front brakes CHEVROLET CAMARO 1967 1.G Chassis Owner's Manual

BRAKES 5-22

2.
Replace ail push rods and pull back springs.

3.
Connect hose or line to wheel cylinder.

NOTE:
If replacing front wheel cylinder, con-

nect hose and inspect installation as outlined in

"Hydraulic Brake Hose Replacement".

4.
Install drum and wheel.

5. Bleed brakes as outlined in this section.

ANCHOR PIN

Front Wheel

1.
Raise front of vehicle and place on jack stands.

2.
Remove wheel and drum as outlined in this section.

3.
Remove brake shoe pull back springs, link and guide

plate.

4.
Disengage anchor pin lock and remove anchor pin by

turning counterclockwise.

5. Place new lock plate on anchor pin and pass pin

through the hole in flange plate and screw into tapped

hole in spindle support.

6. Torque pin to 130 lb. ft. and lock by peening over

washer tabs.

7. Install brake shoe guide plate, link and pull back

springs.

8. Adjust brakes, install drum and wheel as outlined

in this section. Test brake operation.

Rear Wheel

Two type anchor pins are used in production for the

rear wheels. The riveted type is not serviced and if

failure or damage should occur to either the anchor

pin or flange plate, both parts will have to be replaced

and the threaded type anchor pin used.

Threaded Type

1.
Raise rear of vehicle and place on jack stands,

2.
Remove wheel and drum as outlined in this section.

3.
Remove brake shoe pull back springs, link and guide

plate.

4.
Remove anchor pin retaining nut and washer and

remove pin from flange plate.

5. Position anchor pin to flange plate, install lock

washer and nut, and torque pin to 80 lb. ft.

6. Install brake shoe guide plate, link and pull back

springs.

7. Adjust brakes and install drum and wheel as outlined

in this section.

8. Test brake operation.

BRAKE DRUMS

Front brake drums are the demountable type; that is,

they can be removed without removing the hub. Rear

brake drums are demountable and may be removed

wihtout removing the axle shaft.

A lanced "knock out" area (fig. 34) is provided in

the web of the brake drum for servicing purposes in

the event retracting of the brake shoes is required in

order to remove the drum.

A small screw driver or hooked wire may be inserted

to disengage the automatic adjuster actuating lever so

the star wheel may be turned.

Removal

1.
Raise vehicle and place on jack stand.
2.
Remove wheel and tire assembly, back off brake

adjustment and remove drum.

Inspection and Reconditioning

Whenever brake drums are removed they should be

thoroughly cleaned and inspected for cracks, scores,

deep grooves, and out-of-round. Any of these conditions

must be corrected since they can impair the efficiency

of brake operation and also can cause premature failure

of other parts.

Smooth up any slight scores by polishing with fine

emery cloth. Heavy or extensive scoring will cause

excessive brake lining wear and it will probably be

necessary to rebore in order to true up the braking

surface.

An out-of-round drum makes accurate brake shoe

adjustment impossible and is likely to cause excessive

wear of other parts of brake mechanism due to its

eccentric action.

A drum that is more than .008" out-of-round on the

diameter is unfit for service and should be rebored.

Out-of^round, as well as taper and wear can be ac-

curately measured with an inside micrometer fitted

with proper extension rods.

If drum is to be rebored for use with standard size

brake facings which are worn very little, only enough

metal should be removed to obtain a true smooth braking

surface.

If drum has to be rebored more than .020" over the

standard diameter, it should be rebored to .060" diameter

oversize and the brake facing should be replaced with

.030"
oversize facings.

A brake drum must not be rebored more than .060"

over the maximum standard diameter, since removal

of more metal will effect, dissipation of heat and may

cause distortion of drum. Chevrolet brake facing is

not furnished larger than .030" oversize and this will

not work efficiently in drums bored more than .060"

oversize.

Brake drums may be refinished either by turning or

grinding. Best brake performance is obtained by turning

drums with a very fine feed. To insure maximum lining

life,
the refinished braking surface must be smooth and

free from chatter or tool marks, and run-out must not

exceed .005" total indicator reading.

Cleaning

New brake drums in parts stock are given a light.

coating of rust proofing oil to prevent the formation of

rust on the critical braking surfaces during the time

that the drums are in storage.

