Service Valves (Air Conditioning) - Jeep 1979 CJ-5 Technical & Service Manual

erant 12 OR R-12. It is transparent and colorless in both
the- liquid and vapor state. Since it has a boiling point of
21.7°F below zero at atmospheric pressure, it vaporizes
at all normal temperatures and pressures. The vapor is
heavier than air, nonflammable and nonexplosive. It is
nonpoisonous except when in direct contact with open
flame, and is noncorrosive except when combined with
water. Observe the following precautions when handling
R-12.
R-12 evaporates so rapidly at normal atmospheric
pressures and temperatures that it tends to freeze any-
thing it contacts. For this reason, extreme care must be
taken to prevent any liquid refrigerant from contacting
the skin and especially the eyes.
WARNING: Always wear safety goggles when serv-
icing the refrigeration part of the air conditioning sys-
tem. Keep a bottle of sterile mineral oil and a weak
solution of boric acid handy when working on the refrig-
eration system. Should any liquid refrigerant get into
the eyes, use a few drops of mineral oil to wash them out
(R-12 is rapidly absorbed by oil). Next, wash the eyes
with the weak solution of boric acid. Call a doctor imme-
diately, even though irritation has ceased after the first
aid treatment
WARNING: Do not heat R-12 above 125 °F.
In most instances, moderate heat is required to bring
the pressure of the refrigerant in its container above the
pressure of the system when charging or adding refrig-
erant. A bucket or large pan of hot water not over 125 °F
is all the heat required for this purpose. Do not heat the
refrigerant container with a blowtorch or any other
means that would raise temperature and pressure above
this temperature. Do not weld, steam clean or heat the
system components or refrigerant lines.
K E E P
R - 1 2 C O N T A I N E R S U P R I G H T
w h e n
charging the system, so as to utilize the vapor instead
of the liquid.
When metering R-12 into the refrigeration system,
keep the supply tank or cans in an upright position. If
the refrigerant container is on its side or upside down,
liquid referigerant will enter the system and damage the
compressor.
WARNING: Always work in a well-ventilated area.
Always maintain good ventilation in the working
area. Always discharge the refrigerant into the service
bay exhaust system or outside the building. Large quan-
tities of refrigerant vapor in a small, poorly ventilated
room can displace the air and cause suffocation.
Although R-12 vapor is normally nonpoisonous, it can
be changed into a very poisonous gas if allowed to come
in contact with an open flame. Do not discharge large
quantities of refrigerant in an area having an open
flame. A poisonous gas is produced when using the ha-
lide torch leak detector. Avoid inhaling the fumes from
the leak detector.
CAUTION: Do not allow liquid refrigerant to touch
bright metal.
Refrigerant will tarnish bright metal and chrome sur-
faces. Avoid splashing refrigerant on any surface. Re-
frigerant in combination with moisture is very corrosive
and can cause great damage to all metal surfaces.
SERVICE VALVES
The discharge and suction service valves are mounted
on the compressor cylinder head and are used for diag-
nosis, charging, discharging, evacuating, and component
removal.
The service valves are three-position valves (fig. 3E-2).
The normal operating position, shown in figure 3E-2,
View B, has the valve stem turned counterclockwise to
the back-seated (full-out) position.
- When the valve stem is turned clockwise to the front-
seated (full-in) position (fig. 3E-2, View A), the com-
pressor is isolated from the system. This position is used
when removing the compressor or when checking com-
pressor oil level.
1 - TO SERVICE PORT
2 - T O HOSE
3 - T O COMPRESSOR
V I E W C - MiDiPOSlTIONEP A J 4 1 4 8 3
ig. 31-2 Ssriici Mm Operating Pislilais