Originally Posted by JHZR2

Evacuated, refilled with R12, now very frosty. The delta was about 2 lbs on a 2.9 lb system. Works great. Compressor cycles much more gently, and when the system is running, no hissing in the lines (indicative I guess of a phase change where there is not supposed to be one due to low pressure?). Held solid vacuum for over 30 minutes.

Will overhaul the system later this summer - wanted to get on the road with cool air.

No indication of 134a, and they evacuated the system no problem. Told me that lots of mechanics just charge some 134a onto R12 because it works to some extent. Not legal or right, just what they have seen done before. Kind of like a real lousy conversion, but where some R12 is in there (I suppose to keep the oil moving).

Anyway, it works beautifully.