I have a 2008 Trailblazer LT..4.6 motor. I replaced the belt tensioner and pulley. I bought it from Advanced Auto and a new belt because the tensioner was vibrating. Well, the vibrating went away BUT then the truck began to squeal HORRIBLY!!!!! I thought it was the power steering and or the power steering pulley going bad. So I replaced both yesterday. I got the power steering pulley from the dealership and the new pump from Advanced Auto. To possibly clear up a few questions before anyone asks...YES, I did make sure the o-ring on the metal line going into the pump was intact, there are no leaking coming from anywhere, I did bleed the system after I installed the new pump and I cleaned the new belt tensioner, pulley and new power steering pulley.

It is still doing the same thing. When you turn the wheel hard right or left the power steering pulley seems like it locks up some and when you first turn on the truck it squeals so badly it wakes up the entire neighborhood. I am at a loss!!!!!!!

I read on another forum here that it might be the belt still. I read something about the belt size and number??????

Is there a possibility that the belt is the wrong size (to big by just a hair) causing it to bounce when the steering wheel is turned, causing the belt to release slight pressure off the power steering pulley or belt tensioner which is not allowing the power steering pulley to spin properly and making it squeal? Keep in mind that I did buy the belt from Advanced Auto and they are F'ing morons in that store and are famous for selling the wrong parts to people.

any help would be really appreciated before I give up and drop the truck off at the shop. Thank you

 

remove the belt and compare it to the one you took off.

Are you sure the belt is routed correctly?

how did you bleed the power steering system? If you did it wrong the pump will groan but not squeal.

 

old belt and new belt look the same to me. yes its routed properly and i bled the system at the nut on rack and pinion....it squeals horribly...doesnt groan

 

i take it the noise is gone when the engine is run with the belt off?

did you spin and check for play in all the other pulleys when changing the belt?

a mechanics stethoscope is very usefull for finding noisey pulleys.

To check a belt I sometimes spray brake cleaner on the belt when the engines running. if the squealing stops momentarily, its probably the belt.

Another thing to try is to smear some rtv sealant on the belt, then run the engine. If the noise is gone, its the belt.

 

I am leaning toward the belt as well. I sprayed some wd40 on it and it fixed the problem right away last night. when my wife started it back up this morning it was squealing again. everything i am reading on the research i am doing is leaning toward the belt. keep in mind that i did get the belt from advanced auto and they are famous in the store i go into for f'ing up a wet dream. i think i'll get a new belt somewhere else today...

 

get an a/c delco belt

 

Some vehicles can have a different size alternator pulley if its a higher output one..that could cause a belt size difference...

 

It was the belt. I stopped and got an ac delco at the dealership. Paid $70 for it but its fixed. No thanks to the dip s**** at advanced auto for once again selling me the wrong part. Thanks for the help gents