Brought to you by: Patrick Parish – Capitol Air Conditioning If your old R12 Air Conditioning system has failed, a retrofit to R134a may be the best answer. This site documents what is generally involved – parts, procedures, etc. – whether you plan to tackle this yourself or have a professional do it for you.Includes a whole series of steps involved for retrofit in general, as well as separate pages for retrofit issues unique to Acura, Chrysler, Ford, General Motors, Honda, Nissan, Toyota, and Volvo News source: Patrick Parish/Capitol Air Conditioning