R-134a Systems

CAUTION: Do not add R-134a refrigerant oil to an R-12 system. Also, do not add R-12 refrigerant oil YN-9 to a R-134a system. Mixing these two types of refrigerant oils may cause poor lubricant circulation resulting in component failure and damage to the A/C systems.

The Motorcraft Refrigerant Oil YN-12b or equivalent meeting Ford specification WSH-M1C231-B required for R-134a A/C systems was made specifically for the Panasonic compressor and is not suitable for use in other R-134a systems. Never use an R-134a refrigerant oil in R-12 systems.