Sounds like contaminated refrigerant. (too much air/moisture) it can cause your pressures to be really screwey. The stuff in a can is just a "top off" means of charging. If you can get someone to vac it down, the stuff in the can is perfectly fine to use as your recharge. Issue is you already have too much of everything else and not enough actual refrigerant.


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It was contaminated freon. Vac'd it down, more freon, chillin like a villian on penicillin
Thanks Jake01 That diagram was right on,Thanks again Rocky!

 

Welp my a/c compressors freezing up. It freeked me out, looked like it was smoking, but when I pooped the hood, it wasn't. Nothing was burnt, it still works, but it's did it twice now. Guess I just gota pay attention

 

You probably didn't get all the moisture out. Have a shop evacuate it and then run a really super deep vacuum with a new dryer.

 

Moisture in the refrigerant doesn't cause the evaporator to freeze up... "super deep vacuum" if you can get around 26 in of mercury and can hold that vacuum for 5 mins it's considered refrigerant tight. 30 in Hg is a perfect vacuum; which is way beyond what the automotive industry is capable of. Evac for 15 mins; any moisture in the system will evaporate, refrigerant at atmospheric pressure evaporates completely. Whats freezing up is the fins on the evaporator from moisture in the ambient air. The low pressure line coming from the evaporator should heavily sweat and a slight frost is acceptable. I know this is a little late in the game; but couldn't you just get an H block off of an older a/c unit and rely on it solely? Find a thermistor and strap it to your evaporator core. Radio shack might be able to get something with enough impedance to actually kill the relay if it gets too cold.


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From what i understand you gota use 25% less freon when switching from R12 to 134A, because of the higher preshure.

not a A/C guy just been going through this myself.

Dar