7B-20 Air Conditioning System: Manual Type
• Because the sight glass is not used for this
A/C system, do not perform an additional
charge to the A/C system. To charge the
proper amount of refrigerant, recover and
evacuate the A/C system first. And then,
charge the proper amount of refrigerant
into the A/C system.
• Always charge refrigerant through low
pressure side of A/C system after the initial
charge is performed from the high
pressure side with the engine stopped.
• Never charge refrigerant through high
pressure side of A/C system with engine
• Do not charge refrigerant while
compressor is hot.
• When installing tap valve to refrigerant
container to make a hole there through,
carefully follow directions given by
• A pressure gauge should always be used
before and during refrigerant charge.
• The refrigerant container should be
emptied of refrigerant when discarding it.
• The refrigerant container should not be
heated up to 40 °C (104 °F) or over.
• Refrigerant container should not be
reversed in direction during refrigerant
charge. Reversing in direction causes
liquid refrigerant to enter compressor,
causing troubles, such as compression of
liquid refrigerant and the like.
The air conditioning system contains HFC-
Described here is a method to charge the air
conditioning system with refrigerant from the
refrigerant service container.
When charging refrigerant recovered by
using the refrigerant and recycling
equipment (when recycling refrigerant),
follow the procedure described in the
equipment manufacturer's instruction
The initial charge of the A/C system is performed
through the high pressure side with the engine stopped.
And next, this method must be followed by charging from
the low pressure side with the engine running.
1) Check if hoses are routed properly after evacuating
2) Connect low charging hose (1) and high charging
hose (2) of the manifold gauge set (3) in position.
Then, open refrigerant container valve (4) to purge
the charging line.
3) Open the high pressure side valve (5) and charge
refrigerant to system.
4) After a while, open the low pressure side valve (6)
and close the high pressure side valve.
Make sure that high pressure side valve is
5) Start engine and keep engine speed at 1500 r/min,
and then operate A/C system.
6) Charge A/C system with refrigerant in vapor state. At
this time, refrigerant container should be held