apply MoS2 grease

20–25 (2.0–2.5/14–18) Glow plug

42–62 (4.3–6.3/31–46)

SM7411

MoS2..........Molybdenum disulfide paste.

W5-1-10

EX255-EX285

GENERAL INFORMATION Cylinder Body N•m (kgf•m/lb.ft)

42–62 (4.3–6.3/31–46)

21–30 (2.1–3.1/15–22)

21–30 (2.1–3.1/15–22) 21–30 (2.1–3.1/15–22)

226–245 (23–25/166–181) Apply engine oil 16–25 (1.6–2.6/12–19)

SM7412

EX255-EX285

W5-1-11

GENERAL INFORMATION Oil Pan and Dipstick N•m (kgf•m/lb.ft)

25–30 (2.6–3.1/19–22)

21–30 (2.1–3.1/15–22)

69–88 (7–9/51–65)

SM7413

W5-1-12

EX255-EX285

GENERAL INFORMATION Camshaft and Rocker Arm N•m (kgf•m/lb.ft)

25–35 (2.6–3.6/19–26) 25–35 (2.6–3.6/19–26)

21–30 (2.1–3.1/15–22)

21–30 (2.1–3.1/15–22)

142–172 (14.5–17.5/105–127) Lubricate with engine oil

44–64 (4.5–6.5/33–47)

SM7414

EX255-EX285

W5-1-13

GENERAL INFORMATION Crankshaft, Piston, and Flywheel N•m (kgf•m/lb.ft)

Apply MoS2 grease

197–240 (20.1–24.5/145–177) Apply MoS2 grease

Apply engine oil

SM7415

W5-1-14

EX255-EX285

GENERAL INFORMATION Thermostat and Thermostat Housing N•m (kgf•m/lb.ft)

21–30 (2.1–3.1/15–22)

42–62 (4.3–6.3/31–46)

42–62 (4.3–6.3/31–46)

SM7416

EX255-EX285

W5-1-15

GENERAL INFORMATION Thermostat and Thermostat Housing N•m (kgf•m/lb.ft)

21–30 (2.1–3.1/15–22)

42–62 (4.3–6.3/31–46)

21–30 (2.1–3.1/15–22)

25–31 (2.6–3.2/19–23)

SM7417

W5-1-16

EX255-EX285

GENERAL INFORMATION Timing Gear Case and Flywheel Housing N•m (kgf•m/lb.ft)

21–30 (2.1–3.1/15–22)

147-167 (15-17/108-123) 21–30 (2.1–3.1/15–22)

Outer side

147-167 (15-17/108-123)

21–30 (2.1–3.1/15–22) Inner side

SM7418

EX255-EX285

W5-1-17

GENERAL INFORMATION Oil Cooler, Oil Filter, and Oil Pump N•m (kgf•m/lb.ft)

Refer to the section MAINTENANCE

42–62 (4.3–6.3/31–46)

42–62 (4.3–6.3/31–46)

21–30 (2.1–3.1/15–22)

14–24 (1.4–2.4/10–17)

SM7419

W5-1-18

EX255-EX285

GENERAL INFORMATION Fuel System N•m (kgf•m/lb.ft)

16–18 (1.6–1.8/12–13) 33–49 (3.4–5.0/25–36) 17–21 (1.7–2.1/12–15)

33–49 (3.4–5.0/25–36)

42–62 (4.3–6.3/31–46)

16–18 (1.6–1.8/12–13)

16–18 (1.6–1.8/12–13)

28–32 (2.9–3.3/21–24)

16–18 (1.6–1.8/12–13)

21–30 (2.1–3.1/15–22) 3.9–7.8 (0.4–0.8/2.9–5.8)

SM7420

EX255-EX285

W5-1-19

GENERAL INFORMATION Turbocharger N•m (kgf•m/lb.ft)

16–25 (1.6–2.6/12–19)

42–62 (4.3–6.3/31–46)

28–46 (2.9–4.7/21–34)

16–25 (1.6–2.6/12–19)

SM7421

W5-1-20

EX255-EX285

GENERAL INFORMATION STANDARD TORQUE SPECIFICATION The tightening torque values given in the tables below are applicable to the bolts unless otherwise specified. Standard Bolt

N•m (kgf•m/Ib.ft)

Bolt Identification Bolt Diameter x pitch (mm) M 6 x 1.0

3.9-7.8 (0.4-0.8/2.9-5.8)

4.9-9.8 (0.5-1.0/3.6-7.2)

——————-

M 8 x 1.25

7.8-17.7 (0.8-1.8/5.8-13.0)

11.8-22.6 (1.2-2.3/8.7-16.6)

16.7-30.4 (1.7-3.1/12.3-22.4)

M10 x 1.25

20.6-34.3 (2.1-3.5/5.2-25.3)

27.5-46.1 (2.8-4.7/20.3-33.4)

37.3-62.8 (3.8-6.4/27.5-46.3)

* M10 x 1.5

19.6-33.4 (2.0-3.4/14.5-24.6)

27.5-45.1 (2.8-4.6/20.3-33.3)

36.3-59.8 (3.7-6.1/26.8-44.1)

M12 x 1.25

49.1-73.6 (5.0-7.5/36.2-54.2)

60.8-91.2 (6.2-9.3/44.8-67.3)

75.5-114.0 (7.7-11.6/55.7-83.9)

* M12 x 1.75

45.1-68.7 (4.6-7.0/33.3-50.6)

56.9-84.4 (5.8-8.6/42.0-62.2)

71.6-107.0 (7.3-10.9/52.8-78.8)

M14 x 1.5

76.5-115.0 (7.811.7/56.4-84.6)

93.2-139.0 (9.5-14.2/68.7-103.0)

114.0-171.0 (11.6-17.4/83.9-126.0)

* M14 x 2.0

71.6-107.0 (7.3-10.9/52.8-78.8)

88.3-131.0 (9.0-13.4/65.1-96.9)

107.0-160.0 (10.9-16.3/78.8-118.0)

M16 x 1.5

104.0-157.0 (10.6-16.0/76.7-115.7)

135.0-204.0 (13.8-20.8/99.8-150.0)

160.0-240.0 (16.3-24.5/118.0-177.0)

* M16 x 2.0

100.0-149.0 (10.2-15.2/73.8-110.0)

129.0-194.0 (13.2-19.8/95.5-143.0)

153.0-230.0 (15.6-23.4/113.0-169.0)

M18 x 1.5

151.0-226.0 (15.4-23.0/111.0-166.0)

195.0-293.0 (19.9-29.9/144.0-216.0)

230.0-345.0 (23.4-35.2/169.0-255.0)

* M18 x 2.5

151.0-226.0 (15.4-23.0/111.0-166.0)

196.0-294.0 (20.0-30.0/145.0-217.0)

231.0-346.0 (23.6-35.3/171.0-255.0)

M20 x 1.5

206.0-310.0 (21.0-31.6/152.0-229.0)

270.0-405.0 (27.5-41.3/199.0-299.0)

317.0-476.0 (32.3-48.5/234.0-351.0)

* M20 x 2.5

190.0-286.0 (19.4-29.2/140.0-211.0)

249.0-375.0 (25.4-38.2/184.0-276.0)

293.0-440.0 (29.9-44.9/216.0-325.0)

M22 x 1.5

251.0-414.0 (25.6-42.2/185.0-305.0)

363.0-544.0 (37.0-55.5/268.0-401.0)

425.0-637.0 (43.3-64.9/313.0-469.0)

* M22 x 2.5

218.0-328.0 (22.2-33.4/161.0-242.0)

338.0-507.0 (34.5-51.7/250.0-374.0)

394.0-592.0 (40.2-60.4/291.0-437.0)

M24 x 2.0

359.0-540.0 (36.6-55.0/265.0-398.0)

431.0-711.0 (43.9-72.5/318.0-524.0)

554.0-831.0 (56.5-84.7/409.0-613.0)

* M24 x 3.0

338.0-507.0 (34.5-51.7/250.0-374.0)

406.0-608.0 (41.4-62.0/299.0-448.0)

521.0-782.0 (53.1-79.7/384.0-576.0)

An asterisk (*) indicates that the bolts are used for female threaded parts that are made of soft materials such as casting.

EX255-EX285

W5-1-21

GENERAL INFORMATION Flanged head bolt

N•m (kgf•m/Ib.ft)

Bolt Identification Bolt Diameter x pitch (mm) M 6 x 1.0

4.6-8.5 (0.5-0.9/3.6-6.5)

6.6-12.2 (0.6-1.2/4.3-8.7)

-------------------

M 8 x 1.25

10.5-19.6 (1.1-2.0/8.0-14.5)

15.3-28.4 (1.6-2.9/11.6-21.0)

18.1-33.6 (2.1-3.4/15.2-25.0)

M10 x 1.25

23.1-38.5 (2.4-3.9/17.4-28.2)

35.4-58.9 (3.6-6.1/26.0-44.1)

42.3-70.5 (4.3-7.2/31.1-52.1)

* M10 x 1.5

22.3-37.2 (2.3-3.8/16.6-27.5)

34.5-57.5 (3.5-5.8/25.3-42.0)

40.1-66.9 (4.1-6.8/29.7-49.2)

M12 x 1.25

54.9-82.3 (5.6-8.4/40.1-60.8)

77.7-117.0 (7.9-11.9/57.1-86.1)

85.0-128.0 (8.7-13.0/62.9-94.0)

* M12 x 1.75

51.0-76.5 (5.2-7.8/37.6-56.4)

71.4-107.0 (7.3-10.9/52.8-78.8)

79.5-119.0 (8.1-12.2/58.6-88.2)

M14 x 1.5

83.0-125.0 (8.5-12.7/61.5-91.9)

115.0-172.0 (11.7-17.6/84.6-127.0)

123.0-185.0 (12.6-18.9/91.1-137.0)

* M14 x 2.0

77.2-116.0 (7.9-11.8/57.1-85.3)

108.0-162.0 (11.1-16.6/80.3-120.0)

116.0-173.0 (11.8-17.7/85.3-128.0)

116.0-173.0 (11.8-17.7/85.3-128)

171.0-257.0 (17.4-26.2/126.0-190.0)

177.0-265.0 (18.0-27.1/130.0-196.0)

109.0-164.0 (11.2-16.7/81.0-121.0)

163.0-244.0 (16.6-24.9/120.0-180.0)

169.0-253.0 (17.2-25.8/124.0-187.0)

M16 x 1.5 * M16 x 2.0

A bolt with an asterisk (*) is used for female screws of soft material such as cast iron.

W5-1-22

EX255-EX285

GENERAL INFORMATION SPECIAL TOOL LIST

ITEM NO.

ILLUSTRATION

PART NO.

PARTS NAME

PAGE

1.

5-85317-001-0

Compression gauge adaptor

W5-2-12

2.

1-85111-003-0

Cylinder head bolt wrench

W5-3-6

3.

9-8521-0122-0

Crankshaft taper bushing remover

W5-3-7

4.

5-8840-2360-0

Rear oil seal remover

W5-3-7

5.

1-85235-006-0

Valve spring compressor

W5-3-11 W5-5-4

6.

1-85232-001-0 9-85220-035-0

Valve guide remover and installer

W5-4-2

7.

9-8523-1818-0

Camshaft bearing remover and installer

W5-4-10

8.

9-8523-1169-0

Cylinder liner remover

W5-4-11

9.

5-8523-1004-0

Cylinder liner remover ankle

W5-4-11

10.

5-8522-1018-0

Cylinder liner installer

W5-4-13

EX255-EX285

W5-1-23

GENERAL INFORMATION

ITEM NO.

ILLUSTRATION

PART NO.

PARTS NAME

PAGE

11.

9-8523-1369-0

Connecting rod bushing installer

W5-4-18

12.

9-8521-0141-0

Crankshaft gear remover

W5-4-24

13.

9-8522-0033-0

Crankshaft gear installer

W5-4-24

14.

9-8522-0034-0

Crankshaft front oil seal installer

W5-4-25

15.

1-85221-005-0

Valve stem oil seal installer

W5-5-4

16.

9-8522-1251-0

Piston ring compressor

W5-5-10

17.

5-8840-9025-0

Rear oil seal installer

W5-5-11

W5-1-24

EX255-EX285

GENERAL INFORMATION IDENTIFICATIONS Engine Serial Number The engine number is stamped on the front left hand side of the cylinder body.

Engine serial number SM7422

Injection Pump Number Injection volume should be adjusted after referring to the adjustment data applicable to the injection pump installed. The injection pump identification number (A) is stamped on the injection pump identification plate. NOTE: Always check the identification number before beginning a service operation. Applicable service data will vary according to the Identification number. Use of the wrong service data will result in reduced engine performance and engine damage.

Pump No. NP-PE (LICENCE BOSCH) Identification number

SM7423

EX255-EX285

W5-2-1

MAINTENANCE LUBRICATING SYSTEM Main Oil Filter Replacement Cartridge (Spin-On) Type

REMOVAL Removal and Installer: Filter Wrench 1. Loosen the used oil filter by turning it counterclockwise with the filter wrench. 2. Discard the used oil filter. INSTALLATION 1. Wipe the oil filter mounting face with a clean rag. This will allow the new oil filter to seat properly. 2. Lightly oil the O-ring. 3. Turn in the new oil filter until the sealing face is fitted against the O-ring. 4. Use the filter wrench to turn in the oil filter an additional 3/4 of a turn or one turn. 5. Check the engine oil level and replenish to the specified level if required. 6. Start the engine and check for oil leakage from the oil filter.

Main oil filter

Partial filter SM7424

W5-2-2

EX255-EX285

MAINTENANCE FUEL SYSTEM Fuel Filter Replacement Cartridge (Spin-On) Type

REMOVAL 1. Loosen the fuel filter by turning it counterclockwise with the filter wrench or your hand. Discard the used filter. 2. Wipe the fuel filter fitting face clean with a rag. This will allow the new fuel filter to seat properly.

SM7425

INSTALLATION 1. Apply a light coat of engine oil to the O-ring. 2. Supply fuel to the new fuel filter. This will facilitate air bleeding. 3. Turn in the new fuel filter until the filter O-ring is fitted against the sealing face. 4. Use the filter wrench to turn in the fuel filter an additional 2/3 of a turn. Overflow Valve Check the overflow valve for clogging. Check the ball side for suction leakage. kPa (kgf/cm2/psi) Overflow Valve Opening Pressure (Reference)

147 (1.5/21)

SM7426

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W5-2-3

MAINTENANCE Injection Nozzle INSPECTION PROCEDURE 1. Clamp the injection nozzle holder in a vise. 2. Use a wrench to remove the injection nozzle holder cap. 3. Remove the injection nozzle holder from the vise.

SM7427

ADJUSTING PROCEDURE Injection Starting Pressure Check 1. Attach the injection nozzle holder to the injection nozzle tester. 2. Loosen the adjusting screw (1). 3. Check the injection nozzle starting pressure and the spray condition by operating the injection nozzle tester. 4. Adjust the injection nozzle starting pressure. Turn the adjusting screw clockwise while operating the injection nozzle tester handle.

SM7428

SM7429

MPa (kgf/cm2/psi) Injection Starting Pressure

18.1 (185/2630)

WARNING TEST FLUID FROM THE NOZZLE TESTER WILL SPRAY OUT UNDER GREAT PRESSURE. IT CAN EASILY PUNCTURE A PERSON’S SKIN. KEEP YOUR HANDS AWAY FROM THE NOZZLE TESTER AT ALL TIMES.

SM7430

W5-2-4

EX255-EX285

MAINTENANCE Spray Condition Check (During Injection Nozzle Tester Operation) 1. Tighten the cap nut. 2. Check the injection nozzle starting pressure. 3. Check the injection nozzle spray condition. Operate the injection nozzle tester hand lever 4 to 6 times a second while looking for abnormal injection nozzle spray conditions. Refer to the illustration for different spray conditions (1) Good (2) Bad (Restrictions in orifice) (3) Bad (Dripping)

SM7431

Feed Pump Strainer 1. Remove the t bolt. 2. Use a screwdriver to remove the strainer. 3. Wash the strainer in clean diesel fuel.

SM7432

Strainer

SM7433

EX255-EX285

W5-2-5

MAINTENANCE Water Separator (Water Sedimentor) Check the water separator float (1) level. If the float (1) has reached level (2), loosen the drain plug (3) (at the bottom side of the water separator) to drain the water. N•m (kgf•m/ft.lb) Drain Plug Torque

9-15 (0.9-1.5/7-11)

SM7434

Air Bleeding 1. Loosen the feed pump cap (1) on the injection pump. 2. Loosen the fuel filter fuel return eye bolt (2). 3. Operate the feed pump until there are no more bubbles visible in the fuel being discharged from the fuel filter fuel return eye bolt. 4. Retighten the fuel filter fuel return eye bolt. 5. Operate the feed pump several times and check for fuel leakage around the injection pump and the fuel filter.

SM7435

SM7436

W5-2-6

EX255-EX285

MAINTENANCE COOLING SYSTEM Cooling Fan Drive Belt

Depress here 98N (10kgf/22lb)

ADJUSTMENT 1. Check the cooling fan drive belt for cracking and other damage. 2. Check the drive belt tension by exerting a force of 98N (10kgf/22lb) midway between the fan pulley (2) and the alternator (3). 3. Adjust the belt tension by loosening the alternator mounting bolt and the alternator adjusting bolt and pivoting the alternator. Be sure to retighten the bolts after adjusting the belt tension.

Deflection

SM7437

mm (in) Cooling Fan Drive Belt Deflection

7.0-10.0 (0.28-0.39)

Thermostat INSPECTION Visually inspect the thermostat. Replace the thermostat if excessive wear or damage is discovered during inspection. Measure the valve lift.

Thremometer Agitating rod

mm (in) Amount of Valve Lift at 95 °C (203 °F)

10.0 (0.39)

Wood piece

°C(°F) Valve Opening Temperature

80-84 (176-183)

SM7438

EX255-EX285

W5-2-7

MAINTENANCE VALVE CLEARANCE ADJUSTMENT NOTE: The cylinder head bolts were previously tightened with the “Angular Tightening Method”. Therefore, it is not necessary to retighten the cylinder head bolts before adjusting the valve clearance. 1. Bring the piston in either the No. 1 cylinder or the No. 6 cylinder to Top Dead Center on the compression stroke by turning the crankshaft until the TDC notched line on the crankshaft pulley is aligned with the timing pointer. 2. Check to see if there is play in the No. 1 intake and exhaust valve rocker arms. If the No. 1 cylinder intake and exhaust valve rocker arms have play, the No. 1 piston is at TDC on the compression stroke. If the No. 1 cylinder intake and exhaust valve rocker arms are depressed, the No. 6 piston is at TDC on the compression stroke.

