Power steering trouble

[Spack9]

So I replaced the pump on my Z71 yesterday, and followed the GM bleed procedure. Let the truck down onto my garage floor and fired it up. My steering was like butter for 3 lock to lock turns then all of a sudden no power steering. I can barely get some assist around 2,ooorpm but other than that shes dead. I know the shaft didn't shear because its still whining a little. It sounds like it is trying to turn but doesn't have the power. The pump is a Autozone reman so at this point i have to assume it's a bad part. If anyone else has any input please feel free to speak up. I really don't wanna pull it back apart.

FYI: The truck is not the variable assist type. Nor does it have Hydroboost.

 

[Brody]

Had the same issue the past two days on my new aftermarket power steering pump.

Bought a 'PerfectFit' New Power Steering Pump REPC51040 for a C/K FULL SIZE PICKUP 96-02 / YUKON XL 2500 00-12

Basically: No flow, no pressure.

Obviously, very annoyed.

Pulled the rear pump flow control / pressure relief valve fitting (fitting into the pump body aka the high pressure line) installed on the truck. Hoping I could un seize the pressure relief valve, the valve was very hard to move backwards. Despite a spring behind the valve, it appeared with effort, to only retract. It appeared to be partially locked into a midway of bypass. I was able to leaver (with force) the pressure relief valve completely to the front of the pump (in full bypass). The pressure relief valve did not spring back.

Flushed mineral Terpentine into the pressure relief value, hoping to unstick it. Left it soaking for hours. No luck.

Had to pull the pump and try to knock the pressure relief valve it out.

Pump removed, I was unable to remove the pressure relief valve with a magnet.

I had to apply a rather substantial amount of compressed air to the pressure bypass galley (which you can see nearest the fitting seal). This forced the valve out towards the rear of the pump.

Valve removed, I was horrified.

The pre assembly lube a factory had turned into a solidified varnish and caused the pressure relief valve to lock partially bypassed. The spring and valve were coated in it.

It would explain why after googling, several persons have complained about no flow no pressure on aftermarket pumps. Some claim it rectifies after running warm. I assume the gunk starts to liquify.

I (without thinking) cleaned the valve up before snapping the photos. Should have photographed it in its filthiness. The internal sieve is loaded with varnished pre-lube. The red chunkies on the cardboard is the baked on varnish pre-lube.

Will be tearing the pump down shortly. Might be worth consideration / a look at given your issue..

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[chipskittles]

all the rebuild pumps are garbage. I went through 3 before I got one that would work. I even tried an AC Delco GM service part, supposedly what the dealer would use, and it was DOA. Ended up with an o'reilly pump, so far so good.

 

[Brody]

Pulled the pump apart finally.

Sold as:
14-00-REPC510406
CHEVY C/K FULL SIZE PICKUP 96-02/ SUBURBAN XL 2500 00-09 POWERSTEERINGPUMP

Manufacture:
PerfectFit Group

Complete Garbage. Caked with red varnish solids and chunkies brand new.

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Hopefully it deters someone from buying these.

The replacement ACDelco GM Original Equipment 15909826 Power Steering Pump worked out of the box (as it should). Lesson learnt.

 

[tinfoil_hat]

Here's a thought. What if you ran it with ATF for a while to dissolve that hard assembly lube?

 

[Breakdown]

ATF according to the dealerships I've dealt with is what they recommend for some reason on their power steering systems. I've talked with three different mechanics and they said a lot of times when they replace them at the shop they fill the system with atf vice power steering fluid. Not sure if it's to clean the prelube out and break it down but it seems to be standard practice in play with gm today.

 

[tinfoil_hat]

I secretly suspect ATF is better than PSF in just about every way. PSF has a form of seal swell in it. That's about the only advantage.