AC compressor squeal

[erkme73]

Two troubleshooting posts in a row! When it rains, it pours. Just waiting for the third problem to pop up...

As ambient temps got above 80ｰ, I started using the AC. When I shut the engine off, and restart it within a few minutes, if the AC switch was left on, the AC belt would start to immediately squeal. If I turned off the AC switch, the squealing would stop. I could turn it back on again, and the AC and it wouldn't squeal again for the duration that the engine stays on. Unfortunately, over the last week or two, it started squealing at random times.

I checked the tension on the belt and it had some play - so I tightened it up just a bit more, and the squealing has completely stopped. For the last two or three days, with temps in the high 80's, it hasn't squealed once - until today.

The tensioner pulley does have some wear (it appears to be twice as wide as the actual belt), but the bearing is firm (no play). The AC cools very well. However, at this point, I'm not sure if I should tighten the belt a bit more, or toss in the towel and call for service.

I'm reasonably familiar with how AC systems work and their components, but I don't have any gauges, vacuum pump, or replacement refrigerant. Nor do I have the proper experience to confidently start troubleshooting.

What do the resident AC experts recommend? Use small words and speak slowly, please

 

[RNeumann]

If the belt has squealed is has glazed over and will only slip more and more. If you can replace the belt you will have more than likely solved the problem.
Belt dressing or other chemicals only work for about 30’....don’t waste your time or money.

 

[PILOON]

Whenever a belt driven device squeals it generally is due to a slipping V belt.
A worn (read glazed) belt will generally do that.
Belt dressing might cure the squeal but B4 calling service why not simply install a new belt?
Over time belts get glazed and slip and squeal.

 

[erkme73]

Thanks for the suggestion. I can certainly do that, and that may well be the next step. My concern is that by reducing the slipping, I'm only concealing a bigger problem that might get worse. If I replace the belt and the problem is a seizing compressor, or low/high oil/refrigerant level, will I not do more harm? If not, I'll get a belt tomorrow.

 

[oosik]

What RNeumann said ++. However, I have used a spray belt dressing successfully. Stoped belt squeal for a year - respray the belt every spring. Finally after six years - belt broke and was replaced. This was on my 1982 Troybilt Horse rototiller.

Best way to fix your problem - as RNeumann indicated - replace belt.

 

[RNeumann]

I think that’s over concern. Replace the belt and enjoy the cold air.

 

[Oldoak]

I think that’s over concern. Replace the belt and enjoy the cold air.

:thumbsup:

 

[Harry in Ky]

I won't dispute the possibility of a worn(or somehow defective) belt as a contributor to pulley squeal. On the other hand, even a properly adjusted belt in relatively good shape can be over taxed. Since you don't have access to pressure gauges, I suggest you check again for restriction through the condenser and radiator. If your tractor has those silly screens in front of either (or both), take them off. Just a casual "look/see" in therewith them in place won't always tell you the whole story. Get an air nozzle with a wand that blows air at a right angle and go over ALL the cooling coils. Using the wand you can force air between the fins and tubes, not just across the front. Spend some time at it, and cover as much area as you can. When I do this, it can take twenty or thirty minutes but can surprise you with how much dirt and fluff comes out. If this is what you find, the belt is probably not the problem.
As a side note, if it were me I'd put the screens on a shelf somewhere, and not back on the tractor. The stuff I find in the fins went right through the screen anyway.

 

[RNeumann]

All maintenance items for a system that isn’t blowing cold........OP states his system is blowing cold.

 

[erkme73]

I'll take this as a mid-season reminder to blow out the radiators/exchangers. I'll head to town tomorrow to get a replacement belt. And just to show how wet-behind-the-ears I am, does the A54 on the belt tell me everything I need to know to hit an auto store? A quick search on Google reveals belts that look the same, and all seem to have a 54-56" length...