BRAKES
SECTION 5
CONTENTS OF THIS SECTION
Duo Servo Brakes
Disc Brakes
Page
5-1 Power Brakes
5-24 Special Tools
Page
5-31
5-32
DUO-SERVO BRAKES
INDEX
Page
General Description 5-1
Maintenance and Adjustments 5-3
Hydraulic Brake Fluid .. . 5-3
Bleeding Hydraulic System 5-3
Pressure Bleeding 5-3
Manual Bleeding 5_4
Push Rod to Main Cylinder Clearance 5-5
Hydraulic Brake Lines 5-5
Hydraulic Brake Hose 5-5
Hydraulic Brake Tubing 5-6
Brake Adjustment. .................... 5-7
Service Brake 5-7
Parking Brake 5-8
Component Replacement and Repairs 5-9
Parking Brake - Chevrolet, Chevelle and
Camaro 5^9
Pedal Assembly 5-9
Front Cable ,. . . 5-9
Center Cable 5-9
Rear Cables. . 5-9
Parking Brake - Chevy n 5-9
Lever Assembly 5-9
Idler Lever 5-11
Front Cable 5-11
Rear Cable . . ; 5-12
Parking Brake - Corvette 5-13
Lever Assembly . . . . 5-13
Front Cable 5-14
Rear Cable . . 5-14
Brake Pedal 5-15
Shoes and Linings 5-16
Organic 5-16
Metallic 5-17
Main Cylinder 5-18
Wheel Cylinders 5-21
Anchor Pin 5-22
Front Wheel 5-22
Rear Wheel 5-22
Brake Drums • 5-22
Brake Pipe Distribution and Switch Assembly . . . . . 5-23
Camaro Pressure Regulator Valve 5-23
GENERAL DESCRIPTION
All 1967 models are equipped with a new split brake
system as a safety feature. If a wheel cylinder or brake
line should fail at either the front end or rear end of
the vehicle, the operator can still bring the vehicle to
a controlled stop. The system is designed with separate
hydraulic systems for the front and rear brake using
a dual master cylinder (fig. 1). The design of the master
cylinder is similar to that used on the 1966 Corvette
in that it has two entirely separate reservoirs and outlets
in a common body casting. The front reservoir and outlet
is connected to the front wheel brakes, and the rear
reservoir and outlet is connected to the rear wheel
brakes. Two pistons within the master cylinder receive
mechanical pressure from the brake pedal push rod and
transmit it through the brake lines as hydraulic pressure
to the wheel cylinders. The filler cap is accessible from
inside the engine compartment.
A new brake pipe distribution and switch assembly
is mounted below the main cylinder. The front and rear
hydraulic brake lines are routed from the main cylinder,
through the brake pipe distribution and switch assembly,
to the front and rear brakes as shown in Figure 2. The
switch is wired electrically to the brake alarm indicator
light on the instrument panel. In the event of fluid loss
in either the front or rear brake system the indicator
on the instrument panel will illuminate red. (The indi-
cator will also' be illuminated when the parking brake is
applied.)
On Camaro models equipped with air conditioning, the
rear brake hydraulic line is routed through a pressure
regulator valve mounted on the left frame side rail
(fig. 3). The valve controls the hydraulic pressure to
the rear brakes resulting in the correct pressure balance
between the front and rear hydraulic systems.
The self-adjusting brakes (fig. 4), used on both front
and rear of all models, are the Duo-Servo single anchor
type which utilize the momentum of the vehicle to assist
in the brake application. The self-energizing or
self-
actuating force is applied to both brake shoes at each
wheel in both forward and reverse motion. The brake
shoe linings are bonded to the shoes.
Wheel cylinders are the double piston type permitting
even distribution of pressure to each brake shoe. To
keep out dust and moisture, both ejads of each wheel
cylinder are sealed with a rubber booC The wheel
cylinders have no adjustments.
The Chevrolet, Chevelle, and Camaro parking brakes
have a foot operated ratchet type pedal mounted to the
left of the steering column. A cable assembly connects
the pedal to an intermediate cable by means of an equal-
izer, where the adjustment for the parking brake is
incorporated. The intermediate cable attaches to the
CHEVROLET CHASSIS SERVICE MANUAL
BRAKES 5-2
DELCO MORAINE MAIN CYLINDER
BENDIX MAIN CYLINDER
Fig.
I—Main
Cylinder
two rear cables which operate the rear service brake.
