Moaning and Groaning
 

Power steering pumps is failing on my 88 560SEL. I have done a search and only found info on power steering rebuild. I have the kit and it looks like it only fixes leaks. My pump does leak, however, it moans non stop when full of fluid and is loader when turning. Anyone know why? The fluid is bit foamy after turning the car off.

Anyone?

Have you tried sucking out the fluid with a turkey baster (several times) and refilling with synthetic fluid....

I am trying to think of the cheaper possible fixes first...

I once had a q45 that I filled with transmission fluid in the power steering case.... turns out the pump hated that fluid and groaned....replaced with real synthetic (valvoline)power steering fluid...and it behaved normally.

Now on the down side...I once owned a 72 mercedes that developed the groan....turned out it was the steering box...very expensive...

Don't forget the filter as well. Change the fluid and filter before you buy a new pump.

Do not use ATF!!!

forgot about the filter....and I just changed one (and the fluid) in the 300ce this weekend....old one was pretty dirty....

Also purge the air. You have to keep turning the steering back and forth with the cap off until all the air is out.

One other thing >> when a fluid is "foamy" > it's usually an indication that the fluid has been overfilled > the excess fluid gets thrashed about > ergo the foam.

more is not necessarily "better" when it comes to fluids [except in beer]