Common Fault Diagnosis and Troubleshooting for Hydraulic Excavators

1. Walking Weakness Fault

Walking weakness is one of the common faults in hydraulic excavators, mainly characterized by slow walking speed and difficulty climbing slopes.

Fault Causes:

1. Insufficient hydraulic oil or deteriorated oil quality

2. Severe wear of travel motor

3. Insufficient travel pump pressure

4. Travel control valve stuck

Troubleshooting Methods:

1. Check the hydraulic oil level, add if insufficient, replace if oil quality is deteriorated

2. Test the travel motor pressure, repair or replace if necessary

3. Check the working status of the travel pump, adjust pressure or replace

4. Clean or replace the travel control valve

2. Reduced Digging Efficiency

Reduced digging efficiency is characterized by insufficient bucket digging force and slow movement.

Fault Causes:

1. Insufficient main pump pressure

2. Excessive hydraulic oil temperature

3. Damaged hydraulic cylinder seals

4. Control valve wear

Troubleshooting Methods:

1. Test the main pump output pressure, adjust or repair

2. Check the cooling system, clean the radiator

3. Replace hydraulic cylinder seals

4. Repair or replace the control valve

3. Hydraulic System Abnormal Noise

Abnormal noise in hydraulic system is usually caused by hydraulic pump, hydraulic motor or control valve faults.

Fault Causes:

1. Hydraulic pump cavitation, air intake

2. Air mixed in hydraulic oil

3. Damaged hydraulic pump or motor bearings

4. Control valve spool wear

Troubleshooting Methods:

1. Check if the suction pipe is leaking, tighten the joints

2. Remove air from the system

3. Replace hydraulic pump or motor bearings

4. Repair or replace the control valve

4. Swing System Fault

Swing system faults are characterized by slow swing speed, weakness or vibration.

Fault Causes:

1. Swing motor failure

2. Swing bearing wear

3. Swing control valve problems

Troubleshooting Methods:

1. Test swing motor pressure and flow

2. Check swing bearing clearance, replace if necessary

3. Check and adjust the swing control valve

5. Hydraulic Oil Overheating

Hydraulic oil overheating will reduce system efficiency and even damage components.

Fault Causes:

1. Insufficient hydraulic oil

2. Radiator blocked

3. Excessive system pressure

4. Reduced hydraulic pump efficiency

Troubleshooting Methods:

1. Add hydraulic oil to the specified level

2. Clean dust and debris from the radiator surface

3. Check and adjust system pressure

4. Overhaul or replace the hydraulic pump

6. Fault Diagnosis Precautions

1. Understand the fault phenomenon and occurrence process in detail before diagnosis

2. Follow the principle of "from easy to difficult, from outside to inside" for troubleshooting

3. Use special tools and original parts during repair

4. Conduct trial operation after repair to confirm the fault has been eliminated

7. Summary

Fault diagnosis of hydraulic excavators requires rich experience and systematic methods. By mastering common fault diagnosis skills, problems can be quickly located and effective troubleshooting measures can be taken to reduce equipment downtime and improve work efficiency.