I checked the low side pressure, it is at about 45psi running.
I had a leek in the system (shrader valve) and recharged it with r134a, then I was told the oils wont mix of some bull crap but the AC was working pretty good. So I ordered some Freeze 12 off ebay to put in it instead. I had the r134a removed and I put in 3 cans of Freeze 12 (3 12 OZ cans) and 2 OZ of oil.

The accumulator and low side lines get cold enough to cause condensation, and the low side pressure is 45-50. So why is my vent tempurature only 65deg on a 90deg day? The heat/cool door is switching all the way.

 

With Freeze 12, do you use the same amount as R12 (2.25 lbs)? Or do you use less? I know when I did Autofrost they wanted me to use 80% as much. Constant 45 psi running sounds like a bit of overcharge.

Freeze 12 won't get below 50° no matter how good it is. It's 80% R134a while the other 20% is a warmer refrigerant than R134a.

 

I agree. 45psi is overcharge, and it won't work properly that way. Either adjust your low-side switch to a lower pressure(30-35ish), or have the system "properly" bled-down to the correct level.

 

so maybe I should swap out my Freeze 12 with some autofrost?

 

So what is the normal temperature coming out of the vents with R134 system??? I just had mine changed from R12 to R134.

 

This is for 4th gen R134a F-bodies. Gives a decent approximation of how things should cool.

The Autofrost is definitely cold. The only issue I could see is the oils. It's meant to use Mineral oil (same as R12). R134a uses PAG or POE oils. You would probably have to work around the shrader valve issue too. Autofrost connects with R12 valves and you probably have R134a or Freeze12 valves on there right now.

 

I'm having a similar problem maybe one of you can help?

i bought NEW COMPRESSOR and had r12 put in it and it was great. it all leaked out due to a leaking o-ring and i went to the same shop and he couldnt put r12 in anymore for whatever reason so he just put in r134 and my a/c feels kinda cold up close, but never cools down my car and i sweat to death. any ideas what i should do?

 

I'm not sure of this... just a guess.... but I don't think r-134a will work nearly as well in an r-12 system as it will in a r-134a system. The stuff can be good but needs a larger condenser than the one in the thirdgen. My advice would be to keep it r-12. The stuff is all over e-bay and sometimes you can find it at yard sales (I know a guy who found a lady selling the stuff in 30# bottles for $50/bottle last year). It's out there and it's the best(at least in a thirdgen). It may be a bit more expensive but you get what you pay for.

 

Thanks for the chart of operating temperatures. Looks like my new R134 system is all right.

 

actually the Freeze 12 uses the same oil as R12, and the same fittings/ shrader valves. Its a direct replacement, I just wonder if its any better? My system was much colder before.

 

http://www.refrigerantsales.com/webdocs/af/af_qa.pdf

Handy reading. I read it a couple times before installing.