Checking Power Steering Fluid

[TLD]

When checking the fluid movement in the power steering reservoir, I see some very slow movement of the fluid with the engine running. How much movement should someone see? I have problems with steering returning to center after a corner. I have replaced the ball joints, steering hoses, reservoir and upper strut mounts. There is no noise coming from the pump and no leaks after replacing the hoses. The steering feels good but it is just the return to center issue. How should one check to determine whether the pump or rack is bad? Really don't want to replace both if not needed. Thanks for any help.

[hide1]

What fluid did you use? Sounds like you covered all your bases. Do you have power steering when at a stand still? If yes, and its just not returning to center its probably the rack.

[bweier]

What fluid did you use? Sounds like you covered all your bases. Do you have power steering when at a stand still? If yes, and its just not returning to center its probably the rack.

I recommend Pentosin ATF 1 for Power Steering fluid...at least for my 98 M S52

[TLD]

I used RedLine ATF

[TH3 Shifty]

I use what BMW put in from the factory, pentosin

[DRMe36M3]

its PS fluid...as long as its clean it wont matter.

[Lints]

its PS fluid...as long as its clean it wont matter.

Not quite. It's not exactly PS fluid, it calls for ATF...

[DRMe36M3]

Truth

[flyfishvt]

Failure to return to center is usually an alignment issue.

Steering rack failure generally results in very difficult steering

[hide1]

It actually says 'ATF Fluid' on the reservoir cap... underneath all that caked on dust somewhere of course.

[Tbaker474]

I had a return to center issue in my car, and it turned out that the pump was the culprit. Put in a new pump and problem solved. YMMV.

[TLD]

Update. I found some Sea Foam for power steering systems and flushed my system and refilled with new fluid. Now the car will sit and idle just fine and the steering seems to be better, however, when you take the car out for a drive there is a whining noise at higher RPM's. I guess I will just replace the remaining parts (rack, pump and lines) because I at a loss to determine the problem.