Jeep 1996 Grand Cherokee Service Manual - page 1399
above. Lower ambient temperatures, below approxi-
mately -1°C (30°F) during cold weather will also open
the switch contacts. This is due to the pressure/tem-
perature relationship of the refrigerant in the sys-
tem.
The low pressure cycling clutch switch is a factory-
calibrated unit. It cannot be adjusted or otherwise
repaired. If faulty, the switch must be replaced.
REFRIGERANT
The R-134a refrigerant used in this air condition-
ing system is a non-toxic, non-flammable, clear, and
colorless liquefied gas. R-134a refrigerant is not com-
patible with R-12 refrigerant in an air conditioning
system. Even a small amount of R-12, added to a
R-134a refrigerant system, will cause compressor
failure, refrigerant oil sludge, or poor air conditioning
system performance.
The refrigerant system service ports have been
designed to ensure that the system is not acciden-
tally filled with the wrong refrigerant (R-12).
REFRIGERANT LINE COUPLERS
Spring locking couplers are used to connect refrig-
erant lines and other components to the refrigerant
system. The coupling is held together by a garter
spring inside a circular cage.
When the coupling halves are connected, the flared
end of the female fitting slips behind the garter
spring inside the cage of the male fitting. The garter
spring and cage prevent the flared end of the female
fitting from pulling out of the cage. Secondary clips
are installed over the coupling at the factory for
added blow-off protection.
O-rings are used to seal the coupling. These
O-rings are compatible with R-134a refrigerant and
must be replaced with O-rings made of the same
material.
REFRIGERANT LINES
The refrigerant lines are used to carry the refrig-
erant between the various air conditioning system
components. A barrier hose design is used for the air
conditioning system on this vehicle. The ends of the
refrigerant hoses are made from lightweight alumi-
num, and use braze-less fittings. The refrigerant
lines and hoses cannot be repaired and, if faulty,
must be replaced.
REFRIGERANT OIL
The oil used in the 10PA17 compressor is a poly-
alkylene glycol, synthetic (ND8 PAG), wax-free refrig-
erant oil. Use only refrigerant oil of the same type to
service the system. Refrigerant oil will absorb any
moisture it comes in contact with, even moisture in
the air. The oil container should be kept tightly
capped until it is ready to be used. Then, cap the oil
immediately after using, to prevent contamination.
REFRIGERANT SYSTEM SERVICE EQUIPMENT
WARNING: EYE PROTECTION MUST BE WORN
WHEN SERVICING AN AIR CONDITIONING REFRIG-
ERANT SYSTEM. TURN OFF (ROTATE CLOCKWISE)
ALL VALVES ON THE EQUIPMENT BEING USED,
BEFORE PROCEEDING WITH THIS OPERATION.
FAILURE TO OBSERVE THESE WARNINGS MAY
RESULT IN PERSONAL INJURY.
When servicing the air conditioning system, a
refrigerant charging station and a recovery/recycling
device for R-134a must be used. This device must
meet SAE Standard J2210. Contact an automotive
service equipment supplier for refrigerant charging
and recycling/recovering equipment. Refer to the
operating instructions provided with the equipment
for proper operation.
A manifold gauge set may be needed with some
charging and/or recovery/recycling devices (Fig. 5).
The service hoses on the gauge set being used should
have manual (turn wheel), or automatic, back-flow
valves at the service port connector ends. This will
prevent refrigerant from being released into the
atmosphere.
MANIFOLD GAUGE SET CONNECTIONS
CAUTION: Do not use an R-12 manifold gauge set
on an R-134a system. The refrigerants are not com-
patible and system damage will result.
Fig. 5 Manifold Gauge Set
24 - 8
HEATING AND AIR CONDITIONING
ZJ
DESCRIPTION AND OPERATION (Continued)