Can different/fresh PS fluid affect steering wheel

[chefwong]

So after 40K, I replace the PS fluid in the reservoir 4 times via baster . I do have fresh new tires and a alignment as well BUT I don't think these 2 come into play....


The steering feels much looser, still decent feedback but definately much looser. It's the correct fluid though - I used Amsoil ATF in my BMW X5. Usually, when I throw the summer tars on, the steering is actually a bit harder than with winters due tgo 18 vs 20" tires, and much wider 315 20" tires.....

But after doing a PS fluid change, it's definately looser. Not Ford Tauraus loose,but loose enough that I can feel it.


Any suggestions.

 

[BGK]

I would check to be sure ATF IS the correct spec for PS fluid for your vehicle. It might not be.

Recently I suctioned out the ps fluid in the ps reservoir in a Saturn that we own, and replaced it with Valvoline high mileage ps fluid. Afterwards, the whistle the steering previously made completely went away. There was also a slight ps leak before and it is gone as well.

 

[ewetho]

Fresh fluid may have cleaned the relief valves and lubed the system properly.

Double-check fluid specs and see how it goes.

 

[ConfederateTyrant]

I did an Auto-RX treatment on my 1995 Mercury Grand Marquis' power steering, then flushed it with Amsoil Super Shift since my car requires Type F. I noticed that it got a little looser, and became easier to turn the wheel. Nothing but improvements elsewhere, so I do not consider the looser feel as a sign of something bad happening.

 

[Pablo]

Define "looser". Easier to turn? Car wanders on road?

 

[chefwong]

The OEM fluid is Castrol Dex III.
Amsoils site does list their Universal ATF as a compatible fluid for my vehicle - BMW X5.

The steering is looser. Previously, while the steering wheel felt a little on the heavy side *to turn*, it had good *weight* and feedback. It was sometimes a CHORE making broken U's but not anymore . That's how much of a difference I can feel from the steering wheel.

The steering wheel now is very Fluid when turning lock to lock, and I don't recall ever being able to do this so smoothly with the 20"s on.

However, I just took it for a spin to duplicate some of the problems I have been hearing as well.....just needed a quiet day with the windows down.

When cold, there seems to be a slight noise from the pump as I back out. However, even with the car warm, even turning the wheel to 3'oclock or going counterclockwise to 9'oclock, it emits a noise as well. Going lock2lock, it obviously has noise.

Paul, any advice or suggestions.
With the more fluid steering (and the car has never had such fluid steering - literally I can say possibly 100% less resistance than previously)it feels a little floaty as well through the steering wheel.

I'm stumped.

 

[Bill in Utah]

I've always done the same drain like you did with many cars/trucks and never noticed a change..

I've used regular PS fluid to syn dex III and no difference.

Interesting you have. And in a BMW which shuts off the PS assist better than other makes..

Wonder if your having a additive clash? The mix of new and old?

bill

 

[Pablo]

I've never heard of something quite like this from fluid alone. Makes me wonder is something was gumming up and is now free. Did you do the tires and alignment at the same time?

 

[chefwong]

Hmmmm Bill. So far I've done 4 changes via the reservoir which used by 1 quart exactly. Maybe I should continue with another quart until I get diminishing returns ?

Yes, brand new tars and alighment done at the same time.
It felt fine pre fluid swapping. No noise at the rack/pump at all.

It still handles great - just that the steering seems like it's too much to the point where it's not as tactile through the steering wheel as it was previously....But the noise is still an issue as well.

I'd like to pinpoint this before I bring it to my wrench. He's a good drives away and worth it (I drive 1 hr plus just to have him patch my tires), but hopefully you guys can shed some insight.

 

[dailydriver]

Are you running the EXACT same pressures in the summer tires as last year (when you took them off for the winters)??

 

[chefwong]

Yes - same pressue I keeps 33/32. I have a TPM that display Real Time pressures, temps, etc. It still does not address the noise or steering wheel issues I am having.

 

[unDummy]

Visc of the fluid can make the steering feel under or overboosted.

If you're not happy with Amsoil as a PSF, then just replace it. Use another ATF or PSF!

If the steering feels looser, then you need someone competent to inspect the entire front end. Some component is worn, out of spec, or think alignment isn't as good as you think it is.

Oversized heavy rims/tires beat the snot out of suspension components. Sounds like you're finally beginning to notice the wear and tear in your front end!

 

[Squishy]

How exactly does viscosity affect the steering feel? Is it thicker = hard to turn? The Escort could use a looser steering wheel...maybe I'll try some Dex VI in there.

 

[chefwong]

I stopped by the local parts store and they did not have Castrol DIII, but did stock the Castrol Multi ATF in stock.....

Just short of M1 ATF, any suggestions fellas. I'm hoping it's not by coincidence that it's the rack that's got issues...The moaning/squeaking has not gone away. I checked PS levels, and they're fine.

 

[wander2039]

In my experience different fluids can cause either less resistance or more depending on the viscosity of the fluid. When I put Mobil 1 atf in our Escape compared to the regular AAP Mercon the resistance is quite a bit less. I just put AAP Mercon V in it and it stayed the same as the Mobil 1. My work Escape I put some regular Mercon and it stiffen up quite a bit compared to whatever was in there before. On the Ranger at idle it's the same no matter what i've used. Although at higher rpms the thicker the fluid the stiffer it gets, sychromax is one of the thicker i've used. The thicker fluid also reduces the whine quite a bit, no difference on the Escapes.

 

[mechtech2]

If you had posted only that you just got fresh tires and an alignment, we would have universally concluded that it was the sole cause of your looser feeling steering.

 

[Doc8404]

if you are spec'd for ATF in your PS, use MaxLife ATF.
if you are spec'd for PSF in your PS, use MaxLife PSF.

 

[OriginHacker21]

Hey Chefwong, I recently did a PS fluid replacement from OEM to Valvoline synpower. Like you my steering wheel became a lot easier to turn and on Uturns it is quite noticeable. It isn't wandering the road but sure does feel a lot easier to turn. I actually was going to start a post about this till I saw your post. Unlike you, I didn't do anything with my tires/alignment so I think we're onto something here. Smoother as in less resistance.

 

[mjfx]

I am pretty sure you need to increase the pressure in the rear tires.. ~36psi if its anything like my car ('98 328i).

I also have this feeling.. and its almost scary. What I've learned from other BMW owners is that if the resorvoir was neglected or starved, the p/s pump will make nows forever after that point.

And the discussion about the "correct" ATF is interesting.. What ATF type does BMW ask for?

 

[chefwong]

OEM spec is 32 all around.
Depending on load, I adjust.
32 single drivers does seem to be the best in regards to handeling/mileage. However my *normal* setup is 34-36 F 32R which helps with the Understeer.

BMW PS calls for Dex III.

I actually stopped by the dealership to pick up Dex III. They don't sell it ! So off to Autozone, and I picked up the Castrol Multi-Vehicle ATF (Dex III Mercon ATF).

I just did one reservoir baster swap. Will changes via reservior for the next couple of times and report back !
I'm keeping my fingers crossed.