Refrigerant Oil Addition

The R-134a A/C system FS-10 A/C compressor uses a unique high-quality refrigerant oil, Motorcraft Part Number YN-12b or an equivalent refrigerant oil meeting Ford specification WSH-M1C231-B. An oil charge of 207 ml (7 oz.) is used in a new system. It is extremely important that only the specified type and quantity of refrigerant oil be used in the FS-10 A/C compressor. If there is a surplus of oil in the system, it will circulate with the refrigerant, reducing the cooling capacity of the system. Using too little oil or oil not meeting the Ford specification will result in poor lubrication of the A/C compressor.

When replacing a component of the refrigerant system, the procedures must be followed to ensure that the total oil charge in the system is correct after the new part is installed.

When the A/C compressor is operated, oil gradually leaves the compressor and is circulated through the system with the refrigerant. Eventually, a balanced condition is reached in which a certain amount of oil is retained in the A/C compressor and a certain amount is continually circulated. If a component of the system is removed after the system has been operated, some oil will go with it. To maintain the original total oil charge, add oil as required to the new replacement part.