1967 CHEVROLET CAMARO fluid

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
5-3

PRIMARY

SHOE

PAWL
WIRE LINK

OVERRIDE

LEVER

VERRIDE

SPRING

RETURN

SPRING

STAR
WHEEL

Fig.
3—Camaro
Pressure
Regulator
Valve
Fig.
4-Self-Adjusting
Brake

MAINTENANCE AND ADJUSTMENTS

In any service operation it is extremely important

that absolute cleanliness be observed. Any foreign matter

in the hydraulic system will tend to clog the lines, ruin

the rubber cups of the main and wheel cylinders and

cause inefficient operation or even failure of the braking

system. Dirt or grease on a brake lining may cause

that brake to grab first on brake application and fade

out on heavy brake application.

The split system consists basically of two separate

brake systems. When a failure is encountered on either,

the other is adequate to stop the vehicle. If one system

is not functioning, it is normal for the brake pedal lash

and pedal effort to substantially increase. This occurs

because of the design of the master cylinder which

incorporates ah actuating piston for each system. When

the rear system loses fluid and takes in air, its piston

will bottom against the front piston. When the front

system loses fluid and takes in air, its piston will

bottom on the end of the main cylinders body. The loss

of fluid in one of the systems causes an uneven hydraulic

pressure balance between the front and rear systems.

The brake pipe distribution and switch assembly, near

the main cylinder, detects the loss of pressure and il-

luminates the brake alarm indicator light on the instru-

ment panel. The pressure loss is felt at the brake pedal

by an apparent lack of brakes for most of the brake

travel and then, when failed chamber is bottomed, the

pedal will harden.

HYDRAULIC BRAKE FLUID

Use GM Hydraulic Brake Fluid, Supreme No. 11 or

equivalent when servicing brakes. This brake fluid is

satisfactory for any climate and has all the qualities

necessary for proper operation, such as a high boiling

point to prevent vapor lock and the ability to remain

fluid at low temperatures.
In the event that improper fluid has entered the system,

it will be necessary to service the system as follows:

1.
Drain the entire system.

2.
Thoroughly flush the system with clean alcohol,

188
proof,
or a hydraulic system cleaning fluid

such as "Declene".

3.
Replace all rubber parts of the system, including

brake hoses.

4.
Refill the system.

5. Bleed the system.

BLEEDING HYDRAULIC SYSTEM

The hydraulic brake system must be bled whenever

any line has been disconnected or air has in some way

entered the system. A ''spongy" pedal feeling when the

brakes are applied may indicate presence of air in the

system. The system must be absolutely free of air at

all times. Bleeding should be done on the longest line

first; the proper sequence to follow is left rear, right

rear, right front, and left front (fig. 5). Bleeding of

brake system may be performed by one of two methods—

either pressure or manual.

PRESSURE
BLEEDING

1.
Clean all dirt from top of main cylinder and remove

cylinder cover and rubber diaphragm.

2.
Reduce fluid level in main cylinder until reservoirs

are approximately half full.

NOTE:
Make sure brake fluid in bleeder equip-

ment is at operating level and that the. equipment

is capable of exerting 30 to 50 lbs. hydraulic

pressure on the brake system.

3.
Install brake bleeder adapter J-22489 (fig. 6) on

main cylinder. Connect hose from bleeder equipment

to bleeder adapter and open release valve on bleeder

equipment.

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES 5-4

RF

3

^ FRONT OF

~ VEHICLE

LF

4
RR

CZZZIZ3

2

LR

1

Fig.
5—Correct Bleeding Sequence

4.
Install brake bleeder wrench, Tool J-21472 on bleed-

er valve at wheel cylinder and install one end of

bleeder hose on bleeder valve (fig. 7).

5.
Pour a sufficient amount of brake fluid into a trans-

parent container to insure that end of bleeder hose

will remain submerged during bleeding. Place the

loose end of bleeder hose into the container. Be

sure the hose end is submerged in the fluid.

6. Open wheel cylinder bleeder valve by turning Tool

J-21472 counterclockwise approximately 1/3 of a

turn and observe flow of fluid at end of bleeder

hose.