SM7439

SM7440

Adjust the No. 1 or the No. 6 cylinder valve clearances while their respective cylinders are at TDC on the compression stroke. mm (in) Intake and Exhaust Valve Clearance (cold)

0.40 (0.016)

3. Loosen each valve clearance adjusting screw as shown in the illustration. 4. Insert a 0.40 mm (0.016 in) feeler gauge between the rocker arm and the valve stem end. 5. Turn the valve clearance adjusting screw until a slight drag can be felt on the feeler gauge. 6. Tighten the lock nut securely. 7. Rotate the crankshaft 360°. Realign the crankshaft pulley TDC notched line with the timing pointer. 8. Adjust the clearances for the remaining valves as shown in the illustration. N•m (kgf•m/ft.lb) Rocker Arm Screw Lock Nut Torque

SM7439

Front

When No. 1 cylinder at TDC in compression stroke

SM7441

Front

21-30 (2.1-3.1/15-22)

When No. 6 cylinder at TDC in compression stroke

SM7442

W5-2-8

EX255-EX285

MAINTENANCE INJECTION TIMING NOTE: Take care to avoid entry of dust or foreign particles into the pump interior when the timing adjustment is made. The flange mounted injection pump is installed behind the timing gear case. Checking Procedure 1. Align the crankshaft pulley TDC mark with the pointer. Remove the inspection hole cover at the front of the injection pump on the timing gear case cover. Check the alignment between the pointer (4) on the injection pump gear nut lock plate and the projection area mark (3) on the injection pump gear case. If it is in misalignment, recheck with turning the crankshaft pulley one more turn to repeat the aforegoing procedure to mark sure that it is in alignment. Check the alignment of the notched lines (1) and (2) . (These notched lines were aligned at the factory to set the injection pump body and the mounting flange.) Next, inspect the crankangle position of the injection starting. 2. Reversely turn the crankshaft pulley counterclockwise about 30° crankangle. 3. Disconnect the injection pipe from the No. 1 plunger. This will allow you to visually check the full injection starting flow at No. 1 plunger.

4. Remove the delivery valve holder (1) , the valve seat (2) , valve spring (3) the delivery valve (4) from the No. 1 plunger. 5. Reinstall the delivery holder (1) and tighten it to the specified torque. Do not reinstall the delivery valve spring, the valve seat and the delivery valve. These parts will be reinstalled later.

SM7440

SM7443

SM7444

SM7445

SM7446

EX255-EX285

W5-2-9

MAINTENANCE 6. Hold the fuel control lever at the fully open position.

SM7447

7. Slowly turn the crankshaft pulley clockwise, at the same time, continue to feed the fuel with pumping the priming pump. When the fuel stop to flow out from the No. 1 delivery valve holder, stop the pump instantaneously. This crankangle position is the injection starting of the engine.

SM7448

8. Observe and make sure that mark (injection starting angle line α°) on the crankshaft pulley is aligning with the pointer. The timing line shows the injection starting angle of the engine. Blow out the remaining fuel from the delivery valve holder. Make sure that there is no fuel being delivered from the priming pump.

NOTE: This engine has eight timing notch lines punched on the crankshaft damper pulley. These notched lines must be aligned for correct engine timing. Refer to the illustration. Degree Injection Timing B.T.D.C.

8

Damper pulley

SM7449

W5-2-10

EX255-EX285

MAINTENANCE NOTE: Injection pump injection timing will vary among identical engines, your FIAT KOBELCO Dealer. 9. Remove the delivery valve holder from the No. 1 plunger. 10. Reinstall the delivery valve internal parts (seat, spring, and valve) to the delivery valve holder. 11. Reinstall the delivery valve holder assembly to the No. 1 plunger and tighten it to the specified torque.

Holder

N•m (kgf•m/ft.lb) Delivery Valve Holder 39-44 (4-4.5/29-33) Torque 12. Install the No. 1 cylinder injection pipe and tighten it to the specified torque. N•m (kgf•m/ft.lb) Injection Pipe Nut Torque

28-32 (2.9-3.3/21-24)

NOTE: DO NOT OVERTIGHTEN THE INJECTION PUMP BODY. THE INJECTION PUMP BODY IS MADE OF ALUMINUM. OVERTIGHTENING WILL DISTORT THE INJECTION PUMP BODY SHAPE AND ADVERSELY AFFECT CONTROL RACK OPERATION.

Seat Spring

Derivery Valve

SM7450

EX255-EX285

W5-2-11

MAINTENANCE Adjusting Procedure 1. Align the pointer and the specified timing mark on the crank pulley. 2. Perform the operations described on page W5-2-8 and W5-2-9, steps 3, 4, 5, 6. 3. Loosen the four injection pump fixing nut. 4. To advance the timing Pivot the injection pump at the pump driveshaft toward out. To retard the timing. Pivot the injection pump at the pump driveshaft toward in (toward the cylinder block). Reference; the 1 mm misalignment between the two setting mark lines corresponds to about 2° in crankangle. 5. Do a fine injection pump position adjustment, while continue the pumping operation to feed the fuel, and stop to pivot the injection pump when the fuel stop to flow out from the No. 1 delivery valve holder. 6. Tighten the four injection pump fixing nuts. 7. Once remove the No. 1 delivery valve holder, and reinstall the delivery valve, spring and the valve holder with the specified torque. 8. Install the No. 1 injection pipe and tighten it to the specified torque.

Loosen (Back side nuts also)

SM7451

W5-2-12

EX255-EX285

MAINTENANCE COMPRESSION PRESSURE MEASUREMENT 1. Operate the engine to warm-up until the coolant temperature reaches to 75 °C (167 °F). 2. Remove all of the glow plugs and the injection pipes. 3. Attach a compression gauge to the No. 1 cylinder glow plug installation threads. Compression gauge adaptor

NOTE: Compression pressure may be measured starting at any cylinder and in no particular cylinder order. However, it is very important that the compression pressure be measured in each cylinder. Therefore, start at the No.1 cylinder and work back. In this way, you will be sure to measure the compression pressure in each cylinder.

SM7458

Compression Gauge: Compression Gauge Adapter: 5-85317-001-0 (JKM-1015)

4. Crank the engine with the starter motor and take the compression gauge reading. MPa (kgf/cm2/psi) at 200 min-1 at sea level Standard

Limit

3.0 (31/440)

2.5 (26/370)

5. Repeat the procedure (Steps 2 and 3) for the remaining cylinders. Compression pressure should be approximately the same for each cylinder. A variation exceeding 200 kPa (2 kgf/cm2/28 psi) is unacceptable. If the measured value exceeds the specified limit, the related parts must be checked.

SM7459

EX255-EX285

W5-2-13

MAINTENANCE TURBOCHARGER INSPECTION 1. Check the air intake duct connections for air leakage.

SM7460

2. Check the air duct connections for air leakage.

SM7461

3. Check the exhaust duct connections for smoke leakage. 4. Check the turbocharger mounting nuts for looseness.

SM7462

5. Check the oil feed pipe for oil leakage.

SM7463

6. Check the oil return pipe ts for oil leakage.

SM7464

W5-2-14

EX255-EX285

MAINTENANCE ENGINE REPAIR KIT

VIEW (A)

SM7465

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18.

Cylinder head gasket Cylinder head cover gasket Cylinder head cover nut gasket Chamber cover fixing bolt gasket Oil pump hole cover gasket Oil relief valve gasket Water drain valve gasket Gear case to cylinder block gasket Crank pulley to gear case oil seal Gear case cover gasket Crankshaft rear end oil seal Valve guide oil seal Drain plug gasket Oil pan gasket Oil pipe gasket Oil filter gasket Oil filter fixing bolt gasket Oil cooler gasket

19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36.

Oil pipe t gasket t bolt gasket Oil pipe gasket Injection pump oil pipe gasket Injection pump oil pipe gasket Water pump gasket Thermostat housing gasket Intake manifold gasket Inlet pipe manifold gasket Exhaust manifold gasket Exhaust manifold to turbocharger gasket Oil feed pipe gasket Oil drain pipe gasket Oil drain pipe gasket Overflow fuel pipe gasket Injection nozzle gasket Injection nozzle leak off pipe gasket Thermostat gasket

EX255-EX285

W5-2-15

MAINTENANCE RECOMMENDED LUBRICANTS ENGINE TYPE

TYPE OF LUBRICANT (API)

With turbocharger

Diesel engine oil CD grade

ENGINE OIL VISCOSITY CHART

ENGINE OIL VISCOSITY GRADE-AMBIENT TEMPERATURE [Single grade]

Ambient temperature

(5ºF)

(59ºF)

(77ºF)

(86ºF)

[Multi-grade]

SM7033

W5-2-16

EX255-EX285

MAINTENANCE NOTE

EX255-EX285

W5-3-1

ENGINE DISASSEMBLY EXTERNAL PARTS

SM7466

Right-hand Side Disassembly Steps 1. Cooling fan 2. Not installed 3. Not installed 4. Intake pipe 5. Fuel return pipe 6. Fuel pipe; fuel filter to injection pump 7. Fuel pipe; feed pump to filter 8. Injection pipe and leak off pipe

9. 10. 11. 12. ▲ 13. 14. 15. 16.

Injection nozzle Oil pipe; injection pump to cylinder body Not installed Oil pipe; filter to oil cooler Injection pump with injection pump gear Fuel filter Oil filters Glow plug

W5-3-2

EX255-EX285

ENGINE DISASSEMBLY Important Operations 13. Injection Pump with Injection Pump Gear Use the shipping plugs (or something similar) to seal the injection pump delivery valve ports. This will prevent the entry of foreign material. 1) Remove the injection pump flange bolts. 2) Pull the injection pump with the injection pump drive gear free. Refer to the illustration. SM7467

EX255-EX285

W5-3-3

ENGINE DISASSEMBLY

SM7469

Left-hand Side Disassembly Steps 1. Dipstick and guide tube 2. Air breather 3. Oil feed pipe 4. Oil drain pipe ▲ 5. Turbocharger 6. Gasket

7. 8. 9. 10. 11.

Starter Fan belt Alternator Fan pulley Cylinder head cover

W5-3-4

EX255-EX285

ENGINE DISASSEMBLY Important Operations 5. Turbocharger Plug oil ports in turbocharger body immediately after removal of the turbocharger.

SM7470

EX255-EX285

W5-3-5

ENGINE DISASSEMBLY MAJOR COMPONENTS

* : Repair kit SM7471

Disassembly Steps - I ▲ 1. Rubber hose; water by- 2. Rocker arm shaft assembly ▲ 3. Push rod 4. Cylinder head bolt 5. Cylinder head assembly 6. Cylinder head gasket 7. Water pump assembly

8. ▲ 9. ▲ 10. 11. 12. 13. ▲ 14. ▲ 15. 16.

Tappet chamber cover Oil pump driving pinion Starting handle nut Taper bushing Crankshaft pulley and dust thrower Timing gear cover Oil thrower Flywheel Rear oil seal

W5-3-6

EX255-EX285

ENGINE DISASSEMBLY Important Operations 2. Rocker Arm Shaft Loosen the rocker arm shaft fixing bolts a little at a time in numerical sequence as specified.

SM7472

4. Cylinder Head Bolts Loosen the cylinder head bolts a little at a time in the numerical order shown in the illustration. Cylinder head bolt wrench: 1-85111-003-0

Front

SM7473

10. Crankshaft Pulley Nut Wrench: 54 mm (2.13 in) Use an appropriate wrench to remove the crankshaft pulley nut.

Crankshaft pulley

Wrench

SM7474

EX255-EX285

W5-3-7

ENGINE DISASSEMBLY 11. Taper Bushing Remover: 9-8521-0122-0 Use the taper bushing remover to remove the crankshaft end taper bushing.

Taper bushing

Crankshaft

Pulley Taper bushing remover SM7475

15. Flywheel Loosen the flywheel bolt a little at a time in the numerical order as specified.

SM7476

16. Crankshaft Rear Oil Seal (Axial Type) With the oil seal pushed in deep, install the special tool as shown in the illustration and remove the oil seal. Oil Seal Remover: 5-8840-2360-0

SM7477

W5-3-8

EX255-EX285

ENGINE DISASSEMBLY


Disassembly Steps - II 1. Oil cooler 2. Oil pan 3. Oil pump and coupling 4. Flywheel housing 5. Piston and connecting rod ▲ 6. Idler gear ▲ 7. Camshaft 8. Tappet

9. 10. ▲ 11. 12. 13. 14. 15. 16.

Timing gear case Idler gear shaft Crankshaft bearing cap Crankshaft bearing (lower half) Thrust bearing Crankshaft Crankshaft bearing (upper half) Oiling jet

EX255-EX285

W5-3-9

ENGINE DISASSEMBLY Important Operations 6. Idler Gear Measure the following points before disassembly. mm (in) Idler Gear End Play

Standard

Limit

0.128-0.185 (0.005-0.0070)

0.2 (0.008) Feeler gauge

mm (in) Timing Gears Backlash

Standard

Limit

0.10-0.17 (0.004-0.007)

0.3 (0.012)

SM7479

Includes the crankshaft gear, the camshaft gear, and the idler gear.

Dial indicator SM7480

7. Camshaft Measure the following points before disassembly.

Crankshaft gear

mm (in) Cam Gear End Play

Standard

Limit

0.050-0.114 (0.002-0.005)

0.2 (0.008)

Thrust plate Feeler gauge

Camshaft

SM7481

11. Crankshaft Bearing Cap Measure the crankshaft end play at the thrust bearing (center main bearing) before disassembly.

Feeler gauge

mm (in)

Crankshaft End Play

Standard

Limit

0.15-0.33 (0.006-0.013)

0.4 (0.016) Crankshaft SM7482

W5-3-10

EX255-EX285

ENGINE DISASSEMBLY ROCKER ARM AND ROCKER ARM SHAFT

SM7483

Disassembly Steps 1. Bracket 2. Rocker arm

3. 4.

Spring Rocker arm shaft

EX255-EX285

W5-3-11

ENGINE DISASSEMBLY CYLINDER HEAD


Disassembly Steps 1. Exhaust manifold and gasket 2. Intake manifold and gasket 3. Water outlet pipe 4. Thermostat 5. Thermostat housing and gasket ▲ 6. Split collar

7. 8. 9. 10. 11.

Spring seat (upper) Valve spring Spring seat (lower) Valve Valve stem oil seal

Important Operation 6. Split collar Use the valve spring compressor to remove the split collar. Valve Spring Compressor: 1-85235-006-0

Valve spring compressor SM7485

W5-3-12

EX255-EX285

ENGINE DISASSEMBLY PISTON AND CONNECTING ROD

SM7486

Disassembly Steps ▲ 1. Piston rings ▲ 2. Snap ring ▲ 3. Piston pin and connecting rod

4. 5.

Piston Connecting rod bearing

EX255-EX285

W5-3-13

ENGINE DISASSEMBLY Important Operation NOTE: Remove any carbon deposits from the upper part of the cylinder bore. This will prevent damage to the piston and the piston rings when they are removed from the cylinder bore. Carbon deposits

SM7487

1.

Piston Rings Use a piston ring remover to remove the piston rings. Do not attempt to use some other tool. Piston ring stretching will result in reduced piston ring tension. Piston ring remover:

Piston ring remover

SM7488

2, 3.Snap Ring and Piston Pin (1) Use a pair of snap ring pliers to remove the snap ring.

SM7489

(2) Tap the piston pin out with a hammer and brass bar. Piston pin

SM7490

W5-3-14

EX255-EX285

ENGINE DISASSEMBLY NOTE

EX255-EX285

W5-4-1

ENGINE INSPECTION AND REPAIR NOTE: Make the necessary adjustments, repairs, and part replacements if excessive wear or damage is discovered during inspection.

CYLINDER HEAD Cylinder Head Lower Face Warpage 1. Use a straight edge and a feeler gauge to measure the four sides and the two diagonals of the cylinder head lower face. 2. Regrind the cylinder head lower face if the measured values are greater than the specified limit but less than the maximum grinding allowance. SM7491

If the measured values exceed the maximum grinding allowance, the cylinder head must be replaced. Cylinder Head Lower Face Warpage mm (in) Standard

Limit

Maximum Grinding Allowance

0.075 0.2 (0.003) or less (0.0079)

0.3 (0.012) SM7492

Cylinder Head Height (Reference)

mm (in)

Standard

Limit

89.95 (3.541)-90.05 (3.545)

89.65 (3.530)

NOTE: If the cylinder head lower face is reground, valve depression must be checked.

SM7493

Water Jacket Water Pressure Test Use the hydraulic gauge to check the water jacket water pressure. Apply water pressure to the water jacket at 490 kPa (5 kgf/cm2/71.1 psi) for three minutes. Check the entire cylinder head for water leakage.

SM7494

W5-4-2

EX255-EX285

ENGINE INSPECTION AND REPAIR VALVE GUIDE Valve Stem and Valve Guide Clearance MEASURING METHOD - I 1. With the valve stem inserted in the valve guide, set the dial indicator needle to “0”. 2. Move the valve head from side to side. Note the total dial indicator reading (TIR). This value is the clearance between the valve stem and the valve guide. If the measured values exceed the specified limit, the valve and the valve guide must be replaced as a set. SM7495

Valve Stem Clearance

mm (in) Standard

Limit

Intake Side TIR

0.039-0.071 0.20 (0.0015-0.0028) (0.008)

Exhaust Side TIR

0.064-0.096 0.25 (0.0025-0.0038) (0.0098)

MEASURING METHOD - II 1. Measure the valve stem outside diameter. 2. Use a caliper calibrator or a telescoping gauge to measure the valve guide inside diameter. The difference between the valve stem outside diameter and the valve guide inside diameter is equal to the valve stem clearance.

