A/C help

Hope it's okay I crossposted from Scotty's board.

Ahem, I know this isn't performance related, but it is technical. And call me a pansy if you want, but before you do let me see you come down to Houston and drive around in stop and go traffic for a few days in the middle of summer when it's 98° and 85% relative humidity without an air conditioner.

Okay, my '71 Swinger has a 318 and factory air. The guy I bought it from said the a/c had been converted over to R-134a and worked at one time but the dash control was broken. So I picked up a used dash control unit and am trying to get things working.

When I first hooked up the switch and turned on the a/c nothing happened. I figured the pressure was low (I don't have 134a guages) so I disconnected the high side pressure switch and shorted the wires. The compressor kicked on and I could see bubbles in the sight glass of the dryer. I decided to take a chance and throw in a can of freon.

About half way through the can, the compressor stopped turning eventhough the clutch was still engaged. It squeeled a bit, but it started spinning again a few seconds later. So I finished that can of freon and then added a small can of PAG oil. I figured maybe it was just a bit low on oil. Well the system was still not cycling on it's own, and there were still lots of bubbles in the sight glass, so I decided to try and add another can of freon.

Again about halfway through the can the compressor stops spinning yet the clutch is engaged. I whacked it with a screwdriver handle and it started spinning again. So I sat and nursed it until I got the whole can of freon in. By then the system started cycling on and off like it should, but most of the time when the compressor tried to kick in the clutch would slip for a few seconds.

So now I have a charged system that does cool, but the compressor clutch slips. I tried spraying some brake cleaner in there to flush out any grease or rust, but it still slips. Any suggestions or home remedies I can try?

BTW, I priced JUST a new clutch at O'Rielley... $119. Ouch!