Hudson 1955 Rambler, Техническое и сервисное руководство

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22 TECHNICAL SERVICE MANUAL
1. Compound Gauge
2. High Pressure Gauge
3. High Pressure Gauge Hand Valve, Open Position
4. Gauge Line, Center Connection, Open to Atmosphere
5. Suction Line, Evaporator to Compressor
6. Discharge Line, Compressor to Condenser
7. Gauge Line, High Pressure Gauge to Discharge Service
Valve
8. Discharge Service Valve, Closed Position
9. Suction Service Valve, "Cracked" Position
10. Gauge Line, Suction Service Valve to Compound
Pressure Gauge
11. Compound Pressure Gauge Hand Valve, Closed Position
FIGURE 26— Evacuation of Air
Conditioning System
Evacuation also dehydrates since it removes
most of the moisture bearing air.
After pumping a good vacuum for 10 to 15
minutes, close the hand valve on the high
pressure gauge on the gauge manifold set and
immediately shut the system off and stop the
engine. There should only be a brief interval
between these two operations.
Return the discharge service valve to the
"cracked" position by turning the valve out
two to three turns. Both the hand valves on
the gauge manifold set remain turned off.
At this time, the vacuum reading on the
compound gauge should remain constant; it
should read from 12" to 18" or better vacuum.
Let the system stand for about 10 to 15
minutes and if the vacuum remains constant,
the system is sealed from the atmosphere. If
the vacuum drops off, there is probably a
loose connection or leak in the system. Correct
by tightening or replacing the leaking part
and repeat the procedure.
Heat a Freon drum in a container of hot
water (125°) or with rags soaked in hot
water. Then attach the drum to the center
connection gauge line.
Loosen the gauge line fitting to the
center connection slightly. "Crack" the drum
valve, purging air from the gauge line with
Freon vapor. Tighten the gauge fitting and
close the drum valve.
Open the hand valve on the pressure gauge
side of the gauge manifold. With the drum
in the upright position, "crack" the drum
valve slightly to admit the vaporized Freon
gas from the top of the drum into the system.
Close the drum valve.
The internal pressure will record on both
gauges; this pressure should be approxi-
mately room temperature of 70° which gives
the equivalent pressure of 70 pounds.
The system should now be completely tested
for leaks (follow "Leak Test Procedure")
with a Halide Leak Detector, Tool 6084.
Eliminate any leaks present by tightening
connections and replacing leaky part and
repeat entire procedure up to this point.
The system may now be charged with
refrigerant following the procedure out-
lined in "Adding Refrigerant—Complete
Charge".
CHARGING THE SYSTEM
The normal charge of refrigerant for the
system is 4 pounds of Freon-12 in the
"Hornet" and "Wasp" Series, and 31/2 pounds
in the "Rambler" Series.
For every pound of Freon-12 in the system,
2 c.c. of Anhydrous Methanol is added to the
Freon-12. Moisture is not soluble with
Freon-12, but with the addition of Methanol
to lower the freezing point, the moisture
will pass through the system. Without
Methanol, moisture would freeze and block
the system particularly at the expansion
valve orifice where the high pressure liquid
is metered into a low pressure liquid.
This is the coldest point in the system.
Although the system is controlled to 32°F.,
it is entirely possible to go a few degrees
below before the temperature control ther-
mostat would cycle the system into the
by-pass circuit.
NOTE: Refer to "Moisture and Air" in
the system for additional information.
The Methanol is added to the compressor
crankcase at the oil filler plug prior to
evacuation in cases where it is not already
added to the Freon in the drum.
The check valve in the compressor crank-
case will prevent the Methanol and oil from
leaving the system. The Methanol will enter
the system in the same manner as the oil
when the system is in normal operation.
The sight glass provided in the liquid
line is used to check the system for a normal