Komatsu K21 K25 Series Forklift Truck Engines Service Manual SM301 – PDF DOWNLOAD

Description

Komatsu K21 K25 Series Forklift Truck Engines Service Manual SM301 – PDF DOWNLOAD

IMAGES PREVIEW OF THE MANUAL:

DESCRIPTION:

Komatsu K21 K25 Series Forklift Truck Engines Service Manual SM301 – PDF DOWNLOAD

Model     K21 Engine S/N                                                               K25 Engine S/N
Year       LPG                   Dual            Gasoline                              LPG                 Dual               Gasoline
2008      K21-046637~ K21-046682~ K21-046895~                      K25-067269~ K25-067294~ K25-067505~
2007      K21-023868~ K21-023873~ K21-024907~                      K25-049259~ K25-049112~ K25-050425~
K21-K48924~ K21-K49292~ K21-K50077~                     K25-K36577~ K25-K37465~ K25-K37661~

INTRODUCTION:

• This Service Manual has been developed as an information resource to help the reader
  learn about, understand, repair and maintain the K21 and K25 engines, and the various
  systems, sensors, diagnostic procedures and diagnostic equipment utilized to maintain,
  adjust and troubleshoot these systems.
• Komatsu is involved in a concentrated and highly technical program of designing and
  developing cleaner burning, more efficient and more powerful engines for use in the
  industrial truck market. As a result, new computerized sensors, systems and diagnostic
  monitors have been created to make the job of maintaining and repairing these systems
  simple and easy.
• Read this manual carefully, refer to it often and learn the testing and adjustment procedures
  to the best of your ability.
• Ensure that, when you are working on or around industrial trucks, Safety is priority Number
  One.
• Follow the instructions and procedures presented in this manual when working on these
  engines and systems. Damage to the equipment, and possible injury to yourself or others,
  may result if these procedures are not adhered to carefully.

TABLE OF CONTENTS:

Komatsu K21 K25 Series Forklift Truck Engines Service Manual SM301 – PDF DOWNLOAD

