How to Diagnose Common Hydraulic System Failure in Volvo Excavators
7/25/20262 min read
Hydraulic systems are the backbone of your Volvo excavator. When a hydraulic failure occurs, your entire job site can grind to a halt, costing you thousands in lost productivity. Recognizing the early warning signs and systematically diagnosing the root cause can prevent catastrophic pump failures and expensive component replacements.
This guide covers how to diagnose the most common hydraulic issues in Volvo excavators, from sluggish cycle times to unusual noises.
Symptom 1: Sluggish Operation or Weak Lifting Power
If your excavator’s boom, arm, or bucket is moving significantly slower than normal or struggling under a load, the issue typically points to hydraulic pressure loss or flow restriction.
Check Fluid Levels and Condition: Start with the basics. Check the hydraulic oil level in the sight glass. Low fluid causes cavitation and pump damage. Inspect the oil itself—if it looks milky or foaming, water or air has entered the system.
Inspect Hydraulic Filters: A clogged or restricted return or suction filter forces the pump to work harder and starves the system of fluid. If it has been more than 1000 hours since your last service, inspect and replace your hydraulic filters immediately.
Test System Pressure: Use a pressure gauge to test main relief valve pressures against factory specifications. Low relief pressure usually indicates a worn hydraulic pump or internal bypass inside a control valve.
Symptom 2: Unusual Noise or High-Pitched Whining from the Pump
A loud whining, screaming, or rattling noise coming from the hydraulic pump area is a red flag that should never be ignored.
Air Aeration (Cavitation): Whining is frequently caused by air entering the suction side of the pump. Check all suction hoses, clamps, and fittings between the hydraulic tank and the main pump for loose connections or microscopic cracks.
Blocked Strainers: Inspect the suction strainer inside the tank. If it is choked with debris, the pump cannot draw fluid smoothly, resulting in destructive cavitation.
Symptom 3: Overheating Hydraulic Oil
Excessive heat thins out hydraulic oil, reducing lubrication efficiency, damaging rubber seals, and causing internal component wear.
Check the Oil Cooler: Mud, dust, and debris frequently build up in the radiator and hydraulic oil cooler fins, blocking airflow. Clean the cooler core thoroughly with compressed air or low-pressure water.
Relief Valve Misadjustment: If a main relief valve is stuck open or set too high, fluid constantly dumps across the relief, generating massive amounts of heat. Check valve temperatures with an infrared thermometer to spot components running hotter than the rest of the system.
At Fluid-X Ltd, we understand that equipment downtime directly impacts your bottom line. That is why we are dedicated to being your comprehensive, end-to-end partner for industrial reliability. We supply a complete range of rugged, high-performance heavy machinery parts and premium industrial lubricants designed to withstand the toughest operating conditions. Beyond parts supply, our experienced team delivers the expert technical services, diagnostics, and hands-on support required to get your machinery back up and running swiftly and safely. Whether you are maintaining a single commercial vehicle or managing an entire fleet, Fluid-X provides the quality components and dependable expertise you need to keep your operations moving forward.
Contact us today.