This rust proofing oil must be carefully removed

before the drum is placed in service to prevent any

of this oil from getting on the brake shoe facings, which

might cause an extreme brake grab condition.

It is recommended that a suitable volatile, non-toxic,

greaseless type solvent be used to clean the oil from the

braking surface of the new brake drums before they are

•placed in service to insure the cleanest possible surface.

Gasoline or kerosene should not be used as there is

danger that a portion of the diluated oil substance may

be left on the braking surface that may later cause

difficulty.

Installation

1.
Make brake adjustment as outlined in this section.

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES
5-24

DISC BRAKES

INDEX

Page

General Description
. 5-24

Maintenance
and
Adjustments
5-24

Bleeding Hydraulic System
5-24

Parking Brake Adjustment
-
Corvette
5-24

Component Replacement
and
Repairs
5-25
Page

Brake Shoes
. . . . . 5-25

Brake Caliper
5-26

Brake Disc
5-29

Main Cylinder.
5-30

Parking Brake Shoes
-
Corvette
5-30

GENERAL DESCRIPTION

Four wheel disc brakes
are
standard equipment
on

the
1967
Corvette,
as in 1966. The
Corvette
may
also

be equipped with heavy duty disc brakes which include

new front calipers, shoes, linings,
and
rear pressure

regulator valve. This heavy duty option
is
used
in

conjunction with
a
vacuum power unit. Front wheel disc

brakes
are
installed
as
optional equipment
on
Chevrolet,

Chevelle, Camaro,
and
Chevy
II
models.

The disc brake,
(fig. 35),
consists
of a
fixed caliper,

rotating disc, splash shield,
and
mounting bracket.
The

caliper assembly contains four pistons and two shoe
and

lining assemblies with
the
lining riveted
to the
steel

shoes.
A
seal
and
dust boot
are
installed
on
each piston,

with
a
piston spring
in the
caliper cylinder bore beneath

each piston.
A
retaining pin extends through each caliper

half
and
both shoes
to
hold
the
shoes and linings
in
posi-

tion
in the
caliper.
On
Corvette heavy duty disc brakes,

two retaining cotter pins
are
used
at
each end
of the

caliper
to
secure
the
shoes
and
linings. Machined
sur-

faces within
the
caliper prevent
the
shoe
and
lining
assembly from rotating with
the
brake disc when pres-

sure
is
applied.

The disc, which
has a
series
of air
vent louvers
to

provide cooling,
is
mounted
on the
front wheel-hub.

The caliper straddles
the
disc and mounts
on a
mounting

bracket attached
to the
steering knuckle with
two
bolts.

The Corvette heavy duty option includes
a
pressure

regulator valve mounted
in the
rear brake line just

below
the
main cylinder. Chevrolet, Chevelle, Camaro,

and Chevy
n
models with disc brakes have
a
pressure

regulator valve mounted
in the
front brake line just

below
the
main cylinder. The valve controls
the
hydraulic

pressure
to the
front
or
rear brakes,
as
applicable,

resulting,
in the
correct pressure balance between
the

front
and
rear hydraulic systems. This valve guards

against premature .lock-up
of
front
or
rear wheels when

brakes
are
applied.

Maintenance, adjustment,
and
service operations which

are
not
included
in
this section
are the
same
as for

the Duo-Servo type brakes.

MAINTENANCE
AND
ADJUSTMENTS

BLEEDING HYDRAULIC SYSTEM

The operation
of
bleeding
the
disc brake hydraulic

system
is the
same
as for
Duo-Servo system outlined

in
the
front
of
this section. Note
the
exceptions below

and refer
to
bleeding procedures under Duo-Servo

brakes.

1.
When pressure bleeding equipment
is
used,
the

correct pressure setting
for
bleeding disc brakes

is 10-2.0
lbs. on
Corvette,
and 40 lbs. on all
other

models.

2.
The
front calipers contain
one
bleeder valve.
The

rear calipers
on
Corvette contain two bleeder valves

(one inboard
and one
outboard) which necessitates

the removal
of the
rear wheels
for
bleeding.

3.
Tapping
the
caliper with
a
rawhide mallet
as the

fluid
is
flowing
out may
assist
in
obtaining
a
good

bleeding
job.

