help needed - cause of foaming power steering fluid?

[Dakota]

I was able to take my Challenger out for a longer spin today (yesterday was the first time).   Everything started out fine, but after driving for about 20 minutes, the power part of my power steering disappeared again.   This also happened during my first trip but that was clearly because of a low fluid level that apparently developed during the first "lock to lock" cycle on the steering box.  When I got back home today and checked the fluid level, the top of the pump reservoir was full of foam.   If I lost any fluid from the foaming, it wasn't much because the level was about where it started once everything cooled down.

I have a stock federal PS pump which I rebuilt (new seals all around) a couple of years ago, but this is the first time it's been actually run with any kind of load on it.   The steering box is a stock unit that received a Firm Feel Stage 3 upgrade a couple of years ago - also it's first time to run.

There are no obvious signs of leaks around the pump, so I'm guessing that I have air getting sucked in around the shaft seal, probably because of what happened on day 1 of driving.  Or am I just experiencing a start-up issue from air trapped in the steering system that will go away with further driving?   

I'm getting ready to order a replacement pump from RockAuto, so please talk me out of it if there's something besides the bad seal happening.

Thanks.

[Burdar]

Not saying you don't have an issue but it's always been my understanding that between the Federal and Saginaw pumps, the Federal were the lesser of the two styles.  Under hard cornering I've heard the Federal pumps have a hard time keeping up and you lose boost.  The Saganaws do a much better job.  I wonder if what you are experiencing is the norm for a Federal pump?    If you were just going for a leisurely drive and not pushing the car hard at all, I'd add a little fluid and retest.  If the level was low, I can definitely see how it could foam up.

[Brads70]

I jack up the front end so the wheels are off the ground, start the engine and cycle the steering lock to lock till all the air is bled out? Not trying to be a "Captain obvious" just not sure this had been done yet?

[Dakota]

I will try what you suggest Brad as I haven't done that cycling with the wheels off the ground yet. You'll have to keep the Cap'n Obvious cape tucked away a little longer.   I'll let you knows what I find out.

Burdar - it was pretty calm driving and once the boost quit it stayed gone until I let the car sit for a hour or so. 

[GoodysGotaCuda]

You should consider disconnecting the tie rods from the knuckles when turning lock to lock.

Depending on the car, your knuckles may bottom before the box does, which means you aren't getting to "full lock" on the box.

Definitely keep it topped off an monitor it for several drives. Depending on the fluid, it might be best to let it sit overnight once it gets very aerated, the air can suspend quite a bit in the fluid.


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[Dakota]

I raised the front end and had my wife cycle the wheel while I watched the reservoir.  After about 15 seconds, fine bubbles started to appear and gradually the fluid started to foam up.   While i was scratching my head about what this meant, a small pool of steering fluid that had pooled on the K member came rolling out.  When I traced the drips,  I could see leaks on the seal with the reservoir.   As this is the 2nd time this has leaked, I've ordered a replacement pump.  So I wait a little longer....

[Burdar]

Is the pump coming with a reservoir or do you have to reuse yours?  The leak might be a bent reservoir.

[Chryco Psycho]

Awesome that you were finally able to get it out for a drive . That is a great feeling !!
Minor setback with the steering issue , usually they blled the air out & are fine but the leak must be part of the issue .

[Dakota]

Is the pump coming with a reservoir or do you have to reuse yours?  The leak might be a bent reservoir.

It comes with a reservoir.  I had the same concern about whether the old reservoir would work. 

[Brads70]

At least the problem surfaced? Hopefully all will be good when you get it replaced. 

[Dmod1974]

Are you running ATF or actual PSF?  Legit power steering fluid is much less susceptible to foaming than ATF, even though both are often used in power steering set ups.

[GoodysGotaCuda]

Are you running ATF or actual PSF?  Legit power steering fluid is much less susceptible to foaming than ATF, even though both are often used in power steering set ups.

I also learned that "power steering fluid" doesn't really have a standard make up. I ended up using AC Delco/GM OEM PS Fluid and had much better results.

[Dakota]

Are you running ATF or actual PSF?  Legit power steering fluid is much less susceptible to foaming than ATF, even though both are often used in power steering set ups.

I'm using Prestone Power Steering Fluid.   I've had no issues with it in other vehicles.   

[Dakota]

The replacement power steering pump from Rock Auto arrived yesterday.  I finished installing it today, and am happy to report that there's no more foam forming in the reservoir or loss of power steering assist.   All better now.

[Chryco Psycho]

I am Glad you got it solved