1967 CHEVROLET CAMARO engine

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

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 5-9

COMPONENT REPLACEMENT AND REPAIRS

PARKING BRAKE-CHEVROLET, CHEVELLE AND

CAMARO (Figs. 19 and 20)

Pedal Assembly

Removal

NOTE:
Remove positive cable from battery to

eliminate the possibility of creating short cir-

cuits under dash.

1.
Place parking brake pedal in released position.

2.
Remove equalizer check nut, and separate cable

stud from equalizer.

3.
Remove two attaching nuts from mounting studs

located in engine compartment.

4.
Remove front cable .ball end from pedal assembly

swivel.

5. Remove pedal assembly to dash brace attaching

screw.

6. Remove pedal assembly by lowering rear slightly

to avoid scratching dash, and pulling, it out of the

firewall.

Installation

1.
Place pedal assembly in position with the two mount-

ing studs protruding through the holes provided in

the firewall.

2.
Install and tighten pedal assembly to dash brace

attaching screw.

3.
Position front cable ball end into pedal assembly

swivel.

4.
Install and tighten two attaching nuts on mounting

studs located in engine compartment.

5. Place
,
equalizer in position on center cable and

insert front cable stud through equalizer and secure

with check nut.

6. Adjust parking brake as outlined under Maintenance

and Adjustments in this section.

7. Connect positive battery cable.

Front Cable

Removal

NOTE:
Remove positive cable from battery to

eliminate the possibility of creating short cir-

cuits under dash.

1.
Place parking brake pedal in released position.

2.
Remove equalizer check nut, and separate cable

, stud from equalizer.

3.
Remove retainer from cable assembly at inner side

of frame rail.

4.
Remove ball end of cable from pedal assembly

swivel.

5. Compress expanded conduit locking fingers at toe

pan arid withdraw cable from car.

6. On Chevelle, if necessary, remove rubber tube

from front cable.

Installation

1.
On Chevelle, if necessary, replace rubber tube

over front cable.

2.
Position cable ball and conduit tip through cutout

in firewall. Make sure conduit locking fingers are

fully expanded and secured in cutout, then position

cable ball into pedal assembly swivel.
3.
Feed stud end of cable through frame rail and se-

cure with retainer on inner side of frame.

4.
Place one check nut on cable stud and insert stud

through equalizer, (make sure center cable is in

position), then place second check nut on stud.

5. Adjust parking brake as outlined in this section.

6. Connect positive battery cable.

Center Cable

Removal

1.
Place parking brake pedal in released position.

2.
Remove equalizer check nut and remove equalizer

from cable.

3.
Remove cable from cable guides.

4.
Disconnect center cable from rear cables at

connectors.

Installation

1.
Install cable ends into rear cable connectors.

2.
Place cable through equalizer and install equalizer

on to front cable stud, secure with check nut. (Do

not tighten.)

3.
Install cable in cable guides (figs. 19 and 20),

4.
Adjust parking brake as outlined in this section.

Rear Cables

Removal

1.
Place parking brake pedal in released position.

2.
Remove equalizer check nut and remove equalizer

from cable.

3.
Remove rear cable from connector.

4.
Remove retainer from rear cable at frame bracket.

Pull cable out of bracket.

5. Remove rear brake drum as outlined in this section.

6. Remove rear brake shoes as outlined in this section.

7. Remove cable end from parking brake actuating

lever.

8. Compress expanded conduit locking fingers at flange

plate entry hole and withdraw cable.

Installation

1.
Pass end of cable and conduit tip through flange

plate entry hole, making sure that conduit locking

fingers all expand fully.

2.
Connect cable end to actuating lever.

3.
Install rear brake shoes, drum and wheel as out-

lined in this section.

4.
Pass cable through frame bracket and install

retainer.

5. Install cable end into cable connector.

6. Position equalizer on center cable and place on

front cable stud, secure with check nut.

