Power Steering — Air Bleed (Mercedes-Benz C-Class W201)

1. With the engine stopped, add the required fluid to the upper mark on the plastic tube, which is installed on the stud of the tank cap. Use only special fluid.

2. With the engine off, to clear the system of trapped air, slowly turn the steering wheel several times from one extreme position to the other. Then add fluid to the reservoir. Repeat this procedure until the level in the reservoir stops falling.

3. Ask an assistant to start the engine, and watch the fluid level yourself. Be prepared to add a lot of fluid at once, since the level may drop quickly when the engine is started. The level must be maintained at all times no lower than the lower mark on the tube.

4. With the engine idling, slowly turn the steering wheel two or three times approximately 45° from the center position left and right, then turn the steering wheel twice from one extreme position to the other. Do not hold the steering wheel at the extreme positions, as this puts a strain on the hydraulic system. Repeat this procedure until no more air bubbles are released into the reservoir.

5. If abnormal noise is heard from the tubes when turning the steering wheel, this indicates that there is still air in the system. Turn the steering wheel to the straight-ahead position and turn off the engine. If the level in the reservoir rises, then there is air in the system and the air bleeding operation must be continued.

6. When all the air has escaped from the system, turn off the engine and let the system cool down. After cooling down, check whether the fluid level is at the maximum mark on the tank wall. If necessary, add fluid (see section "Weekly check").

[Article text obtained from the website: mercedesman.ru]