Question about '91 318is a/c

[WilliamK1974]

Hopefully this is the right place for a thread like this.

Anyhow, I just became the proud owner of a 1991 318is with 192k on the odo. I bought it from a friend who'd done quite a bit of repair work to it. It looks pretty good and runs/drives like a champ. My friend replaced most of the suspension parts and lowered it, so it looks pretty good too.

Down here in the humid South, air conditioning is hard to live without. The car has a compressor and all parts seem to be present. But the a/c doesn't cool well at all, and I have a few questions:

1) The compressor pulley looks like it has two belt grooves on it, though I can't see where more than one belt would come from, nor do I see anything that would need to be driven off the a/c compressor pulley. Any good reason for this?

2) When I first turn on the a/c, it sounds like the compressor belt is squealing badly. The compressor does turn, however. Is this the sign of a worn-out or loose belt? My friend told me how to go about tightening the belt.

3) Dad and I tried to work on it Saturday, though the squealing belt was a curious problem. He has all the gauges to check a/c pressures, and initially, the system pressure was high enough to allow the compressor to turn, but low enough to hinder operation. He added some 134a, as that was what was in the system. the pressure got high quickly, and then stayed there when I shut the system off. Is this a problem?

I'd like to get the system working, though funds aren't unlimited right now. Any advice or suggestions would be welcome.

Thank you,
-Bill

[WilliamK1974]

Kind of an update:

Got the car up on ramps to have a closer look. Compressor isn't like the ones alot of people talk about on here where the belt tension is set with a tensioner pulley. It's done the old fashioned way where the compressor is pulled against the tension of the belt, and bolts are tightened to keep it in place.

It was about to fall off the car. The bolts holding it in place were quite loose and allowing it to shift. I took care of all that.

I saw bubbles in the sight glass when I switched the system on. That's a sign that the fluid's low but circulating, right?

I've added 134a and checked its pressure. Hard to say if there's much improvement. We'll see during the afternoon drive home tomorrow.

[WilliamK1974]

So far, it just looks like I didn't pressurize the system high enough. My dad showed me what I was doing wrong and I took it from there. We had a cool morning yesterday, and it was blissfully cold on the way in, and worked well enough driving home in hotter temps. At least it is capable of working.