SM7496

Valve Guide Replacement REMOVAL Use a hammer and the valve guide remover to drive out the valve guide from the cylinder head lower face. Valve Guide Remover: 9-85220-035-0

INSTALLATION 1. Apply clean engine oil the outer periphery of the valve guide. 2. Attach the installer to the valve guide. 3. Use a hammer to drive in the valve guide from the upper face of the head until the installer’s lower edge meets the head surface. Valve guide installer: 1-85232-001-0 4. After installation, measure the distance (height) from the cylinder head’s upper surface to the upper edge of the valve guide. Height to valve guide upper edge

SM7497

mm (in)

14.1 (0.555) SM7498

EX255-EX285

W5-4-3

ENGINE INSPECTION AND REPAIR VALVE Valve Depression 1. Install the valve (1) to the cylinder head (2). 2. Use a depth gauge or a straight edge with steel rule to measure the valve depression from the cylinder head lower surface. If the measured value exceeds the specified limit, the valve seat insert and/or valve must be replaced. If the valve is replaced, the valve guide must be also replaced. mm (in) Standard

Limit

SM7499

Intake and Exhaust 1.0 (0.039) 2.5 (0.098) Valve Depression

Valve Width 1. Inspect the valve faces for roughness and unevenness. Make smooth the valve surfaces. 2. Measure the valve width. If the measured value exceeds the specified limit, the valve seat insert must be replaced. mm (in) Standard Valve Width

Limit SM7500

1.5 (0.059) 2.0 (0.079)

W5-4-4

EX255-EX285

ENGINE INSPECTION AND REPAIR VALVE SEAT INSERT Removal 1. Arc weld the entire inside circumference (1) of the valve seat insert (2). 2. Allow the valve seat insert to cool for a few minutes. This will invite contraction and make removal of the valve seat insert easier. 3. Use a screwdriver (3) to pry the valve seat insert free. Take care not to damage the cylinder head (4). 4. Carefully remove carbon and other foreign material from the cylinder head insert bore.

SM7501

Installation 1. Carefully place the attachment (1) (having the smaller outside diameter than the valve seat insert) on the valve seat insert (2). NOTE: The smooth side of the attachment must the valve seat insert. 2. Use a bench press (3) to slowly apply pressure to the attachment and press the valve seat insert into place. Amount of pressure needed is more than 25 kN (2,500 kgf/5,512 lb).

SM7502

NOTE: Do not apply an excessive amount of pressure with the bench press. Damage to the valve seat insert will result.

Correction 1. Remove the carbon deposits from the valve seat insert surface. 2. Use valve cutters (15°, 30°, or 75° blades) to remove scratches and other rough areas. This will bring the width back to the standard value of 90° (A). Remove only the scratches and rough areas. Do not cut away too much. Take care not to cut away unblemished areas of the valve seat surfaces. SM7503

EX255-EX285

W5-4-5

ENGINE INSPECTION AND REPAIR Angle Location

Standard

Intake Valve Seat Angle (B)

45°

Exhaust Valve Seat Angle (B)

45°

NOTE: Use an adjustable valve cutter pilot. Do not allow the cutter pilot to wobble inside the valve guide. 3. Apply abrasive compound to the valve seat insert surface. 4. Insert the valve into the valve guide. 5. Hand lap the valve and the valve seat with a lapping cup. This will provide optimum valve and valve seat for effective gas sealing. 6. Check that the valve width is correct. 7. Check that the valve seat insert surface is in with the entire circumference of the valve.

SM7504

SM7505

SM7506

W5-4-6

EX255-EX285

ENGINE INSPECTION AND REPAIR VALVE SPRING Valve Spring Free Length Use a vernier caliper to measure the valve spring free length. If the measured value is less than the specified limit, the valve spring must be replaced. mm (in)

Exhaust and Intake Valve Spring Free Length

Color

Standard

Limit

blue

60.6 (2.39)

58.0 (2.28)

SM7507

Painted portion SM7508

Valve Spring Inclination Use a surface plate and a square to measure the valve spring inclination. If the measured value exceeds the specified limit, the valve spring must be replaced. mm (in) Valve Spring Inclination

Standard

Limit

less than 1.9 (0.075)

2.7 (0.106)

SM7509

Valve Spring Tension Use a spring tester to measure the valve spring tension. If the measured value is less than the specified limit, the valve spring must be replaced. N (kg/Ib) Set Length

Standard

Limit

44.5 mm (1.75 in)

142 (14.5/30.9)

127 (13.0/28.7)

SM7510

EX255-EX285

W5-4-7

ENGINE INSPECTION AND REPAIR TAPPET Inspect the tappets for excessive wear, damage and any abnormalities. Pitted

Crack

Normal

Irregular

SM7511

Use a micrometer to measure the tappet diameter. mm (in) Tappet Diameter

Standard

Limit

27.97-27.98 (1.1020-1.1024)

27.92 (1.1000)

SM7512

Use a dial indicator to measure the clearance between the tappet and cylinder body tappet travelling bore. mm (in) Standard Tappet and Tappet Travelling Bore Clearance

Limit

0.020-0.054 0.1 (0.001-0.002) (0.004) SM7513

W5-4-8

EX255-EX285

ENGINE INSPECTION AND REPAIR ROCKER ARM SHAFT AND ROCKER ARM Inspect all disassembled parts for wear, damage and any abnormalities.

SM7516

Rocker Arm Shaft Outside Diameter Use a micrometer to measure the rocker arm outside diameter. If the measured value is less than the specified limit, the shaft must be replaced. mm (in) Standard Rocker Arm Shaft Diameter

Limit

18.98-19.00 18.85 (0.747-0.748) (0.742)

SM7517

Rocker Arm Shaft and Rocker Arm Clearance 1. Use a vernier caliper to measure the rocker arm bushing inside diameter. mm (in)

Rocker Arm Bushing Inside Diameter

Standard

Limit

19.01-19.03 (0.749-0.750)

19.05 (0.751)

2. Measure the rocker arm shaft outside diameter. Replace either the rocker arm or the rocker arm shaft if the clearance exceeds the specified limit.

SM7518

mm (in) Standard

Limit

Rocker Arm Bushing and 0.01-0.05 0.2 Rocker Arm (0.0004-0.0020) (0.0079) Shaft Clearance 3. Check that the rocker arm oil port is free of obstructions. If necessary, use compressed air to clean the rocker arm oil port. SM7519

EX255-EX285

W5-4-9

ENGINE INSPECTION AND REPAIR Rocker Arm Correction Inspect the rocker arm valve stem surfaces for ridge (1) and scoring (2). If the surfaces have light ridge or scoring, they may be honed with an oil stone. If the ridge or scoring is severe, the rocker arm must be replaced.

SM7515

PUSH ROD Use a filler gauge to measure the valve push rod run out. Roll the push rod along a smooth flat surface (illustration). mm (in) Limit Push Rod Run-Out

0.3 (0.012)

SM7514

IDLER GEAR AND IDLER GEAR SHAFT 1. Use a micrometer to measure the idler gear shaft outside diameter. If measured diameter exceeds specified limit, replace the idler gear shaft. mm (in) Standard Idler Gear Shaft 44.945-44.975 Outside Diameter (1.769-1.771)

Limit 44.9 (1.768) SM7520

2. Use a dial indicator to measure the idler gear inside diameter. mm (in) Idler Gear and Idler Gear Shaft Clearance

Standard

Limit

0.025-0.085 (0.001-0.003)

0.2 (0.008)

SM7521

W5-4-10

EX255-EX285

ENGINE INSPECTION AND REPAIR CAMSHAFT 1. Use the camshaft bearing remover and installer to remove camshaft bearing from the cylinder body. Camshaft Bearing Remover and Installer: 9-8523-1818-0 2. Measure the clearance between the cam journal and the camshaft bearing. mm (in) Standard

Remover and installer SM7522

Limit

Cam Journal and Cam 0.03-0.09 Bearing Clearance (0.001-0.004)

0.15 (0.006) Cam bearing

SM7523

3. Align the camshaft bearing oil holes with the mating oil ports (machined on the cylinder body camshaft bearing fitting bore). Align oil ports

SM7524

4. Use a micrometer to measure the cam lobe height. If the cam lobe height is less than the specified limit, the camshaft must be replaced. mm (in) Standard

Limit

Cam Lobe Height (C-D)

7.71 (0.304) 7.21 (0.284)

Cam Journal Diameter

55.94-55.97 (2.202-2.204) 55.6 (2.189) SM7525

5. Place the camshaft on a measuring stand. Use a dial indicator to measure the camshaft runout. Note the total indicator reading (TIR). If the measured run-out exceeds the specified limit, the camshaft must be replaced. mm (in) Limit Camshaft Run-Out TIR

0.12 (0.005)

SM7526

EX255-EX285

W5-4-11

ENGINE INSPECTION AND REPAIR CYLINDER BODY AND LINER Cylinder Liner Bore Measurement Use a cylinder indicator to measure the cylinder liner bore at measuring position (1) in line with the crankshaft (2) and across the crankshaft (3). Measuring Point (1) mm (in): 20.0 (0.79) (Maximum Wear Portion) If the measured value exceeds the specified limit, the cylinder liner must be replaced. mm (in) Standard Cylinder Liner Bore Total Indicator Reading

SM7527

Limit

105.021-105.060 105.20 (4.1347-4.1362) (4.1417)

NOTE: The inside of the dry type cylinder liner is chrome plated. It cannot be rebored or honed. If the inside of the cylinder liner is scored or scorched, the cylinder liner must be replaced. Cylinder Liner Projection Inspection 1. Hold a straight edge (1) along the top edge of the cylinder liner to be measured. 2. Use a feeler gauge (2) to measure each cylinder liner projection.

SM7528

mm (in) Standard Cylinder Liner Projection

0.03-0.10 (0.001-0.004)

The difference in the cylinder liner projection height between any two adjacent cylinders must not exceed 0.03 mm (0.001 in). Cylinder Liner Replacement REMOVAL 1. Set the cylinder liner remover to the cylinder liner. 2. Check that the remover shaft ankle is firmly gripping the cylinder liner bottom edge. 3. Slowly turn the remover shaft handle counterclockwise to pull the cylinder liner free. Cylinder Liner Remover: 9-8523-1169-0 Cylinder Liner Remover Ankle: 5-8523-1004-0 NOTE: Take care not to damage the cylinder body upper face during the cylinder liner removal procedure.

SM7529

Remover

SM7530

W5-4-12

EX255-EX285

ENGINE INSPECTION AND REPAIR CYLINDER LINER GRADE SELECTION The term “grade” refers to the cylinder body inside diameter and the cylinder liner outside diameter combination. Measure the cylinder body inside diameter and select the appropriate cylinder liner grade. Loose fitting cylinder liners (the liner is too small for the cylinder bore) will adversely affect engine cooling efficiency and may lead to serious engine damage. Cylinder liners which are too large for the cylinder bore will be difficult to install. Cylinder Body Inside Diameter Measurement 1. Take measurements at measuring point (1) across the positions W-W, X-X, Y-Y, and Z-Z. Measuring Point (1): 115 mm (4.531 in) 2. Calculate the average value of the four measurements to determine the correct cylinder liner grade.

Cylinder Bore and Cylinder Liner Outside Diameter Combinations (Reference) mm (in) Grade

Cylinder Bore

SM7531

SM7532

Cylinder Liner Outside Diameter

1

107.001-107.010 107.011-107.020 (4.2126-4.2130) (4.2130-4.2134)

2

107.011-107.020 107 .021-107.030 (4.2130-4.2134) (4.2134-4.2138)

3

107.021-107.030 107 .031-107.040 (4.2134-4.2138 ) (4.2138-4.2142 )

SM7533

Cylinder Liner Outside Diameter Measurement 1. Take measurements at measuring point (1), (2), and (3). Measuring Points mm (in): (1) 20.0 (0.788) (2) 105.0 (4.137) (3) 195.0 (7.683) 2. Calculate the average value of the 6 measurements to determine the correct cylinder liner grade. mm (in) Cylinder Liner Fitting Clearance Standard

0.001-0.019 (0.00004-0.0007)

SM7534

EX255-EX285

W5-4-13

ENGINE INSPECTION AND REPAIR INSTALLATION 1. Carefully wipe away any foreign material from the cylinder liner inside and outside surfaces and the cylinder bore. 2. Use new kerosene or diesel oil to thoroughly clean the cylinder liner and bore surfaces. 3. Use a clean rag to remove all traces of kerosene or diesel oil from the cylinder liner and bore surfaces.

4. Insert the cylinder liner (1) into the cylinder body (2) from the top of the cylinder body. 5. Set the cylinder liner installer (3) to the top of the cylinder liner. Cylinder Liner Installer: 5-8522-1018-0 6. Position the cylinder body so that the installer center (3) is directly beneath the bench press shaft center (4). 7. Check that the cylinder liner is set perpendicular to the cylinder. Check that the cylinder liner does not wobble. 8. Use the bench press to apply an initial seating force of 5 kN (500 kgf/1,102 lb) to the cylinder liner. 9. Use the bench press to apply a final seating force of 25 kN (2,500 kgf/5,512 lb) to fully seat the cylinder liner. 10. After installing the cylinder liner, measure the cylinder liner projection. Refer to “Cylinder Liner Projection Inspection”.

PISTON GRADE SELECTION The term “piston grade” refers to the piston diameter and cylinder liner bore combination. Selection of the proper piston grade will ensure efficient engine operation, free from cylinder liner and piston problems.

SM7531

SM7532

W5-4-14

EX255-EX285

ENGINE INSPECTION AND REPAIR Cylinder Liner Bore Measurement 1. Locate the two measuring points. Cylinder Liner Measuring Point (1): 20 mm (0.788 in) Cylinder Liner Measuring Point (2): 105 mm (4.173 in) 2. Measure the cylinder liner bore at measuring point (1) and (2) in four different directions (W-W, X-X, Y-Y, and Z-Z). 3. Calculate the average value of the eight measurements. mm (in) Cylinder Liner Bore Total Indicator Reading

105.021-105.060 (4.1347-4.1362)

SM7533

Relation between liner bore and piston grade mm (in) Liner Bore Diameter

Piston Grade

105.021-105.040 ( 4.1347-4.1354)

AX

105.041-105.060 (4.1355-4.1362)

CX

NOTE: It is most important that the correct piston grade be used. Failure to select the correct piston grade will result in piston seizure. Always measure the cylinder bore and select the appropriate piston grade.

Piston Outside Diameter Measure the piston outside diameter at the measuring piston shown in the illustration. Piston Grade (For service parts)

mm (in)

AX

CX

104.959-104.974 (4.1322-4.1328)

104.975-104.990 (4.1329-4.1335)

SM7533

Cylinder Liner Bore and Piston Clearance mm (in) Cylinder Liner Bore and Piston Clearance

0.051-0.085 (0.002-0.0033)

Piston Selection Select the same grade number as the one for the cylinder liner inside diameter. NOTE: Cylinder liner piston kit clearances are preset. However, the cylinder liner installation procedure may result in slight decreases in cylinder liner bore clearances.

Grade of cylinder inside diameter

Grade of piston

Combination

AX CX AX CX

AX CX CX AX

OK OK NG NG

EX255-EX285

W5-4-15

ENGINE INSPECTION AND REPAIR PISTON AND PISTON RING Piston Ring and Piston Ring Groove Clearance Use a feeler gauge to measure the clearance between the piston ring and the piston ring groove. Do this at several points around the piston. If the clearance between the piston ring and the piston ring groove exceeds the specified limit, the piston ring must be replaced.

mm (in) Standard

Limit

–

–

SM7539

st

1 Compression Ring

2nd Compression 0.070-0.110 0.15 Ring (0.0028-0.0043) (0.0059) 3rd Compression 0.050-0.090 0.15 Ring (0.0020-0.0035) (0.0059) Oil Ring

0.030-0.070 (0.12-0.28)

0.15 (0.0059)

Piston Ring Gap 1. Insert the piston ring horizontally (in the position it would assume if it were installed to the piston) into the cylinder liner. 2. Use an inverted piston to push the piston ring into the cylinder liner until it reaches either measuring point (1) or measuring point (2). Cylinder liner diameter is the smallest at these two points. Do not allow the piston ring to slant to one side or the other. It must be perfectly horizontal. Cylinder Liner Measuring Point (1): 10 mm (0.39 in) Cylinder Liner Measuring Point (2): 130 mm (5.12 in) 3. Use a feeler gauge to measure the piston ring gap. If the measured value exceeds the specified limit, the piston ring must be replaced.

SM7540

SM7541

mm (in) Standard st

Limit

1 Compression Ring

0.35-0.50 (0.014-0.020)

2nd Compression Ring

0.60-0.75 (0.0236-0.0295)

3rd Compression Ring

0.60-0.75 (0.059) (0.0236-0.0295)

Oil Ring

0.30-0.50 (0.014-0.020)

1.5

W5-4-16

EX255-EX285

ENGINE INSPECTION AND REPAIR PISTON PIN Piston Pin Outside Diameter Use a micrometer to measure the piston pin outside diameter at several points. If the measured piston pin outside diameter exceeds the specified limit, the piston pin must be replace. mm (in)

Piston Pin Outside Diameter

Standard

Limit

35.000-35.005 (1.3780-1.3781)

34.95 (1.3760) SM7542

Piston Pin and Piston Clearance Use an inside dial indicator to measure the piston pin hole. mm (in) Standard Piston Pin Hole Diameter

35.015-35.023 (1.3785-1.3789)

SM7543

Determine the clearance between the piston pin and the piston pin hole by calculating the difference between the piston pin hole diameter and the piston pin outside diameter. mm (in) Standard Piston Pin and Piston Pin Hole Clearance

Limit

0.010-0.023 0.050 (0.00039-0.0009) (0.00197)

SM7544

If an inside dial indicator is not available, use the following procedure to check the piston pin fit. 1. Use a piston heater to heat the piston to approximately 60 °C (140 °F). 2. Push strongly against the piston pin with your thumbs. The piston pin fitting should feel tight.

