Komatsu 125-3 Series Diesel Engine Shop Manual SEBM024209 – PDF DOWNLOAD

Komatsu 125-3 Series Diesel Engine Shop Manual SEBM024209 – PDF DOWNLOAD

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Komatsu 125-3 Series Diesel Engine Shop Manual SEBM024209 – PDF DOWNLOAD

Language : English
Pages : 374
Downloadable : Yes
File Type : PDF
Size: 24.1 MB

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Komatsu 125-3 Series Diesel Engine Shop Manual SEBM024209 – PDF DOWNLOAD

The Komatsu 125-3 Series Diesel Engine Shop Manual SEBM024209 is a comprehensive technical guide that provides detailed information on the maintenance, repair, and overhaul of the Komatsu 125-3 series diesel engine. This engine is commonly used in heavy equipment such as excavators, bulldozers, and wheel loaders.

The manual is organized into several sections, each covering specific aspects of the engine:

1. General Information: This section provides an overview of the engine, including specifications, maintenance intervals, and general operating guidelines.
2. Inspection and Adjustment: This section provides detailed instructions for inspecting and adjusting engine components, such as the fuel injection system, valves, and timing belts.
3. Engine Assembly: This section covers the removal and installation of major engine components, including the cylinder head, crankshaft, and pistons. The manual includes detailed illustrations and specifications to help technicians perform these tasks safely and efficiently.
4. Lubrication System: This section provides information on the engine’s lubrication system, including oil pump removal and installation, oil filter replacement, and oil pressure testing.
5. Cooling System: This section provides information on the engine’s cooling system, including water pump removal and installation, radiator removal and installation, and thermostat replacement.
6. Fuel System: This section covers the engine’s fuel system, including fuel pump removal and installation, fuel injector replacement, and fuel system troubleshooting.
7. Air Intake and Exhaust System: This section provides information on the engine’s air intake and exhaust system, including air filter replacement, turbocharger removal and installation, and exhaust manifold removal and installation.
8. Electrical System: This section provides information on the engine’s electrical system, including alternator and starter motor removal and installation, as well as troubleshooting procedures for electrical faults.
9. Special Tools: This section lists the special tools required for servicing the engine, including part numbers and illustrations.

The Komatsu 125-3 Series Diesel Engine Shop Manual SEBM024209 is an essential reference guide for maintaining and repairing the engine. It provides detailed instructions, specifications, and illustrations to help technicians perform tasks accurately and safely. The manual is a valuable tool for ensuring that the Komatsu 125-3 series diesel engine continues to operate at peak performance, with maximum efficiency and reliability over its long service life.

TABLE OF CONTENTS:

