Verify the AC system is low on refrigerant
Check the vehicle’s AC specifications for the correct refrigerant type and charge amount
Wear safety gloves and eye protection
Turn the engine off
Locate the low-pressure service port
Attach the R134a recharge hose/gauge to the low-pressure port
Start the engine
Turn the AC to maximum cold and highest fan speed
Open the hood and keep clear of moving parts
Read the system pressure on the gauge
Shake the refrigerant can if required by the product instructions
Hold the can upright unless the product instructions say otherwise
Open the refrigerant valve slowly
Add refrigerant in short bursts
Monitor the gauge while charging
Stop adding refrigerant when the pressure reaches the recommended range
Do not overfill the system
Disconnect the recharge hose from the low-pressure port
Replace the service port cap
Check AC vent temperature
Inspect for leaks if cooling is still poor
Dispose of empty cans and used materials properly