Hi Everyone,

I have an A/C question. I have 2 Jags that I had a shop convert from R-12 to R-134a. Each time it cost me about $1,500. It doesn't look to me like they did anything apart from installing a new drier, testing for leaks, adding new Shrader valves, then adding R-134a. I can do all these things myself, and I have a 3rd Jag needing this done (1983 XJ6). However, someone mentioned that the oil for an R-12 unit was not compatible with the PAG oil for an R-134a system. It doesn't look like the shop flushed out the A/C when doing the conversion on the other 2 Jags. Does anyone have any insight on this? I think one shop even mentioned that the type of condenser Jag used can't be flushed. Would really appreciate any feedback anyone could provide!

 

Someone smarter than me will confirm:
1. r12 oil is NOT compatible with r134a oil.
2. All gaskets and seals must be replaced when moving from r12 to r134A.

There may be other things, but I'm pretty sure those two will need to be done. The $1,500 should have covered replacing the refrigerant, replacing the drier, flushing the oil from the compressor, and finally taking apart every pipe and connection and replacing the o-rings with the green kinds. (I believe r134a orings work with r12, but not the other way around)

 

Ester Based oil is used to convert to 134A as it can mix with MINERAL oil.

Jaguar explained it in a TSB over 25 years ago.