7.
Close bleeder valve tightly as soon as bubbles stop

and brake fluid flows in a solid stream from the

bleeder hose.

8. Remove brake bleeder wrench and bleeder hose

from wheel cylinder bleeder valve.

9. Repeat Steps 4 through 8 on the remaining wheel

Cylinders in the correct bleeding sequence (fig. 5).

10.
Disconnect bleeder equipment from brake bleeder

adapter cover J-22489.

NOJE: The main cylinder on certain passenger

car models is tilted upward. When removing

the bleeder adapter on these models, place a

clean dry cloth behind and below the cylinder

to absorb any fluid spillage as the cover is

removed. v
Fig.
7—Bleeding Brakes Using Brake Bleeder

Wrench Tool J-21472

11.
adapter J-22489. Wipe all area

fluid was spilled during adapter

Fig.
6—Brake Bleeder Adapter Tool J-22489—Installed
Remove bleeder

dry of fluid if

removal.

12.
Fill master cylinder reservoirs to within 1/4" of

reservoir rims as shown in Figure 8.

13.
Install main cylinder diaphragm and cover.

MANUAL BLEEDING

1.
Clean all dirt from top of main cylinder and remove

cylinder cover and rubber diaphragm.

2.
Fill main cylinder reservoirs.

3.
Install brake bleeder wrench, Tool J-21472 on bleed-

er valve at wheel cylinder and install one end of

bleeder hose on bleeder valve (fig. 7).

4.
Pour a sufficient amount of brake fluid into a trans-

parent container to insure that end of bleeder hose

will remain submerged during bleeding. Place the

loose end of bleeder hose into the container. Be

sure the hose end is submerged in the fluid.

NOTE: Carefully monitor fluid level at main

cylinder during manual bleeding operations. Do

not bleed enough fluid at one time to drain the

reservoir completely. Replenish the reservoirs

with fluid while bleeding to insure a sufficient

amount of fluid is in the main cylinder at all

times.
To insure that outside air is not sucked

back into the hydraulic system, the bleeder

valve should be closed before the brake pedal

reaches the floor.

5.
Open wheel cylinder bleeder valve by turning Tool

J-21472 counterclockwise approximately 1/3 of a

turn. Slowly depress brake pedal. Just before brake

pedal reaches the end of its travel, close bleeder

valve and allow brake pedal to return slowly to the

fully released position. Repeat this procedure until

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES 5-5

LEVEL CYLINDER

TILTED CYLINDER

Fig.
8—Correct Main Cylinder Fluid Level

expelled brake fluid flows in a solid stream from the

bleeder hose and no bubbles are present, then close

bleeder valve tightly.

6. Remove brake bleeder wrench and bleeder hose from

wheel cylinder bleeder valve.

7. Repeat Steps 2 through 7 on the remaining wheel

cylinders in the correct bleeding sequence (fig. 5).

8. Fill the main cylinder to the levels shown in

Figure 8.

9. Install main cylinder diaphragm and cover.

PUSH ROD TO MAIN CYLINDER CLEARANCE

The brake pedal has a definite stop which is permanent

and not adjustable. This stop consists of a rubber

bumper at the release end of pedal travel. Before

adjusting push rod to main cylinder clearance, make

sure pedal returns to the fully released position freely

and that the pedal retracting spring has hot lost its

tension, then proceed as follows:

1.
Loosen check nut on push rod.

2.
Turn push rod as required to provide correct ad-

justment. Movement of pedal pad before push rod

contacts main cylinder pistons must be 1/16" to

1/4" (fig. 9).

3.
Tighten check nut against clevis, and recheck

movement.

HYDRAULIC BRAKE LINES

Hydraulic Brake Hose

The flexible hoses which carry the hydraulic pressure

from the steel lines to the wheel cylinders are carefully

designed and constructed to withstand all conditions of

stress and twist which they encounter during normal

vehicle usage.
The hoses require no service other than periodic

inspection for damage from road hazards or other like

sources. Should damage occur and replacement become

necessary, the following procedure is to be followed.

Removal

1.
Separate hose from steel line by turning double

flare connector out of hose fitting.

2.
Remove "U" shaped retainer from hose fitting and

withdraw hose from support bracket.

