is this a plausible theory?

[colbystephens]

well, my new powersteering pump started acting up on me the other day (they are going to replace it free of charge - wish they could give me my time back too.) along with the pump acting wierd, the belt squeals on acceleration. i made sure the belt is tight, and so i've been thinking about why it's squealing. it only squeals during large, quick changes in engine speed (ie starting from a stop, or downshifting into 2nd). could it be that the pump shaft has some sort of friction/load on it, such that when the engine speed changes quickly, it pulls the belt fast, but the pump resists the belt and thereby the belt squeals until the pump starts spinning at the proper speed?

 

[neverendingproject]

Maybe you need a new belt? If it gets worn it will slip all over the place.

 

[savagek5diesel]

i've had my pump-to-mounting bracket bolts behind the pulley shake loose and fall out on my pump. Which caused the pump to move around alot and the pulley would rub on the mounting bracket under rpm jumps. It looked fine @ idle watching it (pump sat streight because the belt tension held it there), but the squeeling (sp?) was there under rpm load and turning at slow speeds or idle. Belt would burn across the PS pulley when the pulley got pinned up against mounting bracket. hope this is helpful to ya.

 

[4X4HIGH]

Yep, if the belt is bad it can sqeal. Make double sure the belt is tightened properly and if so then replace it and i'll bet your problem goes away.

 

[colbystephens]

i know the belt is good.
i know the tension is good.
i know the pump is bad.

question is, is my theory plausible?

 

[cybrfire]

I would suppose it is possible. Take the belt off and see if you can turn the pump by hand. I haven't had that exact scenario however, one pump when the belt was removed the pulley shaft fell clean out.

 

[colbystephens]

i'll be replacing the pump again later this week - i know the pulley turns b/c ps works often and the brakes are hydroboost and work all the time., but i think there's friction on the pump shaft.

 

[4X4HIGH]

Rub a bar of soap on the belt and see if the squeal stops.

 

[colbystephens]

if i reduce the friction on the belt, and it stops squealing, this doesn't tell me that there's not friction on the pump shaft, as it will just slip over the pulley more easily. like i said, i'm replacing the pump and we'll see if that stops the squeal. if it does, my supposition is probably right.

 

[4X4HIGH]

If you already know for a fact that the PS pump pulley turns freely and doesn't bind i'm betting 100% on a bad belt. The bar of soap trick will tell you that instantly.

 

[colbystephens]

i don't know that it doesn't ever bind. i think that it has a certain amount of friction which is causing a problem, but i think it still spins. if the belt is able to slide over the pulley which may be binding just enough to allow the belt to have some slip over the pulley, it won't tell me anything because nothing will be visably discernable. anyway, it's all a moot point, as i'm replacing the pump this week. we'll see if it changes anything.