Chevrolet 10 Series 1968, Service Manual

Page: 280 / 713

BRAKES 5-37
Brake drums may be refinished either by turning or
grinding. Best brake performance is obtained by turning
drums with a very fine feed. To insure maximum lining
life, the refinished braking surface must be smooth and
free from chatter or tool marks, and run-out must not
exceed .005" total indicator reading.
Installation
1. Make sure mating surfaces of hub, drum and oil
deflector are clean and smooth and assemble as out­
lined in Section 3.
2. On front, install drum and hub assembly to wheel
spindle and adjust bearings on 1/2, 1 1/2 and 2 ton
as outlined in Section 3. On 3/4 and 1 ton install
drum and retain in place with retaining screws.
3. On rear, assemble drum assembly over hub studs
and install retaining screws, if used.
4. Replace wheel assembly and lower vehicle to floor.
BRAKE PEDAL (EXCEPT TILT CAB AND
CHEVY VAN)
The brake pedal (fig. 63) is an integral design with the
clutch pedal, necessitating the removal of the clutch pedal
before removing the brake pedal.
Removal
1. Remove the clutch pedal as outlined under “ Clutch
Pedal" in Section 7.
2. Remove the pull back spring from the body bracket.
3. Remove the sleeve assembly screw attachment and
remove sleeve.
4. Disengage the push rod from the master cylinder and
drop the pedal to check for worn parts—inspect the
return spring, bracket attachment, and bushings for
needed repairs.
Installation
Reverse the above procedure and make certain the
brake pedal (fig. 63) is secure and adjusted properly be­
fore operating the vehicle. See Maintenance and Adjust­
ments for brake pedal adjustment.
BRAKE PEDAL-TILT CAB
The complete brake pedal consists of two separate
assemblies— upper pedal assembly and lower pedal as­
sembly. The following procedure applies to both pedal
assemblies; however, it is not necessary to remove lower
assembly if only upper assembly is to be replaced.
Rem oval
1. Disconnect and remove brake pedal return spring and
clutch pedal over-center spring.
2. Disconnect main cylinder push rod clevis at lower
pedal arm, and remove push rod and clevis from
main cylinder (fig. 63).
3. Disconnect and remove upper pedal arm.
4. Remove grease fitting from lower pedal arm pivot
sleeve. Access at cutout in underside of channel.
5. Remove retainer and washer from pedal arm pivot
shaft.
6. Remove two screws from pivot sleeve and bracket
assembly, and remove assembly from channel.
7. Withdraw lower pedal arm from channel.
C leaning and Inspection
1. Wash all metal parts with an approved cleaning
solvent.
2. Inspect.
Installation
1. Position lower pedal arm pivot shaft through
channel cutout.
2. Install pivot sleeve through channel cutout so that
pedal arm pivot shaft is retained by sleeve. Install
retaining screws to sleeve bracket, and install
grease fitting. Install washer and retainer to pedal
arm pivot shaft.
3. Position upper pedal arm through toe pan, align
serrations on pedal arms, install retaining bolt,
lock washer and nut. Refer to torque specifications
at rear of manual for correct torque value.
4. Connect clutch pedal over-center spring and brake
pedal return spring.
5. Insert main cylinder push rod through rubber boot
and into piston. Install retaining bolt, lock washer
and nut. Refer to torque specifications at rear of
manual for correct torque valve.
6. Adjust push rod until 1/8 to 1/4 inch free movement
is obtained at pedal pad.
7. Lubricate pivot shaft at fitting.
BRAKE PED A L-CH EV Y VAN (Fig. 64)
Rem oval
1. Disconnect brake pedal return spring.
2. Remove upper to lower brake pedal arm nut and
remove upper arm.
3. Remove nut and eccentric bolt holding main cylin­
der push rod to lower pedal assembly.
4. Remove pivot shaft retainer and screw from bracket
assembly. Remove pivot shaft using a small brass
drift if needed.
5. Remove grease fitting from arm assembly.
Inspection
1. Inspect pivot shaft and pedal bushings for wear or
other damage.
2. If necessary to remove bushings from pedal use a
cape chisel for removal, then deburr.
3. Install new bushings in each side of pedal bore
using a vise as a press.
Installation
1. Reverse r e m o v a l procedure to install p e d a l
assembly.
NOTE:
(A) Assemble eccentric push rod to
pedal attachment bolt with projection in down
position before adjustment. (B) Mark on upper
and lower pedal assemblies must be assembled
in line.
2. Adjust push rod to main cylinder clearance as de­
scribed in this section.
3. Check stop light operation and adjust switch if re­
quired as described in Section 12.
4. Grease fitting until grease passes thru bushing and
comes out both sides of pivot bore.
Adjustment
1. Loosen check nut on the eccentric bolt attachment
between the brake pedal and main cylinder push rod.
2. Turn eccentric bolt as required to provide correct
adjustment. Movement of pedal pad before push rod
contacts main cylinder piston must be 1/16" to 1/4” .
CHEVROLET TRUCK SERVICE MANUAL