Chevrolet 1980 Light Duty Truck Repair Manual page 49

10. Install a shaft nut on the com pressor crankshaft if
the drive plate and clutch assembly are not installed.
11. U sing a box-end wrench or socket and handle,
rotate the com pressor crankshaft or clutch drive plate on
the crankshaft several turns to ensure piston assembly to
cylinder wall lubrication.
12. C onnect the Charging Station H IG H pressure line
or a H IG H pressure gage and G age Adapater J-5420 to the
Test Plate J-9625 H IG H side connector. 13. A ttach on
Adapter J-5420 to the suction or LOW pressure port o f the
Test Plate J-9625 to open the schrader-type valve.
NOTICE:
Oil will drain out o f the com pressor suction
port adapter if the com pressor is positioned w ith the
suction port downward.
14. A ttach the com pressor to the H olding Fixture J-
25008-1 (R -4 compressor), and J-9396 (A -6 com pressor),
and clam p the H olding Fixture in a vise so that the
com pressor can be m anually turned with a wrench.
15. U sing a wrench, rotate the com pressor crankshaft
or drive plate hub 10-com plete revolutions at a speed o f
approxim ately one-revolution per second.
NOTICE:
Turning the com pressor at less than one-
revolution per second can result in a lower pump-up
pressure and disqualify a good pum ping compressor.
AIR CONDITIONING COMPRESSOR OVERHAUL ID -4 3
16. Observe the reading on H IG H pressure gage at the
com pletion o f the tenth revolution o f the compressor. The
pressure reading for a good pum ping com pressor should be
50 psi or above for the R -4 and 60 psi or above for the A -6
compressor. A pressure reading o f less than 45 psi for the
R -4 or 50 psi for the A -6 w ould indicate one or m ore suction
an d /or discharge valves leaking, an internal leak, or an
inoperative valve
disassembled and checked for cause o f leak. Repair as
needed, reassemble and repeat the pum p-up test. Externally
leak t e s t .
17. W hen the pressure pump-up test is com pleted,
release the air pressure from the H IG H side and remove the
Gage Adapters J-5420 and Test Plate J-9625.
18. On the R -4 com pressor, tilt the com pressor so that
the com pressor suction and discharge ports are down. Drain
the oil from the com pressor. On the A -6 compressor,
rem ove oil charge screw and drain the oil sump.
19. A llow the com pressor to drain for 10 minutes, then
charge with the proper am ount o f oil. The oil may be poured
into the suction port.
NOTICE:
If further assem bly or processing is required,
a shipping plate or Test Plate J-9625 should be installed
to keep out air, dirt and moisture until the compressor
is installed.
and the com pressor should be