Order of execution
1. Connect a pressure gauge to the air conditioning system.
2. Place a towel under the open end of the center hose.
3. Slowly open the high pressure valve and discharge the air conditioning system.
Warning! If the refrigerant is rapidly discharged from the air conditioning system, compressor oil may leak out of the system.
4. Check for oil stains on the towel. If so, gently close the valve.
5. After reducing the pressure in the air conditioning system below 3.5 kg/cm2, open the low pressure valve.
6. Open the high and low pressure valves and slowly reduce the pressure in the air conditioning system until the pressure gauge reads 0 kg/cm2.