Caution: Drained hydraulic oil must not be reused. Always fill with new oil VAG G 002 000.
If the oil in the steering system has been changed, be sure to clean the filter with cleaning gasoline.
Fill the expansion tank with hydraulic oil up to the MAX mark.
Raise the car.
With the engine not running, turn the steering wheel several times from one stop to the other, which will remove air from the cylinder.
Add hydraulic oil up to the MAX mark.
Set the wheels to the center position and lower the vehicle.
Start the engine and leave it running at idle. At the same time, monitor the liquid level in the compensation tank. If the level decreases, you should top up the hydraulic oil until the level is constantly at the MAX mark.
Turn the steering wheel from lock to lock until air bubbles stop appearing in the expansion tank.
(The original article is posted on the resource AudiManual.ru)