n a message dated 3/31/11 9:02:42 PM, tpoemer at gmail.com writes: > Do the AC hoses have to be changed when converting from R12 to 134? If so > do the fittings need to be O ringed? > I think the answer to both is yes. Old hoses will often leak any freon, and o-ring fittings & hoses will prevent this. Good luck- J DEryke