Pressure Test Chart (R-134a System)

WARNING: This page is about a different car, the 2006 Suzuki Verona. However, it is still accessible from the selected car via links, so may be relevant.

PRESSURE TEST CHART (R-134A SYSTEM)

Test Results	Related Symptom	Probable Cause	Remedy
Discharge (high) pressure abnormally high	After stopping the compressor, the pressure drops about 299 kPa (28 psi) quickly, then falls gradually	There is air in the system.	Recover, evacuate and recharge the system with the specified amount of refrigerant.
	The condenser is excessively hot.	There is excessive refrigerant in the system.	Recover, evacuate and recharge the system with the specified amount of refrigerant.
	Reduced or no airflow through the condenser.	The condenser or the radiator fins are clogged.	Clean the condenser or the radiator fins.
	Reduced or no airflow through the condenser.	The 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.	Faulty compressor pressure relief valve.	Repair or replace the compressor.
	Low-side pressure is higher than normal.	Faulty compressor seal.	Repair or replace the compressor.
	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.	Frozen expansion valve.	Replace the expansion valve.
	Low Pressure gauge indicates a vacuum.	Faulty expansion valve.	Replace the expansion valve.
	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/drier outlet is cool and the inlet is warm.	The receiver/drier is clogged.	Replace the receiver/drier.
Suction pressure abnormally high	Low pressure hose and check joint are cooler than the temperature around the evaporator.	The expansion valve is opened for too long.	Replace the expansion valve.
		A capillary tube is loose.	Replace the expansion valve.
	Suction pressure is lowered when the condenser is cooled by water.	There is 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.	A gasket is faulty.	Repair or replace the compressor.
		The high pressure valve is faulty.
		Foreign particles are stuck in the high pressure valve.
Suction and discharge pressure abnormally high	Reduced airflow through the condenser.	The condenser or the radiator fins are clogged.	Clean the condenser and the radiator.
	Reduced airflow through the condenser.	The radiator cooling fans are not working properly.	Check the voltage and the radiator cooling fan RPM. Check the fan direction.
	Condenser is excessively hot.	There is 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.
Suction and discharge pressure abnormally low	Temperature around the expansion valve is low compared to that around the receiver/dryer.	The high pressure line is clogged.	Repair or replace the high pressure line.
Refrigerant leaks	The compressor clutch is dirty.	The compressor shaft seal is leaking.	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.	The compressor gasket is leaking.	Repair or replace the compressor.