What changes did GM make to the system when changing from R12 to R134, I believe from 93 to 94? Reason I ask is I have a chance to get a good deal on a brand new compressor that was meant for a pre 94, my car is a 92. Everything in the system is new, all 92 parts, except for the compressor. I haven't recharged the system yet, I intend to use R134 when I do. Would this new compressor work in my system with R134? Would the seals be compatable? I have to believe with the lack of available R12 and to reduce costs all compressors would come with R134 compatable seals. Appreciate any input :confused:

 

It is very easy to convert to R134a. It is a little time consuming to do it correctly. First, you need to drain the mineral oil out of your compressor. Make sure you measure how much oil you drain out of the compressor. If the compressor is new (or rebuilt) and the system has not been run at all, you will replace the mineral oil with the same amount of ester oil (this is the lubricant used for R134a systems). If the system was run, double the amount of oil when putting the ester oil in the system. If the system was run, replace the dryer. The remaining mineral oil in the system is fine. Next, you need to get the conversion kit for the R134a. This is 2 fittings to screw onto your current connections. Once the system is put back together, you need a deep cycle vaccuum. A lot of rental places rent these. You can also buy them for around $50 or so. Put this on the system for 1/2 hour. This will get the system ready to be charged. The A/C system holds 3 lbs of R12. R12 is a little denser than R134a, so you will only use 2.5 lbs of R134a. Get a charging hose and juice up your A/C. You should be running cool now.

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