Table 1: | Discharge High Pressure Abnormally High |
Table 2: | Discharge Pressure Abnormally Low |
Table 3: | Suction Low Pressure Abnormally Low |
Table 4: | Suction Pressure Abnormally High |
Table 5: | Suction and Discharge Pressure Abnormally High Charge |
Table 6: | Suction and Discharge Pressure Abnormally Low |
Table 7: | Refrigerant Leaks |
Symptoms | Checks | Actions | |||
---|---|---|---|---|---|
After stopping the compressor, the pressure drops about 299 kPa (43 psi) quickly, then falls gradually. | Air is in the system. | Recover, evacuate, and recharge the system with the specified amount of refrigerant. | |||
The condenser is excessively hot. | Excessive refrigerant is in the system. | Recover, evacuate, and recharge the system with the specified amount of refrigerant. | |||
Reduced flow or no air flow through the condenser | The condenser or the radiator fins are clogged. | Clean the condenser or the radiator fins. | |||
The condenser or the radiator fan is not working properly. |
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The line to the condenser is excessively hot. | A restricted flow of refrigerant is in the system. | Locate and repair the restriction. |
Symptoms | Checks | Actions | ||||
---|---|---|---|---|---|---|
The condenser is not hot. | Insufficient refrigerant is in the system. |
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High and low pressures are balanced soon after stopping the compressor. | A faulty compressor pressure relief valve is present. | Repair or replace the compressor. | ||||
Low side pressure is higher than normal. | A faulty compressor seal is present. | |||||
The outlet of the expansion valve is not frosted. | A faulty expansion valve is present. | Replace the expansion valve. | ||||
The low pressure gage indicates vacuum. | Moisture is in the system. | Recover, evacuate, and recharge the system. |
Symptoms | Checks | Actions | ||||
---|---|---|---|---|---|---|
The condenser is not hot. | Insufficient refrigerant is in the system. |
| ||||
The expansion valve is not frosted and the low pressure line is not cold. | A frozen expansion valve is present. | Replace the expansion valve. | ||||
The low pressure gage indicates a vacuum. | A faulty expansion valve is present. | |||||
The discharge temperature is low and the airflow from the vents is restricted. | The evaporator is frozen. | Clear the restricted evaporator case drain. | ||||
The expansion valve is frosted. | The expansion valve is clogged. | Clean or replace the expansion valve. | ||||
The receiver/dryer outlet is cool and the inlet is warm. | The receiver/dryer is clogged. | Replace the receiver/dryer. |
Symptoms | Checks | Actions |
---|---|---|
The low-pressure hose and the check joint are cooler than the temperature around the evaporator. | The expansion valve is opened for too long. | Replace the expansion valve. |
The capillary tube is loose. | ||
Suction pressure is lowered when the condenser is cooled by water. | Excessive refrigerant is in the system. | Recover, evacuate, and recharge the system. |
High and low pressure are equalized as soon as the compressor is stopped and both gages fluctuate while the compressor is running. | A faulty gasket is present. | Repair or replace the compressor. |
A faulty high-pressure valve is present. | ||
Foreign particles are stuck in the high-pressure valve. |
Symptoms | Checks | Actions | |||
---|---|---|---|---|---|
Airflow through the condenser is reduced. | The condenser or the radiator fins are clogged. | Clean the condenser and the radiator. | |||
The radiator cooling fans are not working properly. |
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The condenser is excessively hot. | Excessive refrigerant is in the system. | Recover, evacuate, and recharge the system. |
Symptoms | Checks | Actions |
---|---|---|
The low-pressure hose and metal end areas are cooler than the evaporator. | The low-pressure hose is clogged or kinked. | Repair or replace the low-pressure hose. |
The temperature around the expansion valve is low compared to the temperature around the receiver/dryer. | The high pressure line is clogged. | Repair or replace the high-pressure line. |
Symptoms | Checks | Actions |
---|---|---|
The compressor clutch is dirty. | The compressor shaft seal is leaking. | Repair or replace the compressor. |
The compressor bolts are dirty. | Leaking occurs around a compressor housing bolt. | Tighten the bolts or replace the compressor. |
The compressor gasket is wet with oil. | The compressor gasket is leaking. | Repair or replace the compressor. |