GMC 1989 Light Duty Truck, Repair Manual, Page: 56 / 998

1B2-12 V5 AIR CONDITIONING COMPRESSOR
2. Gasket (42) (figure 27).
• Place the elongated hole in the gasket over the
rod at the upper left position.
3. Rear valve plate (41).
• Place the elongated hole in the valve plate over
the rod at the upper left position.
4. Suction reed plate (40).
• Place the elongated hole in the plate over the
rod at the upper left position.
• Remove J 34993 C ylinder Alignm ent Rod from
the hole at the 5 o ’clock position.
5. Seals (39 and 37) to the shaft and cylinder body (38)
grooves.
• Dip the seals into 525 viscosity refrigerant oil.
6. Shaft and cylinder body (38) to the rear head (43).
• Locate the relief boss at the rod in the hole at the
upper left position.
7. Bearing (35) and thrust washers (36) in the same
order as removed.
8. Shim (34).
9. Front head (33).
• Locate the relief boss at the pin in the hole at the
upper left position.
• Remove J 34993 C ylinder Alignm ent Rod from
the hole at the upper left position.
10. Through bolts (31) and new gaskets (32).
$
Tighten
• Bolts (31) alternately to 9 N m (80 in. lbs.
11. Refrigerant oil to the compressor.
12. Test plate J 9625-A
• Leak test. Refer to “ Leak T estin g.”
LEAK TESTING
Tools Required:
J 9625-A Pressure Test Plate
J 23500-01 Portable C harging Station
J 34992 Com pressor Holding Fixture
• Be sure the com pressor has no oil internally.
1. Install J 9625-A on the rear head of the compressor.
2. Install the center hose of the m anifold gage set on J
23500-01 to refrigerant drum standing in an upright
position and open the valve on the drum.
3. Install the charging station high and low pressure
lines to the corresponding fittings on J 9625-A using
gage adapters or hoses equipped with valve depre­
ssors. The suction port (low side) of the com pressor
has a large internal opening. The discharge port (high
side) has a sm aller internal opening into the com pres­
sor.
• Open the low pressure control, high pressure control
and the refrigerant control on the charging station to
allow the refrigerant vapor to flow into the com pres­
sor.
Important
• Check for leaks at the pressure relief valve (2),
com pressor front and rear head seals (37) (39),
through bolt head gaskets (32) and compressor
shaft seal (29).
After the leak check, shut off the low pressure control
and the high pressure control on charging station.
If an external leak is present, perform the necessary
correction and recheck for leaks.
Loosen the manifold gage hose connections to the
gage adapters connected to the low and high sides
and allow the vapor pressure to release from the com ­
pressor. If valve depressor type hoses are used,
loosen the hose connections at the gage manifold to
release the vapor pressure from the compressor.
Disconnect both gage adapters or hoses from J 9625-
A.
Add 85 g (3 oz.) new 525 viscosity refrigerant oil to the
com pressor assem bly. Rotate the com plete com ­
pressor assem bly (not the shaft or drive plate hub)
slowly several turns to distribute oil to all cylinder and
piston areas.
Install the shaft nut (21) on the com pressor shaft if the
pulley assem bly and clutch plate and hub assem bly
are not installed.
Using a box-end wrench, or a socket and handle,
rotate the com pressor shaft several turns to lubricate
the pistons and cylinder walls.
Connect the charging station high-pressure line, or a
high-pressure gage and gage adapter to J 9625-A
high-side connector.
Attach an adapter or depressor-type hose to the suc­
tion or low-pressure port of J 9625-A to open the Sch-
rader-type valve. Oil will drain out of the com pressor
suction port adapter if the com pressor is positioned
with the suction port downward.
Attach the com pressor to J 34992 fixture and mount
the com pressor in a vise so that the com pressor will
be in a horizontal position and the shaft can be turned
with a wrench.
Rotate the com pressor shaft or drive plate hub six to
eight com plete revolutions at a speed of approxi­
mately one revolution per second. A slower rotation
can result in a lower pum p-up pressure and disqualify
a good pum ping compressor.
Observe the reading on the high-pressure gage at the
completion of the tenth revolution of the com pressor
shaft. The pressure reading for a good pum ping com ­
pressor should be 690 kPa (100 psi) or above. A pres­
sure reading of less than 620 kPa (90 psi) would
indicate one or more suction and/or discharge valves
leaking, an internal leak, or an inoperative valve. Dis­
assemble the com pressor and repair as necessary.
Reassemble and repeat the pum p-up test.
Following the pressure pum p-up test, release the air
pressure from the high side and remove the gage
adapters and J 9625-A test plate.
Tilt the com pressor to place the suction and dis­
charge ports downward to allow oil to drain from the
compressor.
Allow a 10-minute drain period and then charge the
com pressor with the proper amount of oil. Pour the
new 525 viscosity refrigerant oil into the suction port.
If further assem bly or processing is required, install a
shipping plate or test plate J 9625-A to protect the
com pressor from contam ination.