INTRODUCTION 3
AN OVERVIEW OF MAJOR IMPROVEMENTS FROM CURRENT H-TYPE ENGINES
TO THE NEW K-ENGINES 15
APPLICABLE “EPA” LIFT TRUCK MODELS 17
K-ENGINE SERIAL NUMBER BREAKS BY MODEL YEAR 20
1 GENERAL INFORMATION AND SPECIFICATIONS
How To Use This Manual 1-2
Description 1-2
Definition of Terms 1-2
Definition of Units 1-2
Precautions For Safety And Quality 1-3
Safe Operation 1-3
Correct Operation 1-4
Radio Equipment Installation 1-4
Draining Engine Coolant 1-4
Disconnecting Fuel Piping 1-4
Removing and Disassembling 1-4
Inspection, Correction, and Replacement 1-4
Assembly and Installation 1-4
Parts Requiring Angle Tightening 1-5
Use of Power Tools 1-5
Liquid Gasket Application 1-5
Tightening Torque 1-6
Standard Bolt Tightening Torque 1-6
Engine Part Tightening Torque 1-7
Special Service Tools 1-9
Engine Outside Drawings 1-10
Main Specifications 1-11
Standard And Repair Limit 1-14
Stamped Location Of Engine No 1-18
Trouble Shooting 1-19
Engine Adjustment 1-20
Engine LPG Fuel System 1-25
2 MECHANICAL
Precautions 2-2
Draining Engine Coolant 2-2
Disconnecting Fuel Piping 2-2
6
Removing and Disassembling 2-2
Inspection, Correction, and Replacement 2-2
Assembly and Installation 2-2
Parts Requiring Angle Tightening 2-2
Use of Power Tools 2-2
Liquid Gasket Application 2-3
Engine Outside Drawings 2-4
Main Specifications 2-5
Adjustment Value 2-7
Tightening Torque 2-10
Standard Bolt Tightening Torque 2-10
Engine Part Tightening Torque 2-11
Trouble Shooting 2-13
Special Service Tools 2-15
Removal And Installation Of Engine 2-16
Removal 2-16
Installation 2-17
Inspection 2-17
Engine Service 2-18
Engine Disassembly 2-18
Inspection and Correction 2-25
Engine Assembly 2-38
3 FUEL
Engine Types 3-2
Engine Outside Drawings 3-3
System Diagram 3-4
Unit Layout 3-10
Service Data And Specifications (SDS) 3-11
LPG Fuel System Trouble Diagnosis 3-11
Disassembly And Assembly Of Fuel System 3-13
Removal and Installation of LPG Injector Drive Unit Connector 3-13
Removal and Installation of Electronic Control Throttle Assembly 3-14
Removal and Installation of Gasoline Fuel Injector (Electronic Controlled Gasoline
and Combined Use) 3-15
LPG device (Specifications for LPG and Combined Use) 3-18
Holder Assembly 3-20
LPG Fuel Injector 3-21
LPG Assist Fuel Injector 3-21
LPG Fuel Pressure Sensor 3-22
7
Vaporizer Mechanism and Operation 3-23
Disassembly And Assembly Of Injector Holder 3-25
LPG Fuel Injector 3-25
LPG Assist Fuel Injector 3-26
LPG Fuel Pressure Sensor 3-26
Relief Valve (2 Relief Valves) 3-26
Disassembly And Assembly Of Vaporizer 3-27
4 LUBRICATION AND COOLING SYSTEMS
Lubrication System 4-2
Specifications 4-2
Adjustment Value 4-2
Oil Pressure 4-2
Tightening Torque 4-2
Trouble Shooting 4-3
Lubrication Schematic Diagram 4-4
Oil Pump 4-5
Engine Coolant System 4-6
Specifications 4-6
Adjustment Value 4-6
Tightening Torque 4-6
Trouble Shooting 4-6
Cooling System Configuration 4-7
Water Pump 4-7
Thermostat 4-8
5 SYSTEMS AND DIAGNOSTICS
Engine And Main Body 5-3
Description 5-3
Main Engine System 5-3
Cylinder Block 5-4
Cylinder Head 5-4
Cylinder Head Gasket 5-5
Cylinder Head Bolt 5-5
Piston, Piston Pin and Piston Rings 5-6
Connecting Rod and Connecting Rod Bearing 5-6
Crankshaft 5-7
Main Bearing and Bearing Cap Bolts 5-7
Oil Seal 5-7
Crankshaft Pulley Bushing 5-7
Crankshaft Pulley and Pulley Bolt 5-7
PTO (Power Take-Off) 5-7
Oil Pan 5-8
Rocker Cover and Gasket 5-8
8
Valves 5-9
Description 5-9
Camshaft 5-9
Timing Chain and Sprocket 5-10
Valve Related Parts 5-10
Lubrication System 5-12
