GMC 1976 ZEO 6083 Maintenance Manual page 99

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AIR CONDITIONING SYSTEM
3. Place Seal Protector J-22974 (figure 59) over
end of shaft and
carefully slide the new seal assembly
onto the shaft . Gently twist the tool CLOCKWISE, while
pushing the seal assembly down the shaft
until the seal
assembly engages the flats on the shaft and is seated
in place. Disengage the tool by pressing downward
and twisting tool counterclockwise .
4. Coat the seal face of the new seal seat with
clean 525 viscosity refrigerant oil. Mount the seal
seat on Seal Seat Remover-Installer J-23128 and in-
stall it in the compressor neck, taking care not to
dislodge the seal seat O-ring and being sure the seal
seat makes a good seal with the O-ring . Remove Seal
Protector J-22974 from the end of the shaft (See
figure 58).
5 . Install the new seal seat retainer ring
with its
flat side against the seal seat,
using Snap-Ring Pliers
J-5403 (#21). See Figure 57 . Use the sleeve from
Seal Seat Remover-Installer J-23128 (figure 58) to
press in on the seal seat retainer ring so that it snaps
into its groove.
6. Install Compressor Leak Test Fixture J-9625
on rear head of compressor and connect gage charg-
ing lines as shown for bench test in Figure 61 or
pressurize SUCTION SIDE of compressor on car
with Refrigerant-12 vapor to equalize pressure to the
drum pressure . Temporarily install the shaft nut and,
with compressor in horizontal position and oil sump
down, rotate the compressor shaft in normal direc-
tion of rotation several times by hand . Leak test the
seal with an electronic-type Leak Detector . Correct
any leak found. Remove and discard the shaft nut.
7. Remove any excess oil, resulting from install-
ing the new seal parts, from the shaft and inside the
compressor neck .
8. Install the new absorbent sleeve by rolling the
material into a cylinder, overlapping the ends, and
then slipping the sleeve into the compressor neck
with the overlap towards the top of the compressor .
Figure 61-Leak Testing Compressor
With a small screwdriver or similar instrument, care-
fully spread the sleeve until the ends of the sleeve
butt at the top vertical centerline .
9. Position the new metal sleeve retainer so that
its flange face will be against the front end of the
sleeve . Pulley Puller Pilot J-9395 (See figure 50) may
be used to install the retainer . Press and tap with a
mallet, setting the retainer and sleeve into place (re-
tainer should be recessed approximately 1/32" from
the face of the compressor neck). (See figure 60).
10 . Reinstall the clutch plate and hub assembly
as described in "Compressor Clutch Plate and Hub
Assembly" Replacement procedure.
Some compressor shaft seal leaks may be the result of
mispositioning of the axial plate on the compressor shaft.
The mispositioning of the axial plate may be caused
by improper procedures used during pulley and
driven plate removal, pounding, collisions or drop-
ping the compressor . If the axial plate is misposi-
tioned, the carbon face of the shaft seal assembly may
not contact the seal seat and the rear thrust races and
bearing may be damaged.
If there appears to be too much or insufficient air
gap between the drive and driven plates, dislocation
of the shaft should be suspected. If the carbon seal
is not seating against the seal seat, it will not be
possible to completely evacuate the system as ou-
tlined under "Evacuating the Refrigeration System" .
To check for proper positioning of the axial plate
on the shaft, remove the clutch driven plate and
measure the distance between the front head exten
sion and the flat shoulder on the shaft as shown in
Figure 60 . To measure this distance, use a wire gage
(the clearance should be between .026" and .075").
If the
shaft has been pushed back in the axial plate (meas-
urement greater than .075"), disassemble the com-
pressor and replace the shaft and axial plate
assembly rear thrust races and thrust bearing.
11 . Evacuate and charge system as outlined un-
der "Evacuating and Charging the Refrigeration
System" .
COMPRESSOR PRESSURE RELIEF
VALVE
When necessary to replace the pressure relief
valve, located in the compressor rear head casting,
the valve assembly should be removed after PURG-
ING THE SYSTEM OF REFRIGERANT and a
new valve and gasket installed . The entire system
should then be "Evacuated and Recharged" . (figure
62).