GMC 1986 P-Truck Service Manual page 86

Figure 22—Charging The System With A Disposable Can Or Drum
a. If charging station J-23500-01 is not being
used, discharge the system by slowly
connecting a gage hose to the low side
service fitting on the accumulator and dis­
charge into a bottle (figure 23).
b. As the hose is SLOWLY tightened down
onto the schrader valve, Refrigerant-12 will
d is c h a rg e from the system into the
Figure 23—Discharging The CCOT A/C System
W ithout Charging Station J-23500-10
65. Accum ulator
3. With the low side of the system discharged,
4. If pressure is found, attempt to discharge
5. After discharging, (no vapor escaping with
6. If adding oil is necessary, remove the
AIR CONDITIONING
container. If no discharge occurs, check for
missing or defective schrader depressor in
the hose fitting.
check the high side system fitting (on the
liq u id lin e or m u ffle r) for re m a in in g
pressure.
the high side using the same procedure as
used for the low side. (This condition
indicates a restriction on the high side.
Diagnose and correct before evacuating
and charging).
the hose fully-tightened down), measure
and record the amount. If 15 ml (.05 ounce)
or more, add this amount of new 525
viscosity refrigerant oil plus any quantity in
removed parts before evacuation and
charging with Refrigerant-12 (refer to CCOT
Refrigerant Oil Distribution for the quantity
of oil normally retained in removed parts).
suction hose at the accumulator outlet pipe
connection and pour the correct quantity of
refrigerant oil into the hose or pipe and then
reconnect hose or pipe. (Refer to step
1B-23
F-00030