Operation CHARM: Car repair manuals for everyone.

Refrigerant Oil Addition

When replacing a component of the refrigeration system, follow the correct procedures to ensure the total oil charge is correct after the new component is installed. During normal A/C operation, oil is circulated through the system with the refrigerant and only a small amount is retained in the A/C compressor. If certain components of the system are removed for replacement, some of the refrigerant oil will go with the component. To maintain the original total oil charge, it is necessary to compensate for the oil lost by adding oil to the system with the replacement part.
1. For the A/C evaporator core, add 89 ml (3 ounces) of clean refrigerant oil to the suction accumulator/drier inlet tube whenever the A/C evaporator core is replaced. This will compensate for the refrigerant oil lost in the replaced A/C evaporator core.
2. For the A/C condenser core, add 30 ml (1 ounce) of clean refrigerant oil to the A/C condenser core or the suction accumulator/drier if the A/C condenser core is replaced.
3. When replacing the suction accumulator/drier in conjunction with another component of the refrigeration system, measure the amount of oil drained from the removed suction accumulator/drier into a suitable container.






a. Drill two 13 mm(1/2 inch) holes in the bottom of the suction accumulator/drier to drain the oil.
b. Add the same amount of clean Motorcraft YN-12b refrigerant oil or equivalent meeting Ford specification WSH-M1C231-B plus 60 ml (2 ounces).