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

REAR SUSPENSION AND DRIVE LINE 4-29

REAR AXLE NOISE DIAGNOSIS

Mechanical failures of the rear axle are relatively

simple to locate and correct. Noise in a rear axle is a

little more difficult to diagnose and repair. One of the

most essential parts of rear axle service is proper

diagnosis.

Ail rear axles are noisy to a certain degree. The

action of transmitting the high engine torque through a

90° turn reducing propeller shaft speed produces noise

in rear axles. This point establishes the need for a line

between normal and abnormal or unacceptable axle

noises.

Slight axle noise heard only at a certain speed or under

remote conditions must be considered normal. Axle noise

tends to "peak" at varying speeds and the noise is in no

way indicative of trouble in the axle.

If noise is present in an objectionable form, loud or at

all speeds, an effort should be made to isolate the noise

as being in one particular unit of the vehicle. Axle noise

is often confused with other noises such as tire noise,

transmission noise, propeller shaft vibration and uni-

versal joint noise. Isolation of the noise as in any one

unit requires skill and experience. An attempt to elimini-

ate a slight noise may baffle even the best of diagnos-

ticians. Such practices as raising tire pressure to

eliminate tire noise, listening for the noise at varying

speeds and on drive, float and coast, and under proper

highway conditions, turning the steering wheel from left

to right to detect wheel bearing noise, will aid even the

beginner in detecting alleged axle noises. Axle noises

fall into two categories: gear noise and bearing noise.

GEAR NOISE

Abnormal gear noise can be recognized since it pro-

duces a cycling pitch and will be very pronounced in the

speed range at which it occurs, appearing under either

"drive," "float" or "coast" conditions. Gear noise

tends to peak in a narrow speed range or ranges, while

bearing noise will tend to remain constant in pitch. Ab-

normal gear noise is rare and usually originates from

the scoring of the ring gear and pinion teeth as a result

of insufficient or improper lubrication in new assemblies.

Side gears seldom give trouble as they are used only

when the rear wheels travel at different speeds.

BEARING NOISE

Defective bearings will always produce a whine that is

constant in pitch and varies with vehicle speed. This fact

will allow you to distinguish between bearing noise and

gear noise.

1.
Pinion bearing noise resulting from a bearing failure

can be identified by a constant rough sound. Pinion

bearings are rotating at a higher speed than differen-

tial side bearings or axle shaft bearings. This

particular noise can be picked up best by testing the

car on a smooth road (black top). However, care

should be taken not to confuse tire noise with bear-

ing or gear noise. If any doubt exists, tire treads

should be examined for irregularities that would

produce such noise.

2.
Wheel bearing noise may be confused with rear axle

noise. To differentiate between wheel bearings and

rear axle, drive the vehicle on a smooth road at

medium-low speed. With traffic permitting, turn
Fig.
74—Scored Hypoid Ring Gear

the vehicle sharply right and left. If noise is caused

by wheel bearings, it will increase in the turns be-

cause of the side loading. If noise cannot be isolated

to front or rear wheel bearings, inspection will be

necessary.

3.
Side bearings will produce a constant rough noise of

a slower nature than pinion bearings. Side bearing

noise will not fluctuate in the above wheel bearing

test.

Failure Analysis

The most common types of rear axle failures are

hypoid gear tooth scoring and fracture, differential gear

fracture. and/or differential bearing failure, and axle

shaft bearing failure.

Fig.
75-Cracked Hypoid Ring Gear

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

REAR SUSPENSION AND DRIVE LINE 4-33

Fig.
84—Drive Pinion Flange Removal

J-21057 for heavy-duty axle, press seal into bore

until it seats against shoulder (figs. 85 and 86).

CAUTION: Pinion oil seal flange must not bot-

tom against "carrier. Press seal into carrier

bore until it seats against internal shoulder -

do not apply unnecessary pressure after seal is

seated. To do so will destroy rubber seat ancl

distort seal. ;

11.
Position and align pinion flange on pinion shaft using

Tools J-9458 and
J-8614-1.
Tool J-9458-1 is

threaded onto pinion shaft and nut tightened against

J-9458-2 to pull flange on shaft (fig. 87). Remove
Fig.
86—Drive Pinion Flange Oil Seal

Installation (Heavy-Duty)

J-9458 after flange is seated.

NOTE: The position of the pinion and flange

was previously marked so that reinstallation

may be made with flange and pinion in same

relative position.

CAUTION: Do not attempt to hammer flange

onto pinion shaft. To do so will damage ring

gear and pinion.

12.

13.

14.