3.
Turn hose fitting out of wheel cylinder inlet.

Replacement

1.
Install new copper gasket on cylinder end of hose

(male end).

2.
Moisten threads with brake fluid and install hose in

wheel cylinder inlet.

3.
With weight of car on wheels and suspension in

normal position (front wheels straight ahead) pass

female end of hose through support bracket, allowing

hose to seek its own position. Insert hex of hose

fitting into the 12 point hole in support bracket

in position which induces least twist to hose (figk 10).

NOTE:
Do not twist hose unduly during ^

operation as its natural curvature is absolutely

necessary to maintain proper hose-tot

suspension clearance through full movement o£

the suspension and steering parts.

4.
Install "U" shaped retainer to secure hose in sup-

port bracket.

5. Inspect by removing weight completely from wheel,

turn wheels from lock to lock while observing hose

position. Be sure that hose does not tough other

parts at any time during suspension or wheel travel.

If contact does occur, remove hose retainer and

rotate the female hose end in the support bracket

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES 5-7

LATCH PLATE

DIE BLOCK

TUBE
UPSET FLARE PUNCH

RAM GUIDE

STOP PLATE

Fig.
13—Flaring Operation--Position ing Tubing

2.
Remove the tubing from the die block and deburr

the inside and outside edges.

3.
Install compression couplings on tubing and dip end

of tubing to be flared in hydraulic fluid. This lubri-

cation results in better formation of the flare.

4.
Place on-half of the die blocks in the tool body with

the counterbored ends toward the ram guide. Now

lay the tubing in the block with approximately 1/2"

protruding beyond the end.

Fit the other half of the block into the tool body,

close the latch plate and tighten the nuts "finger

tight".

5. Select the correct size upset flare punch. One end

of this punch is counterbored or hollowed out to

gauge the amount of tubing necessary to form a

double lap flare. Slip the punch into the tool body

with the gauge end toward the die blocks. Install the

ram; then tap lightly until the punch meets the die

, blocks and they are forced securely against the

stop plate (fig. 13).

6. Using the supplied wrench, draw the latch plate

nut down tight to prevent the tube from slipping.

Tightening the nuts alternately (beginning with the

nut at the closed hole in the plate) will prevent

distortion of the plate. Remove the punch and the

ram. Now reverse the punch and put it back into the

tool body. Install the ram and tap it lightly until

the face of the upset flare punch contacts the face

of the die blocks (fig. 14). This completes the

first operation. Remove the ram and the punch.

7. To complete the flare, insert the pointed finish

flare punch and the ram into the tool body. Tap

the ram until a good seat is formed (fig. 15).

NOTE:
The seat should be inspected at inter-

vals during the finishing operation to avoid

over-seating.

LATCH

DIE BLOCK

TUBE
UPSET FLARE PUNCH
RAM GUIDE

RAM
1ST OPERATION

UPSET FLARE

PUNCH
2ND OPERATION

FINISH FLARE

PUNCH

Fig.
15—Flaring Operation—First and Second Flare

BRAKE ADJUSTMENT

Service Brake

Although the brakes are self-adjusting, a preliminary

or initial adjustment may be necessary after the brakes

have been relined or replaced, or whenever the length

of the adjusting screw has been changed. The final

adjustment is made by using the self-adjusting feature.

1.
With brake drum off, disengage the actuator from

the star wheel and rotate the star wheel by spinning

or turning with a small screw driver.

2.
Recommended

a. Use special Tool J-21177; Drum-to-Brake Shoe

Clearance Gauge, to check the diameter of the

brake drum inner surface (fig. 16).

Fig.
14—Flaring Operation—First Flare
Fig.
16—Using Drum-to-Brake Shoe Clearance

Gauge Tool J-21177

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES 5-16

6Y. Adjust clutch pedal travel as outlined in

Section 7.

SHOES AND LININGS

Organic Linings

NOTE:
If brake drums are worn severely, it

may be necessary to retract the adjusting screw.

To gain access to the adjusting screw star

wheel, knock out the lanced area in the web of

the brake drum using a chisel or similar tool.

