Pressure Test

WARNING: This page is about a different car, the 2008 Acura TSX, 2007 Acura TSX, 2006 Acura TSX, 2005 Acura TSX, and 2004 Acura TSX. However, it is still accessible from the selected car via links, so may be relevant.

PRESSURE TEST

Test results	Related symptoms	Probable cause	Remedy
Discharge (high) pressure abnormally high	After stopping A/C compressor, pressure drops about 196 kPa (2.0 kgf/cm² , 28 psi) quickly, and then falls gradually.	Air in system	Recover, evacuate (see SYSTEM EVACUATION ), and recharge with specified amount (see SYSTEM CHARGING ).
	No bubbles in sight glass when A/C condenser is cooled by water.	Excessive refrigerant in system	Recover, evacuate, and recharge with specified amount.
	Reduced or no airflow through A/C condenser.	Clogged A/C condenser or radiator fins A/C condenser or radiator fan not working properly	Clean. Check voltage and fan rpm. Check fan direction.
	Line to A/C condenser is excessively hot.	Restricted flow of refrigerant in system	Restricted lines.
Discharge pressure abnormally low	Excessive bubbles in sight glass; A/C condenser is not hot.	Insufficient refrigerant in system	Check for leak. Charge system.
	High and low-pressures are balanced soon after stopping A/C compressor. Low side is higher than normal.	Faulty A/C compressor discharge valve Faulty A/C compressor seal	Replace the A/C compressor.
	Outlet of expansion valve is not frosted, low-pressure gauge indicates vacuum.	Faulty expansion valve Moisture in system	Replace. Recover, evacuate, and recharge with specified amount.
Suction (low) pressure abnormally low	Excessive bubbles in sight glass; A/C condenser is not hot.	Insufficient refrigerant in system	Repair the leaks. Recover, evacuate, and recharge with specified amount. Charge as required.
	Expansion valve is not frosted, and low-pressure line is not cold. Low-pressure gauge indicates vacuum.	Frozen expansion valve (Moisture in system) Faulty expansion valve	Recover, evacuate, and recharge with specified amount. Replace the expansion valve.
	Discharge temperature is low, and the airflow from vents is restricted.	Frozen evaporator	Run the fan with A/C compressor off, then check evaporator temperature sensor.
	Expansion valve is frosted.	Clogged expansion valve	Clean or replace.
Suction pressure abnormally high	Low-pressure hose and service port are cooler than the temperature around evaporator.	Expansion valve open too long	Repair or replace.
	Suction pressure is lowered when A/C condenser is cooled by water.	Excessive refrigerant in system	Recover, evacuate, and recharge with specified amount.
	High and low-pressures are equalized as soon as the A/C compressor is stopped, and both gauges fluctuate while running.	Faulty gasket Faulty high-pressure valve Foreign particle stuck in high-pressure valve	Replace the A/C compressor.
Suction and discharge pressures abnormally high	Reduced airflow through A/C condenser.	Clogged A/C condenser or radiator fins A/C condenser or radiator fan not working properly	Clean. Check voltage and fan rpm. Check fan direction.
Suction and discharge pressures abnormally high	No bubbles in sight glass when A/C condenser is cooled by water.	Excessive refrigerant in system	Recover, evacuate, and recharge with specified amount.
Suction and discharge pressures abnormally low	Low-pressure hose and metal fittings areas are cooler than evaporator.	Clogged or kinked low-pressure hose parts	Repair or replace.
Suction and discharge pressures abnormally low	Temperature around expansion valve is too low compared with that around receiver/dryer.	Clogged high-pressure line	Repair or replace.
Refrigerant leaks	A/C compressor clutch is dirty.	A/C compressor shaft seal leaking	Replace the A/C compressor.
	A/C compressor bolt(s) are dirty.	Leaking around bolt(s)	Tighten bolt(s) or replace A/C compressor.
	A/C compressor gasket is wet with oil.	Gasket leaking	Replace the A/C compressor.
	A/C fitting is dirty.	Leaking O-ring	Clean the A/C fitting and replace the O-ring.