Charging The System; Refrigerant Drum Method - Pontiac Grand Prix Service Manual

1A-4 1969 PONTIAC SERVICE MANUAL
vacuum cannot be pulled to the minimum specification
for the respective altitude, it indicates a leak in the
system, gauge connections or a defective vacuum
pump. In thls case, it will be necessary to check for
leaks as outlined below, after a small amount of
Refrigerant-12 has been added to the low side of the
system.
a. Turn hand shut-off valves at the low and high
pressure gauge of the gauge set to full clockwise
position with the vacuum pump operating, then stop
pump-
b. Connect flexible line from center fitting of the
gauge set to refrigerant drum (drum should be at room
temperature).
NOTE: It may be necessary to use reducer J
5462-4
with washer J 5462-9 to attach flexible hose to refrigerant
drum.
c. Open shut-off valve on drum and loosen flexible line
fitting at center fitting at gauge set so that refrigerant will
purge all air from line. Tighten flexible fitting when
certain all air has been purged from line.
d. Open suction valve on gauge set. This will allow
refrigerant to pass from the drum into the system.
When pressure stops rising, close suction valve on
gauge set and valve at refrigerant drum (as refrigerant
drum is at room temperature, only a small refrigerant
charge will enter the system).
e. Using leak detector J 6084, check all fittings in the
system, compressor shaft seal and on gauge set for
evidence of leakage. When general area of leak has
been found with the test torch, a liquid leak detector
may be helpful in locating the exact point of leakage.
After leak has been corrected, evacuate the system
again.
6. Turn the hand shutt-off valves at the low and high
pressure gauge of the gauge set to the full clockwise
position with the vacuum pump operating, then stop
pump. Carefully check low pressure gauge to see that
vacuum remains constant. If vacuum reduces, it
indicates a leak in the system or gauge connections.
See NOTE in step 5 above for method of locating leak.
CHARGING THE SYSTEM
The system should be charged only after being
evacuated as outlined in EVACUATING THE SYS-
TEM.
REFRIGERANT DRUM METHOD
1. Connect center flexible line of gauge set to
refrigerant drum.
NOTE: It may be necessary to use reducer J
5462-4
kith washer J 5462-3 and fitting J 5462-9 to attach flexible
line to refrigerant drum.
2. Place refrigerant drum in a pail of water which has
been heated to a maximum of 125OF.
CAUTIQN: Do not allow temperature of water to
exceed I2PF. High temperature will cause excessive
pressure and possible softening of fusible safety plugs in
the refrigerant drum. It may not be necessary to use hot
water i f a large drum is used (over approximately 100
lbs.).
3. Place refrigerant drum (in pail of water) on scales
(bathroom or commercial, preferably commercial),
Fig. 1A-3.
CAUTION: Do not turn refrigerant drum upside down
as this would allow liquid refrigerant to ent-er compressor
which may cause damage.
4. If line at center gauge fitting has not been purged of
air, loosen line at center fitting on gauge set and crack
valve on refrigerant drum to blow air from line.
Retighten line at center fitting and record exact peight
of refrigerant tank in water on the scales.
5. Open valve on refrigerant drum and both valves on
gauge set to allow refrigerant to now into system.
Continue charging until the scales show that 4 1/8
pounds of refrigerant have been transferred from
refrigerant drum to system for Pontiac or Tempest.
THE FREON CHARGE FOR THE FIREBIRD
CUSTOM AIR CONDITIONING SYSTEM IS 3 3/4
LBS.
NOTE: If full charge cannot be obtained, close both
valves on gauge set, start engine, and turn temperature
control knob to fill cold position with NORMAL or A/C
button depressed. Open low pressure valve on gauge set
slowly and leave open untilfull charge is added.
CA UTION: Observe high pressure gauge while charging
with compressor running. Shut off engine i f pressure
exceeds
375
psi. A large fan placed in front of the car
will help reduce excessively high headpressure.
6. Close both valves on gauge set (high pressure valve
will already be closed if charging was completed by
running compressor) and close valve on refrigerant
drum.
NOTE: If the engine was used to complete the
Refrigerant-I d ~ r g e into the system, close valve on
refrigerant drum to permit compressor to draw any
refrigerant lefi in the line from the drum to the center
filling of the gauge set, then close the low pressure valve
on the gauge set.
7. Operate engine at 2000 rpm with temperature
control knob at full cold position and blower control
for high speed with NORMAL or A/C button
depressed. After ten miliutes of operation, observe
appearance of refrigerant in receiver-dehydrator. If