Release the actuator from the star wheel by

lifting with a small screw driver and back off

the star wheel with a second screw driver (press

down on the handle to retract shoes).

CAUTION: After knocking out the metal, be

sure to remove it from the inside of the drum .

and clean all metal from the brake compartment.

A new hole cover must be installed when drum

is reinstalled.

Removal

1.
Raise the vehicle and plate on jack stands.

2.
Loosen check nuts at parking brake equalizer suffi-

ciently to remove, all tension from brake cable.

3.
Remove brake drums.

NOTE:
Since there are wheel cylinder piston

stops to prevent pistons from leaving cylinders,

it is not necessary to install wheel cylinder

clamps when brake shoes are removed; however,

brake pedal must not be depressed while drums

are removed.

4.
Unhook brake shoe pull back springs from anchor

pin and link end, using Tool J-8049 (fig. 27).

5. Remove the actuator return spring and link.

6. Remove hold-down pins and springs (fig. 28).

7. Remove the actuator assembly.
NOTE:
The actuator, pivot and override spring

are an assembly. It is not recommended that

they be disassembled for service purposes,

unless they are broken. It is much easier to

assemble and disassemble the brakes by leaving

them intact.

8. Separate the brake shoes by removing adjusting

screw and spring.

9. Remove parking brake lever from secondary brake

shoe (rear only).

Inspection

1.
Clean all dirt out of brake drum using care to avoid

getting dirt into front wheel bearings. Inspect drums

for roughness, scoring or out-of-round. Replace or

recondition drums as required.

2.
Inspect wheel bearings and oil seal, and replace

any necessary parts.

3.
On Chevrolet only:

Carefully pull lower edges of wheel cylinder boots

away from cylinders and note whether interior is

wet with brake fluid. Excessive fluid at this point

indicates leakage past piston cups and a need for

wheel cylinder overhaul or replacement.

NOTE:
A slight amount of fluid is nearly always

present and acts as lubricant for the piston.

4.
Check cylinders with internal boots by carefully pull-

ing a small part of the boot out of the cylinder.

Note whether interior is wet with brake fluid. Ex-

cessive fluid at this point indicates leakage past

piston cups and a need for wheel cylinder overhaul

or replacement.

5. Check all brake flange plate attaching bolts to make

sure that they are tight. Clean all rust and dirt

from shoe contact faces on flange plate (fig. 29),

using fine emery cloth.

Installation

CAUTION: Make certain to install recom-

Fig.
27-Unhooking Pull Back Spring
Fig.
28—Removing Hold-Down Springs and Pins

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES 5-20

boss to the front brakes will not contain a check

valve and spring. .

Removal

1.
Wipe main cylinder and lines clean with a clean

cloth. Place dry cloths below main cylinder area to

absorb any fluid spillage.

2.
Disconnect hydraulic lines at main cylinder. Cover

line ends with clean lint-free material to prevent

foreign matter from entering the system.

3.
Disconnect the push rod from the brake pedal.

4.
Unbolt and remove the main cylinder from the

firewall.

5.
Remove the main cylinder mounting gasket and boot.

6. Remove the main cylinder cover and dump out the

fluid. Pump the remaining fluid from the cylinder

by depressing the push rod.

Disassembly (Fig. 32)

1.
Clamp main cylinder in a bench vice.

2.
Remove push rod retainer.

3.
Remove secondary piston stop bolt from bottom of

front fluid reservoir.

4.
Remove the snap ring retainer and primary piston

assembly. Remove the secondary piston, piston

spring, and retainer by blowing air through the stop

bolt hole. (If no air is available, a piece of wire

may be used. Bend approximately 1/4 inch of one

end into -a right angle, hook the secondary piston

and pull it out.)

5.
Position main cylinder in vice with outlet holes

facing up.

6. Drill a 13/64 inch hole through both check valve

seats.

7 Tap out both seats using a 1/4 - 20 tap.

8. Install a spare brake line tube nut in the outlet

hole.
Place a flat washer on a one inch screw

(threaded to screw into tapped hole), and thread

screw into threaded hole in tube seat. Hold the

screw to keep it from turning and back out the

tube nut. This will remove the tube seat.