SM7545

EX255-EX285

W5-4-17

ENGINE INSPECTION AND REPAIR CONNECTING ROD Connecting Rod Alignment Use a connecting rod aligner to measure the connecting rod’s twist distortion and parralelism between the rod’s large and small ends. If the measured value exceeds the limit, replace the connecting rod. Connecting Rod Alignment (Per Length of 100 mm (3.94 in)) Standard Twist, Parallelism 0.05 (0.002) or less

mm (in) Limit 0.20 (0.0079)

SM7546

Piston Pin and Connecting Rod Small End Bushing Clearance Use a caliper calibrator and a micrometer to measure the piston pin and connecting rod small end bushing clearance. If the clearance between the piston pin and the connecting rod small end bushing exceeds the specified limit, replace either the piston pin or the connecting rod bushing. mm (in) Standard

Limit

Piston Pin and Connecting 0.012-0.025 0.05 Rod Small End (0.00047-0.00098) (0.00197) Bushing Clearance

Connecting Rod Bushing Replacement REMOVAL 1. Clamp the connecting rod in a vise. 2. Use a brass bar and a bench press or hammer to remove the connecting rod bushing.

SM7547

W5-4-18

EX255-EX285

ENGINE INSPECTION AND REPAIR INSTALLATION Use the connecting rod bushing installer to install the connecting rod bushing. Connecting Rod Bushing Installer: 9-8523-1369-0 (J-29765) NOTE: The connecting rod bushing oil port must be aligned with the connecting rod oil port. 3. Use a piston pin hole grinder (1) fitted with a reamer (2) or an adjustable pilot reamer to ream the piston pin hole.

SM7548

mm (in) Standard Connecting Rod Bushing Inside Diameter

35.017-35.025 (1.3786-1.3789)

SM7549

Connecting Rod Bearing Inspection 1. Fit the connecting rod bearing lower half into the connecting rod bearing cap. 2. Check the connecting rod bearing lower half tension. If the tension is insufficient, the bearing must be replaced. 3. Tighten the connecting rod and the bearing cap to the specified torque. N•m (kgf•m/ft.lb) st

Connecting Rod and Bearing Cap Bolt Tightening Torque

1 step

2nd step

39 (4/29)

60°-90° SM7550

4. Use an inside dial indicator to measure the connecting rod inside diameter. mm (in) Standard Connecting Rod Bearing Nominal Diameter

64 (2.520)

SM7551

EX255-EX285

W5-4-19

ENGINE INSPECTION AND REPAIR CRANKSHAFT Crankshaft and Bearing Inspection 1. Inspect the crankshaft journal surfaces and the crank pin surfaces for excessive wear and damage. 2. Inspect the oil seal fitting surfaces of the crankshaft front and rear ends for excessive wear and damage. 3. Replace or repair the crankshaft if any excessive wear or damage is discovered. 4. Inspect the crankshaft oil ports for obstructions. 5. Use high pressure air to clean the oil ports if necessary. Crankshaft Journal and Crankpin Outside Diameter 1. Use a micrometer to measure the crankshaft journal outside diameter across points (1) - (1) and (2) - (2). 2. Use the micrometer to measure the crankshaft journal outside diameter at the two points (3) and (4). 3. Repeat steps 1. and 2. to measure the crankpin outside diameter. mm (in) Position at Center Crankshaft Bearing Only Journal Other Diameter Bearings

Standard 79.905-79.925 (3.1459-3.1467) 79.919-79.939 (3.1464-3.1472) mm (in) Standard

Crankpin Diameter

63.924-63.944 (2.5167-2. 517 5)

4. Measure the crankshaft journal outside diameter (and/or the crankpin outside diameter) and the bearing inside diameters to determine the bearing clearance. Crankshaft Journal and Bearing Clearances If the bearing clearance exceeds the specified limit, the bearing must be replaced. mm (in) Position at Crankshaft Journal and Main Bearing Clearance

Center Bearing Only Other Bearings

Standard

Limit

0,039-0.098 (0.0015-0.0039) 0.025-0.084 (0.0010-0.0033)

0.11 (0.0043)

Crankpin and Bearing Clearance mm (in) Standard

Limit

Crankpin and 0.03-0.073 0.10 Connecting Rod (0.0012-0.0029) (0.0039) Bearing Clearance

SM7552

W5-4-20

EX255-EX285

ENGINE INSPECTION AND REPAIR Crankshaft Journal Bearing Inside Diameter 1. Install the main bearing cap with bearings to the cylinder body with the specified torque and facing the arrow mark on the bearing cap toward front. Place them in order of punched cylinder numbers. 2. Use an inside dial indicator to measure the main bearing diameters. N•m (kgf•m/ft.lb) Main Bearing Cap Torque

226 - 245 (23 - 25/160 - 181)

SM7553

mm (in) Main Bearing Nominal Diameter

80 (3.149)

Crankshaft Run-Out 1. Mount the crankshaft on a set of V-blocks. 2. Set a dial indicator to the center of the crankshaft journal. 3. Gently turn the crankshaft in the normal direction of engine rotation. Read the dial indicator (TIR) as you turn the crankshaft. If the measured value exceeds the specified limit, the crankshaft must be replaced. mm (in) Crankshaft Run-Out

Standard

Limit

0.05 (0.002) or less

0.40 (0.016)

SM7554

If the crankshaft generated a crack after repair, replace the crankshaft. Crankshaft can not be bench pressed, because it is finished with tufftride method.

Main Bearing and Connecting Rod Bearing Tension Check to see if the bearing has enough tension, so that good finger pressure is needed to fit the bearing into position.

SM7550

EX255-EX285

W5-4-21

ENGINE INSPECTION AND REPAIR Plastigage Clearance Measurements This is another method to measure the crank journal bearing clearance.

CRANKSHAFT JOURNAL BEARING CLEARANCE 1. Clean the cylinder body, the journal bearing fitting portions, the bearing cap, and the inside the outside surfaces of the bearing. 2. Install the new journal bearing to the cylinder body. 3. Carefully place the crankshaft on the bearing. 4. Rotate the crankshaft approximately 30° to seat the bearing. 5. Place the Plastigage (arrow) over the crankshaft journal across the full width of the bearing. Apply engine oil to the Plastigage to keep it from falling. 6. Install the bearing cap with the bearing. 7. Tighten the bearing cap to the specified torque. Do not allow the crankshaft to turn during bearing cap installation and tightening. 8. Remove the bearing cap. 9. Compare the width of the plastigage attached to either the crankshaft or the bearing against the scale printed on the plastigage container. If the measured value exceeds the limit, perform the following additional steps. 1) Use a micrometer to measure the crankshaft outside diameter. 2) Use an inside dial indicator to measure the bearing inside diameter. 3) Replace the crankshaft and/or the bearing if the measured values) exceed the limit.

SM7555

SM7556

SM7557

W5-4-22

EX255-EX285

ENGINE INSPECTION AND REPAIR CRANKPIN BEARING CLEARANCE 1. Clean the crankshaft, the connecting rod, the bearing cap, and the bearings. 2. Install the bearing to the connecting rod. Do not allow the crankshaft to move when installing the bearing cap. 3. Hold the connecting rod (with the bearing installed) against the crankpin. 4. Attach the plastigage to the crankpin. Apply engine oil to the plastigage to keep it from falling. 5. Install the connecting rod bearing cap and tighten it to the specified torque. Do not allow the connecting rod to move when installing and tightening the bearing cap. 6. Remove the bearing cap. 7. Compare the width of the plastigage attached to either the crankshaft or the bearing against the scale printed on the plastigage container. If the measured value exceeds the limit, perform the following additional steps. 1) Use a micrometer to measure the crankpin outside diameter. 2) Use an inside dial indicator to measure the bearing inside diameter. 3) Replace the crankshaft and/or the bearing if the measured values) exceed the limit.

EX255-EX285

W5-4-23

ENGINE INSPECTION AND REPAIR Crankshaft Regrinding

NOTE: Crankshaft can not be reground because it is finished with TUFFTRIDE method. For the crankshaft on this engine no attempt should be made to grind finish the faces of the journals and crankpins as they are TUFFTRIDED (Special hardening treatment). Therefore, the undersize bearings are not prepared.

Crankshaft Tufftriding INSPECTION 1. Use an organic cleaner to thoroughly clean the crankshaft. There must be no traces of oil on the surfaces to be inspected. 2. Prepare a 10% solution of ammonium cuprous chloride (dissolved in distilled water). 3. Use a spot glass rod to apply the solution to the surface to be inspected. Hold the surface to be inspected perfectly horizontal to prevent the solution from running. NOTE: Do not allow the solution to come in with the oil ports and their surrounding area.

JUDGEMENT 1. Wait for thirty to forty seconds. If there is no discoloration after thirty or forty seconds, the crankshaft is usable. If discoloration appears (the surface being tested will become the color of copper), the crankshaft must be replaced. 2. Clean the surface being tested with clean water of steam immediately after completing the test. NOTE: The ammonium cuprous chloride solution is highly corrosive. Because of this, it is imperative that the surfaces being tested be cleaned immediately after completing the test.

Ammonium cuprous chloride

Test liquid should not be applied to area around oil port

Face in with crank pin or journal

SM7558

W5-4-24

EX255-EX285

ENGINE INSPECTION AND REPAIR Crankshaft Gear INSPECTION Visually inspect the crankshaft gear. Replace the crankshaft gear if excessive wear or damage is discovered.

REMOVAL Use the crankshaft gear remover to remove the crankshaft gear. Crankshaft Gear Remover: 9-8521-0141-0

Remover

SM7559

INSTALLATION Use the crankshaft gear installer to install the crankshaft gear. Crankshaft Gear Installer: 9-8522-0033-0

Installer

SM7560

EX255-EX285

W5-4-25

ENGINE INSPECTION AND REPAIR FLYWHEEL AND FLYWHEEL HOUSING Ring Gear Inspection Inspect the ring gear. If the ring gear teeth are broken or excessively worn, the ring gear must be replaced. Ring Gear Replacement REMOVAL Strike around the edges of the ring gear with a hammer and chisel to remove it.

INSTALLATION 1. Heat the ring gear evenly with a gas-burner to invite thermal expansion. Do not allow the temperature of the ring gear to exceed 200 °C (390 °F). 2. Use a hammer to install the ring gear when it is sufficiently heated.

SM7561

SM7562

TIMING GEAR CASE COVER Crankshaft Front Oil Seal Replacement REMOVAL Use an adapter and a hammer to remove the crankshaft front end oil seal.

INSTALLATION Use the crankshaft front oil seal installer to install the crankshaft front oil seal. Crankshaft Front Oil Seal Installer: 9-8522-0034-0 SM7563

W5-4-26

EX255-EX285

ENGINE INSPECTION AND REPAIR NOTE

EX255-EX285

W5-5-1

ENGINE REASSEMBLY PISTON AND CONNECTING ROD

SM7564

Reassembly Steps ▲ 1. Piston ▲ 2. Connecting-rod ▲ 3. Piston pin, Snap ring

▲ 4. ▲ 5.

Piston ring Connecting rod bearing

W5-5-2

EX255-EX285

ENGINE REASSEMBLY Important Operations 1. Piston Use a piston heater to heat the pistons to approximately 60 °C (140 °F).

Conventional piston heater

2. Connecting Rod 1) Install the connecting rod to the piston with setting the marks as illustrated. 2) Install the piston pin into the piston and the connecting rod bushing. Refer the description of piston pin in page W5-4-16.

3. Piston Pin, Snap Ring 1) Use a pair of snap ring pliers to install the piston pin snap ring. 2) Check that the piston moves smoothly on the piston pin.

4. Piston Ring 1) Use a piston ring installer to install the three piston rings. Piston Ring Installer Install the piston rings in the following order. (1) Oil ring (2) 3rd compression ring (3) 2nd compression ring (4) 1st compression ring The marked side of the three compression rings must be facing up. rd The undercut side of the 3 compression ring will be facing down. As the oil ring has no any facing mark, it may face in either direction. 2) Lubricate the piston ring surfaces with engine oil. 3) Check that the piston rings rotate smoothly in the piston ring grooves.

SM7565

Piston head Front mark (▲) Put cylinder number marked side in this position

SM7566

SM7489

5. Connecting Rod Bearing 1) Install the connecting rod bearings to the connecting rod large-end and the connecting rod cap. 2) Install the bearing cap to the connecting rod with semi-tightening the cap bolts. 3) Lubricate the bearing with engine oil.

Marked side up 1st comp 2nd comp 3rd comp Oil

SM7567

EX255-EX285

W5-5-3

ENGINE REASSEMBLY CYLINDER HEAD


Reassembly Steps ▲ 1. Valve stem oil seal ▲ 2. Intake and exhaust valves 3. Spring seat (Lower) ▲ 4. Intake and exhaust valve springs 5. Spring seat (Upper) or valve rotator ▲ 6. Spring seat split collar

7. 8. 9. ▲ 10. ▲ 11.

Thermostat housing and gasket Thermostat Water outlet pipe Intake manifold and gasket Exhaust manifold and gasket

W5-5-4

EX255-EX285

ENGINE REASSEMBLY Important Operations Installer

1. Valve Stem Oil Seal 1) Lubricate the oil seals and valve stem sealing areas with engine oil. 2) Use a valve stem oil seal installer to install the oil seal. Valve Stem Oil Seal Installer: 1-85221-005-0 SM7569

2. Intake and Exhaust Valves 1) Place the cylinder head on a flat wooden surface. 2) Lubricate valve stems with engine oil. 3) Install the valves to the intake or exhaust guides. Install the valves to their original lapped valve seats. SM7570

4. Intake and Exhaust Valve Springs Install the valve springs with their painted end (the close pitched end) facing down.

Painted portion SM7508

6. Spring Seat Split Collar 1) Use a spring compressor to push the valve spring into position. 2) Install the spring seat split collar. Set the spring seat split collar by tapping lightly around the head of the collar with a rubber hammer. Spring Compressor: 1-85235-006-0 Spring compressor

SM7485

SM7571

EX255-EX285

W5-5-5

ENGINE REASSEMBLY 10. Intake Manifold and Gasket 1) Install the intake manifold gasket. The intake manifold gasket must be installed with its unchamfered corner facing up and to the front of the engine. Refer to the illustration. 2) Install the intake manifold. 3) Tighten the intake manifold bolts to the specified torque a little at a time in the numerical order shown in the illustration.

Unchamfered corner

Rear SM7572

N•m (kgf•m/Ib.ft) Intake Monifold Bolt Torque

21-30 (2.1-3.1/15-22)

SM7573

11. Exhaust Manifold and Gasket 1) Install the exhaust manifold gasket. The “TOP” mark must be facing up. 2) Install the exhaust manifold. 3) Tighten the exhaust manifold bolts to the specified torque a little at a time in the numerical order shown in the illustration.

TOP SM7574

N•m (kgf•m/Ib.ft) Exhaust Manifold Bolt Torque

25-31 (2.6-3.2/19-23)

SM7575

4) Install either end of the distance tube to the spot facing.

Distance tube

Spot facing SM7576

W5-5-6

EX255-EX285

ENGINE REASSEMBLY ROCKER ARM AND ROCKER ARM SHAFT

SM7577

Reassembly Steps ▲ 1. Rocker arm shaft 2. Spring

3. Rocker arm 4. Bracket

Important Operation 1. Rocker Arm Shaft The rocker arm shaft must be installed with the oil ports facing up.

EX255-EX285

W5-5-7

ENGINE REASSEMBLY MAJOR COMPONENT


Reassembly Steps-I ▲ 1. Oil jet ▲ 2. Crankshaft bearing (upper half) 3. Crankshaft ▲ 4. Thrust bearing ▲ 5. Crankshaft bearing (lower half) and crankshaft bearing cap ▲ 6. Timing gear case * 7. Tappet ▲ 8. Camshaft

▲ 9. ▲ 10. ▲ 11. ▲ 12. ▲ 13. ▲ 14. ▲ 15. ▲ 16. *

Idler gear shaft Idler gear Piston and connecting rod Oil pump and coupling Flywheel housing Rear oil seal Oil pan Oil cooler The tappet must be installed before the camshaft installation.

W5-5-8

EX255-EX285

ENGINE REASSEMBLY Important Operations 1. Oil Jet Install the oil jets taking care not to damage the oil jet nozzles.

N•m (kgf•m/lb.ft) Oil Jet Torque

16-25 (1.6-2.6/12-19)

2. Crankshaft Bearing (Upper Half) 5. Crankshaft Bearing (Lower Half) and Crankshaft Bearing Cap The Crankshaft Bearing Configuration With Oil Groove

Without Oil Groove

Bearing Upper Half

All Upper Halves

–

Bearing Lower Half

–

SM7579

With oil hole and groove (upper)

Fit correctly

All Lower Halves

Take care not to misinstall the bearing halves.

No oil groove and hole (lower)

SM7580

4. Thrust Bearing Install the thrust bearings with the oil groove side facing the crankshaft sliding face.

Oil groove side SM7581

5. Crankshaft Bearing Cap 1) Lubricate the bearing cap bolts with engine oil. 2) Install the bearing caps to the crankshaft. The arrow mark must be pointing to the front of the engine. 3) Tighten the bearing cap bolts to the specified torque a little at a time in the numerical order shown in the illustration.

Arrow mark (Position No. punched)

Front

SM7582

EX255-EX285

W5-5-9

ENGINE REASSEMBLY N•m (kgf•m/Ib.ft) Crankshaft Bearing Cap Bolt Torque

226-245 (23.0-25.0/166-181)

4) Check that the crankshaft turns smoothly by manually rotating it. 6. Timing Gear Case 1) Apply liquid gasket to the timing gear case surfaces ing the cylinder body. 2) Tighten the timing gear case bolts to the specified torque.

Lubricate with engine oil

SM7583

N•m (kgf•m/Ib.ft) Timing Gear Case Bolt Torque

21-30 (2.1-3.1/15-22)

SM7584

8. Camshaft Tighten the thrust plate bolts through the camshaft gear hole. N•m (kgf•m/Ib.ft) Thrust Plate Bolt Torque

21-30 (2.1-3.1/15-22) N•m (kgf•m/Ib.ft)

Camshaft Gear Bolt Torque

142-172 (14.5-17.5/105-127)

Camshaft gear

SM7585

Oil port

9. Idler Gear Shaft Use the thrust collar fixing bolt as a guide to install the idler gear shaft. The oil port must be facing the camshaft.

10. Idler Gear 1) Install the idler gear. Set the timing marks A and B as shown in the illustration. 2) Tighten the idler gear bolts seating the thrust collar to the specified torque. The thrust collar must be installed with the chamfered side facing the front of the engine.