15.
Pack the cavity between end of pinion splines and

pinion flange with a non-hardening sealer (such as

Permatex Type A) prior to installing washer and

nut on pinion.

Install washer and a new self-locking nut on pinion

shaft. Tighten nut to remove end play and continue

alternately tightening in small increments and check-

ing preload with torque wrench until it is the same

as that recorded in Step 4.

Reassemble the rear universal joint, and torque

"V" bolt nuts to specifications.

Lower vehicle to floor and road test for leaks.

Fig.
85—Drive Pinion Flange Oil Seal

Installation (Light-Duty)
Fig.
87—Drive Pinion Flange Installation

CHEVROLET CHASSIS SERVICE MANUAL

REAR SUSPENSION AND DRIVE LINE 4-37

9. Connect spring end link bolts as outlined under

Spring--Installation, in this section.

10.
Remove filler plug, located on right side of cover,

and fill -with hypoid lubricant to level of filler hole.

11.
Lower vehicle and road test for leaks, noise and

general performance.

POSITRACTION DIFFERENTIAL UNIT

The optionally available Positraction differential unit

is installed in the conventional carrier to replace the

standard differential unit.

Service procedures for the Positraction equipped axle

are the same as on a conventional axle except for the.

operations listed below.

On the Vehicle Check

If vehicle is equipped with a manual transmission, shift

transmission into neutral.

1.
Raise rear of vehicle until wheels are off the ground,

remove one wheel and tire assembly.

2.
Attach Adapter J-5748 to axle shaft flange and install

a
1/2-13
bolt into adapter (fig. 97).

3.
With wheel and tire assembly still on vehicle held

firmly to prevent turning, measure torque required
Fig.
97—Measuring Positraction Rotating Torque

to rotate opposite axle shaft with a 0-150# torque

wrench attached to J-5748. Torque should be 70

ft.
lbs. minimum new, and no less than 40 ft. lbs. if

used.

PROPELLER SHAFT AND UNIVERSAL JOINTS

INDEX

Page
Page

General Description 4-37

Component Parts Replacement. 4-38

Propeller Shaft (Dana) 4-38

Removal 4-38

Repairs 4-38
Installation 4-39

Propeller Shaft (Saginaw) 4-40

Removal 4-40

Repairs 4-40

Installation 4-41

GENERAL DESCRIPTION

The one-piece, exposed-type, tubular propeller shaft is

used on all models. The cardon-type universal joints are

of the extended-life design and do not require periodic

maintenance. A splined front yoke on the front end of the

propeller shaft extends into a splined coupling on the

transmission output shaft. This slip joint permits slight

lengthening and shortening of the propeller shaft to com-

pensate for up and down movement of the rear axle
assembly.

A light duty (fig. 98) and a heavy duty (fig. 99) version

of the tubular propeller shaft is used. The heavy-duty

shaft incorporates a damper, as part of the sleeve yoke,

at the transmission end of the shaft. This damper is not

serviced separately—the sleeve and damper (fig. 100)

must be replaced as an assembly.

Two different methods are used to retain the trunnions

Fig.
98—Light-Duty Propeller Shaft Cross-Section (Dana Design)

CHEVROLET CHASSIS SERVICE MANUAL

REAR SUSPENSION AND DRIVE LINE 4-40

Fig.
106—Removing Propeller Shaft from Companion Flange

PROPELLER SHAFT (SAGINAW)

Removal

1.
Raise vehicle sufficiently to permit access to propel-

ler shaft and mark relationship of rear yoke to

companion flange.

2.
Remove trunnion bearing retaining strap attaching

screws from both bearings (fig. 106).

3.
Lower rear of propeller shaft, being careful not to

dislodge bearing caps from trunnion, and tape bear-

ing caps to trunnion.

4.
Withdraw propeller shaft front yoke from transmis-

.sion by moving shaft rearward, passing it under the

axle housing. Watch for oil leakage from transmis-

sion output shaft housing.

Repairs

NOTE:
Because of the elastic properties of the

nylon retainers, the trunnions must be pressed

from the yokes. Pressing the trunnions from the

yokes will shear the retainers which renders

the bearing caps unsuitable for reuse. A service

Jdt, which employs a snap ring to retain the

trunnion, must be used when reassembling the

propeller shaft (fig. 107).

1.
Remove trunnion at differential end of propeller shaft

Fig.
107—Service Kir Trunnion (Saginaw)
Fig.
108—Pressing Trunnion Bearing from Propeller Shaft

using the following procedure:

a. Support trunnion on a press bed so that the

propeller shaft yoke can be moved downward.