9. Repeat Step 8 above on second tube seat.

10.
Remove the check valves and springs from the cavi-

ties beneath the tube seats.

11.
Remove the primary seal, primary seal protector,

and secondary seals from the secondary piston.

Remove the piston extension screw securing the

primary piston spring to the primary piston. Re-

move the spring retainer, primary seal, primary

seal protector, and secondary seal from the pri-

mary piston.

Cleaning and Inspection

1.
Remove main cylinder casting from vice and inspect

the bore for corrosion, pits, and foreign matter.

Be sure that the outlet ports are clean and free of

brass cuttings from the tube seat removal operation.

2.
Inspect the fluid reservoirs for foreign matter.

Check the bypass and compensating ports to the

cylinder bore to insure that they are not restricted.

Do not use wire to check ports.

NOTE: Before washing parts, hands must be

clean. Do not wash hands in gasoline or oil

before cleaning parts. Use soap and water only.

3.
Use Declene or equivalent to clean all metal parts

thoroughly. Immerse parts in the cleaning fluid and
brush with hair brush to remove foreign matter.

Blow out all passages, orifices, and valve holes. Air

dry the parts and place on clean paper or lint-free

clean cloth.

NOTE: Be sure to keep parts clean until re-

assembly. Rewash parts, if there is any occa-

sion to doubt cleanliness.

4.
Check pistons for scratches or other visual damage;

replace if necessary.

Assembly (Fig. 32)

Use care when reassembling the main cylinder check

valves. Improper assembly of the check valve seats

will result in distortion of the seats. If this occurs,

there will be no check valve action and a loss of brake

pedal travel will result; the pedal will have to be pumped

one or more times before actual car braking occurs.

1.
Place the main cylinder in a vice with the outlet

holes facing up. Place the check valve springs, in

the outlet holes. Be sure the springs are seated

in the bottom of the holes. Place new rubber check

valves over the springs, being careful not to dis-

place the springs from the spring seats.

2.
Place new brass tube seats in the outlet holes. Be

sure seats are not cocked as this would cause burrs

to be turned up as the tube seats are pressed in.

. Thread a spare brake line tube nut into the outlet

hole and turn the nut down until the tube seat bot-

toms.
Remove the tube nut and check the outlet hole

for loose burrs, which might have been turned up

when the tube seat was pressed down. Repeat this

process to bottom the second seat.

3.
Put new secondary seals in the two grooves in the

end of the secondary piston assembly. The seal

which is nearest the end will have its lips facing

toward that end. The seal in the second groove

should have its lips facing toward the portion of

the secondary piston which contains the small com-

pensating holes.

4.
Assemble a new primary seal protector and primary

seal over the end of the secondary piston with the

flat side of the seal seats against the seal protector,

and the protector against the flange of the piston

which contains the small compensating holes.

5.
Assemble the new secondary seal into the groove on

the push rod end of the primary piston. The lips of

this seal should face toward the small compensating

holes in the opposite end of the primary piston.

6. Assemble the new primary seal protector and pri-

mary seal on the end of-the primary piston with the

flat side of the. seal seated against the seal protector,

and the protector against the flange on the piston

which contains the compensating holes.

7.
Assemble the spring retainer in one end of the

primary piston spring and the secondary piston

stop in the other end. Place the end of the spring

over the end of the primary piston with the spring

retainer seats inside of the lips of the primary

seal.

8. Remove all cleaning liquid from the threaded hole

in the primary piston. Place the piston extension

screw down through the secondary piston stop and

the primary spring retainer and screw it into the

primary piston until it bottoms out.

9. Coat the bore of the master cylinder with clean

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES 5-21

brake fluid. Coat the primary and secondary seals

on the secondary piston with clean brake fluid. Insert

the secondary piston spring retainer into the sec-

ondary piston spring. Place the retainer and spring

down over the end of the secondary piston until the

retainer locates inside of the lips of the primary

cup.

10.
Hold the master cylinder with the open end of the

bore down. Push the secondary piston into the bore

until the spring seats against the closed end of the

bore.