SM7586

Injection pump gear

Idle gear

N•m (kgf•m/Ib.ft) Idle Gear Bolt Torque

44-64 (4.5-6.5/33-47)

"C" mark

"B" mark

Camshaft gear "A" mark Crankshaft gear

SM7587

W5-5-10

EX255-EX285

ENGINE REASSEMBLY 11. Piston and Connecting Rod 1) Set the piston ring gaps as shown in the illustration. 2) Lubricate the piston, the piston rings, and the connecting rod bearings with engine oil. 3) Position the piston front mark towards the front of the engine.

4) Use the piston ring compressor to compress the piston rings. Piston Ring Compressor: 9-8522-1251-0 5) Use a hammer grip to push the piston in until it makes with the crankpin. At the same time, rotate the crankshaft until the crankpin reaches its highest point.

SM7588

Piston ring compressor

Front mark

(▲)

SM7589

6) Set the bearing cap cylinder number marks and the connecting rod cylinder number marks. The marks must be facing the exhaust manifold.

Cylinder number

7) Lubricate the connecting rod cap bolt threads and setting fases with Mos grease. 8) Use the angular tightening method to tighten the connecting rod cap bolts to the specified torque.

SM7590

N•m (kgf•m/lb.ft) st

Connecting Rod Bolt Torque and Angle

1 step

2nd step

39 (4/29)

60°-90°

12. Oil Pump and Coupling 1) Lubricate the oil pump with the specified grade of engine oil. 2) Install the oil pump with the coupling. 3) Tighten the oil pump bolts to the specified torque.

SM7591

Coupling

N•m (kgf•m/Ib.ft) Oil Pump Bolt Torque

42-62 (4.3-6.4/31-46)

SM7592

EX255-EX285

W5-5-11

ENGINE REASSEMBLY 13. Flywheel Housing 1) Apply a sealant to the shaded area of the illustration. 2) Install the flywheel housing. Tighten the flywheel housing bolts to the specified torque. N•m (kgf•m/Ib.ft) 147-167 Flywheel Housing Outer Bolt (15.0-17.0/108-123) Bolt Torque

Inner Bolt

21-30 (2.1-3.1/15-22) SM7593

14. Rear Oil Seal (Axial Type) 1) Tighten the adapter to the crankshaft rear end section with 2 bolts. 2) Insert the oil seal into the peripheral section of adapter. 3) Insert the sleeve into the adapter section, and tighten it with a bolt until the adapter section hits the sleeve. 4) Remove the adapter and the sleeve. 5) With the seal pressed in, check the dimension of the oil seal section. Standard Dimension = 11.6 ± 0.3 mm (0.457 ± 0.012 in) Oil Seal Installer: 5-8840-9025-0

11.6±0.3mm (0.457±0.012in)

SM7594

15. Oil Pan 1) Apply sealant to the area indicated by the arrows in the illustration. 2) Install the oil pan gasket 3) Install the oil pan. Tighten the oil pan bolts to the specified torque. N•m (kgf•m/Ib.ft) Oil Pan Bolt Torque

21-30 (2.1-3.1/15-22)

SM7595

16. Oil Cooler 1) Apply sealant to the oil cooler gasket. 2) Install the oil cooler gasket to the oil cooler body case. 3) Install the oil cooler. Tighten the oil cooler bolts to the specified torque. Start from the middle and work out to either side. Refer to the illustration N•m (kgf•m/lb.ft) Oil Cooler Torque

14-24 (1.4-2.4/10-17)

SM7596

W5-5-12

EX255-EX285

ENGINE REASSEMBLY


Reassembly Steps-II ▲ 1. Flywheel ▲ 2. Injection pump and injection pump gear 3. Oil thrower 4. Timing gear cover 5. Crankshaft pulley and dust thrower 6. Taper bushing ▲ 7. Crankshaft pulley nut 8. Oil pump driving pinion

▲ 9. ▲ 10. ▲ 11. ▲ 12. ▲ 13. 14. ▲ 15. 16.

Tappet chamber cover Water pump Cylinder head gasket Cylinder head Cylinder head bolt Push rod Rocker arm and rocker arm shaft Rubber hose (Water by-)

EX255-EX285

W5-5-13

ENGINE REASSEMBLY Important Operations 1. Flywheel 1) Lubricate the flywheel bolt threads. 2) Install the flywheel. The crankshaft rear end dowel pin and the flywheel dowel hole must be aligned. 3) Tighten the flywheel bolts to the specified torque in the numerical order shown in the illustration. Lubricate with engine oil

N•m (kgf•m/lb.ft) Flywheel Bolt Torque

197-240(20.1-24.5/145-177) SM7598

2. Injection Pump and Injection Pump Gear Assembly 1) Install the injection pump bracket with the injection pump to the timing gear case. Dowel the injection pump bracket with the timing gear case. 2) Tighten the injection pump bolts to the specified torque. N•m (kgf•m/Ib.ft) Injection Pump Bolt Torque

21 - 30 (2.1 - 3.1/15 - 22)

SM7468

3) Align the injection pump gear “C” timing mark with the idler gear “C” timing mark. Injection pump gear

"C" mark

Idle gear

"B" mark

Camshaft gear "A" mark Crankshaft gear SM7587

W5-5-14

EX255-EX285

ENGINE REASSEMBLY 7. Crankshaft Pulley Nut 1) Apply MoS2 to the crankshaft pulley nut threads and fitting face. 2) Use the appropriate wrench to tighten the crank shaft pulley nut to the specified torque.

Pulley

N•m (kgf•m/Ib.ft) Crankshaft Pulley Nut Torque

Wrench

539-637 (55-65/378-470)

SM7474

9. Tappet Chamber Cover 1) Apply sealant (TB 1207B) to the tappet chamber cover. 2) Install the tappet chamber cover and tighten the bolts to the specified torque. N•m (kgf•m/lb.ft) Tappet Chamber Cover Bolt Torque

21-30 (2.1 - 3.1/15 - 22)

SM7601

10. Water Pump Apply sealant (Belco Bond No. 4) to the water pump gasket before installing the water pump.

Apply sealant to the cylinder body side only

SM7602

11. Cylinder Head Gasket 12. Cylinder Head 13. Cylinder Head Bolt 1) Carefully place the cylinder head gasket on the cylinder body upper surface. The gasket “TOP” mark must be facing up. 2) Align the cylinder body dowels and the cylinder head dowel holes.

Front, Top mark

Front

SM7603

EX255-EX285

W5-5-15

ENGINE REASSEMBLY 3) Carefully place the cylinder head on the cylinder body. 4) Apply molybdenum disulfide grease to the cylinder head bolt threads and setting faces. 5) Use the “Angular Tightening Method”. 6) Tighten the cylinder head bolt as follows. 1) As cylinder head bolts have two kinds of length, install them at proper location. The shorter ones (6 bolts) must be used at the injection pump side. 2) Follow the numerical sequence shown in the illustration.

Front

SM7604

N•m (kgf•m/lb.ft) Bolt Torque

1st step

2nd step

3rd step

69 (7.0/51)

88 (9.0/65)

90°-120°

15. Rocker Arm and Rocker Arm Shaft 1) Check that the rocker arm shaft bracket lower surface oil port is free from obstruction. 2) Install the rocker arm shaft with the bracket to the cylinder head. 3) Tighten the rocker arm bracket bolts to the specified torque a little at a time in the numerical order shown in the illustration. 4) Lubricate the rocker arm and the rocker arm shaft with engine oil. N•m (kgf•m/Ib.ft) Rocker Arm Shaft Bracket Bolt and Nut Torque

25-35 (2.6-3.6/19-26)

5) Adjust the valve clearance. Refer to MAINTENANCE for the valve clearance adjustment procedure.

SM7605

W5-5-16

EX255-EX285

ENGINE REASSEMBLY

EXTERNAL PARTS

SM7606

Left-hand Side Reassembly Steps ▲ 1. Cylinder head cover 2. Fan pulley 3. Alternator ▲ 4. Fan belt ▲ 5. Starter ▲ 6. Turbocharger mounting flange gasket.

▲ 7. Turbocharger ▲ 8. Oil drain pipe ▲ 9. Oil feed pipe 10. Air breather 11. Dipstick and guide tube

EX255-EX285

W5-5-17

ENGINE REASSEMBLY Important Operations 1. Cylinder Head Cover 1) Check that the rocker arms, the rocker arm shafts, and the valve springs are thoroughly lubricated with engine oil. If required, relubricate these parts. 2) Place the cylinder head cover gasket on the cylinder head cover. Check the head cover gasket for looseness. 3) Tighten the cylinder head cover bolts to the specified torque a little at a time in the sequence shown in the illustration. SM7607

N•m (kgf•m/lb.ft) Cylinder Head Cover Bolt Torque

7.8 - 9.8 (0.8 - 1.0/5.8 - 7.2)

4. Fan Belt Adjust the fan belt tension. Refer to MAINTENANCE for the fan belt tension adjustment.

5. Starter Install the starter to the flywheel housing and tighten the bolts to the specified torque. N•m (kgf•m/lb.ft) Starter Fixing Bolts Torque

75 - 91 (7.6 - 9.3/55 - 67)

SM7608

6. Turbocharger Mounting Flange Gasket Carefully position the gasket with the edged side facing up.

SM7609

W5-5-18

EX255-EX285

ENGINE REASSEMBLY 7. Turbocharger Semitighten the turbocharger mounting nuts. The nuts will be fully tightened after installation of the oil pipes. N•m (kgf•m/lb.ft) Turbocharger Mounting Nut Torque

42-62 (4.3-6.3/31-46)

SM7610

8. Oil Drain Pipe 1) Remove the exhaust manifold distance tube immediately beneath the turbocharger. This will make it easier to install the oil drain pipe. 2) Install the oil drain pipe and tighten the oil drain pipe flange nuts to the specified torque.

Distance tube

N•m (kgf•m/lb.ft) Oil Drain Pipe Torque

28 - 46 (2.9 - 4.7/21 - 34) SM7611

3) Reinstall the exhaust manifold distance tube and tighten it to the specified torque. Exhaust manifold nut torque is shown in the page W5-5-5.

9. Oil Feed Pipe 1) Pre-lubricate the turbocharger with CD grade oil through the oil port shown by the arrow in the illustration. 2) Install the oil feed pipe and tighten the pipe flange bolts to the specified torque. N•m (kgf•m/lb.ft) Oil Feed Pipe Flange Bolt Torque

16 - 25 (1.6 - 2.6/12 - 19)

SM7612

EX255-EX285

W5-5-19

ENGINE REASSEMBLY

SM7613

Right-hand Side Reassembly Steps 1. Glow plug ▲ 2. Injection nozzle ▲ 3. Injection pipe and fuel leak off pipe ▲ 4. Oil filter 5. Oil pipe; filter to cooler 6. Not installed 7. Oil pipe; injection pump to engine body 8. Fuel filter

▲ 9. ▲ 10. ▲ 11. ▲ 12. 13. ▲ 14.

Fuel pipe; feed pump to fuel filter Fuel pipe; fuel filter to injection pump Fuel return pipe Air duct Not installed Cooling fan

W5-5-20

EX255-EX285

ENGINE REASSEMBLY Important Operation 2. Injection Nozzle Install the injection nozzles with the injection nozzle gaskets. Be careful not to damage the nozzle tips.

Dust cover

N•m (kgf•m/lb.ft) Injection Nozzle Bolt Torque

17 - 21 (1.7 - 2.1/12 - 15) Nozzle gasket SM7614

3. Injection Pipe and Fuel Leak Off Pipe 1) Install the fuel injection pipes (1) and tighten the bolts to the specified torque. N•m (kgf•m/lb.ft) Injection Pipe Torque

28 - 32 (2.9 - 3.3/21 - 24)

2) Carefully position and set the clips (2). It is very important that each clip be positioned correctly. An improperly positioned clip will result in objectionable fuel pulsing noise and injection pipe breakage. 3) Install the fuel leak off pipes (3) .

4. Oil filter (When the oil filter is being removed in an oil filter assembly with the filter cover.) 1) Before the installation, set the special gaskets which are included within the repair kit with the oil filter mounting bolts. 2) Apply a coat of LOCTITE 271 on the bolt threads to seal the oil leak from the crankcase. 3) Install the oil filter assembly with tightening the bolts securely. N•m (kgf•m/lb.ft) Oil Filter Assembly Mounting Bolt Torque

42-62 (4.3-6.3/31-46)

SM7615

SM7424

EX255-EX285

W5-5-21

ENGINE REASSEMBLY 9. Fuel Pipe (Feed Pump to Fuel Filter) 10. Fuel Pipe (Fuel Filter to Injection Pump) 11. Fuel Return Pipe Install the fuel pipes and tighten the fuel pipe t bolts to the specified torque. Take care not to interchange the check valves and t bolts. N•m (kgf•m/lb.ft) Fuel Pipe t Bolt Torque

16 - 18 (1.6 - 1.8/12 - 13) SM7617

12. Air Duct Install the air duct and tighten the air duct flange bolts to the specified torque. N•m (kgf•m/lb.ft) Intake Pipe Flange Bolt Torque

21 - 30 (2.1 - 3.1/15 - 22)

SM7618

W5-5-22

EX255-EX285

ENGINE REASSEMBLY ENGINE TUNING OPERATION After reassembly, the engine must be tuned. This will ensure that the engine operates at its maximum efficiency. 1. Mount the engine on a test bench. 2. Fill the engine with the specified oil. 3. Connect the cooling pipes and the fuel pipes.

Reference

Starter switch PREHEAT OFF ON Glow plug

START Control resistor

0.85 mm2 0.5

Charge lamp

1.25 Fuse box

Warning lamp

0.85

Ammeter 0.85 Fusible link

1.25

0.5

Relay

Oil pressure switch

0.85

Starter Battery

Regulator Alternator

Condenser

SM7619

4. Connect the electrical wiring. Refer to the wiring diagram. 5. Connect the air intake line to the air cleaner. 6. Connect the exhaust pipe. 7. Manually operate the fuel feed pump to feed fuel to the engine. 8. Bleed the fuel lines of air. Refer to Page W5-2-5 of Section 2 MAINTENANCE for the air bleeding procedure.

EX255-EX285

W5-5-23

ENGINE REASSEMBLY 9. Crank the engine with the starter (non-ignition operation) for about twenty seconds. This will prelubricate the engine internal components. 10. Start the engine and allow it to run at 750 to 800 rpm for five minutes. 11. Remove the cylinder head cover while the engine is running. 12. Check that the engine oil is continuously circulating from the oil pump to the valve rockers through the cylinder head. If there is no oil circulation or if the oil circulation is sluggish, stop the engine and make the appropriate repairs or adjustments. Reinstall the cylinder head cover. 13. Increase the engine speed to 1,500 rpm to do the engine warming-up operation. 14. Check the engine for oil, fuel, coolant, and air intake leakage. 15. Check for abnormal noise and odor. 16. Check for abnormal electrical charging. 17. Check the engine fastening parts for looseness. 18. When the engine coolant temperature reached to 75 °C (167 °F) or more, increase the engine speed to 2,000 rpm and allow it to run for twenty minutes. This will give the engine the essential run-in operating time. 19. Adjust the engine operation speed to the specified value. 20. Stop the engine to complete the tuning procedure.

W5-5-24

EX255-EX285

ENGINE REASSEMBLY NOTE

EX255-EX285

W5-6-1

LUBRICATING SYSTEM GENERAL DESCRIPTION

Valve opening pressure 780 kPa

Full flow filter

Oil pressure and oil filter warning light

By- valve Valve opening pressure 98 kPa

Oil pressure switch Cylinder body oil gallery

Partial filter


Turbocharger

Oiling jet Piston

Oil pump

Oil relief valve

Oil relief valve

Timing idle gear

Cyl. head valve sys.

Crank Camshaft shaft brgs. brgs.


Inj. pump

Oil cooler

conn. rod brgs.

Paper filter

By- valve

Starter switch Battery

Oil strainer

Oil pan

SM7620

This family of engines uses a normal forced circulation lubricating system. The gear type oil pump is driven by the camshaft oil pump drive. The cartridge (spin-on) type oil filter is used.

W5-6-2

EX255-EX285

LUBRICATING SYSTEM OIL PUMP

SM7621

Disassembly Steps 1. Strainer 2. Suction pipe 3. Cover and dowel

4. Driven gear 5. Drive shaft and gear 6. Driven gear shaft

EX255-EX285

W5-6-3

LUBRICATING SYSTEM Inspection and Repair Make the necessary adjustments, repairs, and part replacements if excessive wear or damage is discovered during inspection.

Visually inspect the disassembled parts for excessive wear and damage OIL PUMP DRIVE GEAR Use a feeler gauge to measure the clearance between the oil pump cover (oil pump case) inside surface and the drive gear. If the clearance exceeds the specified limit, the drive gear and/or the oil pump cover must be replaced. mm (in) Limit Oil Pump Cover and Oil Pump Drive Gear Clearance

SM7622

0.20 (0.0079)

SM7623

OIL PUMP DRIVEN GEAR Use a feeler gauge to measure the clearance between the oil pump case cover inside surface and the driven gear. If the clearance exceeds the specified limit, the driven gear or the oil pump cover must be replaced. mm (in) Limit Oil Pump Body and Driven Gear Clearance

0.15 (0.0059)

Reassembly To assemble, follow the disassembly procedures in reverse order.

SM7624

W5-6-4

EX255-EX285

LUBRICATING SYSTEM OIL COOLER

SM7625

Disassembly Steps 1. Oil cooler element 2. Element gasket 3. By- valve plug

4. 5. 6.

O-ring; plug By- valve spring By- valve

Inspection and Repair Make the necessary adjustments, repairs, and part replacements if excessive wear or damage is discovered during inspection.

