Hello Folks,
How can I visually tell if the a/c system in my 'new to me' 90 240 is still using R-12 or if it has been converted to 134? I've read that the two use different fittings. What would they look like? Anything else to look for?

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mklaw
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1990 240 DL, 150k, auto

more than once i have seen home made addapter hoses that allow 134 to be installed in an r-12 system w/o changing any fittings,so it is best to have the contents analized,evacuated,flushed,and check the system for leaks.good luck

R-12 fittings are (usually) 1/4" with external treads. 134a fittings are 1/2" acme with internal threads, just for the caps. The much larger external surface just has a 'ridge'. Any responsable person that converts a system is supposed ( by law) install a prominant sticker stating that is has been converted to 134a, by whom and when. A MVAC tech can put a 'sniffer' on it and identify what refrigerant is in the system, if all else fails.Hope it helps.