brake CHEVROLET CAMARO 1967 1.G Chassis Owner's Guide

REAR SUSPENSION AND DRIVE LINE 4-30

Fig.
76—Differential Gear Failure

Hypoid Gears

Hypoid gear tooth scoring (fig. 74) is caused generally

by improper break-in, incorrect lube, insufficient gear

backlash or improper 'ring/pinion gear alignment. The

scoring will progressively lead to complete erosion of

the gear tooth, or gear tooth pitting and eventual fracture

with possible attendant damage to bearings, if the initial
scoring condition is not diagnosed in time and corrected.

Hypoid gear scoring is easily recognized by its char-

acteristic loud whine in either drive, coast or under both

conditions. Another cause of hypoid tooth fracture (fig.

75) is extended overloading of the gear set which will

produce fatigue fracture, or shock loading which will

result in sudden failure.

Differential Gears

Common causes of differential gear failure are shock

loading, extended overloading leading to fatigue failure,

and overheating of gear thrust surfaces resulting from

excessive wheel spin and consequent lubrication break-

down. Overheating will lead to seizing of thrust surfaces

or tooth failure (fig. 76).

Bearings

• Failure of axle tapered roller bearings is due pri-

marily to excessive wear caused by long service or

foreign materials in the oil. The second most common

cause of bearing failure is too tight or too loose pre-

load adjustment leading to spalling and eventual failure.

This failure may also lead to hypoid gear scoring due to

the resultant misalignment of the hypoid gear set.

COMPONENT PARTS REPLACEMENT

(Chevrolet, Cheveile, Chevy II and Camaro)

AXLE ASSEMBLY

Removal

1.
Raise vehicle to a height that will permit axle as-

sembly to hang freely and position supports under

both frame side rails.

2.
Disconnect wheel cylinder inlet lines. Disconnect and

remove brake hose and brake line retaining bracket

by removing retaining bolt from carrier cover.

3.
Loosen parking brake equalizer adjusting nut and

disconnect both rear cables at frame bracket and at

control arms. See Section 5 for detail of parking

brake cable removal.

4.
Remove two trunnion bearing "U" bolts from the

rear yoke and separate rear universal joint. Wire

propeller shaft to frame side rail and tape trunnion

bearing cups.

5. Support arid secure axle assembly with an adjustable

lifting device. On Chevrolet and Cheveile models,

loosen upper and lower control arm attaching bolts

at axle housing. (On Chevrolet models, disconnect

tie rod at axle bracket.)

6. Disconnect shock absorbers at axle brackets. Refer

to Shock Absorber Removal procedures outlined in

this section.

7. On Chevrolet and Cheveile models, lower axle as-

sembly until suspension reaches end of travel, then

disconnect spring retainers and withdraw springs

from vehicle.

8. On Chevy II and Camaro models, remove four nuts

securing lower spring seat to axle housing, then

remove spring front eye bolts or spring attaching

bracket and swing spring to rear so that it does not

interfere with axle.

9. On Chevrolet and Cheveile models, disconnect upper

and lower control arm attaching bolts at axle housing*
10.
Lower axle assembly and remove from under vehicle.

Installation

1.
Place axle assembly under vehicle and raise into

position.

2.
On Chevrolet and Cheveile models, install, but do not

tighten, upper and lower control arm attaching bolts

at axle housing.

3.
On Chevrolet models, position coil springs in upper

seats so that end of spring is indexed in seat.

4.
On Chevrolet models, install lower end of spring on

axle bracket or control arm and secure by installing

retainer and bolt. Install lock washer and retainer

nut.

5. On Cheveile pry lower pigtail of spring over vertical

flange of the axle bracket spring seat.

6. On Chevy II and Camaro models, install spring seat

pads and swing springs up into spring seats on axle

housing, making sure upper seat pads are aligned in

axle housing bracket.

7. Install spring front eye bolt and tighten, then install

spring seat lower mounting bracket and retaining

nuts.

8. Raise axle assembly to allow shock absorber and tie

rod installation. Position shock absorber in axle

bracket. Torque nut as outlined in Shock Absorber

Installation procedures.

