Refrigerant Circuit Problems
System Condition 8
1. Low pressure gauge reading is above normal.
2. High pressure gauge reading is below normal.
Note: Ambient temperature is above 21°C (70°F) and the system has a refrigerant charge that is full.
3. The temperature of the air flow from the evaporator is partially cool.
Probable Cause
The compressor has internal leaks. The reed valve has leakage. The compressor piston, rings or cylinders are worn.
* Check the compressor drive belt for the correct tension.
* Perform a leak test. Isolate the problem to the compressor. Refer to the Service Manual, SENR5664, "Refrigerant Leakage - Test" section in Testing and Adjusting.
If an internal leak is found, perform the following procedure.
* Replace the compressor. Refer to the Service Manual, SENR5664, "refrigerant Compressor - remove and Install" section in Disassembly and Assembly.
* Replace the receiver-dryer. Refer to the Service Manual, SENR5664, "Receiver-Dryer - Remove and Install" section in Testing and Adjusting.
* Evacuate the system. Refer to the Service Manual, SENR5664, "Refrigerant System - Evacuate" section in Testing and Adjusting.
* Charge the system with the correct amount of refrigerant by weight. Refer to the Service Manual, SENR5664, "Refrigerant System - Charge" section in Testing and Adjusting.
* After the system is charged and operated for a minimum of ten minutes, perform a performance check. Refer to "Performance Checks for the Air Conditioning System" section.
If an external leak such as a hose connection is found, perform the following procedure.
* Recover the refrigerant. Refer to the Service Manual, SENR5664, "Refrigerant Recovery" section.
* Repair leaks.
If a large amount of refrigerant is lost, check the compressor for the loss of oil.
* Evacuate the system. Refer to the Service Manual, SENR5664, "Refrigerant System - Evacuate" section in Testing and Adjusting.
* Charge the system with the correct amount of refrigerant. Measure the refrigerant by weight. Refer to the Service Manual, SENR5664, "Refrigerant System - Charge" section in Testing and Adjusting.
* After the system is charged and operated for a minimum of ten minutes, perform a performance check. Refer to "Performance Checks for the Air Conditioning System" section.
