Refrigerant Oil: Service and Repair

Refrigerant Oil Addition

CAUTION: During normal A/C operation, oil is circulated through the system with the refrigerant, and a small amount is retained in each component. If certain components of the system are removed for new installation, 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 new part.

1. Rotate the A/C compressor shaft six to eight revolutions while collecting oil in a clean measuring device.
^ If the amount of oil drained from the old A/C compressor is between 85-142 ml (3-5 ounces), pour the same amount plus 30 ml (1 ounce) of clean PAG Refrigerant Compressor Oil (R-134a Systems) F7AZ-19589-DA (Motorcraft YN-12-C) WSH M1C231-B or equivalent into the new A/C compressor.
^ If the amount of oil that was removed from the old A/C compressor is greater than 142 ml (5 ounces), pour the same amount drained of clean PAG Refrigerant Compressor Oil (R-134a Systems) or equivalent into the new A/C compressor.
^ If the amount of oil that was removed from the old A/C compressor is less than 85 ml (3 ounces), pour 85 ml (3 ounces) of clean PAG Refrigerant Compressor Oil (R-134a Systems) or equivalent into the new A/C compressor.

NOTE: Service A/C compressors are shipped without compressor oil.

2. For the suction accumulator/drier, drill one 13 mm (0.52 in) hole in the suction accumulator/drier cylinder and drain the oil into a calibrated container.
^ Add a quantity of new oil to match that drained from the old suction accumulator/drier plus 60 ml (2 ounces) of clean PAG Refrigerant Compressor Oil (R-134a Systems) or equivalent.

3. For the A/C evaporator core, add 89 ml (3 ounces) of clean PAG Refrigerant Compressor Oil (R-134a Systems) or equivalent to the suction accumulator/drier inlet tube.
4. For the A/C condenser core, add 30 ml (1 ounce) of clean PAG Refrigerant Compressor Oil (R-134a Systems) or equivalent to the A/C condenser core or the suction accumulator/drier inlet tube.
5. Add 60 ml (2 ounces) of clean PAG Refrigerant Compressor Oil (R-134a Systems) or equivalent to the suction accumulator/drier inlet tube when carrying out each of the following repairs:
^ installation of a new A/C evaporator core orifice
^ installation of a new A/C compressor pressure relief valve
^ installation of a new refrigerant line
^ repair of an O-ring seal leak
^ repair of a charge port leak

6. Installation of new components that do not require discharge of refrigerant and resulting oil loss, such as the A/C cycling switch and the A/C pressure transducer, do not require additional oil.