Warm air exiting the vents when the air conditioning system is engaged may be an indicator that the refrigerant in the air conditioning system needs replaced. Charging the system can be completed in a few minutes by most novice mechanics. However, the refrigerant in the air conditioning system cannot be flushed without the use of an automotive air conditioning vacuum, which is usually only owned by service centers. The high-pressure system should not be flushed by any method other than using the vacuum.
Take the vehicle to an authorized service center to have the air conditioning system evacuated. An expensive air conditioning vacuum is needed to evacuate the system. Do not attempt to evacuate the system by disconnecting any of the coolant lines.
Remove the cap from the low pressure port of the air conditioning system. The low side pressure port is located on a metal air conditioning line on the passenger side of the engine compartment.
Screw the end of the recharge hose onto the low side pressure port.
Screw the valve end of the recharge hose onto the can of refrigerant. Turn the valve clockwise to pierce the can of refrigerant. Turn the valve counterclockwise to allow the refrigerant to flow through the hose and into the air conditioning system.
Turn the vehicle on and turn the air conditioning to its maximum setting.
Turn the can of refrigerant upside-down and stir it slowly.
Place a thermometer inside the center air duct in the interior of the vehicle. The temperature of a properly-operating air conditioning system should be 30 to 50 degrees colder than the ambient air temperature.
Stir the can until no fluid is left in the can. Unscrew the can from the valve end of the recharge hose.
Attach another can to the valve end of the recharge hose if needed. Turn the valve end clockwise to pierce the can, then turn the valve counterclockwise to allow fluid to flow into the system. No more than 2 12-oz. cans should be added at one time.
Turn the valve end of the hose clockwise to seal the can if any fluid is left when you've completed servicing the air conditioning system. If no fluid is left, unscrew the end of the recharge hose from the low side pressure port. Unscrew the can from the end of the recharge hose.
Turn the vehicle off.