9. Install brake hose and brake line retaining bracket

to carrier and connect wheel cylinder inlet lines.

Connect parking brake cable to frame bracket and

at control arm. Adjust parking brake and bleed

brakes as outlined in Section 5.

10.
Reassemble rear universal joint to companion flange.

11.
Support vehicle at axle and remove supports from

beneath the frame side rails.

12.
Remove supports and lower vehicle to floor. Torque

all affected parts to specifications.

CHEVROLET CHASSIS SERVICE MANUAL

REAR SUSPENSION AND DRIVE LINE 4-31

Fig.
77—Differential Pinion Shaft Removal

AXLE SHAFT

Removal

1.
Raise vehicle to desired working height and remove

wheel and tire assembly and brake drum.

2.
Clean all dirt from area of carrier cover. *

3.
Drain lubricant from carrier by removing cover.

4.
Remove the differential pinion shaft lock screw and

the differential pinion shaft (fig. 77).

5. Push flanged end of axle shaft toward center of

vehicle and remove "C" lock from button end of

shaft.

6. Remove axle shaft from housing, being careful not

to damage oil seal.

Wheel Bolt Replacement .

Press bolts out of axle shaft flange (as illustrated in

Figure 78) and press new bolts into place, making sure

that they are tight and square with flange.

Off Seal and/or Bearing Replacement

•1.
Remove the oil seal by using the button end of the

axle shaft - insert the button end of the shaft behind

the steel case of the oil seal, then pry seal out of

bore being careful not to damage housing.

2.
Insert Tool J-8119 into bore and position it behind

bearing so that tangs on tool engage bearing outer

x race. Remove bearing, using slide hammer as shown

in Figure 79. Figure 80 shows a detail of axle

housing outer end.

3.
Lubricate new bearing with wheel bearing lubricant,

and install bearing so that it bottoms against
Fig.
79—Wheel Bearing Removal

shoulder (fig. 81). To install bearing use Tool

J-21491 for the Chevelle, Camaro and Chevy JI

light-duty axle and Tool J-21051 for all Chevrolet

models and also for Chevelle, Camaro and Chevy tl

models with heavy-duty axle.

Pack cavity between the seal lips with a high melting

point wheel bearing lubricant; position seal on tool

(Use J-21491 for the Chevelle, Camaro and Chevy II

light-duty axle and J-21051 for all Chevrolet models

and also for Chevelle, Camaro and Chevy II models

with heavy-duty axle) and position seal in axle

housing bore, tap seal into place so that it bottoms

against bearing (fig. 81).

Brake Flange Plate Replacement

1.
Remove "brake line at wheel cylinder inlet and dis-

assemble brake components from flange plate. Refer

to Section 5 for brake disassembly procedure.

2.
Remove 4 nuts securing flange plate to axle housing.

3.
Install new flange plate to axle housing and torque

nuts to specifications.

Fig.
78—Wheel Bolt Replacement
Fig.
80-Axle Housing Detail

CHEVROLET CHASSIS SERVICE MANUAL

REAR SUSPENSION AND DRIVE LINE 4-32

HP?

Fig.
81
—Whed Bearing and/or Oil Seal Installation

4.
Install brake components on flange and connect

hydraulic line to wheel cylinder inlet. See Section 5

for brake assembly procedure.

5. Install axle shaft, brake drum and wheel and tire

assembly.

6. Bleed and. adjust brakes as outlined in Section 5.

Installation

1.
Slide axle shaft into place.

CAUTION: Exercise care that splines on end

of shaft do not damage oil seal and that they

engage with splines of differential side gear/

2.
Install axle shaft "C" lock on button end of axle-

shaft and push shaft outward so that shaft lock seats

in counterbore of differential side gear.

3.
Position differential pinion shaft through case and

pinions, aligning hole in shaft with lock screw hole.

Install lock screw and torque to specifications.

4.
Using a new gasket, install carrier cover and torque

bolts to specifications.

CAUTION: Make sure both gasket surfaces on

carrier and cover are clean before installing

new gasket. Torque carrier cover bolts in a

crosswise pattern to ensure uniform draw on

cover gasket.

5. Fill axle with lubricant to a level even with bottom

of filler hole. See Section 0 for proper lubricant.

