Chevrolet 30 Series 1967 Service Manual page 45

system, a filter must be connected to the intake
fitting to prevent any sludge from contaminating the
working parts, which will result in malfunction of the
pump.
• Do not use the vacuum pump as an air compressor.
AVAILABILITY OF REFRIGERANT-12
Refrigerant-12 is available through Parts Stock in 25
lb. drums and in 15 oz. disposable cans.
available for the disposable cans, which may be used as
individual cans or as a group of up to four cans (fig. 44).
Tool J-6272 is used with one through four cans. The
use of the four-can fixture makes it possible to charge
the system with a known quantity of refrigerant without
the use of weighing equipment necessary with the larger
drum. The single can Valve J-6271 can be used for com­
pleting the charge and for miscellaneous operations such
as flushing. The valves are installed by piercing the top
seal of the cans.
Evacuating and charging procedures later in this se c­
tion will make use of the J-8393 Charging Station which
uses the 25 lb. drum of refrigerant.
COMPRESSOR OIL
Special refrigeration lubricant should be used in the
PRE-DELIVERY INSPECTION
1. Check that engine exhaust is suitably ventilated.
2. Check the belt for proper tension.
3. With controls positioned for operation of the system,
operate the unit for ten minutes at approximately
2000 rpm. Observe the clutch pulley bolt to see that
the compressor is operating at the same speed as
the clutch pulley. Any speed variation indicates
clutch slippage.
4. Before turning off the engine, check the sight glass
to see that the unit has a sufficient Refrigerant
charge. The glass should be clear, although during
milder weather it may show traces of bubbles.
in the flow indicates a low charge. No liquid visible
indicates no charge.
5. Check hose clamp connections. If clamp screw
torque is less than 10 lb. in., retighten to 20-25 lb.
in. Do not tighten to new hose specifications or hose
leakage may occur.
. If there is evidence of an oil leak, check the com­
6
pressor to see that the oil charge is satisfactory.
7. Check the system controls for proper operation.
6000 MILE INSPECTION
1. Check unit for any indication of a refrigerant leak.
2. If there is an indication of an oil leak, check the
compressor proper oil charge.
3. Check sight glass for proper charge of Refrigerant-
12
.
4. Tighten the compressor brace and support bolts and
check the belt tension.
5. Check hose clamp connections as in step 5 above.
. Check thermostatic switch setting (Custom and All-
6
Weather Systems.)
PERIODIC SERVICE
• Inspect condenser regularly to be sure that it is not
plugged with leaves or other foreign material.
• Check evaporator drain tubes regularly for dirt or
restrictions.
Valves are
INSPECTION AND
Foam
Leak test the complete system.
HEATER AND AIR CONDITIONING 1A-17
system. It is available in 1 quart graduated bottles
through Parts Stock. This oil is as free from moisture
and comtaminants as it is possible to attain by human
processes. This condition should be preserved by im ­
mediately capping the bottle when not in use.
See "Air Conditioning System Capacities" for the
total system oil capacity.
Due to the porosity of the refrigerant hoses and con­
nections, the system refrigerant level will show a definite
drop after a period of time. Since the compressor oil is
carried throughout the entire system mixed with the
refrigerant a low refrigerant level will cause a dangerous
lack of lubrication. Therefore the refrigerant charge in
the system has a definite tie-in with the amount of oil
found in the compressor and an insufficient charge may
eventually lead to an oil build-up in the evaporator.
COMPRESSOR SERIAL NUMBER
The compressor serial number is located on the serial
number plate on top of the compressor. The serial num­
ber consists of a series of numbers and letters. This
serial number should be referenced on all forms and
correspondence related to the servicing of this part.
PERIODIC SERVICE
• At least once a year, check the system for proper
refrigerant charge and the flexible hoses for brittle­
ness, wear or leaks.
• Every 6000 miles check sight glass for low refrig er­
ant level.
• Check belt tension regularly.
• Every week - during winter months or other periods
when the system is not being operated regularly - run
the system, set for maximum cooling, for 10 or 15
minutes to insure proper lubrication of seals and
moving parts.
INSTALLING GAUGE SET TO CHECK
SYSTEM OPERATION
The Four-season System high pressure gauge connec­
tion is located on the muffler. The low pressure con­
nection is located on the P.O.A. valve.
1. Install Gauge Adapter (J-5420 or J-9459) onto the
high and low pressure hoses of the gauge set.
2. With the engine stopped, remove the caps from the
cored valve gauge connector on the compressor
fittings block and P.O.A. valve.
3. Connect the gauge lines with adapters to the threaded
connector on the compressor fittings block and
P.O.A. Valve.
CAUTION:
When removing gauge lines from
the compressor fittings block be sure to remove
the adapters from the fittings rather than the"
gauge lines from the adapters.
PERFORMANCE TEST
This test may be conducted to determine if the system
is performing in a satisfactory manner and should be
used as a guide by the serviceman in diagnosing trouble
within the system. The following fixed conditions must be
adhered to in order to make it possible to compare the
performance of the system being tested with the stand­
ards below:
1. Doors and windows closed.
2. Hood up and engine exhaust suitably ventilated.
(Car inside or in shade.)
CHEVROLET TRUCK SERVICE MANUAL