HELP, A/C problems

[Chris 93TA]

Need a lot of help with my A/c.
I recharged it after it stopped blowing cold, and it worked for about 10 minutes, then went warm again. (a leak i hear you scream). BUT, i can see no sign of a leak, and when i put the guage on it, it still shows good pressure. Now, get this, last night after it had been blowing hot, I was driving home, and hit the A/C to max, and it started blowing cold again, abvout 5 minutes later it was warm. What gives, I desperately need help with this.

[Bond Hawk]

Could be many things. Clutch is slipping, thermal circuit getting tripped. How did you recharge with R12? Didn't they use that in 93? I'd take it to someone who has the equipment to diagnose it. They won't charge you too much just to diagnose.

[Chris 93TA]

I recharged with R134, the guy at the store said they had changed over in 93.
I am suspecting a leak of sorts, as i did not disconnect the A/C when i took the engine out 2 years ago, and I am thinking now of how close those pipes were when we were lining things back up (with a pry bar of course ) but it did run for over a year with no proble, I was thinking of getting some dye and using the old UV test.

[Joe 1320]

93 used R-12. 94 and later used R-134a.

[Jeff_in_Atl]

I know the fittings on a R12 (screw on) and a R134 (similar to air hose) system are different and so are the cans. If you are not using a gage set and are using the single adapter, I don't see how you could put the wrong freon in without grafting an adapter.

There are several things which can be wrong.
1, The fan is not working or air is not flowing across the coils because of a blockage. (I found an entire page of the want adds in front of my radiator right after I bought it.)
2, The compressor is bad. (if the pressures are still ok, this is not the problem)
3, The oriface/expansion valve is bad or plugged. I have seen oriface tubes get plugged with compressor crap many times but I think GMs use expansion valves which I don't know how they work.

Do you have a gage set or just a low or a high gage? What are you getting (What is the pressure when the compressor kicks on and when does it kick off)

I can get the high side pressures from the OBD connector under the dash. The compressor should kick on at about 200 psi and kick off about 420 psi.

How long does the compressor run when it is running? If it only runs about 4 or 5 seconds, it is overcharged (short cycleing) R134 is a lot more particular about how much freon is in it verses R12. You can overcharge R134 just like a R22 home system and it will stop working while you can't really over charge a R12 system.

Let me know if you need anything else.

[Chris 93TA]

OK, my A/C issue seems resolved.
I stripped it down and replaced the uh-O-Rings on the pipes, now i have cold air again.
Just in time for summer

[Aaron4TAMU]

Just for info, I thought I'd add that the gap on the clutch may be off. My father had a vehicle that he had to rev pretty high before the clutch would enguage.