Komatsu 125-3 Series Diesel Engine Shop Manual SEBM024209 – PDF DOWNLOAD

COVER…………………………………………………………………………………………………………………………………. 1
CONTENTS………………………………………………………………………………………………………………………………. 2
LIST OF REVISED PAGES…………………………………………………………………………………………………………………… 3
SAFETY………………………………………………………………………………………………………………………………… 7
FOREWORD………………………………………………………………………………………………………………………………. 9
GENERAL……………………………………………………………………………………………………………………………. 9
HOW TO READ THE SHOP MANUAL………………………………………………………………………………………………………….. 10
HOISTING INSTRUCTIONS……………………………………………………………………………………………………………….. 11
METHOD OF DISASSEMBLING, CONNECTING PUSH-PULL TYPE COUPLER………………………………………………………………………………. 12
COATING MATERIALS…………………………………………………………………………………………………………………… 14
STANDARD TIGHTENING TORQUE…………………………………………………………………………………………………………… 16
ELECTRIC WIRE CODE………………………………………………………………………………………………………………….. 19
CONVERSION TABLE……………………………………………………………………………………………………………………. 20
UNITS……………………………………………………………………………………………………………………………… 26
01 GENERAL…………………………………………………………………………………………………………………………….. 27
OUTLINE……………………………………………………………………………………………………………………………. 28
SPECIFICATIONS……………………………………………………………………………………………………………………… 32
GENERAL ASSEMBLY DRAWING…………………………………………………………………………………………………………….. 36
WEIGHT TABLE……………………………………………………………………………………………………………………….. 49
ENGINE PERFORMANCE CURVE…………………………………………………………………………………………………………….. 50
11 STRUCTURE AND FUNCTION, MAINTENANCE STANDARD……………………………………………………………………………………………. 61
GENERAL STRUCTURE…………………………………………………………………………………………………………………… 62
INTAKE, EXHAUST SYSTEM………………………………………………………………………………………………………………. 66
INTAKE, EXHAUST SYSTEM…………………………………………………………………………………………………………… 66
AIR CLEANER…………………………………………………………………………………………………………………….. 72
TURBOCHARGER……………………………………………………………………………………………………………………. 73
AFTERCOOLER…………………………………………………………………………………………………………………….. 74
ENGINE BODY………………………………………………………………………………………………………………………… 76
CYLINDER HEAD…………………………………………………………………………………………………………………… 76
CYLINDER BLOCK………………………………………………………………………………………………………………….. 80
CYLINDER LINER………………………………………………………………………………………………………………….. 84
MAIN CIRCULATION SYSTEM………………………………………………………………………………………………………….. 86
CRANKSHAFT……………………………………………………………………………………………………………………… 88
PISTON…………………………………………………………………………………………………………………………. 90
CONNECTING ROD………………………………………………………………………………………………………………….. 92
FLYWHEEL AND FLYWHEEL HOUSING…………………………………………………………………………………………………….. 93
VIBRATION DAMPER………………………………………………………………………………………………………………… 95
TIMING GEAR…………………………………………………………………………………………………………………….. 98
VALVE MECHANISM………………………………………………………………………………………………………………….102
CAMSHAFT………………………………………………………………………………………………………………………..104
CAM FOLLOWER AND PUSH ROD…………………………………………………………………………………………………………105
VALVE AND VALVE GUIDE…………………………………………………………………………………………………………….106
ROCKER ARM SHAFT…………………………………………………………………………………………………………………108
CROSSHEAD……………………………………………………………………………………………………………………….109
LUBRICATION SYSTEM…………………………………………………………………………………………………………………..110
LUBRICATION SYSTEM DIAGRAM………………………………………………………………………………………………………..110
OIL PUMP………………………………………………………………………………………………………………………..111
MAIN RELIFE VALVE………………………………………………………………………………………………………………..113
OIL FILTER………………………………………………………………………………………………………………………114
SAFETY VALVE…………………………………………………………………………………………………………………….115
OIL COOLER………………………………………………………………………………………………………………………116
FUEL SYSTEM…………………………………………………………………………………………………………………………118
FUEL SYSTEM DIAGRAM………………………………………………………………………………………………………………118
OUTLINE OF CRI SYSTEM…………………………………………………………………………………………………………….119
FUEL PIPING……………………………………………………………………………………………………………………..132
FUEL COOLER……………………………………………………………………………………………………………………..134
FUEL FILTER……………………………………………………………………………………………………………………..135
COOLING SYSTEM………………………………………………………………………………………………………………………137
COOLING SYSTEM CHART……………………………………………………………………………………………………………..137
WATER PUMP………………………………………………………………………………………………………………………138
THERMOSTAT………………………………………………………………………………………………………………………141
