GM Power Steering Noise

Joined
Jun 6, 2017
Messages
156
Location
FL, USA
I just bought a 2008 Sierra and I have been fixing it up. The power steering had a whine at start up, idle, and when turning. I flushed the system with 2 qts of Prestone yellow bottle and the whining has quieted down some and the fluid is amber again (the old fluid was brown). My question is, what can I do to eliminate the noise? I was thinking of running the Prestone for a while and switching to a high grade synthetic like Redline once I save a little money. Thanks for any comments or ideas.
 
Lucas PS fluid w/ conditioners quieted a noisy pump a few years ago on an old Buick. Also smoothed the steering in my Honda and Cadillac when flush with standard PS fluid did not. It's pretty cheap (<$10) and available at Walmart.

I realize Lucas is the favorite whipping boy around here, but I cant argue with results. Apparently not all their products are overpriced!
 
I find Honda/Acura fluid too thick for GM PS pumps and add to the whine, especially in cold climates.

If all air bubbles have been burped out, and if you used the conventional Prestone, consider the synthetic Prestone for the next flush:
https://prestone.com/product/prestone-max-american-power-steering-fluid/

Or, visit GM dealer and see if they have 12345866

This LG product can also help with noise. Simply siphon out 4 ounces and top off:

If you want to test a thicker fluid without a flush, then test 4 ounces of Lucas instead:
 
I did do a complete fluid exchange with Royal Purple Max Ez. At least it all the same fluid and not a mixed frakenbrew. Anyways, noise it still there and bled the system like crazy. 🙄
 
From Lubegard, Road test vehicle, making at least 8 complete turns to the left and 8 complete turns to the right. That might help with the 'air purge'.

I don't see Synpower PSF, mentioned in bulletin below, as any better or worse than RP MazEZ. I haven't seen it in stores in years, maybe a decade now.. But, RP MazEZ is a thick 8.5cst/48cst PSF. The synthetic Prestone that I mentioned is 6.7 [email protected]°C and 29.8 cSt @ 40°C.

I haven't had any success with thicker fluids in GM vehicles. You went thicker with RP. And, there is nothing wrong with using Lubegard PSF or their PSF additive. I've used the Frankenbrew successful and the GM PSF systems I service don't whine. Good luck.


Document ID# 1875699
Subject:power Steering Whine Noise - keywords fluid gear hose idle pump turn #PIT4208 - (12/04/2006)
Models:2003-2007 Cadillac Escalade, ESV, EXT2003-2007 Chevrolet Avalanche, Silverado, Silverado Classic, Suburban, Tahoe2003-2007 GMC Sierra, Yukon, Yukon Denali, Yukon XL, Yukon XL Denali2003-2007 Hummer H2

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:
Some owners may comment on a power steering pump whine noise. This whine noise is most commonly heard between idle and 2000 rpm coming from the power steering pump.

Recommendation/Instructions:
Reports of flushing and refilling the power steering system with Valvoline SynPower Power Steering Fluid have reduced or eliminated this noise. Valvoline SynPower Power Steering Fluid is a synthetic fluid and is available at most auto parts stores in quart size containers. In most case 3 or 4 quarts will be needed to flush and fill the system.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
 
Well It gas been a couple weeks and I had to put 1k on it. Seems quieter than befire the change. Going to run it for a while and flush again with some syn.
 
I find Honda/Acura fluid too thick for GM PS pumps and add to the whine, especially in cold climates.

If all air bubbles have been burped out, and if you used the conventional Prestone, consider the synthetic Prestone for the next flush:
https://prestone.com/product/prestone-max-american-power-steering-fluid/

Or, visit GM dealer and see if they have 12345866

This LG product can also help with noise. Simply siphon out 4 ounces and top off:

If you want to test a thicker fluid without a flush, then test 4 ounces of Lucas instead:
Are you recommending the synthetic Lubegard PSF or conventional Lubegard PSF?
 
How does Dex VI compare in viscosity to GM PSF? Last year I had to R&I the rack to change a part and in a pinch refilled with Dex VI. I swear I remember it being more quiet with Dex VI vs PSF.
I ran Dex6 in my 2005 2500HD since it had 285 tires on it and the weak pump couldnt keep up from the tire size and the weight of the diesel engine. It was much quieter and took away the lag when using the brakes and trying to steer at slow speeds.
 
I added a 4oz bottle of the LG PSS 20404 to the reservoir. Seems to be some improvement. I have a little less than a QT of the lubegard synthetic Honda/Acura PS fluid I used for my wife's Honda that I may put in there whenever I drain it again.
 
I've battled this issue for years, used all BUT Valvoline products. Currently using GM fluid (used RP, Acura/Honda, Dex6, LG), there is also GM cold climate fluid. Would hoses (collapsed?) or steering gear box affect whine?
 
I like Honda/Acura P/S fluid in GM units.
@MolaKule has previously spoken about the Honda PSF and that it is a HUGELY different fluid compared to ATF. Not sure this would be a good recommendation for others unless we get some expert info on suitability in this case since I’m not a GM PS pump expert.

OP, if your pump uses regular ATF, Valvoline MaxLife ATF has been a really good replacement in mine- just buy a gallon, jack up the front of the car and leave the wheels hanging. Take the return line off your reservoir, and stick it into a collection vessel; have a helper start the car and spin the wheel back and forth while you pour new fluid into the reservoir. Keep pouring new fluid in til the discharge is the same color as the new fluid; stop the car and replace the return line. Start the car back up, have the helper spin the wheel again and top the fluid up in the reservoir, and then finish with 5-10 more lock-to-lock spins of the wheel to get any air out of the system. This is by far the easiest way to properly “flush” PS fluid.
 
I was going to change my ps fluid, and fill with iso 32 because I already have some.
Over the years I used up a pail of ISO 46 synthetic compressor fluid in various power steering pumps with great results.
But.... Be careful with synthetic compressor fluids and stay away fom the exotic ones.
Mine was Petro Canada "Super Compressor", the name has been changed 6x in the last 10 years.
 
I tried many different PS fluids in my 04 avalanche. The only thing that worked was replacing the PS pump with a new OEM pump. The fluid I have in there now is Lucas PS
 
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