Power Steering Pump: Testing and Inspection

Checking Function of Power-Steering Vane Pump

IMPORTANT!
- Prior to this check, first check all hose connections, the vane pump and the power steering gear for leaks.
- Ensure utmost cleanliness!
- No dirt is allowed to enter the system.

Necessary preliminary tasks:
- Draw off and dispose of hydraulic fluid from fluid reservoir.
- Observe country specific waste disposal regulations.
- Remove front assembly underside protection.
- Disconnect pressure line from vane pump.

Connecting special tool



Connect special tool 32 4 000 with new sealing rings to vane pump and pressure line.
1 = Connection, pump
2 = Connection, steering gear

Checking pump pressure



1. Close valve (A),
2. Open valve (B).
3. Fill and bleed hydraulic system.
4. Start engine.
5. Heat hydraulic fluid to approx. 50°C by moving steering wheel at increased engine speed.
6. Close valve (B) for max. 10 seconds and read pressure.



7. Compare measured pressure with specified nominal pressure.
- Replace vane pump if nominal pump pressure is exceeded by more than 10%.
- Check belt tension if nominal pump pressure is undershot by more than 10%. Replace vane pump if belt tension is OK.

After installation
- Fill and bleed hydraulic system.
- Check pipe connections for leaks.