To recharge a vehicle's air conditioning system, connect the hoses of a gauge set to the unit's low and high side lines, switch on the system, and note the low and high side pressure readings. If the pressure is lower than required, introduce coolant in the system using the gauge till the pressure reaches the required value. Finally, check the vent temperature to test the air conditioner's functionality.Continue Reading
Begin recharging a vehicle's air conditioning system by connecting the set's blue-colored hose to the low side line service port, located between the system's accumulator and compressor. Attach the set's red-colored hose to the high side line service port, located between the system's firewall and condenser.
Now, switch on the engine, and adjust its air conditioner to the maximum, medium blower and recirculating air settings. If the system is charged completely, the gauge should read 35 to 45 pounds per square inch and 200 to 350 pounds per square inch on the low and high side lines, respectively. The readings are lower when it's cold and higher when it's warm.
If the readings are lower than required, attach a can tap to the gauge set's yellow-colored hose, and affix a refrigerant can to the former. Turn the thumbscrew fully in and out to undo the can. Switch on the engine, and turn on the set's blue-colored valve to add the refrigerant.
If the gauge reading is low even when the can is half-empty, add more refrigerant. When the required pressure is attained, switch off the engine, wait for the pressure to stabilize, and disconnect the set's hoses.
Replace the service port caps, and switch on the engine. Finally, check if the difference between the vent and outside air temperatures is a minimum of 40 degrees Fahrenheit.Learn more about Car Parts & Maintenance