Verify the vehicle uses the correct refrigerant type specified on the under-hood label
Inspect the air conditioning system for visible leaks or damage
Wear safety glasses and gloves
Start the engine and set the parking brake
Turn the A/C to maximum cold and highest blower speed
Locate the low-pressure service port
Remove the service port cap
Attach the refrigerant hose or gauge to the low-pressure port
Keep the refrigerant can upright unless the product instructions say otherwise
Open the valve on the refrigerant can
Add refrigerant slowly in short bursts
Monitor the pressure gauge while charging
Stop adding refrigerant when the system reaches the recommended range
Disconnect the hose from the service port
Reinstall the service port cap
Check that the air from the vents is cold
Dispose of any empty can or used equipment properly
Have the system inspected by a qualified technician if cooling remains poor or leaks are suspected