420 SEL Power Steering Pump
 

My power steering pump has just started to make a faint rumbling noise and the fluid is brown and foamy. I changed the fluid and the new fluid became brown and foamy also. I also feel a slight difference in the steering wheel power assistance. The pump and the steering box have no leaks and the belts are at the proper tension. It appears that it's sucking air. Has anyone had this problem? I think I may have to replace the pump but I'm also looking for some input.

Ben

Did you replace the filter?

M.b.doc
 

No, but I will now ,, What's the procedure for replacing the filter ?

Thanks
Ben

This DIY should help. http://www.peachparts.com/Wikka/PsFluidFlush

Silversleeves and MB DOC
 

Thanks very much for the information, I don't think the filter has ever been changed, It's the original 21 year old pump an I have owned this car for 9 years, I've changed every other fluid in the car several times except the power steering fluid. It seems easy enough, I'll call Phil at Fastlane for a filter.

Thanks Again
Ben