Support front of propeller shaft so that shaft is

in a horizontal position.

b.
Using a piece of pipe or similar tool, with an ins-

side diameter slightly larger than 1 1/8", press

bearing from yoke (fig. 108).

c. Apply force on yoke around bearing until nylon

retainer breaks. Continue to apply force until the

downward movement of the yoke forces the bear-

ing as far as possible from the yoke (fig. 109).

d. Complete removal of bearing by tapping around

circumference of exposed portion with a small

hammer (fig. 110).

e. Rotate propeller shaft so that opposite bearing

-may be removed in the manner described above.

f. Remove trunnion from yoke.

Remove trunnion at transmission end of propeller

shaft using the following procedure:

a. Support splined yoke on a press bed and the rear

of the propeller shaft on a stand so that shaft is

horizontal. Be sure that weight is evenly dis-

tributed on each side of the splined yoke and that

the fixed yoke half of the "U" joint is free to

move downward.

b.
Using a piece of pipe or similar tool, with an

inside diameter slightly larger than 1 1/8", press

bearing from yoke (fig. 108).

c. Apply force on yoke around bearing until nylon

retainer breaks. Continue to apply force until the

downward movement of the yoke forces the bear-

ing as far as possible from the yoke (fig. 109).

d. Complete removal of bearing by tapping around

circumference of exposed portion with a small

hammer (fig. 110).

e. Rotate propeller shaft so that opposite bearing

may be removed in the manner described above.

f. Remove splined yoke and trunnion from propeller

shaft.

CHEVROLET CHASSIS SERVICE MANUAL

REAR SUSPENSION AND DRIVE LINE 4-42

Fig.
113—Rear Suspension Special Tools (Chevrolet, Camaro, Chevelle and Chevy II)

1.
J-8614

2.
J-21057

3. J-21468

4. J-5748

5. J-21830

6. J-7574

7. J-7877

8. J-21474

9. J-9458
Companion Flange Remover—Consists of J-8614-1

Holder, J-8614-2 Nut and J-8614-3 Screw.

Drive Pinion Oil Seal Installer—Heavy-Duty Axle.

Drive Pinion Oil Seal Installer—Light Duty

Axle—Used with J-9458.

Positraction Torque Measuring Adapter.

Upper and Lower Control Arm Bushing Puller-

Consists of J-21830-2 Adapter, J-21830-4 Receiver,

J-21830-7 Bridge—Used with J-21058-6 Spacer,

and J-21830-3 Spacer.

Chevrolet Lower Control Arm Front Bushing

Remover/Installer—Consists of J-7574-4 Receiver,

J-7574-1 Remover, J-7574-2 Installer Adapter,

J-7574-3 Spacer.

Chevrolet Tie Rod Bushing Remover/Installer—Consists

of J-7877-1 Remover Adapter, J-7877-2 Bushing

Receiver, J-7877-3 Installer Adapter—Used with

j-7079-2
Handle.

Chevelle Control Arm Bushing Remover—Consists of

J-21474-5 Receiver, J-21474-1 Spacer and

J-21474-2 Adapter.

Drive Pinion Oil Seal Installer—Light Duty

Axle—Used with J-21468.
10.
J-21051 Rear Wheel Bearing and Oil Seal Installer-

Heavy Duty Axle—Used with J-7079-2.

11.
J-21491 Rear Wheel Bearing and Oil Seal Installer—Light

Duty Axle—Used with J-8092.

12.
J-2619 Rear Wheel Bearing and Oil Seal Remover (Slide

Hammer).

13.
J-8119 Rear Wheel Bearing and Oil Seal Remover—Used

with J-2619.

14.
J-21058 Upper and Lower Control Arm Puller—Consists of

J-21058-15 Screw and J-21058-8 Nut—Used

with J-21830.

15.
J-8092 Driver.Handle—Threaded Type.

16.
J-7079-2 Driver Handle—Insert Type.

17.
J-21548 Propeller Shaft "U" Joint Trunnion Seal Installer.

18.
J-21991 Chevelle Upper Control Arm Carrier- Bushing

Remover Adapter.

19.
J-5853 Torque Wrench—In. lbs.

20.
J-5810 Torque Wrench Adapter (3/4" to 3/8")

21.
J-1313 Torque Wrench—ft. lbs.

Tools Not Illustrated

J-22553 Rear Spring Front Bushing Remover/Installer Consists

of J-22553-1 Receiver, J-22553-2 Installer—Used

with J-21978-1 Receiver, J-21058-8 Nut and

J-21058-15 Puller Screw.

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
5-3

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 5-7

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