Discharging The System; Refrigerant Oil Distribution - GMC G Service Manual

IB-26 AIR CONDITIONING

DISCHARGING THE SYSTEM

Before replacing any component, discharge the system.
. Discharge at the low side service fitting.
1
2. With the ignition turned OFF, remove the protective
cap from LOW SIDE service fitting and connect
Charging Station J 23500-01 Gage Set. (Refer to
figure 24.)
a. If Charging Station J 23500-01 is not being
used, discharge the system by slowly connect­
ing a gage hose to the low side service fitting on
the accumulator and discharge into a bottle
(figure 26).
b. As the hose is SLOWLY tightened down onto
the schrader valve, Refrigerant-12 will dis­
charge from the system into the container. If no
discharge occurs, check for missing, worn or
damaged schrader depressor in the hose fitting.
3. With the low side of the system discharged, check the
high side system fitting (on the liquid line or muffler)
for remaining pressure.
4. If pressure is found, attempt to discharge the high
side using the same procedure as used for the low
side. (This condition indicates a restriction on the high
side. Diagnose and correct before evacuating and
charging.)
5. After discharging (no vapor escaping with the hose
fully tightened down), measure and record the
amount of refrigerant oil. If 1.5 ml (0.05 ounce) or
more, add this amount of new 525 viscosity refriger­
ant oil plus any quantity in removed parts before
evacuation and charging with Refrigerant-12 (refer to
CCOT Refrigerant Oil Distribution for the quantity of
oil normally retained in removed parts).
. If adding oil is necessary, remove the suction hose at
6
the accumulator outlet pipe connection and pour the
correct quantity of refrigerant oil into the hose or pipe
and then reconnect the hose or pipe. (Refer to step
number 5 and Refrigerant Oil Distribution for specific
quantity instructions.)
Figure 26 — Discharging without Charging
Station J 23500-01

REFRIGERANT OIL DISTRIBUTION

• A COMPRESSOR — 295.7 ml (10 ounces) of 525
-6
viscosity refrigerant oil.
• R-4 COMPRESSOR 177.4 ml
oil during the following component replacement and
conditions:
1. With no excessive oil leakage:
• Compressor — Remove, drain oil, measure,
and replace the same amount of new oil plus
29.6 ml (1 ounce).
• Evaporator — Add 88.7 ml (3 ounces).
• Condenser — Add 29.6 ml
• Accumulator — R-4 Compressor — Remove,
drain oil, measure, replace the same amount of
new oil plus 59.1 ml (2 ounces) to compensate
for that retained by the original accumulator
desiccant.
• HR Compressor — Remove, drain oil, mea­
-6
sure, and replace same amount of new oil plus
103.5 ml (3.5 ounces) to compensate for that
retained by the original accumulator desiccant.
If no oil can be drained from old accumulator,
add 59.1 ml (2 ounces) new oil to the new
accumulator.
2. With signs of excessive oil leakage:
A COMPRESSOR
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Remove Compressor and Accumulator. Drain,
measure and record total oil from both compo­
nents. Use new oil.
• If less than 180 ml
ounces) of new oil to system.
(6
• If more than 180 ml
amount of new oil as drained.
• If a new accumulator is installed to A
add 59.1 ml (2 ounces) additional oil to compen­
sate for that held/absorbed by the original accu­
mulator desiccant.
HR COMPRESSOR
-6
Remove the accumulator. Drain, measure and
record quantity of oil in accumulator. It is not
necessary to remove and drain the HR
pressor because the compressor only retains a
minimum quantity of oil; it doesn't have an oil
sump area.
• If less than 88.7 ml (3 ounces), add 88.7 ml
(3 ounces) of new oil to the system.
• If more than 88.7 ml (3 ounces), add the same
amount of new oil as drained.
• If a new accumulator is installed, add 103.5 ml
(3.5 ounces) additional oil to compensate for
that absorbed by the original accumulator
desiccant.
R-4 COMPRESSOR
Remove the accumulator. Drain, measure and
record quantity of oil in accumulator. It is not
necessary to remove and drain the R-4 com­
pressor because the compressor only retains a
minimum quantity of oil.
ounces). Add new
(6
ounce).
(1
ounces), add 180 ml
(6
ounces), add the same
(6
system,
-6
com­
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