Refrigerant Oil: Service and Repair

STANDARD PROCEDURE - REFRIGERANT OIL LEVEL

WARNING: REFER TO THE APPLICABLE WARNINGS AND CAUTIONS FOR THIS SYSTEM BEFORE PERFORMING THE FOLLOWING OPERATION.

CAUTION: Use only PAG oils that are designed to work with R-134a refrigerant and the A/C compressor in the vehicle. Refer to the underhood A/C System Specification Label.

It is important to have the correct amount of lubricant in the A/C refrigerant system to ensure proper lubrication of the A/C compressor. Too little lubricant will result in damage to the compressor. Too much lubricant will reduce the cooling capacity of the A/C system and consequently result in higher discharge air temperatures.

The lubricant used in the compressor is polyalka-lene glycol PAG lubricant. Only the refrigerant lubricant approved for use with this vehicle should be used to service the system. Do not use any other lubricant. The lubricant container should be kept tightly capped until it is ready for use. Refrigerant lubricant will quickly absorb any moisture it comes in contact with.

It will not be necessary to check the oil level in the A/C compressor or to add oil, unless there has been an oil loss. An oil loss may occur due to a rupture or leak from a refrigerant line, connector fitting, component or component seal. If a leak occurs, add 30 milliliters (1 fluid ounce) of the recommended refrigerant oil to the refrigerant system after the repair has been made. Refrigerant oil loss will be evident at the leak point by the presence of a wet, shiny surface around the leak.

A/C Component Refrigerant Oil Capacities:

REFRIGERANT OIL LEVEL CHECK
When an air conditioning system is first assembled at the factory, all
components (except the A/C compressor) are refrigerant oil free. After the refrigerant system has been charged with (R-134a) refrigerant and operated, the oil in the A/C compressor is dispersed through the lines and components. The A/C evaporator, A/C condenser, and receiver/drier will retain a significant amount of oil. Refer to the A/C Component Refrigerant Oil Capacities table. When a component is replaced, the specified amount of refrigerant oil must be added. When the compressor is replaced, the amount of oil that is retained in the rest of the system must be drained from the replacement A/C compressor. The oil capacity of the system, minus the amount of oil still in the remaining components (refer to the oil capacity chart below) can be measured and poured into the suction port of the A/C compressor. When a line or component has ruptured and oil has escaped, the receiver/drier must be replaced along with the ruptured component.

Example: On an A/C system the A/C evaporator retains 60 ml. (2 oz.). The A/C condenser retains 30 ml. (1 oz.) of oil, and system capacity may be 150 ml. (5.00 oz.) of oil. 150 ml. minus 90 ml. equals 60 ml. (2.00 oz.).

VERIFY REFRIGERANT LUBRICANT LEVEL
1. Recover the refrigerant from the system.
2. Disconnect the refrigerant lines from the A/C compressor. Cap open lines to prevent moisture from entering the system.
3. Remove A/C compressor from the vehicle.
4. From the suction and discharge ports on the A/C compressor, drain the lubricant from the compressor.
5. Add the system capacity minus the capacity of the components that have not been replaced. Refer to the A/C Component Refrigerant Oil Capacities chart. Add lubricant through the suction and discharge ports on the A/C compressor.
6. Install the A/C compressor and connect the refrigerant lines. Then evacuate and charge refrigerant system.
7. Most reclaim/recycling equipment will measure the lubricant being removed. This amount of lubricant should be added back to the system. If a new A/C compressor is being installed, drain the lubricant from the used compressor, measure the amount drained and discard the used lubricant. Drain the lubricant from the new A/C compressor into a clean container. Return the amount of lubricant measured from the used compressor, plus the amount reclaimed from the system back into the new A/C compressor. Refer to the red aim/recycling equipment manufacturers instructions.