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Discussion Starter #1
So to make a long story short, I have had 10 pumps put on my truck in four months or so.

One cold December morning I cranked the truck to let it warm up and noticed when leaving for work there was a puddle under the truck. Turned out the reservoir apparently had cracked or had some leak. I took it to a trustworthy local mechanic and let them install a remanufactured after market pump. This pump also failed.

After a few more attempts, with pumps failing both at the shop and later after picking up the truck, they took my suggestion and bought a reman OEM pump from a local dealer.

This pump also began whining like hell, louder and louder as weeks went on. I was finally able to get it back to the shop, they had been doing all the additional work for free, so I gave them one more shot. That day they said that they installed four more pumps, the last was a brand new OEM pump.

THE PUMP IS STILL WHINING!!!

I'm goin nuts and am out of options, outside of paying someone else to install another pump. Has anyone had this much of a problem finding a good pump?? All these pumps are failing. All are whining. Some have had reservoirs crack. Some have been found to have a lot of play in the shaft, much like I discovered last night when I inspected all my pulleys and belt.

Any Ideas???
 

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Nipple
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I think there is a separate issue causing the pumps to go bad... Like for me, there was a blockage somewhere in the fluid system causing a surge in pressure which would kill pumps instantly.

It's like a circuit breaker keeps popping in your house, you're not going to blame the breaker, you're going to look for a source in the system that caused it.
 

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I think there is a separate issue causing the pumps to go bad... Like for me, there was a blockage somewhere in the fluid system causing a surge in pressure which would kill pumps instantly.

It's like a circuit breaker keeps popping in your house, you're not going to blame the breaker, you're going to look for a source in the system that caused it.

What he said... There should be a pressure valve if I remember right that screws into the GM pumps. Had a customer who bought 2 pumps from me that didn't have it installed. We had to swap it over from his stock pump. Idk if ours are the same way or not as this was for a car. It was causing his pump to over pressurize the fluid and blow hoses and leak and whine. Just my .02


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Discussion Starter #6
After 10 pumps and flushing the system, I would think any crap would be gone from the system. What else would you suggest to make sure there are no blockages? The mechanic has assured me there is nothing wrong with the hoses or the rack. I'm trying to get the dealer more involved as well....

And so how do I know if there's a pressure valve or not?? What's on the truck now is straight from the dealer.
 

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The valve in the pump I was describing is located in the high side port where the high side line goes to. It's just a small screw in pressure valve. I think it acts as a pressure differential switch if I remember right. I'm sure GM would be able to validate if there is one or what the cause would be


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Discussion Starter #8
Thanks for the reply, I'll take a look. And I'll also be contacting GM concerning their pumps and be in touch with the dealership to confirm.
 

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Have you checked the pressure/flow readings? Are they within spec?





Power Steering Pump Specifications
Engine Code: L52
Engine Size: 3.5L
High Flow (Liters per Minute): 9.10/10.60
High Flow (Gallons per Minute): 2.40/2.80
Pressure Relief (kPa): 9308/9997
Pressure Relief (PSI): 1350/1450

Using a Chassis Ear (Engine Stethoscope), determine if the whine is present at the power steering pump, pulley or at the power steering hoses. If the noise is coming from the hoses try adjusting the routing of the power steering hoses. Hoses touching the frame, body, or engine may cause system noise. Loose connections may not leak, but could allow air into the steering system.


 

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What about some kind of blockage in the rack itself? Also, have the lines themselves been changed or are they the originals? So far it sounds like the only common denominators between all the different kinds is it's the same rack/lines.
 

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Nipple
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What about some kind of blockage in the rack itself?
That's what got me on the used rack that I had installed after my original one snapped, so I buckled down and bought a new one.
 

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Discussion Starter #17
Have you checked the pressure/flow readings? Are they within spec?
I'm getting it back to the shop tomorrow. They have confirmed it is the pump. But I will see if they have the equipment for checking the pressure and flow.
 

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Discussion Starter #18
What about some kind of blockage in the rack itself? Also, have the lines themselves been changed or are they the originals? So far it sounds like the only common denominators between all the different kinds is it's the same rack/lines.
I think that is possible, however after all these pumps and all the fluid, I don't know how some junk in the system could still be present. I was told the lines have been replaced. Only other common denominator is the pulley. The reservoir has come with a few of the new pumps too.
 

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Discussion Starter #19
Has the Power Steering Pump Pulley Installed Depth been checked?


Install the power steering pump pulley (1) flush against the end of the power steering pump shaft (2), with and allowable variance of 0.25 mm (0.010 in.)
That was one of the first things I checked, to be sure some misalignment wasn't causing the belt to put tension on the pulley/shaft in a way that is shouldn't. But it looks flush.
 

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Discussion Starter #20
Are you sure that the belt tensioner isn't that's whining? They're real close to each other and can be easily misdiagnosed.

Tensioner and belt replaced last October. The pump is shot again. There is a lot of play in the shalf. I removed the belt myself earlier in the week. Everything is quiet except the damn PSP. I'm going to replace the idler pulley in a couple days for giggles. The real pisser is that after I replaced the tensioner and belt last year, she was quiet as can be. Now I ride around sounded like I'm ready for lift off.
 
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