1990 AC Question

[Justin Fleming]

So originally the 1990 would have been a R12 system, at this point not knowing the vechicle history I have to beleive someone converter to R134 because it appears they put the fitting conversion pieces that you screw onto the existing R12 fittings. The system is not makred anywhere which they usually would be if converter professionally. My question is can I replace the seals and put R12 back in the system or shoud I install R134 back into the system?

thanks

 

[919jackass]

the fittings are different sounds like you already have the 134A fittings i would go with 134A. the seals won't matter any way

 

[paratrooper307]

It's not a matter of simply switching back and forth. R134 and R-12 systems are incompatible, and so is the type of lubrication oil used. If you try to mix them without completely evacuating the old refrigerant, it can contaminate the system and cause expensive problems. The fittings are different to prevent precisely that problem.

If it has been converted to R134 and works fine, don't mess with it. If it has the fittings on there it should have been converted. Be aware though, there is a possibility that someone could have filled it with an R-12 substitute and changed the fittings. Many of these refrigerants are propane-based and multi-refrigerant compatible. Long odds are its R134, though.