Condenser; Receiver Dehydrator - Pontiac FIREBIRD 1972 Service Manual

1 A-40 1972 PONTIAC SERVICE MANUAL
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T O CONDENSER
Fig. 1A-34 Typical Muffler and Compressor Fitting
A gauge fitting containing a check valve is in the discharge
passage to permit pressure gauge readings.
On F Series models the muffler and the compressor fitting
assembly are separate components with the muffler
located on the fender skirt. on X Series models a muffler
is unnecessary due to system design and only a fitting
assembly is used.
CONDENSER
The condenser is similar to the ordinary car radiator but
is designed to withstand much higher pressures. It is made
up of tubes which carry the refrigerant and cooling fins
which provide rapid transfer of heat. The condenser is
made completely of aluminum.
The condenser is located in front of the engine cooling
system radiator so that it receives a high volume of air
from the movement of the car and from the engine fan. Air
passing over the condenser cools the hot, high pressure
refrigerant gas causing it to condense into high pressure
liquid refrigerant.
RECEIVER DEHYDRATOR
The receiver-dehydrator (Fig. 1A-35) is mounted in the
area of the right side of the radiator support.
The purpose of the receiver part of this assembly is to
insure a solid column of liquid refrigerant to the expansion
valve at all times, when the system is properly charged.
The liquid indicator (many times referred to as a sight
glass) is in the refrigeration system as an aid to diagnosis.
The appearance of bubbles or foam beneath the sight glass
(liquid indicator) above 70°F. ambient indicates air or a
partial discharge of refrigerant in the system. A solid liq-
uid column as seen in the sight glass is difficult to tell from
one that has no refrigerant in the system at all. Two ways
to determine whether the system is properly charged or
empty are to feel the suction pipe in the P.O.A. valve or
to disconnect the compressor clutch while observing the
sight glass. If the system has the proper refrigerant charge,
the suction line at the P.O.A. valve will be cool. Also the
refrigerant column in the sight glass will be seen to col-
lapse soon after the clutch has been disconnected. Foam
may be noted in the sight glass below 70°F. even when the
system is free of air and properly charged. Details of this
condition are in the DIAGNOSIS section.
Liquid refrigerant from the condenser flows into the upper
portion of the receiver which contains a bag of desiccant
(moisture absorbing material). As the refrigerant flows
through an opening in the lower portion of the receiver,
it is also filtered through a mesh screen attached to a baffle
at the bottom of the receiver.
The desiccant in this assembly is to absorb any moisture
that might be present in the system after assembly. The
function of the screen is to trap any foreign material which
may enter the system during assembly. These features of
the assembly prevent obstruction to the valves or damage
to the compressor.
INLET
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DESICCANT
RECEIVER
DEHYDRATOR
ASSEMBLY
FILTER
SCREEN
Fig. 1A-35 Receiver Dehydrator Assembly
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Inside View