EX255-EX285

W5-6-5

LUBRICATING SYSTEM

SM7626

Reassembly Steps 1. By- valve 2. By- valve spring 3. O-ring; plug

4. By- valve plug 5. Element gasket 6. Oil cooler element

Important Operation 6. Oil Cooler Element Install the oil cooler element to the oil cooler, and tighten the cooler element fixing nuts to the specified torque. N•m (kgf•m/lb.ft) Oil Cooler Element Fixing Nut Torque

14-24 (1.4-2.4/10-17)

SM7627

W5-6-6

EX255-EX285

LUBRICATING SYSTEM NOTE

EX255-EX285

W5-7-1

COOLING SYSTEM GENERAL DESCRIPTION

Water outlet pipe Thermostat

Reserve tank

Radiator

Cylinder head

Cylinder body

Water pump

SM7628

This family of engines uses a pressurized, forced circulation cooling system with a V-belt driven centrifugal water pump and a wax pellet thermostat with jiggle valve.

W5-7-2

EX255-EX285

COOLING SYSTEM THERMOSTAT Inspection and Repair Make the necessary adjustments, repairs, and part replacements if excessive wear or damage is discovered during inspection.

Visually inspect the thermostat function referring Section 2 MAINTENANCE in page W5-2-6. Thermometer Agitating rod

Wood piece

SM7438

EX255-EX285

W5-8-1

FUEL SYSTEM GENERAL DESCRIPTION

Nozzle holder

Fuel filter

Feed pump Fuel tank

Water sedimentor Injection pump

SM7629

The fuel system consists of the fuel tank, the water sedimentor, the fuel filter, the injection pump, and the injection nozzle. The fuel from the fuel tank es through the water sedimentor and the fuel filter where water particles and other foreign material are removed from the fuel. Fuel, fed by the injection pump plunger, is delivered to the injection nozzle in the measured volume at the optimum timing for efficient engine operation.

W5-8-2

EX255-EX285

FUEL SYSTEM INJECTION NOZZLE

SM7630

Disassembly Steps 1. Nozzle holder cap nut 2. Cap nut gasket 3. Nozzle adjusting screw 4. Push rod spring 5. Nozzle holder push rod

6. ▲ 7. 8. 9. 10.

Retaining nut Injection nozzle Injection pipe connector Connector gasket Nozzle holder body

Important Operation 7. Nozzle Remove the nozzle assembly from the nozzle body. Keep the parts separately to maintain the proper needle valve to body combination.

SM7631

EX255-EX285

W5-8-3

FUEL SYSTEM Inspection and Repair Make the necessary adjustments, repairs, and part replacements if excessive wear or damage is discovered during inspection.

PUSH ROD SPRING Check the push rod spring for wear, weakness, and corrosion.

SM7632

NOZZLE HOLDER PUSH ROD 1. Check the nozzle holder push rod curvature. 2. Check the nozzle holder push rod and needle valve surfaces for excessive wear and poor .

SM7633

INJECTION NOZZLE 1. Check the injection nozzle needle valve, the valve seat, and the injection nozzle hole for carbon deposits. If carbon deposits are present, the injection nozzle and the needle valve must be replaced. 2. Hold the nozzle body vertically. Pull the needle valve about one-third of the way out of the nozzle body. Release the needle valve. Check that the needle valve falls back into the nozzle body as far as the valve seat. If the needle valve does not fall back into the nozzle body as far as the valve seat, the injection nozzle and the needle valve must be replaced.

SM7634

W5-8-4

EX255-EX285

FUEL SYSTEM

SM7635

Reassembly Steps 1. Nozzle holder body 2. Connector gasket ▲ 3. Injection pipe connector ▲ 4. Injection nozzle ▲ 5. Retaining nut

6. 7. 8. 9. ▲ 10.

Nozzle holder push rod Push rod spring Nozzle adjusting screw Cap nut gasket Nozzle holder cap nut

EX255-EX285

W5-8-5

FUEL SYSTEM Important Operation 1. Injection Pipe Connector N•m (kgf•m/lb.ft) Nozzle Connector Torque

49 - 59 (5.0 - 6.0/36 - 43)

SM7636

4. Injection Nozzle There must be no oil on the surfaces of the injection nozzle and the injection nozzle holder. Clean these surfaces with diesel fuel before installation. The nozzle dowel pin must be aligned with the dowel hole in the nozzle holder body. SM7637

5. Retaining Nut N•m (kgf•m/lb.ft) Nozzle Retaining Nut Torque

59 - 78 (6 .0 - 8.0/43 - 58)

SM7638

Injection Starting Pressure Adjustment The injection nozzle injection starting pressure can be adjusted after the adjusting screw is installed. Refer to “FUEL SYSTEM” on Page W5-2-3 of the “MAINTENANCE” Section of this Workshop Manual. MPa (kgf/cm2/psi) Injection Starting Pressure

18.1 (185/2630)

SM7639

10. Nozzle Holder Cap Nut N•m (kgf•m/lb.ft) Cap Nut Torque

29 - 39 (3.0 - 4.0/22 - 29)

SM7427

W5-8-6

EX255-EX285

FUEL SYSTEM INJECTION PUMP CALIBRATION DATA Identification Plate and Product serial number 1. Injection pump adjustment and repair should be made by the nearest ZEXEL CORPORATION or ROBERT BOSCH Authorized Service Outlet. 2. When you ask such authorized service outlet the adjustment or repair, the identification Plate and Product Serial Number will give them a necessary clue to get technical data distributed by the manufacturers previously. Without this data, the Service Outlet will be unable to effectively service your injection pump. If you are unable to locate the data applicable to your injection pump, please FIAT KOBELCO Dealer. 3. Do not remove the Identification Plate and Product Serial Number from the injection pump. Keep the Identification Plate and Product Serial Number clean at all times. Do not allow it to rust or become illegible.

Pump No. NP-PE (LICENCE BOSCH) Identification Number

SM7423

NOTE: Examples of test conditions and calibration data are as follows.

Test conditions required for the fuel injection amount adjustment Injection Nozzle Injection Nozzle Holder Injection Starting Pressure Injection Line Dimensions Inside Diameter Outside Diameter Length Transfer Pump Pressure Testing Diesel Fuel Operating Temperature Pump Rotation Direction

MPa (kgf/cm2/psi) mm (in.)

*ZEXEL No.: 105160-5130 Bosch Type No.: NP-DLLA149SM304 ZEXEL No.: 105030-4750 18.1 (185/2630)

LE P M EXA

kPa (kgf/cm2/psi) °C (°F)

1.8 (0.071) 6.0 (0.236) 600.0 (23.6) 157 (1.6/23) ISO4113 or SAE Standard Test Oil (SAEJ967D) 40 - 45 (104 - 113) Clockwise (Viewed from the drive side)

EX255-EX285

W5-8-7

FUEL SYSTEM INJ. PUMP CALIBRATION DATA MOTORE MODELLO 6BG1-T

Injection pump :

PES6AD 000000-0000

Ass’y No. Date :

000000-0000

Company : No.

ISUZU 0-00000-0000

Governor : EP/RSV 000000-0000

2

Timing device :

1. Test Conditions: Pump rotation:

clockwise (viewed from drive side)

Nozzle & Nozzle Holder Ass’y : 000000-0000 (BOSCH Type No. EF8511/9A) Nozzle: 000000-0000 (BOSCH Type N. DN12SD12T)

Nozzle Holder: 000000-0000 (BOSCH Type N. EF8511/9)

Nozzle opening pressure: 17.2 MPa (175 kgf/cm2)

Pump pressure: 157 kPa (1.6 kgf/cm2)

E L P M A X E

Injection pipe: Outer Dia. 6 mm x Int. Dia. 2 mm - Length 600 mm

Oil Temp. : 40+5 °C

Test Oil: ISO4113 or SAE Standard Oil (SAE J967d)

Overflow valve opening pressure: 127 kPa (1.3 kgf/cm2) 2. Injection Timing:

Pre-stroke: No. 1 Plunger 3.6 ± 0.05 mm Note: Adjust with rack position of Injection order: 1 ____ 5, 1 ____ 3, 1 ____ 6, 1 ____ 2, 1 ____ 4 60°±30'

120°±30'

180°±30'

240°±30

mm

300°±30''

(interval:

°±30')

Plungers are numbered from the Driver side. Tappet clearance: Bolt adjustment type : More than 0.3 mm for all cylinders. Shim adjustment type : Manually rotate the camshaft 2 ~ 3 times and confirm that it rotates smoothly. 4. Injection Quantity : Adjusting point

Rack Position (mm)

Pump Speed (min-1)

Injection q’ty (cm3/1000 strokes)

Max. var bet. cyl (%)

Fixed

A

10.3

1,075

89.5 ± 1.5

±2

Lever

C

Approx. 7.4

450

9.5 ± 1.3

± 14

Rack

D

–

100

85 ± 5

–

Lever

Remarks Basic

Rack limit

E L P M A EX 5. Timing advance specification: Pump speed (min-1) Advance angle (°)

ZEXEL CORPORATION Service Department 1

3-4-1 Kitano, Niiza-shi, Saitama-ken, 352 Japan

W5-8-8

EX255-EX285

FUEL SYSTEM 3. Governor adjustment Recommended speed droop adjustment screw position: 12 (notches from fully tightened position)

Above 14.0 13.0 Rack limit

Governor spring setting

9.5 9.1±0.1 8.5 8.0±0.1 6.5 6.0 6.0±30

0 300 145±30

475 350

1100

(430)

1130 1210

(1120)

Pump speed (r/min) SM7640

Speed control lever angle

Stop lever angle

op St

Norma l

St op Full-speed

Rack position (mm)

Idle-sub spring setting

Idling Dead point

SM7641

EX255-EX285

W5-9-1

TURBOCHARGER GENERAL DESCRIPTION

RHG6

SM7642

W5-9-2

EX255-EX285

TURBOCHARGER TURBOCHARGER IDENTIFICATION The IHI Turbocharger nameplate gives the date of manufacture and other important information required to identify the unit when service inquiries or part orders are made. The arrow in the illustration indicates the location of the Turbocharger nameplate.

SM7643

The turbocharger nameplate has the following information stamped on it. Refer to the illustration at the left. (1) Turbo Specification Number, Production Year and Month (2) Production Date, Daily Serial Number (3) ISUZU Parts Number

Turbo Spec. Serial No. RHG6 Parts No.

SM7644

EX255-EX285

W5-9-3

TURBOCHARGER

INSPECTION

AND

REPAIR

If excessive wear or damage is discovered during inspection, the appropriate parts must be adjusted, repaired, or replaced. Damage or improper adjustment of the turbocharger will inhibit sufficient air flow to the engine, preventing it from delivering full performance. If the engine demonstrates a significant drop in performance, check for engine damage or wear. If no significant engine damage or wear can be found, it is likely that the turbocharger is at fault. When reduced performance is the result of a faulty turbocharger, your nearest FIAT KOBELCO Dealer for the proper repairs. The following is primarily a description of the particularly important rotor shaft end play, and bearing clearance standard and limit values.

Rotor Shaft Axial Play Measurement 1) Install a dial indicator on the turbine housing as illustrated. 2) Use the dial indicator to measure the rotor shaft axial play with moving the shaft push and pull. Read the total indicator reading (TIR).

Magnet base Turbine housing

mm (in) IHI RHG6 Rotor Shaft Axial Play TIR

Limit

Push and pull Dial indicator

0.11 (0.0043) SM7645

3) If the measured value exceeds the specified limit the shaft must be replaced.

Rotor Shaft Radial Play Measurement 1) Turn over the turbocharger with the turbine exhaust inlet flange facing up. 2) Install a dial indicator to measure the rotor shaft radial play. 3) Use the dial indicator to measure the play. Read the TIR.

Dial indicator

Magnet base

mm (in) IHI RHG6 Rotor Shaft Radial Play TIR

Limit 0.205 (0.0081)

Push and pull

Push and pull Oil inlet SM7646

4) If the measured value exceeds the specified limit replace the shaft.

W5-9-4

EX255-EX285

TURBOCHARGER NOTE

EX255-EX285

W5-10-1

STARTING AND CHARGING STARTER MOTOR Starter identification The starter identification plate is attached to the starter motor outside yoke. The ISUZU part number, the manufacturer’s code number, and other important information are stamped on the plate. Refer to the identification plate together with the “Main Data and Specifications” Tables and accompanying charts in this Manual when requesting service assistance from a qualified electrical repair shop. If you are unable to locate the data applicable to your starter motor, please your FIAT KOBELCO Dealer.

Identification Plate

STARTING MOTOR

SM7647

A: B: C: D:

Isuzu part number Manufacturer’s code number Rated output Manufacturer’s production mark

W5-10-2

EX255-EX285

STARTING AND CHARGING Main Data and Specifications Isuzu Part No.

897225-1990

1-81100-3420

S25-177

S25-172

(V)

24

24

(kW)

4.5

4.5

(s)

30

30

Clockwise

Clockwise

Roller

Roller

Manufacturer’s code No. (HITACHI) Rated voltage Rated output Rating Direction of rotation (Viewed from the pinion side) Clutch type Terminal voltage (No load)

(V)

24

24

Minimum current (No load)

(A)

Less than 100

100

(min-1)

More than 3500

More than 3500

Modules

3

3

Number of teeth

11

11

Starter motor minimum operating speed (No load) Pinion gear

Outside diameter

mm (in.)

40.64 (1.60)

40.64 (1.60)

Travel distance

mm (in.)

1.5 (0.032)

1.5 (0.032)

Yoke outside diameter

mm (in.)

90 (3.54)

90 (3.54)

4

4

Number of poles Magnetic switch (at 20 °C [68 °F]) Series coil resistance

(Ω)

0.187

0.187

Shunt coil resistance

(Ω)

1.31

1.31

Brush length Standard

mm (in.)

22 (0.866)

22 (0.866)

Limit

mm (in.)

14 (0.551)

14 (0.551)

38 (3.85/8.49)

38 (3.85/8.49)

Brush spring standard fitting load

N (kgf/lb.)

Commutator Outside diameter Standard

mm (in.)

37.0 (1.457)

37.0 (1.457)

Limit

mm (in.)

36.5 (1.437)

36.5 (1.437)

mm (in.)

0.1 (0.004)

0.1 (0.004)

mm (in.)

0.5-0.8

0.5-0.8

(0.020-0.031)

(0.020-0.031)

0.2 (0.008)

0.2 (0.008)

Difference between the largest and smallest diameters (Run-out) Limit Depth of undercut mica Standard Limit

mm (in.)

EX255-EX285

W5-10-3

STARTING AND CHARGING Starter motor sectional view

Magnetic switch Gear shaft (Internal gear) Shift lever

Yoke

Gear case Armature Brush

Pinion

Brush holder

Pinion gap (0.3-1.5mm/0.012-0.059in.)

Baffer spring Center bracket (2)

Rear cover

Ball bearing

Through bolt Center bracket (1)

SM7648

Performance

Volt age

Output To

rqu

e

Speed

SM7649

W5-10-4

EX255-EX285

STARTING AND CHARGING ALTERNATOR Alternator Identification The alternator identification plate is attached to the alternator rear bracket. The ISUZU part number, the manufacturer’s code number, and other important information are stamped on the plate. Refer to the identification plate together with the “Main Data and Specifications” Tables and accompanying charts in this Manual when requesting service assistance from a qualified electrical repair shop. If you are unable to locate the data applicable to your alternator, please ISUZU MOTORS LIMITED through your machine supplier.

Identification Plate

SM7650

A: B: C: D: E:

Isuzu part number Manufacturer’s short type name System voltage output Manufacturer’s lot no. Bar code

EX255-EX285

W5-10-5

STARTING AND CHARGING Main Data and Specifications Isuzu Part No.

1-81200-5301

Manufacturer’s code No. (MITSUBISHI)

A004T05486

Rated voltage

(V)

24

Rated output

(A)

50

Rated speed

-1

5000

Rated output at r.p.m No-load output at 0 Amp.

(min ) (A/V/min-1) -1

(V/min )

Direction of rotation as viewed

50/27/5000 24/900 Clockwise

from pulley side Polarity grounded Pulley diameter

(–) mm (in.)

80 (3.15)

Coil resistance at 20°C Field coil

(Ω)

4.4-5.2

Regulator’s applicable Isuzu part No.

1-81260-0170

Manufacturer’s code No.

