Remove two screws and access cover from air conditioner.
Using only R22 refrigerant, set refrigerant tank on scale with the valve down.
Record the weight by marking the dial on the scale with a grease pencil.
Subtract 3.0 pounds (1.35 kg) from reading and mark on dial with grease pencil.
Cap or plug the center hose on the charging manifold.
Install a filter/drier in the low pressure service hose.
Use great care to avoid contact with liquid refrigerant or refrigerant
gas being discharged from any container under pressure. Sudden and
irreversible tissue damage can result from freezing. Wear thermal
protective gloves and a face protector or safety glasses in any situation
where skin or eye contact is possible.
Prevent contact of refrigerant gas with flame or hot metal surfaces.
Heat causes the refrigerant to break down and form carbonyl chloride
(phosgene), a highly toxic and corrosive gas. In case of refrigerant
leaks, ventilate area immediately.
Connect the low pressure service hose to the refrigerant tank.
Remove valve cap from high pressure service valve.
Loosely connect the high pressure service hose to the high pressure service valve.
b. CHARGING PROCEDURE.
Open low pressure manifold valve and refrigerant tank valve.
Open high pressure charging manifold valve slightly to purge service hose, then
Tighten service hose connection at high pressure service valve.
Open high pressure service valve.