Description 5-12
Oil Pump 5-13
Oil Strainer 5-13
Oil Filter 5-13
Engine Oil and Oil Level Gauge (Dipstick) 5-13
Intake / Exhaust 5-14
Description 5-14
Manifold Component Parts Location 5-15
Engine Intake System Component Parts Location 5-15
Electric Throttle Control Actuator (ETCA) 5-16
Intake Manifold 5-16
Exhaust Manifold 5-17
Engine Control System 5-18
Description 18
Circuit Diagrams of Engine Control Module 5-21
Gasoline 5-21
LPG 5-23
Dual Fuel 5-25
Dual Fuel – EPA Tier 2 (2007) 5-27
Fuel System Diagrams 5-29
Gasoline 5-29
LPG 5-31
Dual Fuel 5-33
Gasoline – EPA Tier 2 (2007) 5-35
LPG – EPA Tier 2 (2007) 5-37
Dual Fuel- EPA Tier 2 (2007) 5-39
ECM Terminal Layout 5-41
Fuel Injection Control 5-47
PCV Gas Recirculation Device 5-69
Coolant System 5-72
Description of Coolant System 5-72
Specifications 5-73
Construction 5-73
9
Fuel System Description 5-74
APPENDIX 1 Theory of Fuel Injection Pulse Width Indication 5-77
APPENDIX 2 Service Support Tool Exercise Program 5-81
APPENDIX 3 Error Code List 5-83
APPENDIX 4 Diagnostic Monitor Service Support Tool (SST) 5-89
6 CONTROLS
Precautions 6-4
On Board Diagnostic (OBD) System of Engine 6-4
Precaution 6-4
Special Service Tools 6-7
Description 6-8
Component Parts Location 6-16
ECM Component 6-17
Circuit Diagram 6-20
Control Unit Terminal Layout 6-24
ECM Terminal 6-29
Trouble Diagnosis 6-37
How to Proceed with Trouble Diagnosis 6-37
Trouble Diagnosis Flow Chart 6-38
Diagnosis Chart by Symptom 6-41
Description 6-47
Fail-Safe Function 6-47
Table of DTC 6-48
Self-Diagnosis Function (With Service Tool) 6-53
Self-Diagnosis Function (Without Service tool) 6-55
ECM Active Test 6-56
Basic Inspection 6-57
Inspection of Idle Speed and Ignition Timing 6-57
Throttle Valve Closed Position Learning and Idle Air Volume Learning 6-57
Accelerator Pedal Released Position Learning 6-58
Fuel Pressure Inspection 6-58
Accelerator Pedal Released Position Learning 6-59
Service Tool 6-60
Power Supply And Ground System 6-62
Control Unit Input/Output Signal Specifications 6-62
Circuit Diagram 6-62
Crankshaft Position Sensor (POS) System 6-63
Control Unit Input/Output Signal Specifications 6-63
Circuit Diagram 6-63
Component Parts Inspection 6-63
10
Camshaft Position Sensor (PHASE) System 6-64
Control Unit Input/Output Signal Specifications 6-64
Circuit Diagram 6-64
Component Parts Inspection 6-64
Mass Air Flow Sensor System 6-65
Special Tool Data Monitor Display 6-65
Control Unit Input/Output Signal Specifications 6-65
Circuit Diagram 6-65
Component Parts Inspection 6-65
Engine Coolant Temperature Sensor System 6-66
Service Tool Data Monitor Display 6-66
Control Unit Input/Output Signal Specifications 6-66
Circuit Diagram 6-66
Component Parts Inspection 6-66
Heated Oxygen Sensor System 6-67
Service Tool Data Monitor Display 6-67
Control Unit Input/Output Signal Specifications 6-67
Circuit Diagram 6-67
Throttle Position Sensor System 6-68
Service Tool Data Monitor Display 6-68
Control Unit Input/Output Signal Specifications 6-68
Circuit Diagram 6-68
Component Parts Inspection 6-68
ETC Acceleration Sensor 6-70
Service Tool Data Monitor Display 6-70
Control Unit Input/Output Signal Specifications 6-70
Circuit Diagram 6-70
Component Parts Inspection 6-71
Engine Warning Light System 6-72
Control Unit Input/Output Signal Specifications 6-72
Circuit Diagram 6-72
Intake Air Temperature Sensor 6-73
Service Tool Data Monitor Display 6-73
Control Unit Input/Output Signal Specifications 6-73
Circuit Diagram 6-73
Component Parts Inspection 6-73
