GMC 1976 ZEO 6083 Maintenance Manual page 260

center of the edge of the shoe . Then press the two
tangs at the spring end of the inboard shoe spring
over the bottom edge of the shoe so that they engage
the shoe securely .
4. Position the new inboard shoe and lining as-
sembly (with spring attached) in the caliper so that
the ear end of the shoe and lining is down and the
bottom end up at an angle with the spring resting on
the piston I.D . (figure 56). Press down on both ends
of the shoe until the shoe is in a flat position, resting
on the piston . The spring end of the inboard shoe
support spring should be resting on the I.D . of the
piston .
NOTE :
If the shoe support spring is not installed
correctly, a low or no brake pedal could occur.
5 . Insert new outboard shoe into caliper with no
clearance between shoe and caliper face . (figure 57)
6. Position the caliper over the disc, aligning the
holes in the caliper ears with the holes in the mount-
ing bracket.
Make sure that the brake hose is not twisted or
kinked . Start the bolts through the sleeves in the
inboard caliper ears and through the mounting
bracket making sure that the ends of the bolts pass
under the retaining ears on the inboard shoe . Push
bolts on through to engage the holes in the outboard
shoes and the outboard caliper ears at the same time
threading the bolts into the mounting brackets .
Torque the bolts to 35 ft . lbs.
7. Fill master cylinder reservoir with new brake
fluid No . 5464831 or equivalent to within 1/4" of top
of reservoir.
Figure 57-Installing Outboard Shoe
BRAKES 5- 4 1
8. Depress brake pedal to seat linings against
rotor.
9. Clinch upper ears of outboard shoe by posi-
tioning channel lock pliers with one jaw on top of
upper ear and one jaw in notch on bottom of shoe,
opposite upper ear.
10. After clinching, ears must be flat against
caliper housing with no radial clearance .
11 . If radial clearance exists, repeat clinching
procedure.
12 . Replace the shoe and linings on the other
front wheel disc brake in the same manner . Relining
is to be done in full sets only .
NOTE:
Right and left calipers must not be inter-
changed . When installed properly, the bleed
screw will be on top.
13 . When completed, reinstall the wheel and tire
assemblies . Lower the vehicle to the floor . Add brake
fluid to the master cylinder reservoirs to bring the
level up to within 1/4" of the top.
NOTE: Do not move vehicle until firm brake
pedal is obtained .
Whenever the front wheel disc brakes are relined,
the rear drum brakes should be checked also .
COMBINATION VALVE
INSTALLATION (FIGURE 13)
l . Install valve on mounting bracket.
2. Connect wiring to switch terminal on valve.
3. Connect all brake lines to valve .
4. Bleed entire brake system . Refer to "BLEED-
ING BRAKE SYSTEM" as described earlier in this
section.
MASTER CYLINDER
INSTALLATION
1 . Position master cylinder on power cylinder so
push-rod enters cavity in master cylinder piston .
2. Install two attaching nuts (figure 15).
3 . Connect two hydraulic lines to master cylinder
and tighten fittings securely . (figure 14).