Pressure Test Chart (R-134a System)
WARNING: This page is about a different car, the 2005 Suzuki Reno and 2005 Suzuki Forenza. However, it is still accessible from the selected car via links, so may be relevant.
PRESSURE TEST CHART
| Test Results | Related Symptoms | Probable Cause | Remedy |
|---|---|---|---|
| Discharge (high) pressure abnormally high | After stopping the compressor, the pressure drops about 299 kPa (28 psi) quickly, then falls gradually. | Air in the system. | Recover, evacuate and recharge the system with the specified amount of refrigerant. |
| The condenser is excessively hot. | Excessive refrigerant in the system. | Recover, evacuate and recharge the system with the specified amount of refrigerant. | |
| Reduced or no airflow through the condenser. | Condenser or the radiator fins are clogged. | Clean the condenser or the radiator fins. | |
| Condenser or the radiator fan is not working properly. | Check the voltage and the fan rpm. Check the fan direction. |
||
| Line to the condenser is excessively hot. | Restricted flow of refrigerant in the system. | Locate and repair the restriction. | |
| Discharge pressure abnormally low | The condenser is not hot. | Insufficient refrigerant in the system. | Check the system for a leak. Charge the system. |
| High and low pressures are balanced soon after stopping the compressor. Low-side pressure is higher than normal. |
Faulty compressor pressure relief valve. | Repair or replace the compressor. | |
| Faulty compressor seal. | |||
| The outlet of the expansion valve is not frosted. Low pressure gauge indicates vacuum. |
Faulty expansion valve. | Replace the expansion valve. | |
| Moisture in the system. | Recover, evacuate, and recharge the system. | ||
| Suction (low) pressure abnormally low | Condenser is not hot. | Insufficient refrigerant in the system. | Repair the leaks. Recover, evacuate, and recharge the system. |
| The expansion valve is not frosted and the low pressure line is not cold. Low-Pressure gauge indicates a vacuum. |
Faulty expansion valve. | Replace the expansion valve. | |
| Frozen expansion valve. | |||
| Discharge temperature is low and the airflow from the vents is restricted. | Evaporator is frozen. | Clear the restricted evaporator case drain. | |
| The expansion valve is frosted. | Expansion valve is clogged. | Clean or replace the expansion valve. | |
| The receiver-dryer outlet is cool and the inlet is warm. | Receiver-dryer is clogged. | Replace the receiver-dryer. | |
| Suction pressure abnormally high | Low-pressure hose and check joint are cooler than the temperature around the evaporator. | Expansion valve is opened for too long. | Replace the expansion valve. |
| Capillary tube is loose. | |||
| Suction pressure abnormally high | Suction pressure is lowered when the condenser is cooled by water. | Excessive refrigerant in the system. | Recover, evacuate, and recharge the system. |
| High and low pressure are equalized as soon as the compressor is stopped and both gauges fluctuate while the compressor is running. | Faulty gasket. | Repair or replace the compressor. | |
| Faulty high-pressure valve.(V5 compressor only) | |||
| Foreign particles stuck in the high-pressure valve. (V5 compressor only) | |||
| Suction and discharge pressure abnormally high | Reduced airflow through the condenser. | Clogged condenser or radiator fins. | Clean the condenser and the radiator. |
| Radiator cooling fans working improperly. | Check the voltage and the radiator cooling fan rpm. Check the fan direction. | ||
| Condenser is excessively hot. | Excessive refrigerant in the system. | Recover, evacuate, and recharge the system. | |
| Suction and discharge pressure abnormally low | Low-pressure hose and metal end areas are cooler than the evaporator. | Clogged or kinked low-pressure hose. | Repair or replace the low-pressure hose. |
| Temperature around the expansion valve is low compared to that around the receiver-dryer. | Clogged high-pressure line. | Repair or replace the high-pressure line. | |
| Refrigerant leaks | The compressor clutch is dirty. | Leaking compressor shaft seal. | Repair or replace the compressor. |
| The compressor bolts are dirty. | Leaking around a compressor housing bolt. | Tighten the bolt(s) or replace the compressor. | |
| The compressor gasket is wet with oil. | Leaking compressor gasket. | Repair or replace the compressor. |