The A/C on my 72 Cutlass has stopped working. It was converted to 134a sometime in the past. In August 2010, a friend much better versed in this than I, helped me get it working very well. We put a new expansion valve, POA calibrated for 134a and a condensor also designed for 134a from Classic Auto Air. We also replaced the o rings, screens, pulled a vacuum, used a new filter dryer and put in new oil for 134a. The system worked great, putting out high 30's/low 40 degree air. Sometime in September, it seemed to lose a little of it's effectiveness. I was in and out of the hospital for a back operation with some complications and was pretty much out of it until recently.

Now, the air blows at 78 degrees. The POA and the hose to the compressor frost up, but both the low and the high side are at about 85. And, I hooked up the 134a tank, and it doesn't seem to draw anything in to the system. I live in south Florida, and we are getting to the point that I would like the air to work.

Any ideas what is wrong?

 

Leak! reclaim refrigerant, pressure test with dry nitrogen to 150 psig. Repair leak, vacuum and recharge to exactly the correct weight. Yes you need special tools. DO NOT skip any procedures

 

Are you thinking it is leaking out as fast as I am trying to recharge?

 

i would bet on a leak or a plugged screen. at least it is 134a now. much cheeper than R12.

 

What was done to the compressor during the initial system conversion?

 

The system was converted before I bought the car, so I don't know what was done. The previous owner said it worked, but he didn't ever use it (four years) and it was just low. I added 134a and it immediately came to life and worked reasonably well. The past year, it lost effectivness, I read about cross flow condensors designed for 134a and bought one. At that time, we also replaced the filter dryer, oil, o rings and evacuated the system and it worked much much better for a few months, but now it must have leaked as I only get about 85 on both the high and low side. We didn't do anything to the compressor.

 

Wow, Bummer! BUT, as early guys said; at least it's leaking the CHEAPER and totally available R134...I hate "ghost leak" problems like this! HOPE You get it solved!

 

This sounds like the factory R12 system on my car.
Not used, charged, worked well for a week, quickly lost effectiveness, compressor to poa line frosted up at the end...

I never looked into it, but decided to just rebuild the whole system later on.

 

I had back surgery a few months back, so I'm not bending over much for now. Hopefully it's just a simple leak that can be fixed and I'm back cool again.

 

Good choice. I had back surgery also 4 years before and I did not do much for about 6 months.
Be very careful, since it is easy to mess it up right now.
Was yours endoscopic or traditional? If the later, you might want to rest up for up to a year...

I am still wondering why that freon line would freeze like that, along with half of the POA valve.