I just put the third AC belt on my 2.8 in about a year. The first one went in just a day or two. The second one lasted the rest of the summer last year but finally broke. I just put on a brand new Dayco 17380 and it burned in half in less than 5 minutes. I could feel cool air being blown out of the vents for that short time.
I was thinking that my first two belts broke because they were on too tight so I didn't tighten this one as much. Consequently, it burned through the fastest.
Does this sound like a belt tension problem, a compressor problem, or something else?
How can I tell when my belt(s) are sufficiently tight?
are you sure it is straight? because there really is no way it could be to tight, unless you are putting it on with a dam 4' crow bar. or the compressor is locking up. it does spin freely when its off right, I mean you have turned the pull with no belt on? if so then turn the AC on with the key on but the engine not running, it should lock the pully to turn the compressor into the run position and try turning it then, it really shouldn't feel any different, if it is locking up and not turning your compressor is shot.
when was the last time it was oiled and charged?
Steve
------------------ Technology is great when it works, and one big pain in the ass when it doesn't
The system has not been open to the atmosphere. It was professionally charged last summer and it worked just fine all summer. The weather had turned cool before that belt got eaten. The pully will turn without a belt on. I can try the key-on test tomorrow. I didn't have this belt on anywhere near as tight as the last one.
The system has not been open to the atmosphere. It was professionally charged last summer and it worked just fine all summer. The weather had turned cool before that belt got eaten. The pully will turn without a belt on. I can try the key-on test tomorrow. I didn't have this belt on anywhere near as tight as the last one.
The pulley will turn by hand because it is not engaged to the compressor. You have energize the pulley to clamp it to the compressor. I am guessing the compressor is going out. Same thing happened on my '86... compressor was fine and later it wasn't and broke the belt.
(I say this with the assumption that nothing else has changed on the car).
are you sure it is straight? because there really is no way it could be to tight, unless you are putting it on with a dam 4' crow bar. or the compressor is locking up. it does spin freely when its off right, I mean you have turned the pull with no belt on? if so then turn the AC on with the key on but the engine not running, it should lock the pully to turn the compressor into the run position and try turning it then, it really shouldn't feel any different, if it is locking up and not turning your compressor is shot.
So if I understand correctly, 1. The pulley should spin freely when there is NO BELT on it when the key is off (engine off, AC off) 2. The pulley should also spin freely when there is NO BELT, the key on, and AC switched on.
If the compressor pulley is locked up in either of these two situations, the compressor is bad.
Does that sound right? I have looked at compressors before and I know they have different designations. Which one do I need for my 86 GT automatic? It has an 87 2.8 engine in it if that makes a difference.
I just checked it. The pulley will turn with the key on and the AC switched on. I'm hoping it was a matter of the belt being TOO LOOSE. Gonna get another belt and try it again.
I just checked it. The pulley will turn with the key on and the AC switched on. I'm hoping it was a matter of the belt being TOO LOOSE. Gonna get another belt and try it again.
Maybe... but the compressor could be bad. Putting another belt on isn't that expensive, so give it a try. make sure there is nothing on that pulley that may be wearing the belt. Check the crank pulley also.
Maybe... but the compressor could be bad. Putting another belt on isn't that expensive, so give it a try. make sure there is nothing on that pulley that may be wearing the belt. Check the crank pulley also.
could also be that it is out of alignment, usually less of a problem with the old V type belts but still a problem as far as wear goes, it will wear out prematurely. but then I am just guessing here as well. check the alignment of the 2 pulleys if the compressor mount got bent it could easily be out of alignment. not that easy to see granted because of the placement of the compressor if memory serves me, its shot.
good luck, I know just how much fun it is putting that AC belt on, I didn't even bather to on mine as mine was seized and, hey it's Maine, we only would use it a couple of week a year anyway.
Originally posted by Boostdreamer: The system has not been open to the atmosphere. It was professionally charged last summer and it worked just fine all summer. The weather had turned cool before that belt got eaten. The pully will turn without a belt on. I can try the key-on test tomorrow. I didn't have this belt on anywhere near as tight as the last one.
Likely Compressor is bad or belt is too tight/lose. Iffy Service can kill compressor because different oil don't play well. System ever used R12 and now used R134 need right oil added. Wrong oil hates R12 oil. 2 type of oil for 134 don't play well w/ each other.
Engine Off then AC is off regardless of controls setting. ECM have final thing in line to allow clutch on/off.
Even good compressor is hard to impossible to turn by hand w/ a socket wrench on the main nut on compressor crank shaft. Means turn by hand often means little. Do Not turn it backwards!
Replacing Compressor then most Warranties require to replace ACC/Drier too.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
If the pulley is worn, your belt might be too narrow and is getting caught in the groove. See if you can find a wider belt in the same length. (Might be difficult to do if the store where you're shopping only carries one brand.)
I put another belt on and tightened it as much as I could. So far, so good.
The first two belts I used were old belts off of my parts cars. The first one worked for about 20 minutes. The second one worked for almost a year. The third belt I used was bought new from Amazon this year. It was the Dayco 17380 which is the "upgrade" belt that has been recommended here. The "better" features about this belt include being longer and wider. The problem I encounterd with this larger size was that the compressor ended up being BETWEEN the slots that we use to pry on the compressor to tighten the belt. That made it more difficult to tighten.
However, I was also attempting to leave that belt loose on purpose to see if that would help with longer belt life. I'm certain that leaving the belt looser this time is exactly what made it break so quickly this time. Here's my theory: When the AC is off, the compressor pulley free-wheels so the belt runs smoothly. When you turn the AC on, the pulley meshes with the compressor and it becomes difficult to turn. If the belt is on tight enough, the force of the belt will overcome the friction of the compressor, the pulley will turn, and the compressor will operate.
If the belt is too loose, it cannot grab the compressor pulley tightly enough and the belt will continue to spin with the harmonic balancer. The AC compressor pulley will be held firmly in place by the compression inside. With the belt turning and the pulley "frozen", the belt gets burned up by the heat and friction of spinning around the non-moving AC pulley. That's what killed my belt. It burned in half in less than 5 minutes.
This time I got a stock sized Gate's belt. This is my first new AC belt and I put it on very tightly. I did find a video on YouTube that said the way to tell if your belt is tight enough is to try to twist the longest run between pulleys. If you can twist the belt 90* or less, it is right. If you can twist it more than 90*, it is too loose. A poster on another sight said to tighten belts just tight enough to stop squeeling. I like the first recommendation better.
So I think I'm set for now, if I have anymore trouble, I'll post it here. Thanks to everyone for the help and suggestions and as always, if I've not already given everyone a plus, you get one for your participation in my tech/help thread!
