Hello everybody, I'm brand new to this sight and had a couple questions for you since I am unable to find the information elsewhere.... I have a 1993 dodge pickup that has an R12 refrigerant system in it that does not blow cool air at all, and trying to find R12 without spending a mini fortune is almost impossible. I'm wondering, if I draw the entire system under full vacuum, and recharge with R134a, will that be sufficient in removing all the mineral-based oil from the system?? I do not want to replace the system components to accept 134a just for air conditioning and to my understanding the "stand-in" refrigerant doesn't work worth a hoot. And, if not, I'll just spend the money on the R12 and recharge that way. In that case, can you tell me the weight of liquid needed in a fully evac'd system and the operating pressures across the pressure and vacuum sides?

Ok, a little background information about myself; I am a union pipefitter apprentice that works with a plethora of refrigeration service mechanics so I have a really good grasp of how said units operate, oils required, kinds of refrigerants, pressures, etc. I will be doing all work myself and completely understand all safety needed, equipment use, etc. I hope this question has not been asked before but any and all information on this is extremely appreciated!! Thank you all in advanced.