6. Install brake drum and wheel and tire assembly.

7. Lower vehicle and test operation of axle.

PINION FLANGE, DUST DEFLECTOR

AND/OR OIL SEAL

Replacement

1.
Raise rear of vehicle and place stand jacks under

frame side rails so that axle hangs freely to allow

sufficient working room.

2.
Check wheels for freedom of rotation.

3.
Separate rear universal joint, tape trunnion bearings

to joint, position propeller shaft to one side and tie

it to frame side rail.

4.
Using Tool J-5853 with Adapter J-5810 and a suitable

socket on the pinion flange nut, rotate the pinion

through several complete revolutions and record the

torque required to keep the pinion turning (fig. 82).

If flange is to be reused, mark pinion and flange for

reassembly in the same relative position.

5. Install Tool J-8614-1 on pinion flange and remove

pinion flange nut and washer (fig. 83). (Position
Fig. 82—Measuring Drive Pinion Bearing Preload

J-8614-1 on flange so that the four notches are

toward flange.) Discard nut and use a new one

upon reassembly.

6. Thread pilot end of Tool J-8614-3 into small O.D.

end of J-8614-2. Then with J-8614-1 installed as

in Step 4, insert J-8614-2 into J-8614-1 and turn

it 45 degrees to locked position. Remove flange by

turning J-8614-3 while holding J-8614-1 (fig. 84).

7. Pry old seal out of bore, using a screw driver or a

hammer and chisel.

8. Inspect pinion flange for smooth oil seal surface,

worn drive splines, damaged ears, and for smooth-

ness of bearing contact surface. Replace if

necessary.

9. If deflector requires replacement, remove by tapping

from flange, clean up stake points; install new de-

flector, and stake deflector at three new equally

spaced positions.

NOTE:
Staking operation must be performed

in such a manner that the seal operating surface

is not damaged.

1.0. Pack the cavity between the seal lips of the pinion

flange oil seal with a lithium-base extreme pressure

lubricant, position seal in bore, then using Tools

J-21468 and J-9458, for light-duty axle and Tool

Fig. 83-—Drive Pinion Nut Removal

CHEVROLET CHASSIS SERVICE MANUAL

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
5-3

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 5-6

Fig.
9—Brake Pedal Free Movement

one or two points in appropriate direction, replace

retainer, and re-inspect.

6. Place steel tube connector in hose fitting and tighten

securely.

7. Bleed all brakes as outlined in this section.

8. Do not tighten male end (wheel cylinder end) once

the other end is fixed. If necessary to tighten male

1 end, disconnect hose at opposite end, then reconnect

following above procedure.

Hydraulic Brake Tubing

Hydraulic brake tubing is a double layer annealed

steel terne plate tubing which resists corrosion and has

the physical strength to stand up under the high pr.es-
Fig.
11—Hydraulic Brake Tube Double Flaring Tool

sures which are developed when applying the brakes. In

making up hydraulic brake pipes, it is important that

the proper flaring tool be used to flare the ends of the

tubing for the compression couplings. Unless the tubing

is properly flared, the connections will leak and the

brakes will become ineffective.

CAUTION: When necessary to replace brake

tubing, always use special steel tubing which

is designed to withstand high pressure and re-

sist corrosion. Ordinary copper tubing is not

satisfactory and should not be used.

This safety steel tubing must be double-lap flared at

the ends in order to produce a strong leak-proof joint.

The brake tube flaring. Tool J-8051 (fig. 11) is used to

form the double-lap flare.

Figure 12 shows two pieces of tubing, one with single-

lap flare "A" and the other with double-lap flare "B".

It will be noted that the single-lap flare in "A" split

the tubing while the one shown in "B" is well-formed and

unbroken due to the reinforcement of the double wall.

The following procedure should be followed in making

up hydraulic brake pipes.

Double Lap Flaring

1.
Clamp the tubing in the proper size die blocks with

the flat ends of the blocks toward the end of the

tubing to be cut off. Cut the end of the tubing flush

and square. Using a mill file, dress tubing and

square ends.

Fig.
10-Brake Line Support Bracket

Fig.
12—Single and Double Lap Flaring

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