Changing Power Steering Fluid?

[JayX5]

I'm thinking of changing my PS fluid because it seems kind of hard to turn when parking or driving slow but once I'm at speed it's easier. There is no noise as well, so maybe a PS fluid change might help. However, I did notice some red fluid that leaked under the X the oter day. Any suggestions? The resivoir is still pretty full so not sure if it's the PS fluid. Also, what fluid should I use? I read that any ATF Dexron 3 will work for the power steering fluid.

[motordavid]

Jay,
Dexron III...some use Amsoil.
Here's a thread with lots of info and opins.

Your red drips could be PS or ATF fluid;hard to diagnose.
GL,mD

http://www.xoutpost.com/x5-e53-forum/...steering+fluid

[chefwong]

Hi Jay -

YMMV (your mileage may vary) on this.
This has been my experience so far.

My X is at 42K miles. Besides the oil, I have changed the ATF, TC and differentials back when it was at 42K. When I changed the ATF, it was somewhat gunky and by only doing a pan bolt drain/fill, only about 40% of the fluid was exchanged. I did do another ATF swap as well this season.


The only fluid I have not touched was the PS fluid. So I originally swapped it out with Amsoil Universal ATF. I went through a whole quart , which should have swapped out at least 90% of the fluid . The fluid made the PS feel too boosted and it made the rack have alot of noise.

So I went to the dealer and decided to buy a bottle of *BMW* Dex III fluid . I figuredered that it was Castrol Branded Dex III. The parts guy told me they don't sell that and just go to the local store to buy it. So that I did. Castrols Dex III is now bottled and labeled multi-vehicular ATF. I swapped it out 2X via the reservoir. The firmness on the PS was back BUT about 15% of the noise still lingered. The noise was present even from a cold start and if I turned the steering wheel 1/4 turn left or right.

FWIW, the Castrol branded ATF is thicker than the Amsoil variant.

Flash forward, I did 2 reservoir swaps with M1 ATF. The steering is slightly lighter than with the Castrol Atf and get this....the noise is 95% gone. The m1 is speced *slightly lighter than the Castrol as well. I am still getting noise at the rack - it's not so obvious if I don't pay attention and look for it, but do notice it here and there.

So that's my story with my PS fluid drama. The PS steering is lighter than stock OEM fluid *whatever fluid they put* and I've just not had a chance to revisit it to further diagnose the other 5% of the noise.

[motordavid]

Exc info post, CW...

I remember you commenting on "rack noise" and "feel"...fwiw, I
used Dex III, as it was available here at the "mountain car parts
store", and did a 2X turkey baster swap deal. I could not feel a
friggin diff, and wondered if it was just wasted time. But, the new
Dex did "look" a lot better than the stuff I sucked out.

Hope your last "5% noise" goes away!
BR,mD

[JayX5]

Thanks for the great info. My X doesn't have any noise though. But the steering is just so hard and sometimes it's hard for me to park.

[chefwong]

What size tires do you have. When swapping between 18 winter tars and 20's , yes it is a CHORE to PP.

Just for ref, for anyone else that may search this thread in the future, the higher the # , the thicker the fluid at temp

Castrol Dex III - 7.9 CST
M1 ATF - 7.6 CST
Amsoil ATF - 6.8 CST

[JayX5]

Thanks for the great info once again! I have the 4.6 rims/ tires but it's always been stiff even with the 18s.