The power steering on my wife's '88 at 281k has been very noisy for many months. When the car is running, the power steering makes a constant "whaaaa, whaaa" or moaning type of sound which gets noticeably louder when turning the wheel at very low speed. The sound seems to come through the column and varies with the speed of the engine, which makes me think its either the PS pump or related to the fluid circulating through the system. Using a stethoscope, I couldn't isolate the pump as the source of the noise.

The rack appears to have a slow leak on the passenger side (visible fluid dripping from boot), but I haven't pulled the boot yet to evaluate it's severity. The reservoir does not appear to loose fluid quickly.

I recently changed the PS belt and noticed the alignment of the pump is off somewhat. I plan on replacing the mount bushings shortly to restore correct alignment.

I also changed the PS fluid using the "turkey baster" method and refilled with Mobil 1 synthetic ATF. The fluid is now completely clear. I bled the system several times. This did not reduce the noise level significantly. The old fluid was contaminated with some black junk and also what appeared to be tiny bits of metal, so I know some wear has occurred. However, the rack works ok, i.e. it turns the wheels smoothly in either direction without binding. Balljoints, tie rods, and strut mounts are in great shape.

At any rate, there is definitely a problem. I'm wondering if it is the pump, or rack, or both? A bad or partially blocked line? Possibly air getting into the system? Is there anything else I can do before I start spending money on a new pump or a rack? I have a used PS pump which I could install but it's condition isn't the greatest. I may try that and see if it changes anything.

Any help is appreciated.

-Andy R.
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'92 240 wagon, 268k, '88 240 sedan 280k