Pontiac tempest 1968 Service Manual page 36

CUSTOM A I R C O N D I T I O N I N G
1A-9
Neglect any fluid o i l coating loss i n case of line
change
9
3
0
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 replacements.
4. Replace compressor and system components.
5. Evacuate, charge and perform operational test.
REMOVING AND INSTALLING COMPRESSOR
The compressor, when removed, must be closed
immediately. If the system has been or can be
operated for more than two minutes, circulation of
oil from compressor to other components of system
will require adjustment of the oil charge in the new
compressor as explained above, under REPLACING
COMPONENTS OTHER THAN COMPRESSOR.
After draining and measuring the oil from crank-
case and head of the compressor removed, amount
that has migrated to other parts of the system can
be determined by subtracting the amount drained
from the original oil charge of 11 fluid ozs. The
amount of oil equal to this loss shall be drained from
the new compressor before it is installed.
INSTALLING COMPRESSOR
After idling compressor (on car) to be replaced
for 10 minutes at 1500-2000 engine rpm, at maxi­
mum refrigeration and blower at high speed: DO
NOT add any more oil to the compressor than is
necessary or maximum cooling will be reduced.
1. Compressor replaced with new compressor.
a. Remove compressor and place in a hori­
zontal position with drain plug downward, drain
compressor, measure quantity of oil drained and
then discard it.
b. Drain oil from replacement compressor and
save it.
c. (1) If amount of oil drained in 'a' is more
than 4 ozs., place into the new compressor the
same amount of oil drained from the replaced
compressor.
(2) If amount of oil drained in 'a' is 4 ozs.
or less, place 6 ozs. of oil in the replacement
compressor.
d. Install compressor.
2. Compressor replaced with a field repaired
(overhauled) compressor.
a. Proceed as in section 1 above, and then add
one extra oz. of oil. (More oil is retained in a
drained compressor than one that has been rebuilt.)
REPLACING AN INOPERATIVE COMPRESOR
In the case when it is not possible to idle the com­
pressor to be replaced to effect oil return to it the
following will apply. DO NOT add any more oil than
is necessary or maximum cooling will be reduced.
1. Remove compressor from car, drain and mea­
sure the oil.
2. If amount drained in "1" above is more than
1-1/2 fluid ozs., subtract this amount drained from
the original oil charge of 11 ozs. to obtain "oil
loss". Take new compressor assembly and drain
from it the amount of ''oil loss" above; (provided
the refrigeration system shows no evidence of a
major leak, indicating that little or no oil has been
lost from the system. Minor leak indicating very
slow leakage.)
3. If the amount drained in "1" above is less than
1-1/2 ozs of oil and/or system appears to have lost
an excessive amount of oil then:
a. Disconnect the expansion valve outlet con­
nection (evaporator inlet).
b. Plug suction line connection at P.O.A. valve
outlet.
c. Disconnect oil bleed line at P.O.A. valve,
using care not to damage line.
d. Connect a cylinder of Refrigerant-12 regu­
lated to not exceed 125 psi to this oil bleed fitting
to force any retained oil from the evaporator out
the evaporator inlet fitting. (Reverse flush the
evaporator.) Catch any oil reverse flushed in this
manner. If oil flushed from the system appears
clean, install new compressor with 6-7 ounces
of oil.
4. If oil drained in "V above contains any
foreign material such as chips, or there is evidence
of moisture in the system, replace the receiver-
dehydrator assembly and flush all component parts,
or replace if necessary. After flushing refrigeration
system in this manner, the full oil charge should be
left in the new service compressor or 11 ozs. in­
stalled in an overhauled or repaired compressor.
COMPRESSOR REMOVAL
1. Connect the high and low pressure gauge lines
from the gauge set to the respective connections on
the P.O.A. valve and old compressor on the car. Be
sure valves on gauge set are fully clockwise to close
gauge set to center fitting, that a J 5420 or J 6163
Schrader adapter is between low pressure hose and