Refrigerant Oil: Testing and Inspection

COMPRESSOR OIL

OIL SPECIFICATION
1. The HFC - 134 a system requires a synthetic (PAG) compressor oil whereas the R-1 2 system requires mineral compressor oil. The two oils must never be mixed.
2. Compressor (PAG) oil varies according to compressor model. Be sure to use oil specified for the model of compressor.

HANDLING OF OIL
1. The oil should be free from moisture, dust, metal powder, etc.
2. Do not mix with other oil.
3. The water content in the oil increases when exposed to the air. After use, seal oil from air immediately. (HFC - 134 a Compressor Oil absorbs moisture very easily.)
4. The compressor oil must be stored in steel containers, not in plastic containers.

COMPRESSOR OIL CHECK
The oil used to lubricate the compressor is circulating with the refrigerant.

Whenever replacing any component of the system or a large amount of gas leakage occurs, add oil to maintain the original amount of oil.

Oil total capacity in system : 15O cc ± 10 cc (5.29 ± 0.35 oz.) Compressor
(Service parts) charging amount : 150 cc ± 10 cc (5.29 ± 0.35 oz.)

CHECKING AND ADJUSTING OIL QUANTITY FOR USED COMPRESSOR
1. Perform oil return operation. Refer to Oil Return Operation in this section.
2. Discharge and recover refrigerant and remove the compressor.




3. Drain the compressor oil and measure the extracted oil with a measuring cylinder.
4. If the amount of oil drained is much less than 70 cc (2.47 oz.), some refrigerant may have leaked out. Conduct a leak tests on the connections of each system, and if necessary, repair or replace faulty parts.
5. Check the compressor oil contamination. (Refer to Contamination of Compressor Oil in this section.)




6. Adjust the oil level following the next procedure below.
7. Install the compressor, then evacuate, charge and perform the oil return operation.
8. Check system operation.

WHEN IT IS IMPOSSIBLE TO PERFORM OIL RETURN OPERATION, THE COMPRESSOR OIL SHOULD BE CHECKED IN THE FOLLOWING ORDER:
1. Discharge and recover refrigerant and remove the compressor.
2. Drain the compressor oil and measure the extracted oil with a measuring cylinder.
3. Check the oil for contamination.
4. If more than 70 cc (2.47 oz.) of oil is extracted from the compressor, supply the same amount of oil to the compressor to be installed.
5. If the amount of oil extracted is less than 70 cc (2.47 oz.) recheck the compressor oil in the following order.
6. Supply 70 cc (2.47 oz.) of oil to the compressor and install it onto the vehicle.
7. Evacuate and recharge with the proper amount of refrigerant.
8. Perform the oil return operation.
9. Remove the compressor and recheck the amount of oil.
10. Adjust the compressor oil, if necessary.

CHECKING AND ADJUSTING FOR COMPRESSOR REPLACEMENT
150 cc (5.29 oz.) of oil is charged in compressor (service parts). So it is necessary to drain the proper amount of oil from the new compressor.
1. Perform oil return operation.
2. Discharge and recover the refrigerant and remove the compressor.
3. Drain the compressor oil and measure the extracted oil.
4. Check the compressor oil for contamination.




5. Adjust the oil level as required.
6. Evacuate, charge and perform the oil return operation.
7. Check the system operation.

CONTAMINATION OF COMPRESSOR OIL
Unlike engine oil, no cleaning agent is added to the compressor oil. Even if the compressor runs for a long period of time (approximately one season), the oil never becomes contaminated as long as there is nothing wrong with the compressor or its method of use.

Inspect the extracted oil for any of the following conditions:
1. The capacity of the oil has increased.
2. The oil has changed to red.
3. Foreign substances, metal powder and etc. are present in the oil.
If any of these conditions exists, the compressor oil is contaminated. Whenever contaminated compressor oil is discovered, the receiver/drier must be replaced.

OIL RETURN OPERATION
There is close affinity between the oil and the refrigerant.

During normal operation, part of the oil recalculates with the refrigerant in the system. When checking the amount of oil in the system, or replacing any component of the system, the compressor must be run in advance for oil return operation. The procedure is as follows:
1. Open all the doors and the engine hood.
2. Start the engine and air conditioning switch to "ON" and set the blower motor control knob at its highest position.
3. Run the compressor for more than 20 minutes between 800 and 1,000 rpm in order to operate the system.
4. Stop the engine.