The Chevy II has a single-stroke, ratchet-type parking
brake release lever, located to the right of the steering
column. The lever is connected to the rear wheel brake
assemblies through a two-piece cable and equalizer
assembly. A dash mounted idler lever multiplies force
applied at the parking brake lever and transmits it to
the equalizer by means of the front cable. The one-piece
rear cable passes through the equalizer and is connected
at each end to an actuating lever within the rear brake
assembly.
The Corvette is equipped with a ratchet-type parking
brake lever located behind the console. The parking
brake cable runs forward from the lever to a pulley
assembly mounted on a frame crossmember, then back
to an equalizer near the rear frame crossmember. A
single piece rear cable passes through the equalizer
and back to the rear service brakes.
— CHEVROLET
CAMARO
Fig.
2—Brake Pipe Distribution and Switch Assembly
CHEVROLET CHASSIS SERVICE MANUAL
BRAKES 5-8
Fig.
17—-Checking Brake Shoe Lining Clearance
Using Tool J-21177
b.
Turn the tool to the opposite side and fit over
the brake shoes by turning the star wheel, until
the gauge just slides over the linings (fig. 17).
c. Rotate the gauge around the brake shoe lining
surface to assure prpper clearance.
Alternate
a. Using the brake drum as an adjustment fixture
turn the star wheel until the drum slides over
the brake shoes with a slight drag.
b.
Turn the star wheel 1-1/4 turns to retract the
shoes.
This will allow sufficient lining-to-drum
clearance so final adjustment may be made as
described in Step 4.
3.
Install the drum and wheel.
NOTE: 1: If lanced area in brake drum is
knocked out, be sure all metal has been re-
moved from brake compartment. Install new
hole cover in drum to prevent contamination
of the brakes.
NOTE: 2: Make certain when installing drums
that drums are installed in the same position
as when removed with the drum locating tang
in line with the locating hole in the wheel hub
(fig. 18).
4.
Make final adjustment by making numerous forward
and reverse stops, applying brakes with a firm
pedal effort until a satisfactory brake pedal height
results.
NOTE: Frequent usage of an automatic trans-
mission forward range to halt reverse vehic;..$
motion may prevent the automatic adjuster.:?
from functioning, thereby inducing low pedal
heights.
Fig.
.18—Aligning Drum Tang with Wheel Hub
Parking Broke
The rear brake assemblies serve a dual purpose in
that they are utilized both as a hydraulically operated
service brake and also as a mechanically operated
parking brake. In view of this dual purpose, the service
brake must be properly adjusted as a base for parking
brake adjustment; conversely the parking brake must
be properly adjusted for the service brake to function
as intended.
Adjustment
1.
Jack up both rear wheels.
2.
Apply parking brake, two notches from fully re-
leased position.
3.
Loosen the equalizer forward check nut, and tighten
or loosen the rear nut until a light to moderate drag
is felt when rear wheels are rotated.
4.
Tighten check nuts securely.
5.
Fully release parking brake and rotate rear wheels;
no drag should be present.
Inspection
If complete release of the parking brake is not ob-
tained, unless it is forcibly returned to its released
position, or if application effort is high, check parking
brake assembly for free operation. If operation is sticky
or a bind is experienced, correct as follows:
1.
Clean and lubricate brake cables and equalizer.
2.
Inspect brake assembly for straightness and align-
ment (replace if necessary).
3.
Clean and lubricate parking brake assembly.
4.
Check routing of cables for kinks or binding.
CHEVROLET CHASSIS SERVICE MANUAL
BRAKES 5-9
COMPONENT REPLACEMENT AND REPAIRS
PARKING BRAKE-CHEVROLET, CHEVELLE AND
CAMARO (Figs. 19 and 20)
Pedal Assembly
Removal
NOTE:
Remove positive cable from battery to
eliminate the possibility of creating short cir-
cuits under dash.
1.
Place parking brake pedal in released position.
2.
Remove equalizer check nut, and separate cable
stud from equalizer.
3.
Remove two attaching nuts from mounting studs
located in engine compartment.
4.
Remove front cable .ball end from pedal assembly
swivel.
5. Remove pedal assembly to dash brace attaching
screw.
6. Remove pedal assembly by lowering rear slightly
to avoid scratching dash, and pulling, it out of the
firewall.
Installation
1.
Place pedal assembly in position with the two mount-
ing studs protruding through the holes provided in
the firewall.
2.
Install and tighten pedal assembly to dash brace
attaching screw.
3.
Position front cable ball end into pedal assembly
swivel.
4.
