Refrigerant Oil: Service and Repair
CompressorCompressor Oil
Inspection Procedure
Oil Specification
Always use HFC-134a Swash Plate Compressor Oil ZXL-100PG (ISUZU Part No. 8-47101-338-0) [4JJ1] or ND-OIL8 [4HK1].
Handling of Oil
The oil should be free from moisture, dust, metal powder, etc.
Do not mix with other oil.
The water content in the oil increases when exposed to the air. After use, seal oil from air immediately. (HFC-134a Swash Plate Compressor Oil absorbs moisture very easily.)
The compressor oil must be stored in steel containers, not in plastic containers.
Compressor oil check
The oil used to lubricate the compressor circulates 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 Capacity
Checking and Adjusting for Used Compressor
1. Perform Oil return operation. (Refer to Oil Return Operation below.)
2. Discharge and recover refrigerant and remove the compressor.
3. Drain the compressor oil and measure the extracted oil with a measuring cylinder.
4. 4JJ1:
If the amount of oil drained is much less than 90cc (3.04 US fl oz), some refrigerant may have leaked out. Conduct leak tests on connections of each system, and if necessary, repair or replace faulty parts.
4HK1:
If the amount of oil drained is much less than 60cc (2.03 US fl oz), some refrigerant may have leaked out. Conduct leak tests on connections of each system, and if necessary, repair or replace faulty parts.
5. Check the compressor oil for contamination. (Refer to Contamination of Compressor Oil below.)
6. Adjust oil level following the procedure below.
7. Install the compressor, then evacuate, charge and perform 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:
9. Discharge and recover refrigerant and remove the compressor.
10. Drain the compressor oil and measure the extracted oil with a measuring cylinder.
11. Check the oil for contamination.
12. 4JJ1:
If more than 90cc (3.04 US fl oz) of oil is extracted from the compressor, supply same amount of oil to the compressor to be installed. If the amount of oil extracted is less than 90cc (3.04 US fl oz), recheck the compressor oil in the following order:
4HK1:
If more than 60cc (2.03 US fl oz) of oil is extracted from the compressor, supply same amount of oil to the compressor to be installed. If the amount of oil extracted is less than 60cc (2.03 US fl oz), recheck the compressor oil in the following order:
13. 4JJ1:
Supply 90cc (3.04 US fl oz) of oil to the compressor and install it onto the vehicle.
4HK1:
Supply 60cc (2.03 US fl oz) of oil to the compressor and install it onto the vehicle.
14. Perform oil return operation.
15. Remove the compressor and recheck the amount of oil.
16. Adjust the compressor oil.
Checking and Adjusting for Compressor Replacement
150cc (5.07 US fl oz) [4JJ1] or 100cc (3.38 US fl oz) [4HK1] of oil is charged in compressor (service parts). So it is necessary to drain the proper amount of oil from new compressor.
17. Perform oil return operation.
18. Discharge and recover refrigerant and remove the compressor.
19. Drain the compressor oil and measure the extracted oil with a measuring cylinder.
20. Check the compressor oil for contamination.
21. Adjust oil level following the procedure below.
22. Evacuate, charge and perform oil return operation.
23. Check 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 1 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:
- The capacity of the oil has increased.
- The oil has changed color to red.
- Foreign substances, metal powder, present in the oil.
If any of these conditions exists, 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 recirculates 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:
24. Open all doors and engine hood.
25. Air conditioning switch is 'ON' and run the blower motor at 'Highest' position.
26. Run the compressor for more than 20 minutes between 800 and 1,000 r/min in order to operate the system.
Replacement of Component Parts
When replacing system component parts, supply the following amount of oil to the component parts to be installed.
Refrigeration oil must be replenished if more than two parts are removed at the same time.
After installing these components, check compressor oil.
