Serpentine belt replacement and AC compressor break down


#1

?Mechanic? replaced the serpentine belt on my 1996 Jeep Cherokee (2wd, 135,000 miles). After the replacement and consequent payment ($$), I drove the car for about twenty minutes (literally), when I attempted to turn the AC on. My attempt was followed by a strange noise, and I immediately decided to return to the shop. The ?mechanic? re-checked the car to verify that the belt was properly installed. And after doing that, he informed me that the compressor has been damaged, and therefore it needed to be replaced ($$$). I?m arguing with him, because I believe that there is a direct connection between his previous action (belt replacement) and the AC compressor failure. He says that it is just an unfortunate coincidence. He has ?seen this situation before many times?. Does anybody support or reject my thesis? Thanks!


#2

Compressors do not burn out for no reason. Check to make sure the belt is installed correctly, as the extra power usage might stress it. (I have seen worn fan belts that work fine on low speed but slip badly at high speed.)
If the compressor worked before, it’s probably fine.


#3

More info on the ‘strange noise’ would be helpful. Exactly what did it sound like? A loud squeak or shriek? Sound of metal contacting? Some other sound?

It is possible, I suppose, that a new belt improperly tightened could contribute to A/C compressor failure, but only if the compressor was warn out already - the belt could put extra pressure on the pulley, which could overstress worn parts and cause a failure. But the compressor likely wouldn’t die after 20 minutes if it was fine.


#4

Hi. Thanks for your reply!
The sound was like metal against metal. Clarification: the AC was working fine before the belt replacement. I agree with you re. the pressure on the pulley. Maybe they put the wrong amount of torque. He says that the amount of pressure was correct (100 pounds? I do not remember the value). But it has become a circular argument. He insists that the installation process didn’t damage the compressor. I believe that there is a direct connection because the belt “goes through” the compressor.
Thanks again!


#5

I wonder if he got the belt strung on the pulleys wrong so that it turned the compressor backwards? That would probably not be too good for it but who knows at this point if they won’t own up to it. I don’t believe in coincidences though-idiot mechanics yes.


#6

I see no way a belt installation could have damaged the compressor.
However, I can see the reverse in which a belt can be damaged by a bad compressor clutch bearing or faulty compressor itself.
Guess there’s a reason why you took it in for a belt replacement?


#7

Hello! Actually, I took the car for an OIL change! No apparent problems with the belt. The “mechanic” recommended the belt replacement because of the mileage. That’s why I’m so mad about the whole situation.


#8

Sounds like a “hack” (HVAC term for a bad worker!) ripped you off.
Ask the experts at http://hvac-talk.com/vbb/ but I think he “accidentally” damaged the compressor somehow and did not admit it.


#9

I’m afraid I have no idea without examining the vehicle or hearing the noise.

Still no way I could see a belt change damaging a compressor though. If this compressor is legitimately bad (noisy, and in other words, junk) then there is no way a belt change did this. An unlucky coincidence is about it.

About all I can suggest is get another opinion on it on the offchance the compressor itself is not trashed and the problem is related to a compressor clutch bearing, idler pulley bearing, or tensioner pulley bearing.


#10

If the belt was replaced because it broke, the compressor may have broken it.

Even though the compressor has enough freon, it may need a recharge because the lubricant put in with the freon has degraded over time.


#11

It should be a simple matter with the belt off to grasp the center of the compressor clutch and turn it by hand. If it will not turn or if it is very difficult to turn or rough, then the compressor is bad and the belt had nothing to do with it.


#12

The oil (polyol ester for R134a) will last the entire lifetime of the system. When was the last time a HVAC contractor recommended an A/C oil change?
The only reason to change the oil is if it’s contaminated. And that generally only happens when there’s a major fault in the system.


#13

You know its funny that you say that happened…I just brought my Jeep in for its 130,000 mile maintenance and they said I needed a new belt as well…When I got the Jeep back and tried to turn on the heater it screeched really loud…I brought it back and they got the screeching to stop but now my AC wont work longer than 10 minutes at a time. Whaaaat the…?