Opel 1900 1973 Service Manual page 552

4.
Start the vacuum pump and slowly open low and
high pressure sides of manifold gauge set to avoid
forcing oil out of refrigeration system and pump,
Pressure is now being reduced on both sides of the
refrigeration system. If oil is blown from the vacuum
pump, it should be refilled to the proper level.
5. Observe low pressure gauge and operate vacuum
pump until gauge shows 28-29 inches vacuum. In all
evacuating specifications of 28-29 inches
procedures,
of vacuum is used. This evacuation can only be at-
tained at or near sea level.
For each 1000 feet above
ion is being-performed, the specification should be
lowered by one inch of mercury vacuum. At 5000
feet elevation, only 23 inches to 24 inches of vacuum
can normally obtained.
b e
If vacuum cannot be pulled to the minimum specifi-
cation for the respective altitude, it indicates a leak
in the system or gauge connections or a defective
vacuum pump. In this case, it will be necessary to
check for leaks as described under "Leak Testing
Refrigerant System".
When specified vacuum level (28-29 inches at sea
level) is obtained, continue to run vacuum pump for
ten (10) 'additional minutes. During these ten (10)
minutes:
A. Prepare for charging the system. If using a charg-
ing station, till charging cylinder. If using manifold
gauge set, make all preparations for charging system
as described under "Disposable Can Method" or
"Refrigerant Drum Method".
B. Measure oil loss collected as a result of rapid
discharge.
C. Uncap compressor oil injector (J-24095) and open
valve. Flush J-24095 with refrigerant, close valve and
insert pick-up tube into graduated container of clean
refrigerant oil.
D. Con&ct J-24095 to suction fitting at the compres-
sor adapter fitting. When valve on J-24095 is opened,
the vacuum applied to the discharge side of the sys-
tem will suck oil into system from container. There-
fore, close observation of oil level in the container is
necessary.
E. Note level of oil in container. Open valve on J-
24095 u+il oil level in container is reduced by an
amount equal to that lost during discharge of system,
then shut valve. Take care not to add more oil than
was lost. ,,
F. Disconnect J-24095 and attach pick-up tube fit-
ting to schraeder fitting to cap tool. See Figure 9B-
42.
REFRIGERANT COMPONENTS ALL MODELS
sea level where this operat-
Figure 98.42 Oil Injector J-24095
6. Turn hand shut-off valves at low and high pressure
gauges of gauge set to full clockwise position with
vacuum pump operating, then stop pump. Carefully
check low pressure gauge approximately for two (2)
minutes to see that vacuum remains constant. If
vacuum reduces, it indicates a leak in the system or
gauge connections.
Charging the System
The system should be charged only after being eva-
Refrigerant orurn Method
1. Connect center flexible line of gauge set to refriger-
ant drum.
2. Place refrigerant drum in a pail of water which has
been heated to a maximum of 125 degrees F.
WARNING: Do not allow temperature of water to ex-
ceed I25 degrees E High temperature will cause
safety plugs in the refrigerant drum. It may not be
(over ap)roximateIy 100 lbs.).
3. Place refrigerant drum (in pail of water) on scales
(bathroom or commercial, perferably commercial).