I just discovered today that the air conditioning system on my 1988 Trans Am has apparently been converted to r134a, as it has the red and blue plastic caps on the high and low pressure ports,and the low pressure side appears to have a quick disconnect style adapter. The AC system blows cool but not nearly as Cold as it should be in the compressor cycles on and off frequently. I noticed when removing the red high pressure, it makes a pressurized sound like opening a can of soda. I can also see bubbles coming from the Schrader valve when the Is removed. Is there a way to get a metal cap with an O ring that I can tighten down on that in place of the plastic To prevent the coolant from seeping out if I recharge the system?

 

I had same problem. With mine it was just a faulty Clutch Cycling Switch. Changed and now works fine.

 

Did all the refrigerant leak out when you changed it? I believe the issue with mine is that it simply low on refrigerant, since it doesn't get as cold as it used to. Also when I removed the redcap I could hear a "psst" sound like it was under pressure. Has anyone here ever used a metal And O-ring to see you're a leaky Schrader valve instead of replacing it?

 

You can change the Cycle Switch, no problem. It too has a schrader valve in it to prevent losing the refrigerant. Check auto parts store for the caps. You can take a awl or small dowel and put it into the leaking schrader valve and do a "pop" with it. Compress it and release it. It may seat it better to seal. I had to do that with one of mine.

 

Just keep in mind it might not seal as well either. Had one once upon a time that had a sliver of steel jam in the schrader valve, holding it open. LOL

 

Is a different clutch cycle switch required when converted to r134?

 

No. R12 and R134a operate at close enough pressures.

 

or get one of the Schrader valve tools generally used for car tires and see if the valve just needs to be tightened up a bit. Just stick it in and turn right...

 

They sell kits at the auto parts store. May have to change out the schader valve, oring might be shot or ripped. In the kits there are the large ones. Unfortunately u have to remove and reinstall ... then recharge.