MCi Crusader II 1989 Maintenance Manual page 157

Date 1-1-89·
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MC-9 MAINTENANCE MANUAL
diaphragm, the replacement part is suitable for use with or
without the diaphragm separator.
5. Place the remains of actuator on a smooth suriace with
the push plate down. Connect an air supply (shop air) line to the
locking port
6. By hand, press down the actuator non-pressure plate and
at the same time apply air to the locking port As the shaft is
unlocked, ease the non-pressure plate back and remove the
push plate and shaft assembly with push rod and return spring.
7. Hold the lock cap down against rolle_r spring tension and
completely remove all four capscrews before releasing and
removing the cap.
8. Remove roller spring and spring seat washer. Remove all
eight rollers.
9. Next cautiously apply air at the locking port to assist in
removal of collar and piston, and to remove piston O-ring.
10. Inspect the bearing in shaft bore and remove it only if it is
showing signs of wear.
NOTE: The push rod should not be removed
from the shaft unleu it
is
damaged. If the
rod is removed It must be replaced.
11 . To remove the rod. place a heavy washer over the rod
against the shaft, then position a spacer and a second washer
over the rod and beneath the yoke locknut Turn the locknut
down with a long handled wrench, pulling the push rod from the
shaft.
12. The knurled T-bolts in the non-pressure plate can be
removed and replaced if damaged.
REPAIR
1. Wash all metal parts in a cleaning solvent and dry. Any
reusable parts should be wiped clean. Discard felt breather.
2. Inspect all parts for excessive wear or deterioration. Par-
ticular attention should be given to the piston and collar cores in
the plate.
3. The air passage from the lock port to piston bore should
be clean and not restricted. It may be necessary to remove the
inspection plug to thoroughly clean this passage.
4. Rollers should all be replaced if one or more need replac•
ing. Check the springs for cracks, distortion or corro:;ion.
Replace all parts not serviceable.
REASSEMBLY
1. Line up parts as they
were marked prior to disassembly.
2. Lubricate the piston and collar bores, shaft, piston O-ring
and piston cavity with silicone base lubricant TMC/MCI Part
No. 21-7512-11.
3. Position the O-ring in the pis~on with smooth end down.
Place the collar in its bore in the plate.
4. Position all eight rollers in the groove formed by the top of
the piston and collar rollers.
5. Position the cone shaped roller spring on the washer with
the small end to.washer.
6. Position the cag on the roller spring. Press the cap and
hold while installing capscrews evenly.
7. Turn the non-pressure plate lock mechanism installed
and position the return spring in the plate with the large end
down.
8. Position the push plate and shaft over the· spring and
press down
so
the shaft moves through the lock. The lock
should hold the shaft position against return spring. If not.
check assembly at this point
9. Install the service diaphragm, service pressure plate and
clamping ring.
NOTE: If the service diaphragm has a bead
molded into it (figure 4-30), a diaphragm
separator must be used.
10. Install the auxiliary diaphragm, auxiliary pressure plate
and clamping ring.
11. Tighten clamping ring bolts, in both clamping rings
evenly.
12.
Install the new breather felt, then the splash guard down
over the boot
INSTALLATION
CAUTION: On lnstallatlon, actuators must
be Installed with the drain slot ·pointing
down and towards the center line of the
vehicle.
1. Mount chamber on the mounting bracket and tighten
securely.
2. Fasten the actuator push rod yoke to the slack adjuster
with the yoke pin. Lock the yoke pin with a cotter pin. The angle
formed by the push rod and slack adjuster arm should be
greater than 90 degrees.
3.
Connect the air lines to the chamber. Take care that the
correct line is installed in the correct port
4. Adjust brakes.
SERVICE DIAPHRAGM
Figure 4-33. Diaphragm Configuration in
Drive Axle Brake Chambers.