4.
On
Chevrolet, Chevelle, Camaro
and
Chevy
II, the

spring loaded
end of the
pressure regulator valve

(fig.
36)
must
be
held (valve
in
open position) while

bleeding. This
is
done
by
depressing
and
holding

in
the
plunger
in the
end
of
the valve either
by
hand,

by taping,
or by
clamping.
PARKING BRAKE-CORVETTE

Adjustment

1.
Raise rear
end of
vehicle
and
place
on
jack stands.

2.
Remove rear wheels.

3/
Loosen brake cables
at the
equalizer until
the
park-

ing brake levers move freely
to the "off"
position

with slack
in the
cables.

4.
Turn
the
disc until
the
adjusting screw can
be
seen

through
the
hole
in the
disc.

5. Insert
an
adjusting tool
or
screw driver through
the

hole
in the
disc
and
tighten
the
adjusting screw
by

moving your hand away from
the
floor
on
both
the

left and right sides
(fig. 37).

6. Tighten until
the
disc will
not
move, then back
off

ten
(10)
notches.

7. Apply
the
parking brake four
(4)
notches from inside

the
car.

8. Tighten
the
brake cables
at the
equalizer
to
produce

a light drag with
the
wheels mounted.

9. Fully release
the
parking brake handle
and
rotate

the rear wheels.
No
drag should be evident with
the

handle released.

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES 5-25

CORVETTE
CHEVELLE-CAMARO-CHEVY II

Fig.
35-Disc Brake-Cutaway View

COMPONENT REPLACEMENT AND REPAIRS

BRAKE SHOES

Shoes 'with bonded linings should be replaced when the

groove in the center of the lining is worn off leaving

approximately 1/16 inch of lining thickness. Shoes with

linings retained by rivets should be replaced when the

lining is worn to approximately .020" thickness over

the rivet heads.

Removal

1.
Siphon 2/3 of the brake fluid from the main cylinder

reservoirs.

CAUTION: If fluid is not removed, insertion

of the new full thickness lining will force the

pistons back into the housing displacing fluid •••

into the master cylinder. This will cause fee

main cylinder to overflow,, Do not drain the

reservoirs completely or air will be pumped

into the system. ~
2.
Raise vehicle and place on jackstands.

3..
Remove wheels.

4.
Remove and discard the cotter pin from the inboard

end of the shoe retaining pin and slide out the re-

taining pin. On Corvette with heavy duty disc brakes,

two retaining pins must be removed, one on each

end of the caliper assembly.

5. Remove the inboard shoe by rotating either end of

shoe out of caliper and pulling shoe out.

6. Insert new shoe with lining into position. Use a

putty knife to push each piston back as the shoe is

inserted as shown in Figure 38.

7. Replace the outboard shoe as described above. When

both caliper shoes have been replaced, install the

shoe retaining pin through outboard caliper
half,

outboard shoe, inboard shoe, and inboard caliper

half.
Insert a new 3/32 x 5/8 plated cotter pin

through the retaining pin and bend back ends of

cotter pin. (On Corvette heavy duty front caliper,

CHEVROLET CHASSIS SERVICE

BRAKES 5-26

PRESSURE

REGULATOR

VALVE

CHEVROLET
PRESSURE

REGULATOR

VALVE

CAMARO

Fig.
36—Pressure Regulator Valve—Chevrolet and Camaro Shown

install two retaining cotter pins, one at each end of

the caliper.)

8. Repeat above procedure at each wheel where shoes

are to be replaced.

9. Refill main cylinder to fluid level shown in Figure

8. If necessary, bleed brake system as outlined in

this section.

10.
Install wheels and lower vehicle.

BRAKE
CALIPER

Removal

1.
Raise vehicle and place on jackstands.
2.
Remove wheel.

3.
On front caliper, disconnect the brake hose at brake

line support bracket. On Corvette rear caliper,

disconnect the brake tubing from the inboard caliper.

Tape the open tube or line end to prevent foreign

matter from entering the system.

4.
Pull cotter pin from end of shoe assembly retaining

pin.
Remove the pin and shoe assembly from the

Fig.
37—Adjusting Parking Brake Shoes
Fig.
38—Replacing Shoe and Lining Assembly

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES 5-27

CHEVELLE
, CHEVY II AND CAMARO SHOWN

1.
Caliper Belts

2.
Bleeder Valve

3. Caliper Half

4.
Piston Spring
Fig.
39-Caliper Assembly-Exploded View

5. Seal

6. Piston

7. Piston Boot

8. Brake Shoes
9. "O" Ri

10.
Caliper

11.
Retaining Pin

12.
Cotter Pin

caliper. Two retaining pins must be removed on

heavy duty Corvette front calipers. Identify the

inboard and outboard shoe if they are to be reused.

