2. Place a clean rag under the open end of the center manifold fitting hose.
3. Slowly open the high pressure line nipple valve to gradually evacuate the refrigerant from the system.
Caution: If the refrigerant is pumped out very quickly (rapid pressure release), compressor oil may be released from the system.
4. Check for compressor oil stains on the rags (i.e. oil leaking out with the refrigerant). If the rags are oily, carefully close the high-pressure line nipple valve.
(The article is borrowed from an online resource: HyundaiBook.ru)
5. If the pressure gauge reading on the measuring manifold drops below 350 kPa, slowly open the low pressure line nipple valve.
6. Slowly open the valves of the low and high pressure line fittings to reduce the pressure in the system until the pressure gauge shows 0 kPa.