LPG Injector system Control Unit Input/Output Specifications 6-74
LPG Assist Injector System 6-76
Control Unit Input/Output Signal Specifications 6-76
Circuit Diagram 6-76
Component Parts Inspection 6-76
11
LPG Fuel Pressure Sensor System 6-77
Control Unit Input/Output Signal Specifications 6-77
Circuit Diagram 6-77
LPG Assistance Injector 6-77
PNP Switch System 6-79
Service Tool Data Monitor Display 6-79
Control Unit Input/Output Signal Specifications 6-79
Circuit Diagram 6-79
Component Parts Inspection 6-79
Stop Lamp Switch System 6-80
Service Tool Data Monitor Display 6-80
Control Unit Input/Output Signal Specifications 6-80
Circuit Diagram 6-80
Component Parts Inspection 6-80
Service Tool Data Monitor Display 6-81
Control Unit Input/Output Signal Specifications 6-81
Circuit Diagram 6-81
Vehicle Speed Sensor System 6-82
Control Unit Input/Output Signal Specifications 6-82
Circuit Diagram 6-82
Ignition System 6-83
Service Tool Data Monitor Display 6-83
Control Unit Input/Output Signal Specifications 6-83
Circuit Diagram 6-83
Component Parts Inspection 6-83
Spark Plug 6-83
Ignition Coil 6-84
Service Tool Data Monitor Display 6-85
Control Unit Input/Output Signal Specifications 6-85
Circuit Diagram 6-85
Component Parts Inspection 6-85
Injector 6-85
Fuel Pump System 6-87
Service Tool Data Monitor Display 6-87
Control Unit Input/Output Signal Specifications 6-87
Circuit Diagram 6-87
Fuel Pump 6-87
Throttle Control Motor System 6-88
Circuit Diagram 6-88
Component Parts Inspection 6-88
Heated Oxygen Sensor Heater System 6-89
Service Tool Data Monitor Display 6-89
Control Unit Input/Output Signal Specifications 6-89
Circuit Diagram 6-89
12
Component Parts Inspection 6-89
Blowby Gas Recirculation Device 6-90
System Diagram 6-90
Component Parts Inspection 6-90
Fuel Cut Function Inspection Procedure 6-91
Removal And Installation Of ECCS Components 6-92
ECM 6-92
LPG Injector Drive Unit 6-93
Throttle Control Motor (Electric Throttle Control Actuator Assembly) 6-93
Throttle Position Sensor (Electric Throttle Control Assembly) 6-93
Accelerator Pedal Position Sensor (Accelerator Pedal Assembly) 6-93
LPG Injector Holder 6-94
Intake Air Temperature Sensor (with Air Flow Sensor) 6-94
Fuel Injector 6-94
Service Data 6-95
7 TUNE-UP
Specifications 7-2
Tightening Torque 7-3
Trouble Shooting 7-4
Engine Inspection And Adjustment 7-9
Retighten Cylinder Head Bolts 7-9
Retighten Manifold Nuts 7-9
Adjusting Valve Clearance 7-9
Inspect And Adjust Accessory Belt 7-10
Replace Oil And Oil Filter 7-10
Changing Engine Coolant 7-11
Compression Pressure Inspection 7-12
Spark Plug Inspection And Replacement 7-12
8 ELECTRICAL SYSTEM
Adjustment Value 8-2
Trouble Diagnosis 8-3
Starter Motor 8-4
Starter Motor Specifications 8-4
Component Parts Location 8-4
Overhaul 8-5
Assembly Inspection 8-7
Alternator 8-8
Alternator Components 8-8
Alternator Disassembly 8-9
13
9 MAINTENANCE
Specifications 9-2
Inspection and Adjustment 9-2
Cylinder Head 9-2
Cylinder Block 9-2
Piston 9-2
Connecting Rod 9-3
Crankshaft 9-3
Flywheel 9-4
Camshaft 9-4
Valve 9-5
Tightening Torque 9-6
Maintenance Schedule 9-8
Perform Inspection 9-8
Oil and Grease Capacity 9-10
On Board Inspection and Service 9-11
Tightening of Head Bolt 9-11
Retightening of Manifold Nut and Bolt 9-11
Intake/Exhaust Valve Clearance Adjustment 9-11
Intake/Exhaust Valve Clearance (Hot) 9-12
Inspection and Adjustment of Engine Drive Belt 9-12
Replacement of Oil and Oil Filter 9-12

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