A866X38282

W5-10-6

EX255-EX285

STARTING AND CHARGING Alternator Sectional Wiew

STARTER RECTIFIER

ROTOR BEARING PULLEY

BEARING

IC REGULATOR

REAR BRACKET

FRONT BRACKET COIL ASSEMBLY (FIELD COIL) SM7651

Charging Circuit

ADDITIONAL DIODES STARTER COIL

INDICATOR LAMP

DIODE TRIO

KEY SWITCH

BATTERY (24V) FIELD COIL IC REGULATOR

ALTERNATOR SM7652

EX255-EX285

W5-11-1

TROUBLESHOOTING HARD STARTING 1) STARTER INOPERATIVE Checkpoint

Neutral switch (If so equipped)

Battery

Trouble Cause

NG

NG

NG

NG

Defective neutral switch

Loose battery cable terminals Poor connections due to rusting

Battery discharged or weak

Fan belt loose or broken

Remedy

NG

Replace the neutral switch

NG

Clean and/or retighten the battery cable terminals

NG

Recharge or replace the battery

NG

Adjust or replace the fan belt

OK

Fusible link

NG

Fusible link shorted

NG

Replace the fusible link

OK

Starter switch

NG

Defective starter switch or starter relay

NG

Replace the starter switch or the starter relay

NG

Defective magnetic switch or starter relay

NG

Repair or replace the magnetic switch

NG

Repair or replace the starter motor

OK

Starter

OK NG Starter

Defective starter motor

W5-11-2

EX255-EX285

TROUBLESHOOTING HARD STARTING 2) STARTER OPERATES BUT ENGINE DOES NOT TURN OVER Checkpoint

Battery

Trouble Cause

NG

NG

NG

Loose battery cable terminals Poor connections due to rusting

Battery discharged or weak

Fan belt loose or broken

Remedy

NG

Clean and/or retighten the battery cable terminals

NG

Recharge or replace the battery

NG

Adjust or replace the fan belt

OK

Starter

NG

NG

Defective pinion gear

Defective magnetic switch

NG

Replace the pinion gear

NG

Repair or replace the magnetic switch

NG

Brush wear Weak brush spring

NG

Replace the brush and/or the brush spring

NG

Piston, crank bearing seizure, or other damage

NG

Repair or replace the related parts

OK

Engine

EX255-EX285

W5-11-3

TROUBLESHOOTING HARD STARTING 3) ENGINE TURNS OVER BUT DOES NOT START FUEL IS BEING DELIVERED TO THE INJECTION PUMP Checkpoint

Injection nozzle

Trouble Cause

NG

Injection nozzle injection starting pressure too low Improper spray condition

Remedy

NG

Adjust or replace the injection nozzle

OK

Injection pump

NG

Defective fuel injection nozzle resulting in fuel drippage after fuel injection

NG

NG

Defective injection pump control rack operation

NG

Repair or replace the injection pump control rack

NG

Injection pump plunger worn or stuck

NG

Replace the injection pump plunger assembly

Replace the delivery valve

W5-11-4

EX255-EX285

TROUBLESHOOTING HARD STARTING 4) ENGINE TURNS OVER BUT DOES NOT START Checkpoint

Trouble Cause

Engine stop mechanism

NG

Defective engine stop mechanism control wire improperly adjusted

Remedy

NG

Replace the engine stop mechanism Adjust the control wire

FUEL IS NOT BEING DELIVERED TO THE INJECTION PUMP

Fuel

NG

Fuel tank is empty

NG

Fill the fuel tank

OK

Fuel piping

Repair or replace the fuel lines Retighten the fuel line connections

NG

Clogged or damaged fuel lines Loose fuel line connections

NG

NG

Fuel filter overflow valve does not close

NG

Repair or replace the fuel filter overflow valve

NG

Clogged fuel filter element

NG

Replace the fuel filter element or the fuel filter cartridge

NG

Bleed the air from the fuel system

OK

Fuel filter

OK NG Fuel system

Air in the fuel system

EX255-EX285

W5-11-5

TROUBLESHOOTING UNSTABLE LOW IDLING

Checkpoint

Low idling system

Trouble Cause

Remedy

NG

Low idling improperly adjusted

NG

NG

Defective low idling speed control device

NG

Repair or replace the low idling speed control device

NG

Throttle control system improperly adjusted

NG

Adjust the throttle control system

NG

Fuel system leakage or blockage

NG

Repair or replace the fuel system

NG

Bleed the air from the fuel system

Adjust the low idling

OK

Low idling speed control device

OK

Throttle control system

OK

Fuel system

NG

NG

Air in the fuel system

Water particles in the fuel system

NG

Change the fuel

OK

Fuel filter

Continued on the next page

NG


NG


W5-11-6

EX255-EX285

TROUBLESHOOTING UNSTABLE LOW IDLING

Checkpoint

Trouble Cause

Remedy

Continued from the previous page OK

Injection pump

NG

NG

NG

NG

NG

Defective governor lever operation

Broken plunger spring

Worn plunger

Worn camshaft

Worn roller tappet

NG

NG

NG

NG

NG

Repair or replace the governor lever

Replace the plunger spring

Replace the plunger assembly

Replace the camshaft

Replace the roller tappet

OK

Valve clearance

NG

Valve clearance improperly adjusted

NG

Adjust the valve clearance

OK

Compression pressure

NG

Blown out cylinder head gasket Worn cylinder liner Piston ring sticking or broken Improper seating between the valve and the valve seat

NG

Replace the related parts

EX255-EX285

W5-11-7

TROUBLESHOOTING INSUFFICIENT POWER

Checkpoint

Air cleaner

Trouble Cause

NG

Clogged air cleaner element

Remedy

NG

Clean or replace the air cleaner element

OK

Fuel

NG

Water particles in the fuel

NG

Replace the fuel

OK

Fuel filter

NG


NG


NG

Repair or replace the fuel feed pump

NG

Replace the injection nozzle

NG


NG

Replace the fuel injection pipes

OK

Fuel feed pump

NG

Defective fuel feed pump

OK

Injection nozzle

NG

NG

Injection nozzle sticking


OK

Fuel injection pipes


NG

Fuel injection pipes damaged or obstructed

W5-11-8

EX255-EX285


Checkpoint

Trouble Cause

Remedy


Injection pump

NG

NG

NG

NG

NG

NG

NG


Defective delivery valve

Defective timer

Improper control lever operation

Defective injection timing

Weak governor spring

Worn plunger

Worn camshaft

NG

NG


Repair or replace the timer

NG

Adjust or replace the control lever

NG

Adjust the injection timing Repair or replace the injection pump timer

NG

Replace the governor spring

NG

Replace the plunger assembly

NG

Replace the camshaft

EX255-EX285

W5-11-9


Checkpoint

Trouble Cause

Remedy


Injection pump

NG

Worn roller tappet

NG

Replace the roller tappet

OK

Turbocharger


NG

Exhaust gas leakage from the exhaust system Air leakage from the intake system

NG

Repair or replace the related parts

NG

Defective turbocharger assembly

NG

Replace the turbocharger assembly

NG

Blown out cylinder head gasket Worn cylinder liner Piston ring sticking or broken Improper seating between the valve and the valve seat

NG


OK

Valve clearance

NG


NG


OK

Valve spring

NG

Valve spring weak or broken

NG

Replace the valve spring

OK

Exhaust system

NG

Exhaust pipe clogged

NG

Clean the exhaust pipe

OK NG Full load adjusting screw seal

Open and improperly set adjusting screw seal

NG

Adjust and reseal the adjusting screw

W5-11-10

EX255-EX285

TROUBLESHOOTING OVERHEATING

Checkpoint

Cooling water

Trouble Cause

NG

Insufficient cooling water

Remedy

NG

Replenish the cooling water

OK

Fan belt

NG

Fan belt loose or cracked causing slippage

NG

NG

Defective radiator cap or clogged radiator core

NG

Replace the radiator cap or clean the radiator core

NG

Repair or replace the water pump

Replace the fan belt

OK

Radiator

OK

Water pump

NG

Defective water pump

OK

Cylinder head and cylinder body sealing cap

NG

Defective sealing cap resulting in water leakage

NG

Replace the sealing cap

OK

Thermostat

NG

Defective thermostat

NG

Replace the thermostat

OK

Cooling system


NG

Cooling system clogged by foreign material

NG

Clean the foreign material from the cooling system

EX255-EX285

W5-11-11

TROUBLESHOOTING OVERHEATING

Checkpoint

Trouble Cause

Remedy


Fuel injection timing

NG

Fuel injection timing improperly adjusted

NG

Adjust the fuel injection timing

W5-11-12

EX255-EX285

TROUBLESHOOTING WHITE EXHAUST SMOKE

Checkpoint

Fuel

Trouble Cause

NG

Water particles in the fuel

Remedy

NG

Replace the fuel

OK


NG

Delayed fuel injection timing

NG


OK


NG

Blown out cylinder head gasket. Worn cylinder liner Piston ring sticking or broken Improper seating between the valve and the valve seat

NG


OK

Turbocharger

NG

Defective turbocharger

NG

Replace the turbocharger

OK

Inlet and exhaust valves Valve seals

NG

Defective valve seals Worn valves stems and valve guides

NG

NG

Piston rings worn, broken or improperly installed

NG

Replace the valve seals, the valves, and the valve guides

OK

Piston rings

Replace the piston rings or properly install

OK

Cylinder liners

NG

Cylinder lines scored or worn

NG

Replace the cylinder liners

EX255-EX285

W5-11-13

TROUBLESHOOTING DARK EXHAUST SMOKE

Checkpoint

Air cleaner

Trouble Cause

NG


Remedy

NG



OK

Injection nozzle

NG


NG

NG


NG

NG

Defective delivery valve resulting in fuel drippage after fuel injection

NG

OK



OK

Injection pump

NG

Excessive injection volume

NG


Adjust the injection volume

W5-11-14

EX255-EX285

TROUBLESHOOTING OIL PRESSURE DOES NOT RISE

Checkpoint

Engine oil

Trouble Cause

Remedy

NG

Improper viscosity engine, oil Too much engine oil

NG

Replace the engine oil Correct the engine oil volume

NG

Defective oil pressure gauge or unit Defective indicator light

NG

Repair or replace the oil pressure gauge or unit Replace the indicator light

NG

Replace the oil filter element or the oil filter cartridge

NG

Replace the relief valve and/ or the by- valve spring

NG

Clean the oil pump strainer

NG

Replace the oil pump related parts

OK Oil pressure gauge or unit Oil pressure indicator light

OK

Oil filter

NG

Clogged oil filter element

OK

Relief valve and by- valve

NG

Relief valve sticking and/or weak by- valve spring

OK

Oil pump

NG

NG

Clogged oil pump strainer

Worn oil pump related parts

OK

Rocker arm shaft


NG

Worn rocker arm bushing

NG

Replace the rocker arm bushing

EX255-EX285

W5-11-15

TROUBLESHOOTING OIL PRESSURE DOES NOT RISE

Checkpoint

Trouble Cause

Remedy


Camshaft

NG

Worn camshaft and camshaft bearing

NG

Replace the camshaft and the camshaft bearings

NG

Worn crankshaft and bearings

NG

Replace the crankshaft and/ or the bearings

OK

Crankshaft and bearings

W5-11-16

EX255-EX285

TROUBLESHOOTING EXCESSIVE FUEL CONSUMPTION

Checkpoint

Fuel system

Trouble Cause

NG

Fuel leakage

Remedy

NG

Repair or replace the fuel system related parts

NG


OK

Air cleaner

NG


OK

Low idling speed

NG

Poorly adjusted low idle speed

NG

NG


NG


NG


NG


NG

Defective delivery valve resulting is fuel drippage after fuel injection

NG

NG

Air leakage from the turbocharger intake side

NG

Adjust the low idle speed

OK

Injection nozzle

OK


OK

Injection pump


OK

Turbocharger


Repair the turbocharger intake side

EX255-EX285

W5-11-17

TROUBLESHOOTING EXCESSIVE FUEL CONSUMPTION

Checkpoint

Trouble Cause

Remedy


Turbocharger

NG

Defective turbocharger assembly

NG

NG


NG

Replace the turbocharger assembly

OK

Valve clearance


OK


NG

Blown out cylinder head gasket. Worn cylinder liner Piston ring sticking or broken Improper seating between the valve and the valve seat

NG


OK

Valve spring

NG

Valve spring weak or broken

NG

Replace the valve spring

W5-11-18

EX255-EX285

TROUBLESHOOTING EXCESSIVE OIL CONSUMPTION

Checkpoint

Engine oil

Trouble Cause

Remedy

NG

Engine oil unsuitable Too much engine oil

NG

Replace the engine oil Correct the engine oil volume

NG

Oil leakage from the oil seal and/or the gasket

NG

Replace the oil seal and/or the gasket

OK

Oil seal and gasket

OK

Air breather

NG

Clogged air breather

NG

Clean the air breather

OK

Inlet and exhaust valves Valve seals

NG

Defective valve seals Worn valve stems and valve guides

NG

Replace the valve seals, the valves, and the valve guides

NG

Piston rings worn, broken or improperly installed

NG

Replace the piston rings or porperly install

OK

Piston rings

OK

Cylinder liners

NG

Cylinder lines scored or worn

NG

Replace the cylinder liners

EX255-EX285

W5-11-19

TROUBLESHOOTING ABNORMAL ENGINE NOISE 1) ENGINE KNOCKING Checkpoint

Trouble Cause

Remedy

Check to see that the engine has been thoroughly warmed up before beginning the troubleshooting procedure.

Fuel

NG

Fuel unsuitable

NG

Replace the fuel

OK


NG


NG


NG


NG

Replace the head gasket or the piston ring

OK

Injection nozzle

NG

Improper injection nozzle starting pressure and spray condition

OK


NG

Blown out head gasket Broken piston ring

W5-11-20

EX255-EX285

TROUBLESHOOTING ABNORMAL ENGINE NOISE 2) GAS LEAKAGE NOISE Checkpoint

Exhaust pipes

Trouble Cause

Remedy

NG

Loosely connected exhaust pipes Broken exhaust pipes

NG

Tighten the exhaust pipe connections Replace the exhaust pipes

NG

Loose injection nozzles and/ or glow plugs

NG

Replace the washers Tighten the injection nozzles and/or the glow plugs

NG

Loosely connected exhaust manifold and/or glow plugs

NG

Tighten the exhaust manifold connections

NG

Damaged cylinder head gasket

NG

Replace the cylinder head gasket

OK

Injection nozzles and/or glow plugs

OK

Exhaust manifold

OK

Cylinder head gasket

EX255-EX285

W5-11-21

TROUBLESHOOTING ABNORMAL ENGINE NOISE 3) CONTINUOUS NOISE Checkpoint

Fan belt

Trouble Cause

NG

Remedy

NG

Loose fan belt

Readjust the fan belt tension

OK

Cooling fan

NG

Loose cooling fan

NG

Retighten the cooling fan

OK

Water pump bearing

NG

Worn or damaged water pump bearing

NG

Replace the water pump bearing

NG

Defective alternator vacuum pump

or

NG

Repair or replace the alternator or the vacuum pump

NG


NG

OK

Alternator or vacuum pump

OK

Valve clearance


W5-11-22

EX255-EX285

TROUBLESHOOTING ABNORMAL ENGINE NOISE 4) SLAPPING NOISE Checkpoint

Valve clearance

Trouble Cause

NG


Remedy

NG


OK

Rocker arm

NG

Damaged rocker arm

NG

Replace the rocker arm

OK

Flywheel

NG

Loose flywheel bolts

NG

Retighten the flywheel bolts

OK

Crankshaft and thrust bearings

NG

Worn or damaged crankshaft and/or thrust bearings

NG

NG

Worn or damaged crankshaft and/or connecting rod bearings

NG

NG

Worn or damaged connecting rod bushing and piston pin

NG

Replace the connecting rod bushing and/or the piston pin

NG

Worn or damaged piston and cylinder liner Foreign material in the cylinder

NG

Replace the piston and the cylinder liner

Replace the crankshaft and/ or the thrust bearings

OK

Crankshaft and connecting rod bearings

Replace the crankshaft and/or the connecting rod bearings

OK

Connecting rod bushing and piston pin

OK

Piston and cylinder liner

EX255-EX285

W5-12-1

REPAIR STANDARDS GENERAL RULES 1. These tables provide standards relating the repair. 2. These Repair Standards are based on inspection items, together with dimensions, assembly standards, limit values, and repair procedures. (1) Nominal dimensions are the standard production values. (2) Assembly standards considered to be the values used as objectives during the assembly procedures which follow repairs; as a result, they may be somewhat at variance with the assembly dimensions of a new engine. (3) Limit values refer to the measured values resulting from wear, etc., beyond which a part must not be used. If a measured value falls beyond the limit value, the part involved must be repaired or replaced. (4) "Repair Procedures" indicates normal repair methods. (5) Unless otherwise stated, the unit of numerical values in tables should be taken to refer to millimeters mm (in). 3. Explanation of Used in Tables (1) The dimension of "wear" refers to the difference between the dimensions of a part which is not worn (or the "nominal dimension" of a part without wear) and the dimension of the part suffering from the most wear (the dimension of the worn part). (2) Uneven wear means the difference between the maximum and minimum wear values. 4. When repairs are requested on the overall engine, first perform bench tests to determine what parts require repairs, then perform the minimum disassembly and repairs required to correct the problems. When repairs on a specific engine part are requested, repairs to be made in reference to the relevant items in accordance with the repair standards listed in this manual.

Name of Part

Time for engine disassembly and repair

Nominal Dimension

Inspection Item

Cylinder compression pressure MPa (kgf/cm2/psi)

Assembly Standard Value

3.0 (31/440)

Limit

Repair Procedure

2.5 (26/370) Disassemble and repair engine

Fuel consumption

L/h

100%

140%

Lubricating oil consumption

L/h

100%

200%

Comments Water temperature 70 - 85°C, (158-185°F) engine speed 200 min-1 (varies depending on altitude) New engine performance is assumed 100%

Dia 105 (4.1339)

Dia 105.2 (4.1417)

Upper step wear must be repaired, or replace with standard dimension liner

(Ref) Cylinder & liner interference

Cylinder Block

Engine Body

0.001- 0.019 (0.00004 - 0.0007)

REPAIR STANDARDS

Wear on liner bore Measured at A-A 24.120

W5-12-2

Major Category

Liner projection

0.03 - 0.10 (0.001- 0.004)

0.05 or less (0.002)

Pressure test: 3 minutes kPa (kgf/cm2/psi)

490 (5/71.1)

0.2 (0.0079)

Must be repairable

0.3 (0.0118)

Leaks require repair or replacement

EX255-EX285

Cylinder block upper face warpage

Some projection must be present

Difference in liner projection between neighboring cylinders not to exceed 0.03 (0.001)


Limit

1.0 (0.039)

2.5 (0.098)

Replace insert

Valve seat angle: α 45°

1.5 (0.059)

2.0 (0.079)

Repair with valve seat cutter

After repair, be sure to lap surfaces

0.075 or less (0.003)

0.2 0.079

Cannot be repaired: must replace cylinder head

Warpage of manifold mounting surface

0.05 or less (0.002)

0.4 (0.016)

repair

Water-pressure test, 3 minutes kPa (kgf/cm2/psi)

490 (5/71.1)

Name of Part

Inspection Item

Nominal Dimension

Repair Procedure

EX255-EX285

Major Category

Comments

Valve seat depression: B (both inlet and exhaust) (Insert) (Cylinder head) Bottom surface to cylinder

Valve Same for inlet & exhaust Must not protrude from lower surface of cylinder head

Cylinder Head

Engine Body

Warpage and flatness of cylinder head lower face (mounting surface)

Cylinder head bolts tightening torque (angular tightening method) N•m (kgf-m/lb•ft)

• Clean bolt mounting surfaces and threads, and apply molybdenum disulfide grease. • Never tighten again after using angular tightening method. • Reuse bolts max. 2 times

W5-12-3

69 (7.0/51) ↓ 88 (9.0/65) ↓ 90° - 120°

Leaks require repair or replacement

REPAIR STANDARDS

width with valve seat: A

Inspection Item

Nominal Dimension


Limit

Repair Procedure

Comments

Clearance with major axis 0.051 - 0.085 (0.002 - 0.0033)

Piston pin and piston pin hole clearance

0.010 - 0.023 (0.00039-0.0009)

0.05 (0.00197)

Replace piston or piston pin

Pin wear

35.000 - 35.005 (1.3780 -1.3781)

34.95 (1.3760)

Replace piston pin

1.5 (0.059)

