i was on the highway pulling over in a rest stop and when i got there i heard a screeching which i soon realized was coming from my van...when i went to stop my brakes were stiff as anything. under the hood i could see that the belt that connects the altnernator to the vacuum pump (pretty sure thats whats below the alternator?) was hardly moving at all and thats what was screeching.

it was a bad snow storm and so i had to be towed and left at a random mechanics.

any thoughts on what this is and how much they might be about to take me for to fix it?

 

I just did mine. The pully is pressed on and its 2 -10mm bolts holding the entire bracket and pump... and I belive its a 13mm to take the bracket off the pump... and install is reveresed ... pretty simple... u can cut the belt off and drive it but u have to get used to syanding on the brakes... I drove mine for 2 years with out a vac pump..... wow what a diff a new one is..... I think they are about 150 at oriley.

 

i was reading about the parts that could be replaced (bearings, diaphragm, etc). do these symptoms sound like i should just replace the whole vacuum pump?

 

yeah, just replace the whole pump.
the pulley is a bit tricky to get off, you need a purpose-built puller like this one http://www.google.com/aclk?sa=l&ai=C...+pulley+puller - and at my parts store we had to grind down their puller quite a bit to get it onto the pulley.

i've killed 3 pumps in 2 years because cardone rebuilds them so well, just like they build everything else they do. the first replacement lasted a whole 2 miles before it started knocking. so if you can find it from a different manufacturer, do so! if you do get cardone, keep the reciept where you can find it, you'll probably need to replace it again at some point.

 

I had a local shop use a puller for power steering pump pulleys.The bolts have to go behind the pulley before pressing it back on(ask how I know).

 

I bought mine from rock auto I think it was 80 shipped to the house

 

Harbor Freight has a puller/pusher for the pulley. And yeah, either put the bolts in place, or remove/install the pulley while the pump is on the engine.

 

well, i just put my new vacuum pump on in 5degree weather...that was fun. it was even more fun to find out it didnt' fix the problem. still a screechign sound and the belt isn't moving. what next?
oh yeah, in terms of the puller i just had the pulley swapped at a shop near me.

 

you have v belts right?
is alternator spinning fine?

 

If that's a separate v-belt just to drive the vac pump, remove it and run the engine for a while. You won't have brake boost of course, or HVAC control if you have A/C, but it will tell you pretty quickly whether it's the source of the problem. It could be the two pulleys are way out of alignment with each other.

 

Greg50H, I looked again, and the alternator isn't turning. the alternator has two belts and the one to the vac pump isn't moving at all. the belt on the other alternator pulley is spinning, but the actual fins on the alternator aren't turning.

madpogue, its about zero degrees out right now but tomoro i'll try what you suggested and pull the vac belt off and run the engine and see what happens?

 

sounds like your alternator siezed up. take off the alternator belt and try to spin it by hand. it should be smooth and free, but i bet its locked up solid if you're seeing in not turn.
time for a new alternator

 

edit: ok. pulled the alternator belts. the alternator spins as i assume its supposed to. the pulley on the vacuum pump, on the other hand, doesn't spin in quite the same way...it spins like it has a counterweight or something...get some momentum and it spins a half turn then you need momentum for the next half turn, etc

 

Edit again - the vacuum pump is supposed to feel that way - alternating more and less resistance. That's its pumping action. But if the alternator spins freely and quietly in your hand, but it wasn't turning with the engine, and the belt driving it was moving, then either that belt is waay stretched, or the contact surfaces glazed to the point that the belt is useless, or the alternator mounting has slipped and lost the belt tension. Whichever it is, it's probably prudent to try a new alternator belt. The fun part is, if yours is configured like I think it is, you have to remove the double-run belts for the water pump and power steering first in order to get the alt belt off.

Is there _any_ noise or roughness or looseness noticeable when you turn the alternator pulley by hand?

 

that seems strange. it sure sounds like it would be locked up with the belts on there, or else it would be turning. maybe try putting the vacuum pump belt back on, setting it with that belt a little tighter than you should, and leaving off the belt that drives the alternator, then trying to turn the 2 together by hand. you should feel the resistance of the vacuum pump as you spin them together and otherwise be smooth.
i'm still thinking your alternator has a bearing problem, and the test i just described will allow you to feel it with something close to the normal belt tension pulling on it. if you have a problem in its bearings, i expect this will make it obvious.

if you only had a loose or glazed belt, it wouldn't have started screaming at you so suddenly, it would have had that squeal right after starting for several seconds, then gone away....
but that said, once you fix the root of the problem, a new belt would be a good choice since yours has now been abused by fighting its way over a stuck pulley.