1984 Ford F150 A/C Conversion

You're gonna need to replace the accumulator ( dryer ) the aluminum canister bolted to the firewall by the heater-box ( It holds about 1/3 of the systems oil & any moister that has been gathered within the system). You also should replace the o'rings ( the old ones are usually black & new ones are green in color & are compatible with the ester oil used in 134A systems) Drain any old oil in the system & replace it with the same amount of Ester oil. Install the 134A fittings, have the system vacuumed down & checked for leaks and then filled with the 134A freon. Note: Usually the system will only require about 2/3 the amount of 134A freon as to the systems original amount of R12. That should keep you cool. Good luck with your project. RJR100

I have retrofitted both my '93 Ford Escort and my '87 F- 250 with R134a without changing anything but the o-rings (the reason the systems were low in the first place) and adding some PAG oil. You don't have to replace anything else. What rjr100 suggests are "Best Practices" and I don't want to say that he's wrong - I'm saying that all that trouble and expense isn't necessary. The Escoret I retrofitted with a kit from PepBoys 10 years ago. The truck only 2 years ago. Works great for less than $60 per vehicle.