power steering pump whine issues

Well, here's the update. It worked a ton better! But... it still has an issue somewhere. After driving down the mountain pass dropping around 2000 ft, I could tell the brakes were not as good as when they started. This was not due to brake heat. Its not a steep grade, but you lightly apply the brakes throughout the drive down. I came to a stop, turned the wheel, and could hear the pump whine a little. Steering assist was fine, I could just hear it. Before I condemn the pump, I'm going to ditch the power steering fluid and change it back to ATF. That's what I would always run in the past, and I never had an issue like this before.. I've read that power steering fluid can foam when using a hydroboost, where as ATF won't. The internet is quite divided on ATF vs PS fluid, so there's that.. Everything is installed and working properly, so maybe this will lick the issue. The pump still whines when its cold, so the pump COULD be the problem. We shall see after I swap the fluid out.

AuroraGirl said:

The gmt400 have a bolt on cooler , but yours is better because of the size. I would use fuel injection clamps last thing you need is hot hydraulic oil spraying all over everything up there and it not being super obvious since it wont smoke as quickly and your now looking at reduced brakes and steering. The clamps are a big deal

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Not a bad Idea. I used the clamps that came with the cooler kit. I usually prefer EFI clamps, but I didn't have any in my garage at the time. I looked into OEM cooler and kinda laughed at the price. This Hayden cooler is quite a bit larger, and I placed it in a better air flow location, and it was over half the cost.

kylenautique said:

Well, here's the update. It worked a ton better! But... it still has an issue somewhere. After driving down the mountain pass dropping around 2000 ft, I could tell the brakes were not as good as when they started. This was not due to brake heat. Its not a steep grade, but you lightly apply the brakes throughout the drive down. I came to a stop, turned the wheel, and could hear the pump whine a little. Steering assist was fine, I could just hear it. Before I condemn the pump, I'm going to ditch the power steering fluid and change it back to ATF. That's what I would always run in the past, and I never had an issue like this before.. I've read that power steering fluid can foam when using a hydroboost, where as ATF won't. The internet is quite divided on ATF vs PS fluid, so there's that.. Everything is installed and working properly, so maybe this will lick the issue. The pump still whines when its cold, so the pump COULD be the problem. We shall see after I swap the fluid out.

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HOw long was your brake pedal applied?

GOing down a grade, you should NOT have had your foot applied to it

AuroraGirl said:

HOw long was your brake pedal applied?

GOing down a grade, you should NOT have had your foot applied to it

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Not much. I've driven up and down this road thousands of times with my old hydroboost system. This issue has only started recently. I'm going to switch back to ATF and see if this resolves the issue before I replace the pump again...

I'd be REALLY surprised if switching from PS fluid--which is actually recommended--to ATF which isn't, would actually fix this.

Schurkey said:

I'd be REALLY surprised if switching from PS fluid--which is actually recommended--to ATF which isn't, would actually fix this.

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throwing parts at it isnt helping for sure, esp the wrong ones. view fluids as a part and it helps conceptualize it sometimes.

And with such a low capacity system, thats not a sump system, switching back is not wise. Has the OP tried Seafoam trans tune yet? I wrote about it before..

AuroraGirl said:

throwing parts at it isnt helping for sure, esp the wrong ones. view fluids as a part and it helps conceptualize it sometimes.

And with such a low capacity system, thats not a sump system, switching back is not wise. Has the OP tried Seafoam trans tune yet? I wrote about it before..

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I always ran Dex/merc 3 in my pumps before. Everything now may be correct, but power steering fluid under heat from a hydroboost can foam. I've now read in multiple places that if you cut the PS fluid with dexron, it stops the foaming. Might as well try it.

kylenautique said:

I always ran Dex/merc 3 in my pumps before. Everything now may be correct, but power steering fluid under heat from a hydroboost can foam. I've now read in multiple places that if you cut the PS fluid with dexron, it stops the foaming. Might as well try it.

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So...you drive around for awhile, use the brakes, steer back and forth, get everything good and warm, then you stop, pop the hood, pull off the cap to the PS reservoir...and it's full of foam? You shut the engine off, and the foam takes awhile to subside into liquid again?

Or you see lots of fluid movement from the return nipples of the hydroboost and the steering gear, but there isn't any foam? You shut the engine off, and you have liquid PS fluid almost instantly?

Far as I know, PS fluid has anti-foam additives just like PS fluid and engine oil. (I have to admit that I don't see "anti-foam" listed on the backs of the few PS fluid bottles I just looked at.)

Schurkey said:

So...you drive around for awhile, use the brakes, steer back and forth, get everything good and warm, then you stop, pop the hood, pull off the cap to the PS reservoir...and it's full of foam? You shut the engine off, and the foam takes awhile to subside into liquid again?

Or you see lots of fluid movement from the return nipples of the hydroboost and the steering gear, but there isn't any foam? You shut the engine off, and you have liquid PS fluid almost instantly?

Far as I know, PS fluid has anti-foam additives just like PS fluid and engine oil. (I have to admit that I don't see "anti-foam" listed on the backs of the few PS fluid bottles I just looked at.)

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I haven't checked the fluid while driving, but I can feel it in the brakes and steering. I'm actually intrigued on the royal purple synthetic fluid. I may try that rather then dexron. It has double the heat rating of standard PS fluid and states its anti-foaming. This may be the solution for Hydroboost.

you do NOT want foam in your power steering fluid. Foam is inevitable formation, however, when you flush the system. Under normal circumstances after being bled it should not be foaming. Foaming means the reutrn fluid is moving too fast, its got transmission fluid in it which is designed to foam for a different purpose/reason, its got too little a reservoir, or there is a leaking hose allowing air to be sucked into the system. Realize that anti foam means two things. One, traps air and it releases it elsewhere, desireable in certain systems since you may not move a lot of GPM of fluid and you want to keep there from getting air pockets that end up in the worst corners of the system, or you have the stuff meant to discourage the formation of bubbles at all costs so that it doesnt end up sucking them in the pressure side because that will cause heat wear and deposits esp in a lower capacity, higher flow system in continous operation.

Depending on the transmission setup, a transmission might also be desireable to use a flluid like that, but gm doesnt anymore(at least since dex3-dexvi original vehicles, im not speaking to newer ones since they tend to be trash and ill never be owning them)

Also, as we established gm said themselves that ATF shouldnt be used because of compatibility with their own systems seals. Not saying the aftermarket stuff you have isnt going to be the same, but if you have any oriignal components or made to oem spec, id be worried about the foam i would introduce by having the seal let air be pulled in. If you had more fluid to deal with, id understand where you are coming from, because then the air would have time to rise out as well as fluid to cool and stay cooler and for the returned fluid to be less turbulent as it would slow down to a stand still, and the fluid level being higher would make it less likely any churning could happen.

Sounds like to me if you have better steering feel when driving and braking youre using too heavy of a viscosity flluid, as dex 3 drops in viscosity pretty far, but dexron vi doesnt drop as far as dex 3 does. but dex vi is most definitely going to ruin some seals.
This royal purple sounds interesting, have a link? Id like to check it out. Its probably a good option based on the brand but never let a product go without some interrogation. Names mean a lot less once youre already burned. Or find out after the fact its some shameless private labeling of a normal run of the mil product you wouldnt buy ever