Komatsu 125E-6 series engine

This is a comprehensive workshop manual, 322 pages.

00 Index and foreword . ...............................................................................................................................00-1
Index . ..................................................................................................................................................00-2
Foreword, safety and general information . ..........................................................................................00-5
Important safety notice . ..............................................................................................................................00-5
How to read the shop manual. .................................................................................................................. 00-10
Explanation of terms for maintenance standard . ...................................................................................... 00-12
Handling of fuel system devices . .............................................................................................................. 00-14
Handling of intake system parts. ............................................................................................................... 00-15
Handling of hydraulic equipment. .............................................................................................................. 00-16
Method of disconnecting and connecting push-pull type coupler. ............................................................. 00-18
Handling of electrical equipment. .............................................................................................................. 00-21
How to read electric wire code. ................................................................................................................. 00-29
Precautions when performing operation . .................................................................................................. 00-32
Standard tightening torque table. .............................................................................................................. 00-35
List of abbreviation . .................................................................................................................................. 00-39
Conversion table. ...................................................................................................................................... 00-43
01 Specification. ..........................................................................................................................................01-1
Table of contents . ................................................................................................................................01-2
Specifications. ......................................................................................................................................01-3
Exhaust gas regulation . ..............................................................................................................................01-3
Applicable machines . ..................................................................................................................................01-6
Specifications . ............................................................................................................................................01-7
General view . ..............................................................................................................................................01-9
Weight table . ............................................................................................................................................ 01-18
Engine performance curve . ...................................................................................................................... 01-19
10 Structure and function . ...........................................................................................................................10-1
Table of contents . .......................................................................................................................................10-2
Components layout. ....................................................................................................................................10-3
Components layout drawing. ........................................................................................................10-3
Intake and exhaust system parts. ........................................................................................................10-6
Intake and exhaust system layout drawing . .........................................................................................10-6
Intake and exhaust system circuit diagram . .........................................................................................10-7
Air cleaner. ...........................................................................................................................................10-9
KVGT. ................................................................................................................................................ 10-10
Aftercooler. ........................................................................................................................................ 10-16
EGR system piping drawing . ............................................................................................................. 10-17
EGR system circuit diagram. ............................................................................................................. 10-19
EGR valve. ........................................................................................................................................ 10-20
EGR cooler. ....................................................................................................................................... 10-22
Mixing connector. .............................................................................................................................. 10-24
KCCV layout drawing . ....................................................................................................................... 10-25
KCCV ventilator . ................................................................................................................................ 10-27
KDPF. ................................................................................................................................................ 10-31
Engine main body parts. .................................................................................................................... 10-36
Cylinder head . ................................................................................................................................... 10-36
Cylinder block. ................................................................................................................................... 10-38
Main moving parts. ............................................................................................................................ 10-40
Vibration damper. .............................................................................................................................. 10-43
Timing gear . ...................................................................................................................................... 10-44
Front cover . ....................................................................................................................................... 10-46
Valve system . .................................................................................................................................... 10-47
Flywheel and flywheel housing. ......................................................................................................... 10-50
Lubrication system. ........................................................................................................................... 10-51
Lubrication system parts layout drawing. ................................................................................... 10-51
Lubrication system diagram . ...................................................................................................... 10-52
Oil pump . ................................................................................................................................... 10-53
Boost oil pump. .......................................................................................................................... 10-54
Oil filter. ...................................................................................................................................... 10-55
00-2
Oil cooler. .......................................................................................................................................... 10-56
Oil cooler thermo-valve. ..................................................................................................................... 10-57
Oil pan . ............................................................................................................................................. 10-58
Fuel system . ..................................................................................................................................... 10-59
Fuel system parts layout drawing. ..................................................................................................... 10-59
Fuel system circuit diagram. .............................................................................................................. 10-61
Outline of CRI system. ....................................................................................................................... 10-64
Fuel dozing. ....................................................................................................................................... 10-77
Pre-filter . ........................................................................................................................................... 10-80
Main filter . ......................................................................................................................................... 10-81
Cooling system. ................................................................................................................................. 10-82
Cooling system parts layout drawing. ................................................................................................ 10-82
Cooling system circuit diagram. ......................................................................................................... 10-83
Water pump. ...................................................................................................................................... 10-84
Thermostat. ....................................................................................................................................... 10-85
Electrical equipment. ......................................................................................................................... 10-87
Alternator . ................................................................................................................................................ 10-87
Alternator mounting. ................................................................................................................................. 10-91
With built-in safety relay (7.5 kW). ............................................................................................................. 10-92
With built-in safety relay (11 kW). .............................................................................................................. 10-94
Fuel feed pump. ........................................................................................................................................ 10-96
Fuel feed pump switch. ............................................................................................................................. 10-97
Engine wiring harness . ............................................................................................................................. 10-98
Engine controller. ................................................................................................................................... 10-100
Sensors . ................................................................................................................................................ 10-106
20 Standard value table . .............................................................................................................................20-1
Table of contents . .......................................................................................................................................20-2
Standard service value table. ......................................................................................................................20-3
Standard value table for engine . .................................................................................................................20-3
Running-in standard and performance test standard . .................................................................................20-7
50 Disassembly and assembly . ..................................................................................................................50-1
Table of contents . .......................................................................................................................................50-2
General information on disassembly and assembly. ...................................................................................50-3
How to read this manual . .....................................................................................................................50-3
Coating materials list . ..........................................................................................................................50-5
Special tool list. ....................................................................................................................................50-9
Sketch of special tool. ........................................................................................................................ 50-11
Disassembly and assembly . ............................................................................................................. 50-14
General disassembly of engine . ............................................................................................................... 50-14
General assembly of engine. .................................................................................................................... 50-35
Removal and installation procedure of supply pump as single component. .............................................. 50-79
Engine front oil seal replacement procedure . ........................................................................................... 50-84
Engine rear oil seal replacement procedure. ............................................................................................ 50-87
60 Maintenance standard. ...........................................................................................................................60-1
Table of contents . .......................................................................................................................................60-2
Intake and exhaust system parts. ................................................................................................................60-3
KVGT. ...........................................................................................................................................60-3
Engine main body parts. ......................................................................................................................60-4
Cylinder head . ..............................................................................................................................60-4
Cylinder block. ..............................................................................................................................60-5
Cylinder liner . ...............................................................................................................................60-7
Crankshaft. ...................................................................................................................................60-8
Cam follower and push rod . .........................................................................................................60-9
Piston . ....................................................................................................................................... 60-11
Connecting rod . ......................................................................................................................... 60-13
Vibration damper. ....................................................................................................................... 60-15
Timing gear . ............................................................................................................................... 60-16
Camshaft . .................................................................................................................................. 60-17
Valve and valve guide. ............................................................................................................... 60-18
125E-6 SERIES
00-3
Rocker arm. ....................................................................................................................................... 60-20
Crosshead and guide . ....................................................................................................................... 60-21
Flywheel. ........................................................................................................................................... 60-22
Lubrication system. ........................................................................................................................... 60-24
Main relief valve. ............................................................................................................................... 60-24
Safety valve. ...................................................................................................................................... 60-25
Cooling system. ................................................................................................................................. 60-26
Oil cooler. ................................................................................................................................................. 60-26
Water pump. ............................................................................................................................................. 60-27
Thermostat. .............................................................................................................................................. 60-28
Index. ............................................................................................................................................................... 1