Compressor Fitting HVAC: Service Precautions
CAUTION: Refrigerant Compressor Oil (mineral oil) F73Z-19577-AA (Motorcraft YN-9-A) should be used to lubricate R-134a refrigerant system O-ring seals only and should not be added to R-134a refrigerant systems as an A/C compressor lubricant. PAG Refrigerant Compressor Oil F7AZ-19D589-DA (Motorcraft YN-12-C) or equivalent meeting Ford specification WSH-M1C231-B only should be used as an A/C compressor lubricant.