5. Remove the end of brake hose at bracket by re-

moving U-shaped retainer from the hose fitting and

withdrawing the hose from bracket.

6. Remove the caliper assembly from the mounting

bracket by removing two hex head bolts.

Disassembly (Fig. 39)

1.
Clean exterior of caliper with Declene, or equivalent.

On Chevrolet and Corvette front caliper, remove

brake hose.

2.
Separate the caliper halves by removing the two

large hex head bolts. Remove the two small "O"

rings from the cavities around the fluid transfer

holes in the two ends of the caliper halves.

3.
To free the piston boots so that the pistons may be

removed, push the piston down into the caliper

as far as it will go. Insert a screwdriver blade

under the inner edge of the steel ring in the boot,

and using the piston as a fulcrum, pry the boot from

its seat in the caliper
half.
CAUTION: Use care not to puncture seal when

removing pistons from caliper. ' ~

4.
Remove the pistons and piston springs from the

caliper
half.
Remove the boot and seal from their

grooves in the piston.

Cleaning and Inspection

1.
Clean all metal parts using Declene, or equivalent.

Remove all traces of dirt and grease. Do not use

mineral base solvents to clean brake parts.

2.
Using an air hose, blow out all fluid passages in the

caliper halves, making sure that there is no dirt

or foreign material blocking any of these passages.

3.
Discard all rubber parts. Boots, seals, and "O"

rings should be replaced with new service kit parts.

4.
Carefully inspect the piston bores in the caliper

halves. They must be free of scores and pits. A

scored or otherwise damaged bore will cause leaks

and unsatisfactory brake operation. Replace the

caliper half if either bore is damaged to the extent

that polishing with very fine crocus cloth will not

restore it.

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES 5-28

Fig.
40—Installing Piston in Caliper Bore Using

Tool J-22591
Fig.
41—Installing Boot Seal in Caliper Bore

Using Tool J-22592

5.
Check the fit of the piston in the bore using a feeler

gage.
Clearance should be as follows:

2 1/16 inch Bore .0045 to .010

1 7/8 inch Bore .0045 to .010

1 3/8 inch Bore .0035 to .009

If the bore is not damaged, and the clearance exceeds

either of the upper limits, a new piston will be required.

Assembly

1.
Assemble the seal in the groove in the piston which

is closest to the flat end of the piston. The lip on

the seal must face toward the large end of the

piston. Be sure lips are in the piston groove and do

not extend over the step in the end of the groove.

2.
Place the spring in the bottom of the piston bore.

3.
Lubricate the seal with dean brake fluid.

4.
Install the piston assembly in the bore using appli-

cable piston rign compressor Tool J-22639, 22629

or 22591 as shown in Figure 40. Use care not to

damage the seal lip as piston is pressed past the

edge of the bore. .

5.
Assemble the boot in the groove of the piston closest

to the concave end of the piston. The fold in the boot

must face toward the end of the piston with the seal

on it.

6. Depress the pistons and check that they slide

smoothly into the bore until the end of the piston is

flush with the end of the bore. If not, re check piston

assembly and location of the piston spring and the

seal.

7.
Position applicable boot seal installer Tool J-22592,

J-22628, or J-22638 over the piston and seat the

steel boot retaining ring evenly in the counterbore

as shown in Figure 41. The boot retaining ring must

be flush or below the machined face of the caliper.

Any distortion or uneven seating could allow con-

taminating and corrosive elements to enter the bore.
8. Position the t:O}> rings in the small cavities around

the brake fluid transfer holes in both ends of the

outboard caliper halves. Lubricate the hex head

. bolts with Delco Brake Lube or clip in clean brake

fluid. Fit caliper halves together and secure with

bolts.
Refer to torque specifications in rear of

manual for correct torque valves.

Installation

1.
Carefully mount the assembled caliper over the edge

of the disc. Use a putty knife to depress pistons so

that the caliper can be lowered into position on the

disc (fig. 42). Use care to prevent damage to boots

• on the edge of the disc as the caliper is mounted.

