Chevrolet 1977 10 Series, Руководство по ремонту, Страница: 175 / 468

BRAKES 5-9
NORM AL
LANCE
DEEP
LANCE
N OR M AL
LANCE
Fig. 5 -3 B ~ L a n ce s in Rear H o u sin g
rear housing, using care not to damage rear housing seal.
Bosses on center plate m ust be aligned with cutouts in rear
housing to remove the assembly.
21. Wet the rear diaphragm retainer with denatured
alcohol and remove the retainer using fingers only.
22. Clam p Tool J-22839 in a vise. Place the diaphragm
and plate assembly on the tool with the tool seated in the hex
opening in the front plate.
23. Twist the rear diaphragm plate counterclockwise,
using hand leverage on the outer edge of the plate. It may
be necessary to use a 1" x 1-3/16" x 8" wood strip as a lever
in cover slot on outside circumference of rear plate.
24. A fter the two (2) plates have been loosened, remove
the plates from Tool J-22839 and place on a bench with the
front plate down. Unscrew the rear plate completely and
carefully lift it off the front plate hub, grasping the air valve
Fig. 5 -4 B --H o ld in g and S e p a ra tin g H o u s in g s U sin g J -2 2 8 0 5
and J -9 5 0 4 in A rb o r Press
plunger and valve return spring as the parts are separated (fig.
5-5B).
25. Remove the square ring seal from the shoulder of
the front diaphragm plate hub.
26. Remove the reaction disc from inside the front
diaphragm plate hub. Carefully slide the center plate off the
hub of the front plate.
27. Remove the diaphragm s from the plates.
28. Use a blunt punch or 1-1/4" socket to drive seal from
rear housing (figs. 5-6B and 5-7B).
Cleaning
All parts to be reused should be washed in denatured
alcohol or brake fluid. D ry the parts with compressed air and
place them on clean paper or lint free cloth.
Small rust spots inside the shells may be removed with
crocus cloth or fine emery cloth. Be sure to clean thoroughly
after using any abrasive.
Inspect all parts and replace any that are damaged or
show excessive wear.
Assembly
1. Press the new bearing and seal into the cavity in the
rear housing using Tool J-22677 (fig. 5-8B). The flat rubber
surface of the seal should be 5/16" below the flat, inside
surface of the rear housing.
2. Install reaction disc in hub of front plate with small
tip toward hole. Use rounded rod to seat disc.
3. M ount Tool J-22839 in vise.
4. Install front diaphragm on front plate. Long fold of
diaphragm m ust be facing down.
5. Install Tool J-22733 over threads on front plate hub
(fig. 5-9B).
6. Apply a light film of silicone lubricant to front plate
hub and to seal in center plate, then guide center plate, seal
first, onto the front plate hub, being careful not to damage
center plate seal. Remove Seal Protector J-22733.
7. Apply a light coat of silicone lubricant to bearing
surfaces of air valve plunger, being careful not to apply
lubricant to rubber grom m et inside plunger. Install square
ring seal on shoulder of front plate hub and install valve
plunger return spring and plunger in base of front plate hub
(fig. 5-10B).
8. Set rear plate over hub of front plate, and using hands
only, screw plate on hub, making sure that valve and spring
are properly aligned. H and torque plates to 150 in. lbs. Check
travel of valve plunger with index finger.
9. Assemble rear diaphragm to rear plate and place lip
of diaphragm in groove in rear plate. Install diaphragm
retainer over rear diaphragm and lip of center plate. Using
fingers, press retainer until it seats on shoulder of center plate
(fig. 5-1 IB).
10. Apply talcum powder to inside wall of rear housing
and silicone lubricant to the scalloped cutouts of front
housing and to seal in rear housing. Assemble diaphragm and
plate assembly into rear housing by carefully guiding rear
plate hub through seal in rear housing. Bosses on center plate
must be aligned between lances in rear housing for
reassembly. W ork outer rim of front diaphragm into rear
housing with screwdriver blade so that it is under lances in
housing.
11. A ttach base of Holding Fixture J-22805 to front
housing with nuts and washers and draw down tight to
eliminate bending or damage to studs.
12. Secure front housing and Holding Fixture J-22805
J-2 2 8 0 5
1
V i "
OPEN END
W RENCH
J -9 5 0 4