Install and tighten two attaching nuts on mounting
studs located in engine compartment.
5. Place
,
equalizer in position on center cable and
insert front cable stud through equalizer and secure
with check nut.
6. Adjust parking brake as outlined under Maintenance
and Adjustments in this section.
7. Connect positive battery cable.
Front Cable
Removal
NOTE:
Remove positive cable from battery to
eliminate the possibility of creating short cir-
cuits under dash.
1.
Place parking brake pedal in released position.
2.
Remove equalizer check nut, and separate cable
, stud from equalizer.
3.
Remove retainer from cable assembly at inner side
of frame rail.
4.
Remove ball end of cable from pedal assembly
swivel.
5. Compress expanded conduit locking fingers at toe
pan arid withdraw cable from car.
6. On Chevelle, if necessary, remove rubber tube
from front cable.
Installation
1.
On Chevelle, if necessary, replace rubber tube
over front cable.
2.
Position cable ball and conduit tip through cutout
in firewall. Make sure conduit locking fingers are
fully expanded and secured in cutout, then position
cable ball into pedal assembly swivel.
3.
Feed stud end of cable through frame rail and se-
cure with retainer on inner side of frame.
4.
Place one check nut on cable stud and insert stud
through equalizer, (make sure center cable is in
position), then place second check nut on stud.
5. Adjust parking brake as outlined in this section.
6. Connect positive battery cable.
Center Cable
Removal
1.
Place parking brake pedal in released position.
2.
Remove equalizer check nut and remove equalizer
from cable.
3.
Remove cable from cable guides.
4.
Disconnect center cable from rear cables at
connectors.
Installation
1.
Install cable ends into rear cable connectors.
2.
Place cable through equalizer and install equalizer
on to front cable stud, secure with check nut. (Do
not tighten.)
3.
Install cable in cable guides (figs. 19 and 20),
4.
Adjust parking brake as outlined in this section.
Rear Cables
Removal
1.
Place parking brake pedal in released position.
2.
Remove equalizer check nut and remove equalizer
from cable.
3.
Remove rear cable from connector.
4.
Remove retainer from rear cable at frame bracket.
Pull cable out of bracket.
5. Remove rear brake drum as outlined in this section.
6. Remove rear brake shoes as outlined in this section.
7. Remove cable end from parking brake actuating
lever.
8. Compress expanded conduit locking fingers at flange
plate entry hole and withdraw cable.
Installation
1.
Pass end of cable and conduit tip through flange
plate entry hole, making sure that conduit locking
fingers all expand fully.
2.
Connect cable end to actuating lever.
3.
Install rear brake shoes, drum and wheel as out-
lined in this section.
4.
Pass cable through frame bracket and install
retainer.
5. Install cable end into cable connector.
6. Position equalizer on center cable and place on
front cable stud, secure with check nut.
7. Make sure all center cable guides are in place
and adjust parking brake as outlined in this section.
PARKING BRAKE-CHEVY II (Fig. 21)
Lever Assembly
Removal
NOTE:
Remove positive cable from battery
to eliminate possibility of creating short cir-
cuits under dash.
CHEVROLET CHASSIS SERVICE MANUAL
BRAKES 5-10
\
Fig.
19—Parking Brake System-Chevrolet and Chevelle
CHEVROLET CHASSIS SERVICE MANUAL
BRAKES 5-11
VIEW A
VIEWB
CAMARO
Fig.
20—Parking Brake System—Camano
1.
Place parking brake lever in released position.
2.
Remove return spring at equalizer.
3.
Remove equalizer check nut, and separate cable
stud from equalizer.
4.
Remove clevis pin clip and pin from idler lever
assembly.
5. Remove two lever dash attaching screws, and remove
lever assembly from vehicle.
Installation
1.
Place lever assembly into position and secure with
the two lever to dash attaching screws.
2.
Place idler lever in position with lever assembly,
align holes and install clevis pin and clip.
3.
Position equalizer on front cable stud and secure
with check nut.
4.
Install return spring at equalizer.
5. Adjust parking brake as outlined under Maintenance
and Adjustments in this section.
6. Connect positive battery cable.
Idler Lever
Removal
NOTE:
Remove positive cable from battery
to eliminate possibility of creating short cir-
cuits under dash.
1.
Place parking brake lever in released' position.
2.
Eemove return spring at equalizer.
3.
Remove equalizer check nut, and separate cable stud
from equalizer.
4.
Remove clevis pin clip and pin from idler lever
assembly.
