Applicable Systems
EC220 Excavator
Symptoms
Brake system pressure below safe operating range; parking brake may engage automatically for safety.
Possible Causes
- Brake accumulator charge pressure low
- Brake pump worn or failed
- Brake system external leak
Troubleshooting Steps
- Step 1: Check brake accumulator pre-charge pressure
Pre-charge 60-80 bar (nitrogen) - Step 2: Test brake pump output pressure
Pump output >= 130 bar at idle - Step 3: Inspect all brake lines and fittings for leaks
No visible leaks - Step 4: Check brake fluid level and condition
Fluid at correct level, clean - Step 5: Replace brake pump or accumulator if faulty
Brake pressure within safe range
How to Reset
Clear via Volvo Tech Tool; may require brake system bleeding.
Common Replacement Parts
- Brake Accumulator P/N: VOE15890236
- Brake Pump P/N: VOE15890237
Frequently Asked Questions
- Q: What is Volvo dual-circuit braking?
Volvo wheel loaders use dual-circuit brake system for redundancy. If one circuit fails, the other provides braking. Low pressure warning requires immediate stop.
Source: volvo fault codes reference
Category: Heavy Equipment