CORROSION RESISTOR……………………………………………………………………………………………………………….143
ELECTRICAL SYSTEM……………………………………………………………………………………………………………………144
ALTERNATOR MOUNTING………………………………………………………………………………………………………………144
ALTERNATOR………………………………………………………………………………………………………………………147
STARTING MOTOR…………………………………………………………………………………………………………………..152
STARTING AID…………………………………………………………………………………………………………………….154
12 TESTING AND ADJUSTING, TROUBLESHOOTING………………………………………………………………………………………………….157
TESTING AND ADJUSTING DATA……………………………………………………………………………………………………………160
STANDARD VALUE TABLE FOR ELECTRICAL PARTS………………………………………………………………………………………………166
TESTING AND ADJUSTING TOOL LIST……………………………………………………………………………………………………….168
TESTING AND ADJUSTING………………………………………………………………………………………………………………..169
MEASURING INTAKE AIR PRESSURE (BOOT PRESSURE)……………………………………………………………………………………….169
MEASURING EXHAUST TEMPERATURE……………………………………………………………………………………………………..170
ADJUSTING VALVE CLEARANCE…………………………………………………………………………………………………………172
MEASURING COMPRESSION PRESSURE…………………………………………………………………………………………………….174
MEASURING BLOW-BY PRESSURE………………………………………………………………………………………………………..176
MEASURING ENGINE OIL PRESSURE……………………………………………………………………………………………………..177
MEASURING FUEL PRESSURE…………………………………………………………………………………………………………..178
ADJUSTING ENGINE SPEED SENSOR……………………………………………………………………………………………………..179
TESTING AND ADJUSTING FUEL INJECTION TIMING…………………………………………………………………………………………180
HANDLING EQUIPMENT IN FUEL SYSTEM………………………………………………………………………………………………….186
RELEASING REMAINING PRESSURE IN FUEL SYSTEM…………………………………………………………………………………………186
BLEEDING AIR FROM FUEL CIRCUIT…………………………………………………………………………………………………….187
REDUCED CYLINDER MODE OPERATION FOR ENGINE………………………………………………………………………………………….189
CHECKING FOR LEAKAGE IN FUEL SYSTEM………………………………………………………………………………………………..190
ADJUSTING ENGINE STOP MOTOR LEVER………………………………………………………………………………………………….191
CALIBRATION DATA…………………………………………………………………………………………………………………….194
PERFORMANCE TEST…………………………………………………………………………………………………………………….196
RUN-IN STANDARD………………………………………………………………………………………………………………….196
PERFORMANCE TEST STANDARDS………………………………………………………………………………………………………..198
TROUBLESHOOTING……………………………………………………………………………………………………………………..205
TROUBLESHOOTING OF ENGINE SYSTEM (S MODE)…………………………………………………………………………………………..205
POINTS TO REMEMBER WHEN TROUBLESHOOTING…………………………………………………………………………………………206
METHOD OF USING TROUBLESHOOTING CHARTS………………………………………………………………………………………….207
S-1 Starting performance is poor (starting always takes time)……………………………………………………………………..211
S-2 Engine does not start……………………………………………………………………………………………………..212
S-3 Engine does not pick up smoothly (follow-up is poor)………………………………………………………………………….215
S-4 Engine stops during operations……………………………………………………………………………………………..216
S-5 Engine does not rotate smoothly (hunting)……………………………………………………………………………………217
S-6 Engine lacks output (or lacks power)………………………………………………………………………………………..218
S-7 Exhaust smoke is black (incomplete combustion)……………………………………………………………………………….219
S-8 Oil consumption is excessive (or exhaust smoke is blue)……………………………………………………………………….220
S-9 Oil becomes contaminated quickly……………………………………………………………………………………………221
S-10 Fuel consumption is excessive……………………………………………………………………………………………..222
S-11 Oil is in cooling water (or water spurts back, or water level goes down)……………………………………………………….223
S-12 Oil pressure caution lamp lights up (drop in oil pressure)……………………………………………………………………224
S-13 Oil level rises (water, fuel in oil)……………………………………………………………………………………….225
S-14 Water temperature becomes too high (overheating)…………………………………………………………………………….226
S-15 Abnormal noise is made……………………………………………………………………………………………………227
S-16 Vibration is excessive……………………………………………………………………………………………………228
TROUBLESHOOTING OF ELECTRICAL SYSTEM (E MODE)……………………………………………………………………………………….229
POINTS TO REMEMBER WHEN TROUBLESHOOTING…………………………………………………………………………………………231
METHOD OF USING TROUBLESHOOTING FLOWCHART……………………………………………………………………………………….232