2.
Secure the caliper to the mounting bracket with two

hex head bolts. Refer to torque specifications in

rear of manual for correct torque values.

CAUTION: If replacing old shoe assemblies,

be sure to get the shoes in the same position

from which they were removed. New shoe as-

semblies have an arrow printed on the back,

showing the direction of forward disc rotation.

3.
Install the shoe and lining assemblies as outlined in

this section.

4.
On Chevrolet and Corvette front calipers, place a

new copper gasket on the male end of the front

wheel brake hose. On all models, install brake hose

in the calipers. With the wheels straight ahead,

pass the female end of the brake hose through the

support bracket.

5.
Make sure the tube seat is clean and connect the

break line tube nut to the caliper. Tighten securely.

6. Allowing the hose to seek a normal position, without

twist, insert hex of the hose fitting into the 12-point

hole in the support bracket and secure it in place

with the "V"-shaped retainer. Turn the steering

geometry from lock to lock while observing the hose.

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES 5-29

Fig.
42—Installing Caliper on Disc

Check that the hose does not touch other parts at

any time during suspension or geometry travel.

If contact does occur, remove the U-shaped retainer

and rotate the end of the hose in the support bracket

one or two points in a direction which will eliminate

hose contact. Reinstall the retainer and recheck

for hose contact. If it is satisfactory, place the

steel tube connector in the hose fitting and tighten

securely.

If rear brake caliper is being serviced, connect

brake line to caliper.

Bleed brakes as outlined in this section.

Install wheels and lower vehicle.

BRAKE DISC

Servicing of the disc brakes is extremely critical

due to tolerances required in machining of the brake

disc to insure proper brake operation. In manufacturing

the brake disc, tolerances of the rubbing surfaces for

flatness is .001 and for parallelism is .0005, while

lateral runout of the faces must not exceed .004 total.

The maintenance of these close controls of the shape of

the rubbing surfaces is necessary to prevent brake

roughness. In addition, the surface finish must be non-

directional and maintained at 30-50 micro-inches. This

control of the rubbing surface finish is necessary to

avoid pulls and erratic performance and promote long

lining life and equal lining wear of both left and right

brakes.

tight scoring of the disc surfaces not exceeding .015

in depth, which may result from normal use, is not

detrimental to brake operation.

When the total disc thickness is less than .965 for the

1"
thick disc or 1.215 for the 1-1/4" thick disc, it should

be replaced. Disc thicknesses less than this can permit

the shoes to come out of contact with the shoe abutments

and cause malfunction.

Because performance is not impaired by surface im-

perfection not exceeding .015 deep, refinishing of the

rubbing surface is not necessary.
Fig.
43—Dial Indicating Disc Runout

Since extremely accurate control of the finishing oper-

ation is necessary for proper performance and excess

metal removal can cause malfunction, refinishing of the

rubbing surface is not recommended.

Checking Procedure (Fig. 43)

Front

Tighten the adjusting nut of the wheel bearing until all

play has been removed. It should be just loose enough

to allow the wheel to turn. Clamp a dial indicator to the

caliper so that its button contacts the disc at a point about

1 inch from the outer edge. When the disc is turned, the

indicator reading should not exceed .002 inches. If runout

exceeds this amount the hub and disc assembly should

be replaced. Due to the close tolerances involved it is

not recommended that the front discs be machined or

serviced separately.

After checking the runout, readjust, the wheel bearings

as outlined in Section 3 of this manual.

Rear—Corvette Only

Check the rear wheel bearing end play, as outlined in

Section 4 of this manual. Then dial indicate the disc face.

If lateral runout of the disc exceeds the bearing end play

by .003 inches, the disc should be refaced (not to exceed

.040 inches) or replaced.

Removal

1.
Raise vehicle and remove wheel and tire assembly.

/ 2. Remove brake caliper as outlined in this section.

3.
Drill out the five rivets attaching the disc to the hub

or spindle.

4.
Remove brake disc from vehicle.

5. Complete the removal of the five rivets from the

hub or spindle.

Installation

1.
Install the disc to the hub or spindle aligning the lug

bolts with the holes in the disc.

