Hydraulic System Service Manual

Product Overview

This comprehensive service manual provides detailed instructions for the maintenance, troubleshooting, and repair of hydraulic systems in machinery. It is essential for ensuring the optimal performance and longevity of your equipment. This manual is especially useful for diagnosing issues when a machine is inoperative despite having a working engine.

Table of Contents

1. Content
2. Introduction
3. Engine
4. Hydraulics System
5. Pneumatic System
6. Frames and Ballasting
7. Tracks and Track Suspension
8. Cab Climate Control
9. Electrical System
10. Booms, Dippers, and Buckets
11. Dozer Blade and Arm
12. Platform, Cab, Bodywork, and Decals
13. Electrical Schematic
14. Hydraulic Schematic

Manual Extract: Hydraulic Systems – Service Instruction – Troubleshooting

Step-by-Step Troubleshooting Guide

For cases of machines being inoperative with the engine still functioning:

1. Check the oil level in the hydraulic oil tank.

   • If the oil level is below the lower red line on the level gauge, refill with hydraulic oil to the standard level.
   • If the oil level is between the red lines on the level gauge, proceed to step 2.

2. Examine the noise from the hydraulic pump.

   • If abnormal noise is present, the hydraulic pump may be broken. Disassemble and repair it.
   • If no abnormal noise is detected, continue to step 3.

3. Inspect the noise from the hydraulic pump connections.

   • If abnormal noise is detected, the hydraulic pump or engine may be faulty. Refer to the manual for further instructions.
   • If no abnormal noise is found, proceed to step 4.

4. Measure the primary pilot pressure.

   • If within 2.452 u2013 3.432 MPa (355.663 u2013 497.812 psi), proceed to step 5.
   • If outside this range, proceed to step 6.

5. Check for pilot piping clogs and oil leaks.

   • If clogging or leaking is found, clean or repair the piping.
   • If no issues are detected, the pilot valve may be faulty. Disassemble and repair it.

6. Check the gear pump for oil delivery issues.

   • If the gear pump delivers oil, the pilot relief valve may be faulty. Repair or replace it as needed. Refer to the Pump Disassemble (35.106) section.
   • If the gear pump does not deliver oil, it is likely broken. Disassemble and repair as instructed in Pump Disassemble (35.106).

Usage Recommendations

• Regularly check and maintain oil levels to ensure efficient system function.
• Monitor for unusual noises which may indicate potential issues.
• Follow the detailed instructions provided in the manual for any repairs or parts replacements.
• Use this manual as a reference for any maintenance activities related to hydraulic systems.