Volvo EC210D Low Hydraulic Pressure – Weak Machine Power Troubleshooting Guide

The Volvo EC210D excavator may experience low hydraulic pressure, weak machine power, slow functions, or poor digging performance. This issue affects all major operations including boom, arm, bucket, swing, and travel.

This guide explains all major causes, symptoms, and step-by-step troubleshooting for low hydraulic pressure in the EC210D.

Common Symptoms of Low Hydraulic Pressure

• Slow boom, arm, and bucket movement
• Weak digging power
• Slow travel or weak travel on slope
• Slow swing or jerky swing
• Machine stalls under load
• High fuel consumption
• Engine sound changes during operation

Main Causes of Low Hydraulic Pressure

1. Weak Main Hydraulic Pump

• Worn pump pistons
• Damaged pump barrel
• Internal leakage

2. Incorrect Pump Control Pressure

• Weak pump control valve
• Low pilot pressure to pump
• Faulty pump regulator

3. Low Pilot Pressure

• Pilot pump weak
• Blocked pilot filter
• Pilot line leakage

4. Relief Valve Set Too Low

• Weak relief spring
• Contaminated valve seat
• Relief valve stuck partially open

5. Hydraulic Oil Contamination

• Dirty hydraulic oil
• Clogged return filter
• Blocked suction strainer

6. Air in Hydraulic System

• Low oil level
• Loose suction hose
• Air leakage at pump inlet

7. Control Valve Internal Leakage

• Worn spool
• Contaminated valve body
• Internal bypassing

Step-by-Step Troubleshooting

1. Measure Main Pump Pressure

• Check pump delivery pressure
• Compare with Volvo specification
• If low → inspect pump and regulator

2. Check Pump Control Pressure

• Measure control pressure line
• Normal: 35–40 bar
• If low → pilot system issue

3. Inspect Pilot Pressure

• Check pilot pump output
• Clean or replace pilot filter
• Repair pilot line leaks

4. Test Relief Valves

• Check main relief valve setting
• Clean or replace if weak

5. Check Hydraulic Oil Condition

• Replace oil if contaminated
• Replace return filter
• Clean suction strainer

6. Inspect Pump Suction Line

• Check for air leakage
• Tighten clamps
• Replace cracked hoses

7. Inspect Control Valve

• Check for internal leakage
• Clean spools
• Repair worn valve sections

Preventive Maintenance Tips

• Replace hydraulic oil and filters on schedule
• Check pump pressure during every major service
• Clean pilot filter regularly
• Inspect suction hoses for air leaks
• Monitor relief valve settings

Following these steps will restore proper hydraulic pressure and ensure strong machine performance in all operations.

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