E420 Power Steering noise
 

Anyone offer advise on whay might be causing a noise anytime the steering wheel is turned ...like a groaning viberation when turning the wheel, but goes away pretty much when wheel is released? If the P/S pump needs replacing, how much and what is the best sourse? Can a somewhat experienced home mechanic do the replacement. Thanks in advance for any help.

Leaks?
 

The power steering pump in an E420 is prone to leaks. Are you sure that the fluid is at the proper level? I know that the previous owner of my car had the PS pump re-sealed. Apparently MB makes a kit to do this - and it's much cheaper than replacing the entire pump. I think that the kit is around $100 and perhaps 2 hours of labor, not sure though.

Regards,
Troy
1995 E420 71k

Re: E420 Power Steering noise
 

Thanks for the suggestion. The level of the fluid looked okay, however, there were bubbles in the fluid which indicated that there was air in the lines. Adding a little more PS fluid did the trick and it is doing just fine now. Thanks for the help.

Found out that the steering rack banjo fittings were loose and leaking fluid. A 7/16" box wrench works just fine to tighten star stud on the fittings. No leaks at all now...and working perfectly.

Make sure the p/s discharge hose that goes directly to the rack
is not pulled up or twisted upwards. If that line is too tight,
the movement of the engine will work the fitting loose on the pump causing a leak. Make sure there is as much slack in the hose as possible and if is not catching on anything.
I see this often.
Dr.D

Great suggestion. Thanks for the heads up.