Ford Corsar Repair Manual page 786

DISCHARGING, EVACUATING, CHARGING AND CHECKING
Charging
-[Point-51
(Cont'd)
Cycling clutch systems will produce bubbles in sight glass
when clutch engages. Therefore, allow 5 seconds after clutch
engages to determine if bubbles continue, and, if so, add
refrigerant to clear sight glass.
WARNING:
Never charge refrigerant through high-pressure side (dis-
charge side) of system since this will force refrigerant back
into refrigerant can and can may explode.
4. Charge refrigerant while controlling low-pressure gauge
reading at 275 kPa (2.75 bar, 2.8 kg/cm2, 40 psi) or less by
turning in or out low-pressure valve of manifold gauge.
a
Be sure to purge air from charging hose when replacing
can with a new one.
5. Charge the specified amount of refrigerant into system by
weighing charged refrigerant with scale. Overcharging will
cause discharge pressure to rise.
Refrigerant amount:
0.8
-
0.9 kg (1.8
-
2.0 Ib)
The state of the bubbles in sight glass should only be used
for checking whether the amount of charged refrigerant is
small or not. The amount of charged refrigerant can be
correctly judged by means of discharge pressure.
6. After charging, be sure to install valve cap on service valve.
7. Confirm that there are no leaks in system by checking with
a leak detector.
a
When refrigerant charging is performed with a charging
cylinder, charging station, or automatic charging equipment,
engine off, charge only through high side, after specified
refrigerant amount has entered the system, close high
pressure valve on gauge set. Start engine return to idle
speed, operate AIC at maximum temperature setting, high
blower. Observe sight glass to confirm complete charge.
Overcharging will result in increased high pressures, and
reduced performance.