Well, I (finally) got all three correct new belts four our '76 Cutlass Salon and got them installed, but the A/C belt shrieks like a banshee when the compressor clutch is engaged. It is not the belt tension because the compressor belt is tight enough to pick a tune on . . . but at any speed past "crawling" it screams loudly when the A/C is switched on.

Could it be the clutch, or is it compressor rebuild time?

Now: I did put some "compressor juice" (the good "old fashioned kind") into it recently. Should I try pulling some back out? I don't really trust my gauge . . .

Jeff

 

Can you spin the compressor (not the clutch) by hand?
Never add freon until you know what the high & low side PSI readings are with the compressor running, at temp, with ambients factored into the equation. Overpressure will lock the pump and cause damage. The limit switch is designed to protect over/under PSI but it could be on the edge of tripping the high. Or the high limit isn't working.

Take it to a licensed shop that can pull it down, weigh it, and recharge it.

Being a 50-year-old system I'd be changing the oil, the lines, the filter, and the dryer for reliability.

 

Yes, I suspect you overcharged the system. I did similar with my Cutlass back in the 80s - added so much R12 the belt slipped instead of turning the compressor.

I would recommend doing as noted above and bring it to a shop that can charge it properly if you can't do it at home.

 

Thanks to both of you!

Jeff