Refrigerant Oil Addition

ADDING REFRIGERANT OIL

When replacing components of the air-conditioning refrigerant system, measured quantities of a special R-134a polyalkylene glycol (PAG) oil such as Ford F2AZ-19577-AB (Motorcraft YN-12 or YN-12-a) (meeting Ford specification WSH-M1C231-B or equivalent) should be added to the replacement components. It is important that only the specified type and quantity of refrigerant oil be used. A surplus of oil will reduce the cooling capacity of the system. Too little oil will result in poor lubrication of the A/C compressor.

When it is necessary to replace a component of the refrigerant system, the procedures in this section must be followed to ensure that the total oil charge in the system is correct after the new component is installed. When the A/C compressor operates, oil gradually leaves the A/C compressor and circulates 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 refrigerant system component is removed after the system has been operated, some oil will go with it. To maintain the original oil charge, it is necessary to compensate for this by adding the lost amount of oil to the replacement part. The procedures for replacing refrigerant oil are as follows:

During A/C Compressor Replacement

NOTE: The suction accumulator/drier should be replaced whenever the A/C compressor is replaced.

A new service replacement A/C compressor contains 230 ml (7.75 fluid ounces) of specified refrigerant oil. Prior to installing the replacement A/C compressor, drain the oil from the old A/C compressor into a clean calibrated container. Then drain the oil from the new A/C compressor into a clean calibrated container. If the amount of oil removed from the old A/C compressor is:

^ Less than 90 ml (3 ounces), pour 9O ml (3 ounces) of clean refrigerant oil into the new A/C compressor.

^ Between 90-15O ml (3-5 ounces), pour the same amount of clean refrigerant oil into the new A/C compressor.

^ Greater than 15O ml (5 ounces), pour 150 ml (5 ounces) of clean oil into the new A/C compressor.

This will maintain the total oil charge of the system within the specified limits.

R-134a Refrigerant Oil

CAUTION: Do not add R-134a refrigerant oil YN-12 to an R-12 system. Also, do not add R-12 refrigerant oil YN-9 to an 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 refrigerant oil required for R134a A/C systems is a polyalkylene glycol (PAG) oil, Ford specification WSH-M1C231-B or equivalent. This type of refrigerant oil YN- 12 was made specifically for R- 1 34a systems and is not suitable for use in R-12 systems. Never use an R-134a refrigerant oil in R-12 systems.

R-12 systems require the use of a mineral based refrigerant oil with special additives known as YN-9. This type of refrigerant oil was made specifically for R-12 systems and is not suitable for use in R-134a systems. Never use R-12 refrigerant oil YN-9 in R-134a systems.

During Component Replacement

NOTE: Any time a hose or component connection leak is observed, to correctly service the leak, the connector fitting must be separated, cleaned and a new 0-ring installed. The 0-ring and connector surfaces should be lubricated with clean refrigerant oil prior to assembly.

0-ring seal surfaces must be free of dirt, lint, burrs, and scratches.

All 0-rings must be lubricated with clean refrigerant oil immediately prior to installation.

When the A/C compressor operates, oil gradually leaves the A/C compressor and circulates 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 refrigerant system component is removed after the system has been operated, some oil will go with it. To maintain the original oil charge, it is necessary to compensate for the amount of oil lost with the old component by adding an equal amount to the new component. Clean refrigerant oil should be added to the replacement components as follows:

^ A/C evaporator core - Add 90 ml (3 fluid ounces)

^ A/C condenser core - Add 30 ml (1 fluid ounce)

^ Suction accumulator/drier - Drain the oil from the old suction accumulator/drier. Add the same amount plus 5O ml (2 fluid ounces) of clean refrigerant oil to the new suction accumulator/drier.

Pour clean refrigerant oil directly into the replacement component.

Other Refrigerant System Components If any other components such as the A/C evaporator core orifice or a refrigerant line are replaced, no additional refrigerant oil is necessary.