Always conduct a leak test with an electronic leak detector whenever leakage or refrigerant is suspected and when
conducting service operations which are accompanied by disassembly or loosening or connection fittings.
Symptom seen in
refrigeration system
Probable cause
Diagnosis
Remedy
• Pressure too high on low
high pressure sides
• Pressure too low to on
high pressure side
Internal leak in compressor
• Compression defective
• Valve leaking or broken
sliding parts
Repair or replace
compressor
INSPECT FOR LEAKAGE OF REFRIGERANT
In order to use the leak detector properly, read the manual supplied by the manufacturer.
1. Check the torque on the connection fittings and, if too loose, tighten to the proper torque. Check for gas leakage with a
leak detector.
2. If leakage continues even after the fitting has been tightened, discharge the refrigerant from the system, disconnect the
fittings, and check their seating faces for damage. Always replace, even if the damage is slight.
3. Check the compressor oil and add oil if required.
4. Charge the system and recheck for gas leaks. If no leaks are found, evacuate and charge the system again
A/C SYSTEM TESTS
• Air conditioning refrigerant or lubricant vapor can irritate your eyes, nose, or throat.
• Be careful when connecting service equipment.
• Do not breathe refrigerant or vapor.
• Compressed air mixed with R-134a forms a combustible vapor.
• The vapor can burn or explode causing serious injury.
• Never use compressed air to pressure test R-134a service equipment or vehicle air conditioning systems.
1. Connect a R-134a refrigerant recover/recycling/charging station to the high-pressure service port and the low-pressure
service port, following the equipment manufacturer s instructions.
2. Insert a thermometer in the center vent.
Determine the relative humidity and air temperature.
Page 5 of 7
24.04.2008
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