Is there a way to test an A/C compressor to tell if it is good or not before installing it in the car?
And also, what would cause the V-belt on an A-6 compresser to squeel when the system cycles on and also under accileration? It has a new correct belt installed and tension is right.

Your help is appreciated

Possible bad A/C clutch could be causing the squeal. When the system is not cycling, there is no resistance. When the clutch is trying to engage, the internals of the pump could be dragging and causing the pully to stop moving and then will get the wonderful screech and squeal. As for the pump check, not sure on that. Sorry. Hope I helped a little bit at least.

Thanks for the info. I thought it might be the the clutch, but wasn't sure. Are they hard to replace? And can it be done without opening the system?
The A/C is cooling good right now.
Thanx, Randy

Is there a way to test an A/C compressor to tell if it is good or not before installing it in the car?


Not really, you can turn it with one hand while having a couple fingers from your other hand covering the suction and discharge ports and check that it actually pumps. Not a reliable method, nor are there any.

And also, what would cause the V-belt on an A-6 compresser to squeel when the system cycles on and also under accileration? It has a new correct belt installed and tension is right.


Wrong width belt, rust in the v-belt grooves, rust on the hub and pulley surfaces, incorrect clutch gap, pulley bearing, or bad compresser.

Are they hard to replace? And can it be done without opening the system?

No, they aren't hard to replace and you do not have to discharge the system. You will need a clutch hub puller, a pulley puller and a clutch hub installer. You can probably rent these somewhere.

Thanks very much, that helps alot