Refrigerant Oil Addition

OIL TYPE
The FS-6 compressor uses a 500 viscosity refrigerant oil (C9AZ-19557-B or Motorcraft VN-2 or equivalent). An oil charge of 10 fluid ounces is required in a new system. It is important that only the specified type and quantity of refrigerant oil be used in the compressor. If there is a surplus of oil in the system, too much oil will circulate with the refrigerant, reducing the cooling capacity of the system. Too little oil will result in poor lubrication of the compressor.

OIL REPLACEMENT
When it is necessary to replace a component of the refrigerant system, the procedures must be followed to assure that the total oil charge in the system is correct after the new part is installed. When the 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 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, it is necessary to compensate for this by replacing the oil in the new replacement part.

PROCEDURE
The procedures for replacing refrigerant oil are as follows:

During Compressor Replacement
1. A new service replacement compressor contains 10 fluid ounces of the specified refrigerant oil.
2. Prior to installing the replacement compressor, drain four fluid ounces of refrigerant oil from the compressor. This will maintain the total system oil charge within the specified limits.

During Component Replacement
1. When replacing other components of the air conditioning refrigerant system, measured quantities of 500 viscosity refrigerant oil should be added to the component to assure that the total oil charge in the system is correct before the system is operated.
2. Clean refrigerant oil should be added to the replacement components as follows:
a. Evaporator Core: Add three fluid ounces.
b. Condenser: Add one fluid ounce.
c. Accumulator: Drain oil from removed accumulator/drier. Add same amount plus one fluid ounce of clean refrigerant oil to new accumulator.
3. Clean refrigerant oil should be poured directly into the replacement component.
4. If any other components, such as valves or hoses are replaced, no additional refrigerant oil is necessary.