5. Remove cable ball from idler lever.
6. Remove pivot pin clip and pivot pin, then remove
idler lever from vehicle.
Installation
1.
Place, idler lever into position and secure with
the pivot pin and clip.
2.
Connect cable ball to idler lever.
3.
Place idler lever in position with lever assembly,
align holes and install clevis pin and clip.
4.
Position equalizer on front cable stud and secure
with check nut.
5. Install return spring at equalizer.
6. Adjust parking brake as outlined under Maintenance
and Adjustments in this section.
7. Connect positive battery cable.
Front Cable
Removal
NOTE:
Remove positive cable from battery
to eliminate possibility of creating short cir-
cuits under dash.
1.
Place parking brake lever in released position.
CHEVROLET CHASSIS SERVICE MANUAL
BRAKES 5-12
VIEW B
Fig.
21—Parking Brake System-Chevy II
2.
Remove return spring at equalizer.
3.
Remove equalizer check nut, and separate cable
stud from equalizer.
4.
Remove clamp from underbody guide bracket. (Con-
vertible models only, also remove clamp from guide
bracket at underbody support.)
5. Remove cable retainer from underbody bracket.
6. Compress expanded conduit locking fingers at toe
pan,
remove cable ball from idler lever, and with-
draw cable from car.
Installation
1.
Position cable ball and conduit tip through cutout
in toe pan.. Make sure conduit locking fingers are
fully expanded and secured in cutout, then position
cable ball in idler lever clevis.
2.
Present parking brake lever to one notch.
3.
P}ace retainer in conduit groove so that conduit
end is secure in underbody bracket.
4.
Position cable in guide bracket(s) and secure cable
in bracket with clamp(s).
5. Place one check nut on cable stud and insert stud
into equalizer, then place second check nut on stud.
6. Connect cable return spring.
7. Adjust parking brake as outlined in this section.
8. Connect positive battery cable.
Rear Cable
Removal
1.
Place parking brake lever in released position.
2.
Disconnect front cable return spring at equalizer.
3.
Remove check nut from front cable stud, withdraw
stud from equalizer, and remove equalizer from
rear cable.
4.
Remove retainers from grooves in rear cable con-
duit, and remove cable from bracket.
5. Remove cable from center body bumper bracket
and spring clip at shock absorber lower mount.
6. Back off rear service brakes sufficiently to allow
for drum removal.
7. Remove both rear wheels and drums.
8. Remove secondary brake shoe return spring.
9. Remove secondary brake shoe hold-down spring
and pin.
10.
Remove cable end from parking brake actuating
lever.
11.
Compress expanded conduit locking fingers at flange
plate entry hole and withdraw cable.
CHEVROLET CHASSIS SERVICE MANUAL
Installation
1.
Pass end of cable and conduit tip through flange
plate entry hole, making sure that conduit locking
fingers all expand fully.
2.
Compress retaining spring and place cable end in
actuating lever.
3.
Install secondary shoe hold-down pin and spring.
4.
Install secondary shoe return spring.
5. Install drum and wheel.
6. Snap cable conduit into spring clip at shock ab-
sorber lower mount.
7. Install cable conduit in bracket at center body bump-
er bracket.
8. Position cable conduit ends in cable bracket and
install retainers in grooves.
9. Place equalizer on cable and insert forward cable
stud. Install check nut and return spring.
NOTE:
To perform its intended function, equal-
izer must be free to slide on rear cable. Lubri-
cate cable at equalizer with chassis grease.
10.
Adjust rear service brakes and parking brake as
outlined in this section.
BRAKES 5-13
PARKING BRAKE-CORVETTE (Fig. 22)
Lever Assembly
Removal
1.
Place parking brake lever in the fully released
position.
2.
Under vehicle, unhook and remove return, spring.
3.
Remove rear nut from cable stud at equalizer and
allow front cable to hang down.
4.
Inside vehicle, remove six screws securing cover
to underbody. It is necessary to push the seat
cushion down as shown in Figure 23 to gain access
to the lower mounting screw on each side. Remove
the retainer. Lift the cover upward and to the
rear to allow seal to slide out of cover slot and
remove cover.
5. Remove trim seal from lever (fig. 24).
6. Remove screw and washer securing parking brake
alarm switch to side of lever assembly.
7. Remove four bolts securing lever assembly to under-
body and lift lever assembly upward. Remove lever
forward mounting bracket.
Fig.
22—Parking Brake System—Corvette
CHEVROLET CHASSIS SERVICE MANUAL