280s power steering problem

[Jim Taylor]

i have a problem with oil foaming and coming out of the top of the power steering pump on my 280s. What would possibly cause this problem. I have not overfilled this unit but have noticed that the power steering pump has become more noisey over the last few weeks when steering wheel is turned

[Benz Dr.]

Sounds like the level ran low and the pump sucked in some air. Now the fluid is full of air bubbles and it will foam up and run out all over the engine bay.
Raise the front wheels high enough that you can easily move the wheels from side to side. With the engine not running turn the steering wheel back and forth in the center portion of travel. You can go full lock a couple of times to make sure you have all the air purged out.
As you move the steering wheel you should see bubbles coming up through the fluid. As this happens the fluid level should go down and you will need to top it up as needed. Eventually all the air will be forced out and the fluid level will remain constant.
Start the engine and see if there's any more foaming. If it keeps on foaming after all the air is out of the system you have an air leak somewhere. I would look at the line going from the tank to the pump and change it if needed. If you have the fluid canister on top of the pump the seal between the two could be leaking.