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES
5-31

POWER BRAKES

INDEX

General Description 5-31

Maintenance
and"
Adjustments 5-31

Inspection . ... 5_31

Lubrication 5-31

Bleeding Instructions . . . 5.31

Air Cleaner Service . . . , 5.31
Page

Component Replacement 5-31

Power Brake Cylinder ......* 5-31

Removal . . 5-31

Disassembly and Assembly See Overhaul Manual

Installation . . . . 5-31

GENERAL DESCRIPTION

The Power Brake Unit is a self-contained hydraulic

and vacuum unit, utilizing manifold vacuum and atmos-

phere pressure for its power.

This unit permits the use of a low brake pedal as well

as less pedal effort than is required with the conventional

(nonpower) hydraulic brake system. Only two external
line connections are necessary -
one
a vacuum connection

from manifold to check valve located on front shell; the

other, a hydraulic connection from the main cylinder

outlet directly into the hydraulic system. The unit is

mounted on the engine side of the fire wall and directly

connected to the brake pedal.

MAINTENANCE AND ADJUSTMENTS

INSPECTIONS

1.
Check vacuum line and vacuum line connections as

well as vacuum check valve in front shell of power

unit for possible vacuum loss.

2.
Inspect all hydraulic lines and connections at the

wheel cylinders and main cylinder for possible

hydraulic leaks.

3.
Check brake assemblies for scored drums, grease

or brake fluid on linings, worn or glazed linings,

and make necessary adjustments.

4.
Check brake fluid level in the hydraulic reser-

voirs.
The reservoirs should be filled to the levels

shown in Figure 8.

5. Check for loose mounting bolts at main cylinder and

at power section.

6. Check air cleaner filter in power piston extension

and replace filter if necessary.

7. Check brake pedal for binding and misalignment

between pedal
-and
push rod.

LUBRICATION

The power brake unit is lubricated at assembly and
needs no further lubrication other than maintaining

normal reservoir fluid level. The reservoir should be

filled as described in this section.

BLEEDING INSTRUCTIONS

The power system may be bled manually or with a

pressure bleeder as outlined in this section. Use only

GM
Supreme 11 Brake Fluid or equivalent. Do not use the

power assist while bleeding. The engine should not be

running and the vacuum reserve should be reduced to

zero by applying the brake several times before starting

the bleeding procedure.

AIR CLEANER SERVICE

Servicing of the air cleaner is recommended and the

element replaced when restriction becomes severe

enough to affect power brake response. At any other

time, if cleaning of the filter is felt necessary, it should

be shaken free of dirt or washed in soap and water and

thoroughly dried.

COMPONENT REPLACEMENT

POWER BRAKE CYLINDER

Removal

1.
Remove vacuum hose from vacuum check valve.

2.
Disconnect hydraulic lines at main cylinder.

Disconnect push rod at brake pedal assembly.

Remove nuts and lock washers securing power unit

to fire wall, and remove power unit from engine

compartment.
3.

4.

NOTE:
Chevy

to fire wall.
has a three stud attachment

Repair procedures for the power cylinder are outlined

in the Brake Section of the Overhaul Manual-for service
of the main cylinder refer to applicable portion of

"Standard Brakes" in this manual.

Installation

1.
Mount the power brake assembly in place and install

the attaching nuts and lock washers.

2.
Attach vacuum line to check valve.

3.
Secure hydraulic lines to main cylinder.

4.
Attach push rod to brake pedal assembly, and check

operation of stop light.

5. Bleed brakes as outlined in this section.

CAUTION: After replacing the unit on the vehi-

cle,
start the engine and allow vacuum to build

up before applying the brake.

CHEVROLET CHASSIS SERVICE

STEERING
9-32

arm on frame and install mounting bolts, washers

and nuts. No washer is used on Corvette.

Install relay rod to idler arm, ^making certain seal

is on stud. Install and tighten nut.

Install cotter pin.

Refer to torque specifications at rear of manual for'

correct torque values.

Chevy II (Fig. 62}

Removal

1.
Remove cotter pin, nut and washer securing idler

arm to relay rod.

2.
Remove relay rod from idler arm.

3.
If equipped with power steering disconnect power

cylinder shaft from idler arm bracket.

4.
Remove three idler bracket to frame bolts and nuts

and remove bracket and idler arm assembly.

5.
Remove cotter pin, nut, washer and bolt securing the

idler arm to the bracket.

6. Press out the idler arm bushing for replacement.

Installation

NOTE: Installation must be done with front

wheels straight ahead or the car will lead to one

side.

