Hudson 1955 Rambler, Техническое и сервисное руководство

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ALL SEASON AIR CONDITIONING SYSTEM 23
check the system for a normal charge. Bubbles
of vapor passing through the sight glass would
indicate a low or short charge of refrigerant.
Allow the system to run for a period of 5
to 10 minutes to normalize before checking the
sight glass for vapor bubbles. Initially, some
vapor will be present, especially on an
extremely hot humid day.
In a correctly charged system, the liquid
level in the receiver covers the liquid outlet
tube to prevent hot gas from going to the
evaporator. The receiver is normally 50 to 60
per cent filled with liquid.
There is no actual way of determining how
much refrigerant is required if the sight
glass is checked and vapor bubbles are present.
Adding Refrigerant—Partial Charge
This operation is only performed when part of
the charge is lost through a leak.
Leak test (Refer to "Leak Test Procedure").
Correct conditions as required. If leak exists
at connection, tighten. If a part is at fault
and leaks, discharge, replace part, and
complete charge; follow "Complete Charge"
procedure.
Remove the cap from the discharge service
valve port fitting and install a gauge line,
tool J-5418, to the fitting and to the high
presure gauge fitting on the gauge manifold
set, tool J-5725. Remove the cap from the
suction service valve port fitting and install
a gauge line to the fitting and to the
compound gauge fitting on the gauge set.
Close the gauge hand valves to the center
gauge fitting. Install a gauge line to center
fitting on the gauge set.
Install gauge line to Freon drum. Check all
connections to see that they are tight (Fig.
27).
NOTE: An important rule to follow in
charging is that the refrigerant should
always be in a vapor state when added
to the "low" side. The Freon drum will
require the use of heat in order to
charge the refrigerant into the system
in a vaporous state. A bucket of hot
water, 125°F., is adequate. This will
cause the liquid to vaporize as it
leaves the drum. Hot rags wrapped
around the drum will also serve to
vaporize the refrigerant.
With the drum in the upright position, open
the drum valve slightly.
Open the gauge hand valves on the gauge set.
This will open the center charging line to
each charging line to the compressor.
Both service valves are to remain closed to
the gauge fittings. Loosen the flare nut
connections of the charging lines at the
service valves to purge air from the lines and
gauge set. These should only be cracked open
momentarily. Air will be purged or driven out
by the Freon vapor. Retighten the connections.
1. Compound Gauge
2. Pressure Gauge
3. Pressure Gauge Hand Valve, Closed Position
4. Gauge Line, Center Connection to Freon Drum
5. Suction Line, Evaporator to Compressor
6. Freon Drum, Upright Position
7. Discharge Line, Compressor to Condenser
8. Gauge Line, High Pressure Gauge to Discharge Service
Valve
9. Discharge Service Valve, "Cracked" Position
10. Suction Service Valve, "Cracked" Position
11. Gauge Line, Suction Service Valve to Compound Gauge
12. Compound Gauge Hand Valve,Open Position
FIGURE 27— Adding Partial Charge
of Refrigerant
Close the hand valve on the high pressure
gauge on the gauge set. This will close the
gauge to the center fitting. The gauge will
still record pressure on the high side when
the compressor is running with the charge
installed.
"Crack" both service valves.
The Freon drum valve has been "cracked"
slightly until this time. With the drum in
the upright position, open the valve com-
pletely.
Operate the engine and compressor at a
slow idle speed.
Observe the sight glass until a solid
liquid column appears. Then add approxi-
mately 1/2 pound additional refrigerant.
Close the drum valve.
Operate the engine for five minutes at
approximately 1500 to 1800 R.P.M.
Observe gauges, sight glass and entire