ERROR CODE DISPLAYS AND POINTS TO REMEMBER WHEN TROUBLESHOOTING……………………………………………………………………233
ACTION TAKEN BY CONTROLLER AND CONDITION OF MACHINE WHEN ERROR CODE IS DISPLAYED…………………………………………………….236
E-1 Error code [E-1b] [Abnormality in NE revolution sensor system]…………………………………………………………………245
E-2 Error code [E-1C] [Abnormality in G revolution sensor system]………………………………………………………………….246
E-3 Error code [E-20] [Abnormality in model selection system]……………………………………………………………………..247
E-4 Error code [E-22] [Overrun]………………………………………………………………………………………………..248
E-5 Error code [E-23] [Overheat]……………………………………………………………………………………………….248
E-6 Error code [E-24] [Drop in oil pressure]…………………………………………………………………………………….249
E-7 Error code [E-30] [Abnormality in idling validation signal system]……………………………………………………………..250
E-8 Error code [E-31] [Abnormality in throttle sensor system]……………………………………………………………………..252
E-9 Error code [E-34] [Abnormality in water temperature high-temperature sensor system]………………………………………………255
E-10 Error code [E-36] [Abnormality in oil pressure switch system]…………………………………………………………………256
E-11 Error code [E-3C] [Abnormality in boost pressure sensor system]……………………………………………………………….258
E-12 Error code [E-3d] [Abnormality in fuel temperature sensor system]……………………………………………………………..259
E-13 Error code [E-50] [Abnormality in preheating relay connecting point system]…………………………………………………….260
E-14 Error code [E-51] [Abnormality in preheat relay coil system]………………………………………………………………….261
E-15 Error code [E-54] [Short circuit in starting switch C system]…………………………………………………………………262
E-16 Error code [E-56] [Power source system abnormality 1]………………………………………………………………………..264
E-17 Error code [E-57] [Power source system abnormality 2]………………………………………………………………………..266
E-18 Error code [E-5A] [Abnormality in fuel injection quantity control switch signal]………………………………………………..267
E-19 Error code [E-6A] [Abnormality in water temperature low-temperature sensor system]………………………………………………268
E-20 Error code [E-70] [Excess current in fuel supply pump PCV1 system]…………………………………………………………….269
E-21 Error code [E-71] [Excess current in fuel supply pump PCV2 system]…………………………………………………………….270
E-22 Error code [E-74] [Disconnection in fuel supply pump PCV1 system]……………………………………………………………..271
E-23 Error code [E-75] [Disconnection in fuel supply pump PCV2 system]……………………………………………………………..272
E-24 Error code [E-77] [Abnormality in common rail fuel pressure sensor system]……………………………………………………..273
E-25 Error code [E-79] [Common rail fuel high pressure abnormality 1] Error code [E-7A] [Common rail fuel high pressure abnormality 2]….274
E-26 Error code [E-7b] [Fuel supply pump non-force feed 1] Error code [E-7C] [Fuel supply pump non-force feed 2]……………………..276
E-27 Error code [E-7d] [Abnormality in common rail fuel pressure]………………………………………………………………….278
E-28 Error code [E-80] [Defective controller]……………………………………………………………………………………278
E-29 Error code [E-81] [Disconnection in No. 1 fuel injector system]……………………………………………………………….279
E-30 Error code [E-82] [Disconnection in No. 2 fuel injector system]……………………………………………………………….280
E-31 Error code [E-83] [Disconnection in No. 3 fuel injector system]……………………………………………………………….281
E-32 Error code [E-84] [Disconnection in No. 4 fuel injector system]……………………………………………………………….282
E-33 Error code [E-85] [Disconnection in No. 5 fuel injector system]……………………………………………………………….283
E-34 Error code [E-86] [Disconnection in No. 6 fuel injector system]……………………………………………………………….284
E-35 Error code [E-8A] [Short circuit in No. 1, No. 2, No. 3 fuel injector system]…………………………………………………..285
E-36 Error code [E-8b] [Short circuit in No. 4, No. 5, No. 6 fuel injector system]…………………………………………………..288
13 DISASSEMBLY AND ASSEMBLY………………………………………………………………………………………………………………291
METHOD OF USING MANUAL……………………………………………………………………………………………………………….293
PRECAUTIONS WHEN CARRYING OUT OPERATION………………………………………………………………………………………………..294
