Komatsu GD621, GD622, GD623, GD625 Motor Grader Service Manual

Table of Contents

01 GENERAL …………………………………………. 01-1
10 ENGINE
11 STRUCTURE AND FUNCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1
12 TESTING AND ADJUSTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1
13 DISASSEMBLY AND ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1
20 POWER TRAIN
21 STRUCTURE AND FUNCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-1
22 TESTING AND ADJUSTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22-2
23 DISASSEMBLY AND ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23-1
24 MAINTENANCE STANDARD 24-1
40 STEERING SYSTEM
41 STRUCTURE AND FUNCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41-1
42 TESTING AND ADJUSTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42-1
43 DISASSEMBLY AND ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43-1
44 MAINTENANCE STANDARD 44-1
50 BRAKE SYSTEM
51 STRUCTURE AND FUNCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51-1
52 TESTING AND ADJUSTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52-1
53 DISASSEMBLY AND ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53-1
54 MAINTENANCE STANDARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54-1
60 HYDRAULIC SYSTEM
61 STRUCTURE AND FUNCTION . . . . . . . . . . . . . . . . . . : . . . . . . . . . . . . . . . 61-1
62 TESTING AND ADJUSTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62-1
63 DISASSEMBLY AND ASSEMBLY .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63-1
64 MAINTENANCE STANDARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64-1
70 WORK EQUIPMENT
71 STRUCTURE AND FUNCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71-1
72 TESTING AND ADJUSTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72-1
73 DISASSEMBLY AND ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73-1
74 MAINTENANCE STANDARD 74-1
90 OTHERS
91 ELECTRICAL SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91-1
92 INSPECTION TABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92-1

1. Composition of shop manual
This shop manual contains the necessary technical information for services performed in a workshop. For ease of understanding, the manual is divided into the following sections.

10. Structure and function.
This section explains the structure and function of each component. It serves not only to give an understanding for the structure of each component, but also serves as reference material for troubleshooting.

30. Testing, adjusting and Troubleshooting
This section explains checks to be made before and after performing repairs, as well as adjustments to be made at completion of the checks and repairs. Troubleshooting charts correlating Problems to Causes are also included in this section.

50. Disassembly and assembly
This section explains the special tools and procedures for removing, installing, disassembling, and assembling each component, as well as precautions for them. In addition, tightening torque, and quantity and weight of coating material, oil, grease, and coolant necessary for the work are also explained.

90. MAINTENANCE STANDARD
This section gives the judgement standards when inspecting disassembled parts.