OIL-A/C REFRIGERANT
DESCRIPTION
The refrigerant oil used in R-134a refrigerant systems is a synthetic-based, polyalkylene glycol (PAG), wax-free
lubricant. Mineral-based R-12 refrigerant oils are not compatible with PAG oils, and should never be introduced to
an R-134a refrigerant system.
There are different PAG oils available, and each contains a different additive package. Useonlyrefrigerant oil of the
same type as recommended to service the refrigerant system (always refer to the specification tagincluded with
the replacement A/C compressor or the A/C Underhood Specification Label located in the engine compartment).
The Denso 10S17 A/C compressor used in this vehicle when equipped with the 3.7L, 4.7L, 5.7L or 8.3L engine is
designed to use ND-8 PAG refrigerant oil. Use only this type of refrigerantoil when servicing the A/C compressor for
these engines.
The Visteon HS-18 A/C compressor used in this vehicle when equipped with 5.9L diesel engine is designed to use
VC-46 PAG refrigerant oil. Use only this type of refrigerant oil when servicing this A/C compressor.
OPERATION
After performing any refrigerant recovery or recycling operation, always replenish the refrigerant system with the
same amount of the recommended refrigerant oil as was removed. Too little refrigerant oil can cause A/C compres-
sor damage, and too much can reduce A/C system performance.
PAG refrigerant oil is more hygroscopic than mineral oil, and will absorb any moisture it comes into contact with,
even moisture in the air. The PAG oil container should always be kept tightly capped until it is ready to be used.
After use, recap the oil container immediately to prevent moisture contamination.
STANDARD PROCEDURE
REFRIGERANT OIL LEVEL
When an A/C system is assembled at the factory, all components except the A/C compressor are refrigerant oil free.
After the refrigerant system has been charged and operated, the refrigerant oil in the A/C compressor is dispersed
throughout the refrigerant system. The accumulator, A/C evaporator, A/Ccondenser and the A/C compressor will
each retain a significant amount of the needed refrigerant oil.
It is important to have the correct amount of refrigerant oil in the A/C system. This ensures proper lubrication of the
A/C compressor. Too little oil will result in damage to the A/C compressor,while too much oil will reduce the cooling
capacity of the A/C system and consequently result in higher discharge airtemperatures.
CAUTION: The refrigerant oil in the R-134a A/C system is unique depending on the A/C compressor used.
Use only PAG oils that are designed to work with R-134a refrigerant and the A/C compressor in the vehicle.
Always refer to the A/C Underhood Specification Label for the correct oil designation. The oil container
should be kept tightly capped until it is ready for use and then tightly capped after use to prevent contam-
ination from dirt and moisture. Refrigerant oil will quickly absorb any moisture it comes in contact with,
therefore, special effort must be used to keep all R-134a system components moisture-free. Moisture in the
refrigerant oil is very difficult toremove and will cause a reliability problem with the A/C compressor.
NOTE: Most reclaim/recycling equipment will measure the lubricant beingremoved during recovery. This
amount of lubricant should be added back into the system. Refer to the reclaim/recycling equipment man-
ufacturers instructions.
It will not be necessary to check the oil level in the A/C compressor or to addoil, unless there has been an oil loss.
An oil loss may occur due to a rupture or leak from a refrigerant line, a connector fitting, a component, or a com-
ponent seal. If a leak occurs, add 30 milliliters (1 fluid ounce) of refrigerant oil to the refrigerant system after the
repair has been made. Refrigerant oil loss will be evident at the leak pointby the presence of a wet, shiny surface
around the leak.
Refrigerant oil must be added when an accumulator, A/C evaporator or A/C condenser is replaced. See the Refrig-
erant Oil Capacities chart. When an A/C compressor is replaced, the refrigerant oil must be drained from the old
