Mr.F

A few weeks ago I noticed that after engine temps were in operating range my power steering pump would start to whine. No whining at all when cold. Fluid level was fine, no recent power steering components serviced/removed. This progressed into severe foaming and overflowing steering fluid reservoir. Overflowing only after the vehicle is turned off. I wasn't able to find any fluid leaking out, and the indy I took it to wasn't able to diagnose the problem, stating that he also could not find a leak besides the overflow after shut off. It's now at the point where the pump is whining constantly and there is air in the steering rack...

I've read a lot about the e55's and other older MB models having a bad o-ring between reservoir and pump, since my reservoir has a hose in and a hose out this is not something that applies to my vehicle. Besides the small 3 inch piece of hose connecting the hard lines to the reservoir I don't see any other hoses I can replace. I've purchased a set of Oetiker clamps to replace the clamps and two short hoses, but I'm not entirely sure this will fix it.

I haven't been able to find any information referring specifically to the w211 e63. I'm hoping someone else who has gone through this can offer some advice that might help me to avoid a dealer visit.

Any help is greatly appreciated.

bbirdwell

Replace the power steering pump. Most likely a bad bearing running hot and boiling the hydraulic fluid right out of the fill tube. I've experienced this personally.