Chevrolet Light Duty Truck 1973 Service Manual page 70

1A-44 HEATER A N D AIR C O N D IT IO N IN G
to any system having a pressure higher than
indicated on refrigerant containers.
6. If inexperienced, seek professional assistance.
COMPRESSOR OIL
Special refrigeration lubricant should be used in the
system. This oil is as free from moisture and
contaminants as it is possible to attain by human
processes. This condition should be preserved by
immediately 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
connections, the system refrigerant level will show a
INSPECTION A N D
PRE-DELIVERY INSPECTION
1. Check that engine exhaust in suitably ventilated.
2. Check the belt for proper tension.
3. With controls positioned for operation of the
system, operate the unit for five 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 refrigerant
charge (see "Refrigerant Quick Check Procedure").
5. Check refrigerant hose connections:
" 0 " Ring Connections--
charted later in this section under "Refrigerant Line
Connections;" retorque if required. Leak test the
complete system.
6. If there is evidence of an oil leak, check the
compressor to see that the oil charge is satisfactory.
NOTE: A slight amount of oil leakage at the
compressor front seal is considered normal.
7. Check the system controls for proper operation.
6000 MILE INSPECTION
1. Check unit for any indication of a refrigerant leak.
EVACUATING A N D C HA RG IN G PROCEDURES
AIR CONDITIONING SYSTEM CAPACITY
See Capacity Chart on Page 1A-45.
INSTALLING CHARGING STATION
1. High and low pressure gauge line fittings are
provided in the air conditioning system for
attaching the Charging Station.
Check torque of fittings as
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
number 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 assembly.
PERIODIC SERVICE
2. If there is an indication of an oil leak, check the
compressor for proper oil charge.
NOTE: A slight amount of oil leakage at the
compressor front seal is considered normal.
3. Check refrigerant charge (see "R efrigerant Quick
Check Procedure").
4. Tighten the compressor brace and support bolts and
check the belt tension.
5. Check refrigerant hose connections as in Step 5 of
"Pre-Delivery Inspection."
PERIODIC SERVICE
• Inspect condenser regularly to be sure that the fins
are not plugged with leaves or other foreign
material.
• Check evaporator drain tubes regularly for dirt or
restrictions.
• At least once a year, check the system for proper
refrigerant charge and the flexible hoses for
brittleness, wear or leaks.
• Every 6000 miles check for low refrigerant level.
• Check belt tension regularly.
low pressure fitting is located on
C-K Models~The
the accumulator and the high pressure fitting on the
evaporator inlet line.
low pressure fitting is on the
G Models-The
compressor inlet line and the high pressure fitting
on the muffler.
Motor Home Chassis~The
low pressure fitting is on
LIGHT DUTY TRUCK SERVICE MANUAL