Pontiac tempest 1968 Service Manual page 35

1A-8 1967 PONTIAC SERVICE M A N U A L
not have a temperature exceeding 125°F. on scales,
place refrigerant drum In pan containing water,
note weight, and only open low pressure valve on
gauge set.
(2) Start engine, move temperature control
knob to full cold position, and place blower control
for high speed. Operate engine for ten minutes at
2000 rpm to stabilize system.
(3) With compressor operating, slowly open
valve on refrigerant drum and allow refrigerant to
flow into system (through manifold gauge set) until
liquid indicator clears up and immediately shut off
valve at gauge set or on refrigerant drum. Check
weight of refrigerant drum and pail of water. Then
slowly open valve on gauge set (or refrigerant
drum) and add one more pound of refrigerant. Note
total amount of refrigerant added.
b. Refrigerant-12 Disposable Can Method (15
oz. per can).
(1) Make sure the outlet valve on the J 6271
F i t z - A l l valve is fully clockwise and attach the
J 6271 to a "one pound" can of refrigerant as
follows: back off the valve from the top of the
retainer, slip the valve onto the can and turn the
valve into the retainer until tight. DO NOT ac­
cidentally open outlet valve during this operation
as turning the valve into the retainer punctures the
top of the can to make i t ready for charging.
(2) Connect center flexible line of gauge set
to the fitting on the valve.
(3) Start engine, move temperature control
knob to full cold position and blower control for
high speed A / C mode. Operate engine for ten
minutes at 2000 rpm to stabilize system.
(4) With compressor operating, slowly open
valve on refrigerant can and allow refrigerant to
flow into system (through manifold gauge set) until
liquid indicator clears up and immediately shut off
valve at gauge set and on refrigerant can. Check
weight of can and valve assembly and record.
(5) Add an additional one pound of refriger­
ant by adding refrigerant from the can just weighed
until can is empty. Attach another can and add
refrigerant until can and valve assembly weigh the
same as recorded,
6. Close valves at refrigerant drum or can.
7. Test for leaks and make operational check of
system as outlined under OPERATIONAL TEST.
CHECKING COMPRESSOR OIL LEVEL
AND ADDING OIL
The refrigeration system with the six-cylinder
axial compressor requires 11 fluid ozs. of 525
viscosity o i l . After the system has been operated,
o i l circulates throughout the system with the re­
frigerant. Hence, while the system is running, o i l
is leaving the compressor with the high pressure gas
and is returning to the compressor with the suction
gas.
To enhance return of o i l to the compressor, under
partially depleted refrigerant charge conditions on
the custom air conditioning system, an o i l bleed line
from the bottom of the evaporator to the suction line
at the P.O.A. valve has been provided. The core i n
the bleed line fitting at the P.O.A. valve has a special
low force spring i n i t which allows the core to open
a 5 to 12 psi pressure difference. It is important
that this core not be replaced with a standard t i r e
core.
NOTE: The oil level in the compressor should not
be checked as a matter of course, such as is done
in the car engine crankcase.
In general, the compressor o i l level should be
questioned only i n cases where there is evidence of
a major loss of system o i l such as:
a. Broken hose or severe hose fitting leak.
b. O i l sprayed i n large amounts under the hood
due to a badly leaking compressor seal(s).
c. Collision damage to refrigeration system
components.
REPLACING REFRIGERATION S Y S T E M COMPONENTS
OTHER THAN COMPRESSOR
When refrigerant system components other than
the compressor are replaced, the compressor must
also be removed and o i l drained from the compres­
sor. The amount of o i l to put back into the com­
pressor is found as follows: DO NOT add any more
o i l than is necessary, or maximum cooling w i l l be
reduced.
1. Remove the compressor and place i n a h o r i ­
zontal position with the compressor drain plug down­
ward, drain compressor i n an empty graduated
bottle, measure the amount of o i l and discard this
o i l .
2. If the quantity of o i l measured is more than 4
fluid ozs., replace into the compressor the same
amount of clean o i l as the o i l drained, plus the f o l ­
lowing amount for the refrigeration system com­
ponent being changed.
a. Evaporator- 3 fluid ozs.
b. Condenser-1 fluid oz,
c. Receiver-dehydrator assembly-1 fluid oz.