Common Fault Diagnosis and Solutions for Excavator Hydraulic Systems

Common Fault Diagnosis and Solutions for Excavator Hydraulic Systems

Table of Contents

• Introduction
• I. Fault Phenomena and Cause Analysis
• Hydraulic system has no response
• Insufficient digging power
• Machine deviation
• Difficulty in moving the valve stem
• Oil leakage
• Insufficient braking force
• Excessive hydraulic oil temperature
• Air in the hydraulic system
• Hydraulic system leakage
• Hydraulic oil contamination
• II. Fault Diagnosis Methods
• III. Preventive Maintenance
• IV. Precautions
• Summary

Introduction

The hydraulic system is the core component of an excavator, directly affecting its operational efficiency and reliability. This article will detail common fault phenomena in excavator hydraulic systems, analyze their causes, and provide corresponding solutions, aiming to help users better understand and maintain hydraulic systems.

I. Fault Phenomena and Cause Analysis

1. Hydraulic system has no response

• Reasons: Hydraulic oil circuit blockage or breakage, hydraulic pump failure, control valve failure, hydraulic hose rupture, etc.
• Solutions: Check the oil circuit, clean or replace the filter; check the hydraulic pump pressure, replace if necessary; check the control valve, clean or replace the valve core; check the hydraulic hose, replace the damaged part.

2. Insufficient digging power

• Reasons: Hydraulic pump leakage, internal leakage of hydraulic cylinder, control valve pressure adjustment failure, excessive hydraulic oil viscosity, insufficient hydraulic system pressure, etc.
• Solutions: Check the hydraulic pump, replace the seal; check the hydraulic cylinder, replace the seal; adjust the control valve, replace the pressure adjustment spring; replace the hydraulic oil; check the hydraulic system pressure, adjust the relief valve.

3. Machine deviation

• Reasons: Travel motor failure, bending of hydraulic cylinder piston rod, hydraulic hose rupture, hydraulic system pressure imbalance, etc.
• Solutions: Check the travel motor, replace the seal or valve core; replace the piston rod; replace the hydraulic hose; adjust the hydraulic system pressure.

4. Difficulty in moving the valve stem

• Reasons: Valve stem jamming, seal aging, hydraulic oil contamination, etc.
• Solutions: Clean the valve stem, replace the seal; replace the hydraulic oil.

5. Oil leakage

• Reasons: Seal aging, damage, loose joints, hydraulic hose rupture, etc.
• Solutions: Replace the seal; tighten the joint; replace the hydraulic hose.

6. Insufficient braking force

• Reasons: Insufficient brake fluid, brake pad wear, airlock in the brake system, etc.
• Solutions: Supplement brake fluid; replace brake pads; bleed the air.

7. Excessive hydraulic oil temperature

• Reasons: Excessive viscosity of hydraulic oil, hydraulic system leakage, poor heat dissipation, excessive power of hydraulic pump, etc.
• Solutions: Replace hydraulic oil with appropriate viscosity; check and repair leakage points; increase heat dissipation device; reduce working pressure of hydraulic pump.

8. Air in the hydraulic system

• Reasons: Poor sealing of the hydraulic system, blockage of the vent hole of the hydraulic oil tank, etc.
• Solutions: Check and tighten the seals; clean the vent hole.

9. Hydraulic system leakage

• Reasons: Seal aging, damage, loose joints, hydraulic hose rupture, etc.
• Solutions: Replace the seal; tighten the joint; replace the hydraulic hose.

10. Hydraulic oil contamination

• Reasons: Poor sealing of the hydraulic system, water ingress into the hydraulic oil tank, deterioration of hydraulic oil, etc.
• Solutions: Clean the hydraulic system; replace the hydraulic oil.

II. Fault Diagnosis Methods

• Visual inspection: Observe the hydraulic system for any oil leaks, foreign objects, etc.
• Auditory inspection: Listen for abnormal sounds in the hydraulic system, such as hissing or knocking.
• Tactile inspection: Touch the hydraulic components to check for abnormal vibrations or heat.
• Pressure measurement: Measure the pressure of the hydraulic system using a pressure gauge to determine if it is normal.
• Flow measurement: Measure the flow rate of the hydraulic system using a flow meter to determine if it is normal.

III. Preventive Maintenance

• Replace hydraulic oil and filters regularly.
• Check hydraulic lines for wear or aging.
• Observe the working sound of the hydraulic system for any abnormal noises.
• Keep the hydraulic system clean to prevent dust and debris from entering.
• Regularly check the wear condition of hydraulic components.

IV. Precautions

• Before performing maintenance, be sure to cut off the power to the hydraulic system.
• When disassembling hydraulic components, be careful to protect hydraulic hoses and wires.
• When installing hydraulic components, pay attention to the tightening torque of the bolts.
• During maintenance, strictly follow the operating procedures.

Summary

Through in-depth analysis of common faults in excavator hydraulic systems, we can better understand the causes of faults and take appropriate measures for repair and maintenance. Regular inspection and maintenance of the hydraulic system can effectively extend its service life and improve the operating efficiency of the excavator.

Note: The information provided in this article is for reference only. For actual operations, it is necessary to analyze and judge according to the specific situation. It is recommended to consult a professional when repairing a hydraulic system.

Keywords: excavator, hydraulic system, fault diagnosis, solution, repair, maintenance