Replace rings when performing engine disassembly and repair

Gauge inner standard diameter 105 (4.134)

Replace

Measure with ring compressed to standard ring gap

Replace

Measure with expander attached

Piston Ring

Piston Ring Gap

No. 1 compression ring

0.35 - 0.50 (0.014 - 0.020)


0.60 - 0.75 (0.0236-0.0295)


0.60 - 0.75 (0.0236 - 0.0295)

Oil ring

0.30 - 0.50 (0.014 - 0.020)


20.4 - 30.6 (2.08 - 3.12/ 4.59 - 6.88)

9.8 (1.0/2.2)


14.1- 21.2 (1.44 - 2.16/ 3.17 - 4.76)

4.9 (0.5/1.1)


14.1- 21.2 (1.44 - 2.16/ 3.17 - 4.76)

4.9 (0.5/1.1)

Oil ring

36.3 - 55.9 (3.7 - 5.7/ 8.16 -12.6

31 (3.2/7.05)

Tension N (kgf/lb)

EX255-EX285

Clearance with cylinder: grade position from upper face 82 mm (3.228 in)

REPAIR STANDARDS

Main Operating Parts

Pistons

Name of Part

W5-12-4

Major Category

Piston Ring


Name of Part


Limit


–

–


0.070 - 0.110 (0.0028 - 0.0043)

0.15 (0.0059)


0.050 - 0.090 (0.0020 - 0.0035)

0.15 (0.0059)

Oil ring

0.030 - 0.070 (0.0012 - 0.0028)

0.15 (0.0059)

Inspection Item

Clearance between piston ring and ring groove

Repair Procedure

Replace rings or piston

At 90° intervals

Comments When assembling compression rings on piston, be sure ring´s marked surface is up Backwards installation will result in excessive oil consumption No top/bottom to oil ring

REPAIR STANDARDS

Ring gap orientation

Nominal Dimension

EX255-EX285

Major Category

W5-12-5

Name of Part

Inspection Item Uneven wear on journal and pins

Journal Diameter

Nominal Dimension Dia. 80 (3.1496) Dia. 64 (2.5197)

79.905-79.925 (3.1459 - 3.1467)

Other Bearing

79.919 - 79.939 (3.1464 - 3.1472)

Use those with projection and proper arc; take care with back side fit Center Bearing only

0.039 - 0.098 (0.0015 - 0.0039)

Other Bearing

0.025 - 0.084 (0.0010 - 0.0033)

0.11 (0.0043)

Replace bearing

Undersize bearings cannot be used 0.15 - 0.33 (0.006 - 0.013)

0.4 (0.016)

Replace thrust bearings

0.05 or less (0.002)

0.4 (0.016)

Replace

Measure at crankshaft’s No. 4 bearing thrust surface

36 or less

Check dynamic balance

(Ref. value) At ends of journal

EX255-EX285

Perform lapping on gears with burrs; in cases of severe damage, replace.

Ring gear

Crankshaft balance (g-cm)

Do not attempt to grind: always replace with new parts

REPAIR STANDARDS

Crankshaft runout

Replace

Ellipse and taper 0.007 (0.0003)

Journal bearing undersize Crankshaft end play

Comments

Replace

Journal bearing arc spread Clearance between journal and bearing

Repair Procedure

Replace

63.924 - 63.944 (2.5167 - 2.5175)

Journal and pin finish precision (taper and ellipse)

Crankshaft

Limit 0.05 (0.002)

Center Bearing only

Pin Diameter



W5-12-6

Major Category

Inspection Item

Nominal Dimension


Crankshaft bearing cap bolt torque

Crankshaft


Name of Part

226 - 245 (23-25/166-181)

Limit

Repair Procedure

EX255-EX285

Major Category

Comments

Apply engine oil to threads and seating areas of bolts before tightening

Do not catch foreign matter in bolts

In case of oil leak, replace oil seal

Check for oil seal collapse

N•m (kgf-m/Ib• ft) Crankshaft rear oil seal wear

REPAIR STANDARDS W5-12-7

Name of Part

Inspection Item

Nominal Dimension


Limit

Clearance between connecting rod bearing and crankpin

0.030 - 0.073 (0.0012 - 0.0029)

0.10 (0.0039)

between connecting rod bearing and crankpin 0.012 - 0.025 (0.00047 - 0.00098)

0.05 (0.00197)

Replace bushing or pin

Sufficient gap to allow smooth rotation when holding big end Crank must not be ground (no undersizes available)

Connecting rod bearing undersize 0.17 - 0.30 (0.0067 - 0.011)

Connecting rod and crankpin end play

0.35 (0.014)

Replace connecting rod

192 (7.559)

Reference value

Big end to small end hole twist (per 100 mm)

0.05 or less (0.002)

0.2 (0.0079)

Repair or replace

Big end to small end hole parallelism (per 100 mm)

0.05 or less (0.002)

0.2 (0.0079)

Repair or replace

Piston weight difference after assembly g

20 or less

39 (4.0/29) ↓ 60° - 90°

Repair or replace

Apply molybdenum disulfide grease to bolts before tightening

EX255-EX285

Bearing cap bolt tightening torque (angular tightening method) N•m (kgf-m/lb•ft)

Take special care with crankpin precision

REPAIR STANDARDS

Connecting Rod

Replace bearing or crankshaft Replace parts with poor or abrasions

Clearance between smallend bushing and piston pin

Center distance between big end and small end

Comments

Use those with projection and proper arc; take care with back side fit

Connecting rod bearing arc spread


Repair Procedure

W5-12-8

Major Category

Name of Part

Inspection Item Journal uneven wear

Nominal Dimension

Repair Procedure

Comments

Replace camshaft

0.03 - 0.09 (0.001- 0.004)

0.15 (0.006)

Replace camshaft or bearing

Dia. 55.94 - 55.97 (2.202 - 2.204)

Dia. 56.6 (2.189)

Replace camshaft

7.21 (0.284)

Replace camshaft

Minor step wear on cams can be repaired

Replace camshaft

Measure with dial gauge at No. 3 or No. 4 journal, runout during one rotation.

Camshaft

Cam height: A-B 7.71 (0.304)

0.12 (0.005)

Camshaft runout

Camshaft play (front-back direction)

0.050 - 0.114 (0.002- 0.005)

0.2 (0.008)

REPAIR STANDARDS


Dia. 56 (2.205)

Limit 0.05 (0.002)

Dia. 56 (2.205)

Clearance between journal and bearing Journal wear


EX255-EX285

Major Category

W5-12-9

Name of Part

Inspection Item Inlet valve stem wear

Dia. 8.88 (0.3496)

Dia. 9 (0.3543)

Clearance between inlet valve stem and valve guide

0.039 - 0.071 (0.0015-0.0028)

0.20 (0.008)

Clearance between exhaust valve stem and guide

0.064 - 0.096 (0.0025-0.0038)

0.25 (0.0098)

Interference between valve guide and cylinder head

0.024 (0.0009)

Valve thickness

Thickness

14.1 (0.555)

Valve stem oil seal lip

Dia. 8.5 (0.335)

Tension N (kgf/Ib) (When compressed to installed length) 44.5mm(1.752in) Free height

Repair Procedure Replace valve and valve guide together

Comments Measure valve stem at three positions

Replace valve and valve guide together Apply oil to valve guide and press in

1.00 (0.039)

1.5 (0.059)

Height of valve guide above cylinder head

Valve spring

Valves

Limit

Replace valve and valve guide together

Reference value Dia. 8.8 (0.346) 142 (14.5/30.9)

127 (13.0/28.7)

60.6 (2.39)

58.0 (2.28)

less than 1.9 (0.075)

2.7 (0.106)

Replace oil seal

Don't damage lip

REPAIR STANDARDS

Valve System

Exhaust valve stem wear

Assembly Nominal Dimension Standard Value

W5-12-10

Major Category

Replace valve spring

Inclination

EX255-EX285

Name of Part

Inspection Item

Valve System

Valves Air cleaner

Limit

0.4 (0.016)

Comments

Adjust

Clearance between rocker arm shaft and rocker arm

0.01 - 0.05 (0.0004-0.002)

0.2 (0.0079)

Rocker arm shaft wear

18.98 - 19.00 (0.747- 0.748)

Dia. 18.85 (0.742)

Air cleaner element condition

Repair Procedure

Replace bushing or shaft Replace

Special order item from manufacturer

REPAIR STANDARDS

Intake System

Valve clearance (inlet & exhaust) (cold)

Assembly Nominal Dimension Standard Value

EX255-EX285

Major Category

W5-12-11

Lubricating oil pressure kPa (kgf/cm2/psi)

290 - 590 (3.0 - 6.0/43 - 85)

196 (2.0/28)

Clearance between pump body inner wall and gear teeth

0.075 - 0.150 (0.003 - 0.0059)

0.2 (0.0079)

Replace bushing, gear or body

Replace gear or cover

Oil pump and Relief valve

Oil pressure

Limit

Inspection Item

Nominal Dimension

Pumping rate 1650 min-1, SAE #30, pumping pressure 392 kPa (4 kgf/cm2/57 psi) oil temp. 80°C (176°F)

(

)

53.3

End gap between pump cover and gear

0.040 - 0.094 (0.0016 - 0.0037)

0.15 (0.0059)

Clearance between drive shaft and pump body

0.032 - 0.070 (0.0013 - 0.0028)

0.15 (0.0059)

Clearance between drive shaft and bushing

0.045 - 0.078 (0.0018 - 0.0031)

0.15 (0.0059)

Replace bushing

Dia 15.9 (0.626)

Replace shaft

Initial operating pressure of relief valve kPa (kgf/cm2/psi)

Comments

L/min

Dia. 16 (0.6299)

Diameter of drive shaft Oil gallery

441 (4.5/64)

Oil pump

785 (8/114)

Reference value

Clogging and damage to oil filter

Initial operating pressure of main oil filter relief valve kPa (kgf/cm2/psi)

Replace

196 (2.0/28)

Replace cartridge every 500 hours of operation

EX255-EX285

Oil filter

Repair Procedure

REPAIR STANDARDS

Lubricating System


Name of Part

W5-12-12

Major Category

Name of Part

Nominal Dimension

Inspection Item Water pump ball bearing chatter (radial direction) Pumping rate

(


Limit

0.008 - 0.010 (0.0003-0.0004)

0.2 (0.0079)

Repair Procedure

Replace

Comments #6305 (2) #6205 (1)

L/min

pumping speed 3720 min-1, water temp 30°C (86°F) Total head 13.5m(531.5in) or more

)

Clearance between pump impeller and pump body

300

Repair or replace if impeller and pump body are touching

Water pump

Fan belt deflection

About 7 -10 (0.276 - 0.394)

Adjust

Initial thermostat operating temperature (at sea level)

°C (°F)

Thermostat full-open temperature °C (at sea level) (°F)

Fan center and bearing shaft interference

Pulley and fan center clearance

Temperature at which thermostat lift reaches 10mm(0.394in) or more.

0.07 - 0.11 (0.003 - 0.004)

Replace water pump ASM

0.020 - 0.060 (0.0008 - 0.0024)


0.14 or less (0.006)


W5-12-13

Bearing shaft and impeller interference

Replace thermostat if operation is incorrect.

82 ± 2 (179.6 ± 35.6) 95 (203)

(Reference) 98N (10kgf/22lb)

REPAIR STANDARDS

0.3 -1.0 (0.0118 - 0.039)

Press with finger

Cooling System

EX255-EX285

Major Category

Nominal Dimension


Limit

Repair Procedure

Clogged, cracked, loose fuel pipes, injection pipes, nozzle holders; defective seals.

Repair or replace

Fuel filter element clogging or damage

Replace

Delivery valve

Injection pump

Inspection Item

Delivery valve wear

Inspect for damage to valve's piston and seat; replace in case of severe vertical cracks on piston or impact scars on seat with loss of finish gloss. Immerse delivery valve in clean diesel fuel, then lightly press lower part of valve seat with finger and release; replace assembly if valve does not return to original state when finger is released.

Comments

Cartridge type

REPAIR STANDARDS

Fuel System

Piping, etc.

Name of Part

W5-12-14

Major Category

EX255-EX285

Name of Part

Nominal Dimension

Inspection Item


Limit

Repair Procedure

EX255-EX285

Major Category

Comments

Pump Part No. 1-15603-328-0 Adjustment Item Rotation Direction

Clockwise (viewedloose from fuel drivepipes, side) Clogged, cracked, injection pipes, nozzle holders; defective seals. 105780-0000 (BOSCH Type No. DN12SD12T)

Adjustment Conditions

Nozzle opening pressure Fuel pumping pressure

MPa (kgf/cm2/psi)

17.2 (175/2490)

kPa (kgf/cm2/psi)

157 (1.6/23)

Pipe (o.d. x i.d. x lenght)

Dia. 6(0.236) x Dia. 2(0.079) x 600(23.62)

Test fuel

ISO4113 or SAE Standard Oil (SAE J967d)

Fuel temperature

°C (°F)

40 - 45 (104 -113)

Max. var Injection q’ty Pump speed bet. cyl -1 3 (mm /1000 strokes) (min ) (%)

Adjustment point

Rack position mm (in)

A

10.3 (0.4449)

1075

89 ± 1.5

±2

Lever

C

Approx 7.5 (0.295)

450

9 ± 1.3

± 14

Rack

D

–

100

150 ± 5

–

Lever

Fixed

Remarks Basic

Rack limit

W5-12-15

Injiection adjustment

Injection pump

105780-2080 (BOSCH Type No. EF8511/9)

Nozzle holder assembly

REPAIR STANDARDS

Fuel System

Nozzle

Name of Part

Nominal Dimension

Inspection Item


Limit

Repair Procedure

W5-12-16

Major Category

Comments

Governor perfomance curve Recommended speed droop adjustment screw position:9 (notched from fully tightened position) Above 14.0

Stop lever angle

Idle-sub spring setting

10.2-0.5

7.3±0.3

op

7.5

Full-s

8.0

Nomin al

9.8±0.1

peed

10.3

St

Rack position (mm)

Governor spring setting

op

Injection pump

Speed lever angle

10.9±0.1

St

Fuel System

11.0

REPAIR STANDARDS

Rack limit

Dead point Idling

Pump speed (r/min)

EX255-EX285

Name of Part

Nominal Dimension

Inspection Item


Limit

Injection Nozzle

Fuel System

Technology Needle valve seat: 7.8MPa (80 kgf/cm2/138psi) Needle valve shaft seat: s Impress fuel pressure of 29.4Mpa (300kgf/cm2/4267psi) nozzle starting pressure and measure time required for pressure to drop from 24.5MPa (250kgf/cm2 /3556psi) to19.6MPa (200kgf/cm2/2845psi).

(

)

Repair or replace parts with leaks from seat area

Replace

5.0 or more

(1) Visually inspect, no relatively large drops scattered. (2) No drops scattered to one side. (3) No unevenness of spray from jets.

Warning lamp indication Check for looseness, cuts or damaged insulation to wiring.

Repair

Rotor

Shaft runout

0.06 or less (0.0024)

Bearing chatter

Rated output current

27 V (5000 min-1)

0.1 (0.0038)

Fuel used: diesel fuel; 37 - 40 s 120°C (248°F)

Replace faulty parts

If warning indicator lights when engine is operating at normal speeds, check and repair electrical system.

Performance

Charge/ Wiring Discharge (MITSUBISHI 1-81200-530-1) indication

Alternator 24V, 50A

Electrical

(

Comments

REPAIR STANDARDS

Fuel spray and injection Impress fuel pressure of 19.1Mpa (195kgf/cm2/2770psi) (needle valve opening pressure)

)

Repair Procedure

EX255-EX285

Major Category

Replace rotor

Replace bearings

Rotate by hand and check for smooth rotation; no abnormal sound or resistance should be felt.

50A

W5-12-17

Name of Part

Inspection Item

Nominal Dimension


Limit

22 (0.866)

Starter 24V, 7.4 kW (HITACHI 1-81100-342-0)

0.187 20 °C (68 °F)

Shant coil resistance value (Ω)

1.31 20 °C (68 °F)

O. D. Commutator

Rear side (armature) Front (armature) Pinion shaft (shaft) Unloaded characteristics (24V, 100A or less)

Control , glow plug

Battery terminals

0.5 - 0.8 (0.02 - 0.031)

Plates, separator plates, container, etc. Electrolyte turbidity

Dia. 28 (1.102)

Replace

If coil resistance value is severely abnormal, replace switch. Dia. 36.5 (1.437) 0.2 (0.008)

Replace armature Repair 6001 D

Dia. 16 (0.630) Dia. 16 (0.630)

6905 D

Replace if rotation is not smooth or if abnormal sounds are heard.

Smooth pinion operation without noise

3500 min-1

Replace if cut wiring or shorts are found

Special order from original manufacturer; manufacturer's specs.

EX255-EX285

Battery

Dia. 37 (1.457)

Undercut depth

Performance Preheater

Series coil resistance value (Ω)

14 (0.551)

REPAIR STANDARDS

Electrical

Brush height

Ball bearings

Comments

Repair

Loose mount

Magnetic switch

Repair Procedure

W5-12-18

Major Category

Name of Part

Inspection Item

Nominal Dimension


Limit

Repair Procedure

EX255-EX285

Major Category

Comments

Battery

Electrical

Electrolyte specific gravity (at recharging, 20°C) Capacity (20 hours)

Special order from original manufacturer

Electrode voltage Electrolye surface height Engine run-in operation

Final Inspection

3.0 (31/441)

Difference in compression between cylinders, kPa (kgf/cm2/psi) [water temp. 70 - 85 °C, (158 -185 °F) about 200 min-1] Lubricating oil pressure kPa (kgf/cm2/psi)

290 - 590 (3.0 - 6.0/43 - 85)

Output check

85% or more

Fuel consumption check

110% or less

2.5 (26/370)

Inspect

Warm engine

290 (3 0/43)

Inspect

Warm engine

200 or less (2.0/28)

Adjust

REPAIR STANDARDS

Cylinder compression pressure MPa (kgf/cm2/psi) [water temp. 70 - 85 °C, (158 -185 °F) about 200 min-1]

30 minutes or more

When new engine output is 100%

W5-12-19

W5-12-20

NOTE

REPAIR STANDARDS

EX255-EX285




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