Refrigerant Leakage - Test
CAT ProductFinding leaks and repairing leaks from refrigerant is important since the air conditioner is a closed circuit system.
The system must contain at least 0.4 kg (.88 lb) of refrigerant. Install the manifold gauge set. The manifold gauge set can determine if pressure exists in the system. A leak test can be performed if the system indicates pressure.
Note: Refrigerant vapor is heavier than air. For best results, place the black light directly below possible leaks.
Note: Leaks that are in the high pressure side of the system are more easily found if the air conditioner is operated for 5 to 10 minutes. The leak test must be performed immediately after the unit is turned OFF. The leak test for the high pressure side is performed before the pressures in the system equalize. Leaks that are in the low pressure side of the system are more easily found if the air conditioner has been turned OFF for 5 to 10 minutes. The leak test for the low pressure side is performed after the pressures in the system equalize.
1. Move the black light along possible leak points. When a leak is present, the black light will illuminate the dye that is in the refrigerant.
Note: Leaks that are indicated by the presence of dye should always be confirmed with an electronic leak detector.
2. If a leak is found in the air conditioning system, use a 4C-2964 Refrigerant Leak Detector in order to confirm the leak that was detected by the use of the black light.
3. Repair the leak In the air conditioning system and clean the area with 192-4727 Dye Cleaning Solution .
Leak Detector
The 208-1374 Refrigerant Leak Detectors are designed in order to detect leaks as small as 7.4 mL (.25 oz) per year of refrigerant in the air conditioning system. Perform the following procedure in order to determine if the system has a leak.
The system must contain at least 0.4 kg (.88 lb) of refrigerant. Install the manifold gauge set. The manifold gauge set can determine if pressure exists in the system. A leak test can be performed if the system indicates pressure.
Note: Refrigerant vapor is heavier than air. For best results, place the sensor tip directly below possible leaks.
Note: Leaks in the high pressure side of the system are more easily found if the air conditioner is operated for a few minutes. The leak test must be performed immediately after the unit is turned OFF. The leak test for the high pressure side is performed before the pressures in the system equalize. Leaks in the low pressure side of the system are more easily found if the air conditioner has been turned OFF for several minutes. The leak test for the low pressure side is performed after the pressures in the system equalize.
1. Move the sensor tip along possible leak points at a rate of one inch per second.
2. It may not be necessary to recover refrigerant if a loose fitting or a loose connection is causing a leak. Tighten the loose connection and perform the performance check procedure. If necessary, add refrigerant to the air conditioning system. Refer to the Testing and Adjusting, "Refrigerant System - Charge" section for the proper procedure.
3. If the repair of a leak calls for the removal or the replacement of a component, refer to the Service Manual, SENR5664, "Machine Preparation for Disassembly and Assembly" section in Disassembly and Assembly.
Note: Under normal conditions, R134a air conditioning systems that have P80 hoses may lose as much as 0.018 kg (0.0400 lb) of refrigerant per foot of hose per year.
Note: Refrigerants that are not approved by Caterpillar may have higher leakage rates.
