Power Steering Pump going bad?? Suggestions...

2007 Hummer H3 3.7l i5 (122,XXX) miles
Truck started making a whining noise when turning steering wheel, from previous experiences I first checked the power steering fluid and the fluid level was good.
Checked parking spot for any PS fluid on the ground, but nothing found. Rack and pinion seems fine, one of the rubber boots was ripped & the other one at the end of the boot had a little bit of some kind of dried up oil on the outside. PS fluid seemed in good condition with the truck off, I lifted the front wheels of the ground, turned the truck On & turned the steering wheels side to side. Had the PS fluid cap off when turning the wheels and saw that the fluid was bubbly cream color kinda like coffee with milk, checked my online mechanic YouTube to see if anyone had the same issue, found a couple of videos where they removed the PS pump to fix the issue.

Has anyone of y’all had the same thing??? I’m 90% sure is the pump but rectifying here first before I buy the pump won’t hurt...

Sounds like the pump. I've had better luck with AC Delco than parts store brands. I had the same or similar symptoms as you.

Yeah, a pump is something you don't want to go cheap on. You could also rebuild yours too ...if you wanted to keep it all 'factory' original. Not that difficult, but most guys don't want to screw with it. OTOH, ya usually have to swap over the relief valves and fitting and sometimes the reservoir (on some vehicles) to the new pump so, yer not that far from rebuilding the whole thing anyway.

Have you considered just performing a PS fluid flush before you tear things apart? You can do the very easy route or the still pretty easy route. See ChrisFix on youtube for examples.

https://www.youtube.com/watch?v=VuPALAnHjRM
https://www.youtube.com/watch?v=A0fiZCHz5ew
https://www.youtube.com/watch?v=BD3PTy2B1EI

When my PS pump failed I no longer had power assist on the steering; heavy manual steering feel. The GM pump I bought was made in Spain, IIRC. It's an easy enough job to replace if your familiar with the pressed on pulley and using the PS pulley installer/ removal tool. I think the critical part of this job is using the correct PS fluid for the system in our trucks.

Mr_Rich said:

I think the critical part of this job is using the correct PS fluid for the system in our trucks.

Click to expand...

And getting the air out of the system simply by moving the wheel back and forth. Once the air is out, you may need to add more fluid.

And to Mr. Rich's point, my auto parts store pump failed abruptly resulting in the manual steering feel. It happened on the highway but I didn't notice until pulling into a parking spot and I almost hit the next car when the H3 didn't turn as expected.

Throw some Lucas power steering stop leak in it and see if it gets quiet. I’m pretty sure that’s all I have in mine. It was extremely noisy when I bought it so I ordered a new pump and dumped a bottle of Lucas in the old one to shut it up until I could get the new one installed. It’s been three years and the new pump is still in the box.


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Thanks everyone for the info.... will look into changing out the fluid this weekend first. Power steering still kinda works, I can still make one handed turns when driving even with one finger so hopefully my PS pump is not totally trashed, it might just be the old PS fluid not flowing right.... will post an update later on when i get to be done working on it

Yeah I think the guys are right. Based on your description (foaming) there's a good chance new (correct) fluid may be worth a good try. I would advocate changing fluid as others have said, using the 'right' GM fluid. Using the wrong fluid and stop leaks you're likely going to go down the road of 'murdering' an otherwise possibly good pump. Could be there's a coctail of products in there now and you're getting some foaming due to 'something' in the fluid, improper fluid, ...or general fluid breakdown. Unlike other pumps, a power steering pump mainly uses vanes for pumping action ...like an air tool uses vanes. So there's not a lot of o-rings critical to re-seal with a stop leak (which 'swells' the o-rings).

Power steering fluid is calibrated to work in higher temp and pressures than trans fluid and has more anti-foaming agents. A number of special equipment and industrial hydraulic equipment, not just power steering pumps, require fluid that is high in anti-foaming characteristics. Many skid steers and big construction equipment, for example, which see heavy duty hydraulic cycling require a special anti-foaming agent an owner can add to normal hydraulic fluid (or you buy the mfgr brand that already has it added). Fluid repeatedly going back/fourth through small ports and valves can develop non-compressible foam (noise and groan). There are guys on the skid steer forums who run into noise and hydraulic issues b/c they didn't know about it and just used a less expensive off-shelf hydraulic fluid (and their skid steer literally won't move when fluid gets hot). Sounds a lot like what you might have going on. I'm pretty confident the correct GM power steering fluid would contain the proper pre-calibrated amount of anti-foam / anti-wear agents. That's what I advocate you consider ultimately using.
http://my.cardone.com/techdocs/PT 20-0027.pdf



[EDIT:]
Below are a couple links that show a parts breakdown of a related GM pump. If after a fluid change doesn't do anything, read through below (Related GM pumps) and see if you come up with something that helps. If you can get at the fluid control valve on the vehicle, you could pull it out and take it apart ...see if any piece of crap might have lodged in it. It's a small port, easy for something to get in there, like a piece of rubber flake from a hose. If you had it off the vehicle, there's a big snap ring that retains the rear pump cover, which you can remove and disassemble the whole pump (getting it back on might require some pressing). I haven't personally had one of these pumps apart but worked on a few other GM and import pumps. There's not much to them, fairly easy to disassemble and work on. There are little ports inside which, if plugged, could cause trouble ..and vanes could potentially get sticky if the fluid was crap.

To me it's always worth trying to keep the OEM stuff going as long as possible when ya can b/c in most cases it's superior quality to 3rd party aftermarket or rebuilt products.

https://www.slideshare.net/hskekdmmm/2007-chevrolet-trailblazer-service-repair-manual


https://www.2carpros.com/questions/...maro-how-to-repair-rebuild-the-power-steering

Funny thing is that PS pump in my '89 Chevy K1500 has survived for the last thirty years, and four engine swaps using the red PS fluid. My 3T required the clear PS fluid and using the red PS fluid on the Hummer would cause a failure of the pump.