jtsporsche

My car decided throw another alternator belt. which was just replaced in june, before fest.

At that time (early June) i also noticed that BOTH mounting bolts on my AC compressor had broke and left peices in the holes. so i had someone drill the bolts out for me and i replaced the front mounting bolt only, since i couldnt get another for the rear.

Now, the bolt is broken again, and i realize that one of the end ribs (not sure if its the front or rear most rib) on the ac/alternator belt keeps getting torn off.

SO, anyone have any idea why these two things would be happening?

Mike C.

I would guess the compressor is not aligned properly with the crankshaft and the belt is 'walking' off the pulley.

PorscheDoc

So, both mounting bolts were broken, and you only replaced one?

m73m95

There has to be more going on. I think you might be tightening the belt WAY to tight, or the compressor is locked up, or some other fairly obvious problem.


My original rear AC compressor bolt backed out somewhere along the way. I had no issues other than a strange vibration at high RPM. I searched and searched for months until I found the missing bolt (well, the hole it goes in). Never lost the belt, and never broke the front bolt. Though, my AC didn't work at the time, so I don't know what would have happened if I turned the compressor on.

It takes 10min to take the compressor off (if the system is empty from a leak or something). Fix both of the bolts, then you have to figure out what is going on....there is a real problem, its not "just happening". I'm voting for a locked up compressor. That would trash the belt pretty quickly, and might even break the bolts (would be hard to do that though). It would make a horrible noise that Helen Keller could hear, so I doubt you would miss it.... but something strange is happening.

jtsporsche

that was my first thought but when i replaced the belt today i checked. the belt looked straight and evenly on the crank, compressor, and alternator.

only had access to one at the time, ordered two new ones and the diagram or web sites parts list was wrong and it said i needed two of the same bolt, but the bolt would not fit in the rear hole. that being said, does any body know if the two bolts are supposed to be the same or different?

as for the belt tightness, this belt has always squealed loudly, so i just tighten until it doesnt anymore. the ac clutch spins freely, and system has had a leak for years and i never turn it on.

could it be possible one bolt keeps backing out, causing the compressor to shift and put stress on the remaining bolt until it snaps?

thanks for the replies guys, keep'em coming, i dont want to keep buying bolts.

m73m95

If its squealing loudly, then there is something wrong. Tightening it until its stops is what is making the belt come off.

Are you sure you're spinning the right part of the AC compressor? The pulley will (and should) spin freely. Turn just the front part of the compressor. In front of where the belt rides. That is actually what spins the compressor. The pulley is hooked to that with a clutch. I bet $10 you can't turn that by hand.

Mike C.

If you never plan to fix the AC you might want to look into an AC-delete bracket.

jtsporsche

yes, i can spin the front part freely, excuse me for using the term "clutch", i was mistaken. ill let you know where to send the $10

however, last night after replacing the belt, it developed a squeal different than what im used to. someone more knowledgeable than i took a listen and believes that it is the compressor. specifically he said maybe a bearing going bad.

and as stated below, thought about it, but summers here get hot and VERY humid. so thatll be a tough call until i find a job thatll allow me to get another car.

Mike C.

It isn't that expensive or difficult to replace the pulley bearing on the compressor. IIRC, you will need some snap ring pliers.

jtsporsche

not having replaced individual parts of the compressor, ill take your word on that, but, this compressor itself is a rebuilt replacement installed only a few years ago. looking for info on the griffiths kit at the moment

robert944h

Usually when the compressor mount bolts break it is because they were not torqued properly. When left loose the vibration will eventually snap the bolts. I would imagine the reason it broke the second time is because the rear bolt wasn't attached causing the same vibration. The compressor locking up wouldn't cause the bolts to break. The belt may be wearing odd because once the bolts break the compressor is no longer aligned with the crankshaft pulley. So the solution may be, install new bolts (loose fit), tighten the belt per spec(which is pretty darn tight), torque compressor
bolts to spec. Periodically check bolt tightness and belt alignment. Sorry for the long post, hopes this helps

cruise98

Check for a bent pulley also.

The Race Line

yep that is my guess as well. I think you have a bent pulley somewhere.

jtsporsche

a new bolt has already been ordered, once i get everything attatched correctley ill quad-check everything making sure its tight and alligned.

how would you check the straightness of the pullies? is there a more accurate way then just by loking?

thanks again everybody

steve944online

Have you checked the sleeve at the back of your compressor mount ? We see problems like this all the time and the sleeve has usually become worn and oval shaped.