Pontiac FIREBIRD 1972 Service Manual page 115

1A-56 1972 PONTIAC SERVICE MANUAL
a. Evaporator-3 fluid ozs.
b. Condenser-1 fluid oz.
c. Receiver dehydrator assembly- 1 fluid oz.
Neglect any fluid oil coating loss in case of line
change.
3. If the oil quantity drained from the compressor is less
than 4 ozs., replace into the compressor 6 fluid ozs.
of clean oil, plus the amount shown above for the
respective component replacement.
4. Replace compressor and system components.
5. Evacuate, charge and perform operational test.
COLLISION SERVICE
The severity and circumstances of the collision will deter-
mine the extent of repair required. Good judgment must
be used in deciding what steps are necessary to put the
system back into operation.
Each part of the system must be carefully inspected. No
attempt should be made to straighten kinked tubes or
repair any bent or broken units. Check especially for
cracks at soldered connections.
REFRIGERANT SYSTEM OPEN TO ATMOSPHERE
Broken tubes or units will allow air, moisture and dirt to
enter. These parts should be sealed as soon as possible
until such time as they are replaced.
If the system is open for more than 15 or 20 minutes
(depending on humidity), the receiver-dehydrator assem-
bly will absorb an excessive amount of moisture and
should be replaced, and each component of the system
should be cleaned with dry nitrogen and flushed with
liquid refrigerant to remove dirt and moisture.
1. Remove and cap openings in P.O.A. valve, expansion
valve, compressor and receiver dehydrator.
2. Flush P.O.A. valve to compressor hose (includes
compressor fitting) and cap openings.
3. Flush evaporator core and cap openings.
4. Flush compressor to condenser hose (includes muf-
fler and compressor fitting), condenser and con-
denser to receiver hose as an assembly. Cap openings.
5. Flush receiver to expansion valve hose and cap open-
ings.
6. Flush P.O.A. valve, expansion valve and compressor
and install in system.
7. Discard receiver dehydrator and replace with new
part. Add one ounce of refrigerant oil to new receiver
and install in system.
FLUSHING SYSTEM
Flushing can be accomplished by connecting a refrigerant
drum to the unit to be flushed and then turning thedrum
upside down and opening the drum shut-off valve to pour
refrigerant through the unit in reverse direction of normal
system flow. The unit should be supported so that the
refrigerant passing through it will be directed into an area
where -2 1.7"F. will do no damage. (Remember that when
liquid refrigerant is poured from the drum into an area
where atmospheric pressure exists, its temperature will
immediately drop to -2 1.7"F.)
In order to keep the expansion valve open when flushing
the evaporator, the expansion valve bulb must be detached
from the evaporator outlet tube.
INSPECTING COMPRESSOR
If there is no visible evidence of damage, rotate compres-
sor shaft to test for normal reaction. A quick check for
broken reed valves is to turn compressor shaft (using box
end wrench on compressor shaft nut) and check for resist-
ance when turning the shaft. An irregular resistance force
will be felt as each of the pistons goes over top center for
each revolution of the crankshaft. If this pattern is not felt,
it indicates one or more broken compressor reed valves
and the compressor must be repaired.
Inspect oil for foreign material which would indicate in-
ternal damage to the compressor. If no foreign matter is
found in oil, compressor can be used. Flush entire refriger-
ation system with refrigerant, drain oil from compressor
and pour in 11 oz. avoirdupois of new 525 viscosity oil.
REFRIGERANT HOSE ASSEMBLIES
REPAIR
The refrigerant hoses used in the refrigeration system
(Figs. 1A-49 thru 1A-53A) are not serviced in complete
assemblies. These hoses are repaired using a minimum
number of hose fitting packages, hose clamps, O-ring seals
and bulk hose as follows:
.
1. Depressurize system if necessary.
2. Remove defective hose assembly if removal is neces-
sary to.repair hose and cap all openings.
3. Consult parts book for available fitting packages and
hose repair parts and repair hose assemblies observ-
ing the folloiwng precautions: