Checking the tightness of the servo control (Audi A4 B5)

If it is established that the fluid level in the expansion tank has dropped, then the entire steering system must be checked immediately. Otherwise, the servo drive may suddenly fail while driving.

Here are the steps for checking:

1. Turn the steering wheel fully left and right once. This creates maximum pressure in the servo hoses and makes any leaks more visible.

2. While holding the steering wheel against the stop, look for leaks in the following areas:

3. In the bypass valve piston: This is located approximately where the steering column enters the steering gear. When there is a leak, oil flows into the car under the dashboard at the front of the car.

4. In the rack seal. Oil comes out on one of the bellows folds on the front side. To check, loosen the bellows clamps and move it to the side.

5. In the hydraulic pump. To determine the leak, you must first wash the engine.

6. At the hose connection points. Check all the connection points one by one and tighten them if necessary. The tightening torque of the pump connection points is 50 Nm.