Hi,

Had the 535's system evacuated as a prelude to replacing the pressure switch and found that only 1.5 pounds of R12 came out, in a system of over 4 pounds capacity.

Maybe this is a good time to switch over to R134a. Is there a faq that explains what items need to be replaced? Will I also need a different pressure switch and so should return the one I just bought?

Any ideas why I lost so much R12 over a six year span? Normal?

Input most welcome.

Thanks,
Adnan