R
radman
Guest
Recently purchase '78 vette. The original AC does not work. Prior owner had car largely in storage for several years with a few drives each year. I suspect the R12 freon is gone. Would like to replace with R134 or other product. Some have suggested 401a, 409a or 406a as other possibilities. Once I recover the existing R12, can I then add one of the other products and lubricant? Does anthing else need to be done to the system?