SPECIAL TOOL LIST……………………………………………………………………………………………………………………296
SKETCHES OF SPECIAL TOOLS…………………………………………………………………………………………………………….297
GENERAL DISASSEMBLY………………………………………………………………………………………………………………….298
1. Preparation work………………………………………………………………………………………………………………298
2. Starting motor………………………………………………………………………………………………………………..298
3. Turbocharger lubricant return tube………………………………………………………………………………………………298
4. Radiator lower hose……………………………………………………………………………………………………………298
5. Engine oil cooler……………………………………………………………………………………………………………..298
6. Adapter for engine overhauling………………………………………………………………………………………………….299
7. Radiator upper hose……………………………………………………………………………………………………………299
8. Exhaust muffler……………………………………………………………………………………………………………….299
9. Fan securing bracket…………………………………………………………………………………………………………..299
10. Turbocharger lubrication tube………………………………………………………………………………………………….299
11. Turbocharger and exhaust manifold………………………………………………………………………………………………299
12. Fuel filter assembly………………………………………………………………………………………………………….299
13. Oil filter…………………………………………………………………………………………………………………..300
14. Wiring harness……………………………………………………………………………………………………………….300
15. Air cleaner securing bracket…………………………………………………………………………………………………..300
16. Exhaust muffler securing bracket……………………………………………………………………………………………….300
17. High pressure tube clamp………………………………………………………………………………………………………300
18. Suction manifold assembly……………………………………………………………………………………………………..300
19. Supply pump………………………………………………………………………………………………………………….300
20. Common rail………………………………………………………………………………………………………………….301
21. Spill pipe…………………………………………………………………………………………………………………..302
22. Head cover…………………………………………………………………………………………………………………..302
23. Injector harness……………………………………………………………………………………………………………..302
24. Rocker arm…………………………………………………………………………………………………………………..302
25. Push rod…………………………………………………………………………………………………………………….302
26. Injector…………………………………………………………………………………………………………………….302
27. Nozzle tip…………………………………………………………………………………………………………………..303
28. Crosshead……………………………………………………………………………………………………………………303
29. Rocker arm housing……………………………………………………………………………………………………………304
30. Injector harness connector…………………………………………………………………………………………………….304
31. Thermostat…………………………………………………………………………………………………………………..304
32. Cam follower cover……………………………………………………………………………………………………………304
33. Cam follower…………………………………………………………………………………………………………………304
34. Cylinder head assembly………………………………………………………………………………………………………..304
35. Setting to engine overhaul stand……………………………………………………………………………………………….305
36. Oil pan……………………………………………………………………………………………………………………..305
37. Flywheel…………………………………………………………………………………………………………………….305
38. Flywheel housing……………………………………………………………………………………………………………..305
39. Damper………………………………………………………………………………………………………………………306
40. Front support………………………………………………………………………………………………………………..306
41. Front cover………………………………………………………………………………………………………………….306
42. Water pump…………………………………………………………………………………………………………………..306
43. Camshaft…………………………………………………………………………………………………………………….306
44. Oil pump…………………………………………………………………………………………………………………….306
45. Idler gear…………………………………………………………………………………………………………………..306
46. Oil suction pipe……………………………………………………………………………………………………………..307
47. Piston cooling nozzle…………………………………………………………………………………………………………307
48. Piston and connecting rod assembly……………………………………………………………………………………………..307
49. Crankshaft…………………………………………………………………………………………………………………..308
50. Cylinder liner……………………………………………………………………………………………………………….309
GENERAL ASSEMBLY…………………………………………………………………………………………………………………….310
1. Cylinder liner………………………………………………………………………………………………………………..311
2. Crankshaft……………………………………………………………………………………………………………………312
3. Piston and connecting rod assembly………………………………………………………………………………………………315
4. Piston cooling nozzle………………………………………………………………………………………………………….318
5. Oil suction pipe………………………………………………………………………………………………………………319
6. Idler gear……………………………………………………………………………………………………………………319
