Major R-4 Compressor Repair Procedures; R-4 C O M P R E S S O R S H A F T S Eal; Seal Leak Detection - GMC 1982 Light Duty Truck Service Manual

1C 1-10 AIR C O N D ITIO N IN G COMPRESSOR O VERHAUL
6. Inspect the drive surfaces of the Rotor and Drive Plate to be
sure they are still in good condition. Replace as required.
7. Assemble a new Pulley Rim over the Clutch Coil and mount
the Pulley Rim to the Rotor and Bearing assembly, using the
short notch mounting locations, Figure 1C 1-24. The
mounting notches are located 120° apart radially around the
Pulley Rim.
8. Assemble three (3) new lockwashers on the three (3) new
6.4mm-28 x 13.5mm (1/4-28 X 5/16") mounting screws and
apply Loctite 601 (or equivalent sealer) to the entire thread
surface of the mounting screws and the mounting hole
threads in the Rotor. Assemble the three (3) screws into the
short notch mounting hole locations and tighten finger tight.
9. Align the Pulley Rim so that the bottom of the rim notches
touch the mounting screws at all three (3) mounting
locations. Also center the drilled holes in the Pulley Rim with
the remaining mounting holes in the Rotor. When the rim
is positioned properly, tighten the three (3) mounting screws
to 11 N-m (100 in. lbs.) torque.
10. Temporarily make a trial fit of the Inertia Ring to the Pulley
Rim. If any portion of the sheer edge of the Pulley Rim
prevents the installation of the Inertia Ring, the raised edge
may be filed off to remove the excess metal and facilitate
installation. Do not use undue force or cock the ring in
assembling the Inertia Ring in place over the Pulley Rim that
could cause ring distortion or stress.
11. Assemble the Inertia Ring onto the Pulley Rim being careful
to align the Inertia Ring mounting holes with the mounting
holes in the Pulley Rim. If the Inertia Ring cannot be moved
by hand and must be rotated for centering the mounting
holes, use a drift punch or blunt tool and a hammer to
carefully tap at one of the large clearance notches in the
inertia ring to rotate the ring into position, Fig. 1C 1-25.
12. Install the special lock washers onto the 13mm-28 x 13.5mm
(1/4-28 X 17/32") mounting screws and apply Loctite 601
(or equivalent sealer) to the total screw thread and the threads
of the mounting holes in the rotor.
13. Install the screw and washers into the rotor mounting holes
and tighten finger tight. When all screws are in place, torque
each screw to 11 N*m (100 in. lbs.) torque.
14. Using Rotor and Bearing assembly Installer J-26271 and
Universal Handle J-8092, install the Pulley, Clutch Coil,
Rotor and Bearing assembly onto the Front Head of the
compressor. Be sure to locate the clutch coil terminals in the
proper position.
15. Spin the Rotor and Pulley assembly to asure that the pulley
runs "in line." If not, the mounting screws will have to be
loosened and the parts aligned.
16. When all screws are torqued in place, lock all mounting
screws in position by flattening the special washer against two
opposite sides of the hex head screw, using vise-grip pliers.
Form a portion of the lock washer down over the pulley rim
or over the Inertia Ring slot to secure the screws in place.
Do not move the screw heads from the torqued position. See
Fig. 1C1-25.
17. Install the Clutch Hub and Drive Plate as described in "R-4
Compressor Clutch Plate and Hub Asm." Replacement
procedures.
18. Install the compressor drive belt and adjust for proper
tension.
19. Operate the air conditioning system to check for proper
operation.
MAJOR REPAIR PROCEDURES. R-4
COMPRESSOR
Service repair procedures to the Compressor Shaft Seal,
Pressure Relief Valve, or disassembly of the Internal
Compressor Cylinder and Shaft Assembly are considered
"MAJOR" SINCE THE REFRIGERATION SYSTEM MUST BE
COMPLETELY PURGED OF REFRIGERANT before proceeding
and/or because major internal operating and sealing
components of the compressor are being disassembled and
serviced.
When replacing the shaft seal assembly (see Fig. 1C1-28) or
pressure relief valve (see Fig. 1C 1-3) even if the compressor
remains on the vehicle during the operation, it will be necessary
to purge the system of refrigerant (see Section 1B1). Other than
clutch repair procedures, the same holds true for any disassembly
of the compressor.
If the compressor shell, front head or cylinder and shaft
assembly are to be serviced or replaced, the oil in the compressor
must be drained, measured and replaced. (See Section 1B1) to
determine addition of proper oil quantity to new assembly.
A clean workbench, preferably covered with a sheet of clean
paper, orderliness in the work area and a place for all parts being
removed and replaced is of great importance, as is the use of the
proper, clean service tools.
NOTICE:
Any attempt to use make-shift or inadequate
equipment may result in damage and/or
compressor operation.
All parts required for servicing the internal compressor are
protected by a preservation process and packaged in a manner
which will eliminate the necessity of cleaning, washing or flushing
of the parts. The parts can be used in the internal assembly just
as they are removed from the service package.
p a c k a g i n g s h o u l d b e l e f t i n t a c t u n t i l j u s t p r i o r t o i n s t a l l a t i o n

R-4 C O M P R E S S O R S H A F T S EAL

Seal Leak Detection

A shaft seal should not be changed because of an oil-line on
the hood insulator. The Seal is designed to seep some oil for
lubrication purposes. Only change a Shaft Seal when a leak is
detected by evidence of oil sprayed in large amounts and then only
after actual refrigerant leakage is found by using an approved leak
Detector such as J 23400 or equivalent.
Should an R-4 compressor shaft seal ever have to be replaced,
the accumulator in this R-4 system must also be removed from the
vehicle. The oil in the accumulator then must be drained, measured
and replaced according to the directions in Section 1B1 to
determine oil loss.
Remove (On Car)
1. "Discharge the Refrigerant System" according to the
direction in Section 1B1.
2. Loosen and reposition compressor in mounting brackets, if
necessary.
3. Remove Clutch Plate and Hub assembly from compressor as
described in Minor Repairs.
4. Remove the shaft seal seat retainer ring, using Snap Ring
Pliers J 5403.
5. Thoroughly clean inside
surrounding the shaft, the exposed portion of the seal seat and
tfce shaft itself. Any dirt or foreign material getting into
compressor may cause damage.
6. Place Seal Protector J 22974 over the end of the shaft to
prevent chipping the ceramic seat. Fully engage the knurled
tangs of Seal Seat Remover-Installer J 23128 into the recessed
portion of the seal seat by turning the handle clockwise.
Remove the Seal Seat from the compressor with a rotary-
pulling motion (Fig. 1C1-26). Discard the Seat. The handle
must be hand-tightened securely. Do not use a wrench or
plier.
7. With Seal Protector J 22974 still over the end of the shaft,
set Seal Remover-Installer J 9392 down onto shaft end,
turning clockwise, while pressing down to engage Remover
improper
S e a l s a n d p r o t e c t i v e
.
of compressor neck area