There is a problem and im at my wits end. The problem seems to be where the vacuum pump meets the AC.

The belt starts to slowly shift towards the engine. If im lucky enough for it to stay on while the engine is running, when i turn off the engine, it slips.

There seems to be something gravitating the belt towards the engine there.

I already pressed the pulley it as much as possible, it helped a little, but it still slips. I am using the correct belt from oreilleys and autozone. both are slipping.

I have a half inch shorter one to compensate. Its on, but who knows for how long.

First question is: The vacuum pump has a small bracket on the left side (passenger side). I have it placed BEHIND the vacuum pump where the bolts go. There are 3 bolts. The top left and bottom bolt are locking that bracket and vacuum pump. BUT the right side bolt doesnt have the bracket. My question is, did I place the bracked on the wrong isde of the vacuum pump? If not, did I lose a washer that goes on that 3rd bolt that has no bracket? maybe a washer to make up for the brackets thickness??

 

Can someone with a 94 E350 take a picture of their vacuum pump so that I can compare?





Blue shows where the bolts have the bracket. Red shows where there is no bracket. I wonder if I lost a washer... That would make the pulley have a slight angle. That's where the belt is coming off. Directly effects the teeth at the AC pulley. Just climbs right over and starts shredding

 

Does the hood open far enough, and is the engine far forward enough, that you can get a look (and posssibly a pic) directly downward from above? That would give you a better idea if one or another pulley is out of alignment, either at an angle or too far forward/back.

When you say it "slips" when you turn the engine off, do you mean it slips off the vac pulley, between the pulley and the pump? This might actually indicate the alternator is what's out of line, since that's where belt feeds from. Am I remembering ths right? Belt is overall going clockwise, so the next thing "upstream" from the vac pump is the alt, on the right? (BTW, "right" and "left" should ALWAYS be respective to the vehicle, not the viewer. This way it never changes whether you're looking from above, below, forward, aft, etc.)

 

I gave up yesterday. Super frustrated. But woke up at 3:30am thinking about it. Did some digging and I THINK i know what the problem is. First, Ill answer your questions. As far as taking a picture from above, its really hard for me to tell if its out of alignment.

The belt slips behind the Vaccum pump pulley. Since the belts direction is towardsthe AC unit next, it goes over the "teeth" wall. The alternator is before the Vaccum pump. So its not the ALT thats next, its the AC.

I installed that little bracket BETWEEN vacuum pump and engine when replacing the pump. BUT if you look at the following picture, it looks like that bracket does NOT belong between engine and pump. It belongs outside torwards the front.

 

Found this online.

 

Thats why I am requesting picutres of guys pumps. I think i have it installed incorrectly? This would definitely cause that slip. but i might jst be believing whatever I can since im beat right now.

 

Update. fixed the peoblem. that bracket was on the wrong side....

 

I'm sure everyone has had a moment like that. I've gotten into the habit of taking pictures or drawing things before I disassemble stuff.
Glad you got it fixed!

 

I remember asking myself if I should take a picture but thought it was too easy to forget. Lesson learned.

 

^^^^^ I've forgotten how many times I've told myself that.....

Good eye, BTW. That photo you found of the other engine is not very clear; pretty good that you were able to discern the location of that bracket.