Confirm the A/C system uses the correct refrigerant type listed on the under-hood label
Wear safety glasses and gloves
Start the engine and set the A/C to maximum cold and highest fan speed
Open the hood and locate the low-pressure service port
Connect the refrigerant hose or gauge to the low-pressure port only
Check the system pressure before adding refrigerant
Shake the refrigerant can if required by the product instructions
Hold the can upright unless the product instructions say otherwise
Add refrigerant in short bursts while monitoring pressure
Stop adding when the pressure reaches the recommended range
Do not overfill the system
Disconnect the hose and replace the service port cap
Check that the A/C blows cold air
If the system is empty, leaks, or still not cooling, have it inspected by a professional