The Development of a Retrofitting Procedure for CFC-12 Automotive A/C Systems to HFC-134a and P.A.G. Lubricant

Extensive vehicle fleet testing, followed by laboratory analysis of various vital parts of the air-conditioning systems, have been performed in order to develop a procedure for retrofitting existing CFC-12 automotive air-conditioning systems to HFC-134a.

Testing shows that a compressor in good condition that has previously been used with CFC-12, can be re-used with HFC-134a provided that the appropriate oil, desiccant and elastomer is used. Testing has also shown that flushing the system is not necessary.

The procedure in this paper was developed as a result of testing and proposes a procedure that will maintain an “acceptable” life of the compressor at a reasonable cost.