Hi all, my brother wants to convert his r12 system over to an r134 system and so far found a good amount of conflicting info on what all has to be done to convert it over ranging from changing some sensor or something among other stuff. Now I know how to do r134 on my car and other family members cars and have my own guage set with a 30lb tank of r134 and bottle of Pag 150 oil with UV dye. His truck is a 1992 F250 diesel. Trying to find out what all needs to be done to convert it over, have the conversion r134 low and high service ports. He said he read somewhere that you also need to swap out all the o-rings. Trying to find out what needs to be done that wont cost an arm and leg. Any help would be greatly appreciated.

 

When I did mine I bought an o ring kit and replaced all o rings. Auto zone rents out the vacuum pump and some tool that hooks up to an air compressor that will let you use the flush fluid to flush the condenser. I replaced the accumulator and orifice tube. Those were the only two things I replaced as my compressor was good. Although don't make the mistake I did. GET A VARIABLE ORIFICE TUBE. It'll b like 15-20$ but it'll be worth it when you come to an idle. Other than that I believe you put in 80%(?) of the amount of r12 you would normally put with r134. Other than that I didn't replace my low pressure sensor or any of that. I did take off my compressor and replace the oil with ESTER oil NOT PAG.