Power Steering Pump Locks Up???

[jaybrowne671]

Hey Guys!!
I've been away from the forum for a few years as I sold my trusty GMC a while back, but I found her again so here we are! Anyways, I went outside this morning to start her up as usual and when I did there was one hell of a squeal from the PS pump and no power steering. All was fine last night when I got home. I shut the truck down, checked the tension on the belt, checked the fluid, looked for leaks, etc. No problems. Since I had a warranty on the pump I figured I'd rip it off and exchange it. So I put the new pump and belt on, same problem. After the the truck runs for a second the belt spins on the pulley. I ran a rod down the pressure line to make sure its clear (should have been, it was fairly new), can see straight thru the return line, and the gearbox is less than 6 months old (cardone reman). Any ideas??? Thanks in advance for the help!

 

[Blue85]

Is this a serpentine or V-belt? I have heard of tensioners seizing up so they don't really adjust and maintain tension. With the belt off, can you turn the pulley by hand? It would be strange for the new pump to also be seized. Any chance a bolt or bracket is loose or assembled wrong so that it makes contact with the pulley? With a restriction in the system, the pump should still turn, but just stay in bypass. I'm not sure if that carries all the way through to completely blocked, though.

 

[jaybrowne671]

Thanks for the reply! It's a v-belt, and the pump turns fine by hand. Even turns fine under engine power at <400rpm. The old one did the same thing, I even saw the pulley rotating on the shaft a couple times which was a new one to me haha

 

[jaybrowne671]

All 3 bolts on the bracket are tight and it seems to maintain tension no problem. I thought maybe moisture got in there somewhere and froze (stopped working the first night it dipped below 20 here) so I tossed the truck in the garage and cranked up the heat until the gearbox, lines and pump were a toasty 80 degrees to no avail.

 

[K85 Octane]

Is the pulley spinning on the shaft? I'm confused as to what's going on or how it can happen.

 

[jaybrowne671]

With the old pump it was slipping the belt, would catch then the pulley would slip on the shaft. Now with the new pump it just slips the belt until it snaps.

 

[blazer74]

Sure it's not the water pump that seized and throwing u off?

 

[jaybrowne671]

Yeah the water pump and everything else is good, I'm really at a loss here haha

 

[Blue85]

I don't see how a V-belt can provide enough torque to spin a press-fit pulley on the shaft. How can you even see for sure that's what's happening?

Where did these parts come from?

 

[jaybrowne671]

That's what I thought till I sat there and watched it lol. Especially with all the force i had to use on the puller to get it off, and to press the thing on the new pump. It's not doing that with the new pump, that's what was happening with the old one and what inspired me to replace it. Now the pulley moves too slowly to keep up with engine speed and slips until the belt overheats and snaps. Occasionally the pulley (and shaft) stop moving all together, kinda like when you full field an alternator and the belt isnt tight enough. Hope that helps clarify whats going on a little better. All the parts I use come from napa. Thanks for trying to help me figure this one out!

 

[Blue85]

Is the system providing assist? Can you check the alignment of this pulley with the others? You might try pulling the fitting out of the back of the pump and clean it out. If the system is mostly working, but slips under load, switching to a double pulley might help. Is there another groove on the crank pulley the same size? Do you have pics?