1.
Install idler arm bushing, if previously removed.

NOTE: Make certain the outer sleeve of the

bushing does not protrude above surface of idler

arm.

2.
Reverse removal procedure and torque all nuts ac-

cording to specifications.

PITMAN ARM

Removal

1.
Remove cotter pin from pitman arm ball stud and

remove nut.

2.
Remove relay rod from pitman arm by tapping on

side of rod or arm in which the stud mounts with a

hammer while using a heavy hammer or similar tool

as a backing. Pull down on relay rod to remove

from stud.

3.
Remove pitman arm nut from sector shaft and mark

relation of arm position to shaft.

4.
Remove pitman arm with Tool J-6632 as shown in

Figure 2.

Installation

1.
Install pitman arm on sector shaft, lining up the

• marks made upon removal.

2.
Install sector shaft nut.

3.
Position relay rod on to pitman arm. Install nut.

Continue to tighten arm enough to align castellation

with hole in stud and install cotter pin.
STEERING ARM

If, through collision or other damage, it becomes nec-

essary to remove and replace either steering arm, pro-

ceed as follows:

Removal

1.
Remove tie rod from steering arm as outlined in this

section.

2.
Remove front wheel, hub and brake drum as a unit

by removing hub cap and dust cap, cotter pin from

spindle nut and the spindle nut. Pull assembly to-

ward outside of vehicle. If removal is difficult, it

may be necessary to back off brake adjustment to

increase brake shoe-to-drum clearance; see Hy-

draulic Brake Adjustment, Section 5. On models

with disc brakes, remove caliper and disc.

3.
With wheel and drum assembly or caliper and disc

removed, steering arm retaining bolt heads are ac-

cessible and removal of steering arm from vehicle

may be accomplished by removing retaining nuts.

Installation

1.
Place steering arm in position on vehicle and install

retaining bolts*

2.
Install nuts. Use only the special locknut listed for

this use in the Chevrolet Parts Catalog.

3.
Pack wheel bearings using a high quality wheel

bearing lubricant. Install bearings and wheel-hub-

brake drum assembly removed previously. On disc

brake models, install disc and caliper.

4.
Install keyed washer and spindle nut. Proceed as out-

lined under t{ Front Wheel Bearing Adjustment" in

Section 3.

5.
Install tie rod ball stud in steering arm. Be sure that

the dust cover is in place on ball stud.

6. Install castellated nut on ball stud, tighten securely

and install cotter pin.

7.
Following directions given in Section 3 to check cor-

nering wheel relationship and toe-in; correct as

required.

STEERING DAMPER-CORVETTE

Removal

1.
Remove bolt from damper pivot bracket at relay rod.

2.
Remove nut from damper pivot at frame bracket and

withdraw damper assembly.

Damper is serviced as a unit. Replace damper if
3.

damaged or excessively worn.

Installation

1.
Place piston rod end into frame bracket and install

retainers, bushings, and nut.

2.
Insert cylinder end pivot into relay rod bracket and

install through bolt.

CHEVROLET CHASSIS SERVICE MANUAL

WHEELS AND TIRES 10-2

either case, tires will revolve with a side motion and

scrape the tread rubber off. If misalignment is severe,

the rubber will be scraped off of both tires (or all four

tires if front toe is not correct); if slight, only one will

be affected.

The scraping action against the face of the tire causes

a small feather edge of rubber to appear on
one .side
of

the tread and this feather edge is certain indication of

misalignment (fig. 1). The remedy is. readjusting toe-in

within specifications, or rechecking the entire front end

alignment if necessary.

Heei and Toe

This is a saw-toothed effect where one end of each

tread block is worn more than the other.

The end that wears is the one that first grips the road

when the brakes are applied.

Heel and toe wear is less noticeable onsrear tires than

on front tires, because the propelling action of the rear

wheels creates a force which tends to wear the opposite

end of the tread blocks. The two forces, propelling and

braking, make for more even wear of the rear tires,
whereas only the braking forces act on the front wheels,

and the saw-tooth effect is more noticeable.

A' certain amount of heel and toe wear is normal.

Excessive wear is usually due to high speed driving and

excessive use of brakes. The best remedy, in addition

UNDERINFLATION WEAR

Fig.
1 - Toe In or Toe Out Misalignment Wear
Fig.
2 - Over and Under Inflation Wear

CHEVROLET CHASSIS SERVICE MANUAL