11.
Position the master cylinder in a vise with the

open end of the bore up. Coat the primary and

secondary seal on the primary piston with clean

brake fluid. Push the primary piston assembly,

spring end first, into the bore of the master cylinder*

Hold the piston down and snap the lock ring into

position in the small groove in the I.D. of the bore.

12.
Push the primary piston down to move the secondary

piston forward far enough to clear the stop screw

hole in the bottom of the front fluid reservoir. Install

the stop screw.

13.
Install reservoir diaphragm in the reservoir cover

and install the cover on the main cylinder. Push

bail wire into position to secure the reservoir cover.

Installation

1.
Assemble the push rod through the push rod retainer,

if it has been disassembled.

2.
Push the retainer over the end of the main cylinder.

Assemble new boot over push rod and press it down

over the push rod retainer. Slide new mounting

gasket into position.

3.
Secure .the main cylinder to the firewall with mount-

ing bolts.

4.
Connect the push rod clevis to the brake pedal with

pin and retainer.

5. Connect the brake lines to the main cylinder.

6. Fill the main cylinder reservoirs to the levels

shown in Figure 8. Bleed the brake system as out-

lined in this section.

7. K necessary, adjust the brake pedal free play as

outlined in this section.

WHEEL CYLINDER (Fig. 33)

The wheel cylinder boots should be removed from a

cylinder body only when they are visibly damaged or

leaking fluid. Wheel cylinders having torn, cut, or heat-

cracked boots should be completely overhauled.

Removal

1.
Raise vehicle and place on jack stands.

Fig.
33-Chevelle Wheel Cylinder—Exploded View

1.
Push Rod Boot 6. Spring

2.
Piston 7. Piston Cup

3. Piston Cup 8. Piston

4.
Housing 9. Push Rod Boot

5. Fluid Inlet
2.
Remove wheel and tire assembly. Back off brake

adjustment, if necessary, and remove drum.

3.
Disconnect brake system hydraulic line from

cylinder.

4.
Remove brake shoe pull back springs.

5. Remove screws securing wheel cylinder to flange

plate. Disengage cylinder push rods from brake

shoes and remove cylinder.

NOTE:
On Chevrolet, it is necessary to re-

move the anchor pin which holds the front wheel

cylinder to flange plate to remove the front

wheel cylinder.

Disassembly

1.
Remove boots from cylinder ends with pliers and

discard boots.

2.
Remove and discard pistons and cups.

Inspection and Cleaning

NOTE:
Staining is not to be confused with

corrosion. Corrosion can be identified as pits

or excessive bore roughness.

1.
Inspect cylinder bore. Check for staining and corro-

sion.
Discard cylinder if corroded.

2.
Polish any discolored or stained area with crocus

cloth by revolving the cylinder on the cloth sup-

ported by a finger. Do not slide tfce cloth in a

lengthwise manner under pressure.

NOTE:
Before washing parts, hands must be

clean. Do not wash hands in gasoline or oil

before cleaning parts. Use soap and water to

clean hands.

3.
Wash the cylinder and metal parts in Declene or

equivalent.

4.
Shake excess cleaning fluid from the cylinder-. Do

not use a rag to dry the cylinder as lint from the rag

cannot be kept from the cylinder bore surfaces.

5. Check piston for scratches or other visual damage;

replace if necessary.

Assembly (Fig. 33)

1.
Lubricate the cylinder bore and counterbore with

clean brake fluid and insert spring - expander

assembly.

2.
Install new cups with flat surfaces toward outer

ends of cylinder. Be sure cups are lint and dirt free

before insertion. Do not lubricate cups prior to

assembly.

3.
Install new Durex pistons into cylinder with flat

surfaces toward center of cylinder. Do not lubri-

cate pistons before installation.

4.
Press new boots into cylinder counterbores by hand.

Do not lubricate boots prior to installation.

Installation

1.
Position wheel cylinder to brake flange plate. Install

screws and tighten securely.

NOTE:
On Chevrolet front wheels, mount front

wheel cylinders to the brake flange plate by

installing the threaded anchor pin through the

wheel cylinder housing and tighten to 130 lb. ft.

To secure, peen over the flat washer on the

anchor pin.

CHEVROLET CHASSIS SERVICE MANUAL