7. Oil pump……………………………………………………………………………………………………………………..319
8. Camshaft……………………………………………………………………………………………………………………..320
9. Cam followers…………………………………………………………………………………………………………………320
10. Cam follower covers…………………………………………………………………………………………………………..320
11. Water pump…………………………………………………………………………………………………………………..320
12. Fuel supply pump driving gear………………………………………………………………………………………………….320
13. Front cover………………………………………………………………………………………………………………….321
14. Flywheel housing……………………………………………………………………………………………………………..322
15. Rear seal……………………………………………………………………………………………………………………323
16. Flywheel…………………………………………………………………………………………………………………….325
17. Damper………………………………………………………………………………………………………………………325
18. Oil pan……………………………………………………………………………………………………………………..326
19. Removing engine assembly from engineoverhaul stand……………………………………………………………………………….326
20. Setting engine assembly on blocks………………………………………………………………………………………………326
21. Cylinder head………………………………………………………………………………………………………………..326
22. Cylinder head assembly………………………………………………………………………………………………………..326
23. Rocker arm housing……………………………………………………………………………………………………………328
24. Assembling injector harness connector torocker arm housing………………………………………………………………………..328
25. Crosshead……………………………………………………………………………………………………………………328
26. Pushrod……………………………………………………………………………………………………………………..329
27. Rocker arm…………………………………………………………………………………………………………………..329
28. Adjusting valve clearance……………………………………………………………………………………………………..329
29. Nozzle tip…………………………………………………………………………………………………………………..329
30. Fuel injector………………………………………………………………………………………………………………..331
31. Head cover…………………………………………………………………………………………………………………..331
32. Spill pipe…………………………………………………………………………………………………………………..331
33. Thermostat…………………………………………………………………………………………………………………..332
34. Engine oil cooler…………………………………………………………………………………………………………….332
35. Engine cooling water temperature sensor…………………………………………………………………………………………332
36. Engine oil supply tube………………………………………………………………………………………………………..332
37. High-pressure tube for common rail……………………………………………………………………………………………..332
38. Suction manifold……………………………………………………………………………………………………………..333
39. Engine oil filter…………………………………………………………………………………………………………….334
40. Fuel filter………………………………………………………………………………………………………………….334
41. Turbocharger and exhaust manifold assembly………………………………………………………………………………………334
42. Starting motor……………………………………………………………………………………………………………….334
43. Fan bracket lifting hook………………………………………………………………………………………………………335
44. Wiring harness……………………………………………………………………………………………………………….335
45. Air cleaner………………………………………………………………………………………………………………….335
46. Exhaust muffler………………………………………………………………………………………………………………335
15 REPAIR AND REPLACEMENT OF PARTS………………………………………………………………………………………………………..337
CYLINDER HEAD……………………………………………………………………………………………………………………….339
REPLACING VALVE SEAT INSERT……………………………………………………………………………………………………….339
REPLACING NOZZLE HOLDER SLEEVE…………………………………………………………………………………………………….344
REPLACING VALUE GUIDE…………………………………………………………………………………………………………….347
REPLACING CROSS HEAD GUIDE………………………………………………………………………………………………………..348
GRINDING THE VALVE……………………………………………………………………………………………………………….349
GRINDING THE FITTING FACE OF CYLINDER HEAD………………………………………………………………………………………….349
PRESSURE TEST……………………………………………………………………………………………………………………350
CYLINDER BLOCK………………………………………………………………………………………………………………………352
REPLACING CAM BUSHING…………………………………………………………………………………………………………….352
REPLACING CAM GEAR……………………………………………………………………………………………………………….355
REPLACING FLYWHEEL RING GEAR………………………………………………………………………………………………………355
REPLACING ENGINE REAR SEAL………………………………………………………………………………………………………..356
REPLACING CONNECTING ROD SMALL END BUSHING………………………………………………………………………………………….361
REPLACING MAIN BEARING CAP………………………………………………………………………………………………………..362
GRINDING CRANKSHAFT………………………………………………………………………………………………………………365
REPLACING WEAR SLEEVE (When equipped with sleeve)……………………………………………………………………………………374