Verify the refrigerant type on the vehicle label
Inspect the system for visible leaks or damage
Check compressor clutch operation and belt condition
Connect A/C manifold gauges to the service ports
Read the low-side and high-side pressures
Start the engine and set A/C to maximum cooling
Open windows and set blower to high
Add the correct refrigerant slowly through the low-side port
Monitor pressure readings while charging
Stop charging when the specified pressure and amount are reached
Do not overfill the system
Check vent temperature after charging
Inspect for leaks again after recharging
Replace service port caps securely
Use proper recovery equipment if refrigerant must be removed
Follow local laws and safety procedures when handling refrigerant