Chevrolet 30 Series 1967 Service Manual page 258

BRAKES 5-44
brake fluid on linings, worn or glazed linings, and
make necessary adjustments.
4. Check the brake fluid level in the hydraulic reser­
voir. The reservoir should be filled to within 1/2"
of the top of the filler cap opening. Inspect the
reservoir cover for fluid leaks at gasket.
5. Check for loose mounting bolts at main cylinder and
at power section.
. Check air cleaner filter located in the power piston
6
extension—replace filter if necessary.
7. Check brake pedal for bending and misalignment
between pedal and push rod.
Lubrication
The M aster-Vac power brake unit is lubricated at as­
sembly and needs no further lubrication other than main­
taining normal reservoir fluid level.
Removal (Fig. 73)
1. Disconnect push rod clevis at brake pedal arm.
NOTE: If clearance hole through fire wall is
not large enough, it may be necessary to remove
clevis from push rod. Note approximate location
of clevis on rod.
2. Disconnect vacuum hose from check valve in front
shell of power section.
3. Disconnect hydraulic lines at main cylinder. Cover
main cylinder outlet ports and ends of brake tubes
to prevent entry of foreign matter.
4. Disconnect stoplight switch wires.
5. Remove four nuts and lockwashers securing power
unit to fire wall, and remove power unit and spacer
from engine compartment.
Installation
1. Mount the power brake assembly and spacer in place
and install four attaching nuts and lockwashers. Be
certain to place push rod through cutout in fire wall.
2. Attach vacuum line to check valve.
3. Connect stoplight switch wires.
4. Secure hydraulic lines to main cylinder.
5. Adjust push rod clevis to brake pedal assembly.
Adjust pedal height by means of clevis on brake
pedal push rod at pedal. Pedal height is obtained
by measuring from floor covering at toe pan to top
of pedal pad.
NOTE: Check operation of stop light after ad­
justing pedal height.
. Bleed brakes as outlined in this section.
6
NOTE: After completing the bleeding opera­
tion, make sure reservoir fluid level is at cor­
rect height. The reservoir should be filled to
1/4 inch of filler cap opening.
7. Check operation of the brakes as outlined in this
section.
should be filled as described in this section, using only
recommended brake fluid.
Bleeding Instructions
The power system may be bled manually or with a
pressure bleeder as outlined in this section.
Use only recommended brake fluid. Do not use power
assist while bleeding. The engine should not be running
and the vacuum reserve should be reduced to zero, by
applying the brake several times before starting the
bleeding procedure.
Air Cleaner Service
The air cleaner filter used with the power brake unit
should be cleaned at least twice a year. To clean, re­
move air cleaner element and wash thoroughly in cleaning
The reservoir
solvent—allow element to dry before reinstalling.
SERVICE OPERATIONS
MAIN CYLINDER-SINGLE RESERVOIR TYPE
(Midland Ross)
NOTE:
CE-CS-SA50-60 series vehicles.
Removal (Fig. 1)
1. Wipe main cylinder and line clean with a clean cloth.
Place dry cloths below main cylinder area to absorb
any fluid spillage.
2. Disconnect hydraulic line from main cylinder. Cover
open line end with clean lint-free material to prevent
foreign matter from entering the system. Disconnect
vacuum hose from manifold.
3. Remove main cylinder from power booster.
This model cylinder is installed on
Fig . 73—Power C ylin d e r Bracket and Spacer
CHEVROLET TRUCK SERVICE MANUAL