Verify the correct refrigerant type and charge amount on the vehicle label
Inspect the system for leaks and repair any leaks before charging
Recover any remaining refrigerant with approved recovery equipment
Replace the receiver-drier or accumulator if required by the service procedure
Evacuate the system with a vacuum pump
Hold vacuum and confirm the system maintains vacuum
Connect the refrigerant supply to the correct service port
Use a manifold gauge set or approved charging equipment
Charge the specified amount of refrigerant by weight
Start the engine and set the A/C to maximum cooling
Continue charging only as directed by the vehicle service procedure
Monitor system pressures and vent temperature during charging
Stop charging when the specified charge amount is reached
Disconnect the equipment and reinstall service port caps
Check for proper operation and inspect for leaks again