7. Make sure all center cable guides are in place

and adjust parking brake as outlined in this section.

PARKING BRAKE-CHEVY II (Fig. 21)

Lever Assembly

Removal

NOTE:
Remove positive cable from battery

to eliminate possibility of creating short cir-

cuits under dash.

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES 5-15

Brake Shoes

Refer to parking brake shoe service procedures under

Disc Brakes in this section.

BRAKE PEDAL (Fig. 26)

Removal

NOTE: Refer to Section 1A for removal

air conditioning components if necessary.
of

1.

5.

b.

c.
Disconnect clutch pedal return spring (manual trans-

mission models only).

Disconnect clutch push rod at pedal.

Disconnect brake pedal return spring (Chevelle and

Camaro only).

Disconnect brake pedal from main cylinder push

rod by removing retainer and clevis pin.

Corvette only:

a. Remove steering column from vehicle as outlined

in Section 9.

Support main cylinder frdm inside engine com-

partment and remove four support brace nuts.

Remove four nuts and bolts securing support

plate to bracket and remove support plate.

d. Remove two screws securing bracket to under-

side of instrument panel and lower bracket and

pedals to floor.

Remove retainer from right side of pedal pivot

shaft.

7.
Slide clutch pedal assembly to the left and remove

from support brace.

8. Withdraw brake pedal and all nylon bushings.

Inspection

1.
Clean all metal parts with a good nontoxic cleaning

solvent.

2.
Wipe nylon bushings clean with a clean cloth.
6
CAUTION: Nylon bushings should not be treated

with cleaning agent of any nature.

3.
Inspect all nylon bushings for wear and damage.

4.
Inspect mating surface of bushings for wear and

damage—replace parts as required.

Installation

1.
Lubricate and install nylon bushings on pedal pivot

shaft, right side of support brace cutout, and through

both ends of brake pedal bore.

2.
Chevrolet, Chevy n, and Corvette: Position brake

pedal return spring on pedal arm and place pedal

assembly in support brace. Index return spring in

support brace cutout.

3.
Chevelle and Camaro: Place pedal assembly in

support brace.

4.
Slide pedal pivot shaft through support brace and

brake pedal bore.

5.
Install retainer to right side of pedal pivot shaft.

6. Corvette only:

a. Install bracket with pedal assemblies to underside

of instrument panel with two screws.

b.
Install support plate on bracket with four bolts

and nuts. • • ' •

c. Place main cylinder in position and install four

bracket and cylinder mounting bolts; secure en-

tire assembly with four nuts.

d. Install steering column in vehicle as outlined

in Section 9.

7.
Chevelle and Camaro: Install brake pedal return

spring.

8. On manual transmission models, connect clutch pedal

push rod to pedal bracket and install retainer. In-

stall clutch pedal return spring.

9. Adjust brake pedal free travel as outlined in this

section. Adjust stoplight switch as outlined in Section

CHEVROLET

CHEVELLE

Fig.
26—Brake Pedal Installation

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

SECTION 6

ENGINE

CONTENTS
OF
THIS SECTION

Page

Engine Tune Up
6-1
Torque Sequence

Engine Mechanical
(In
Line)
6-12
Special Tools
. .

Engine Mechanical (V8)
6-24
Page

6-39

6-40

ENGINE TUNE UP

INDEX

Page

General Description
. 6-1

Mechanical Checks and Adjustments
6-1

Spark Plug Removal
6-1

Test Compression
6-1

Service and Install Spark Plugs
6-2

Service Ignition System
6-3

Service Battery
and
Battery Cables
6-5

Service Delcotron
and
Regulator
6-5

Service
Fan
Belt
6-5

Service Manifold Heat Valve
6-5

Tighten Manifold
6-5

Service Fuel Lines
and
Fuel Filter ..........
6-6

Service Cooling System
6-6

Check and Adjust Accelerator Linkage
6-6

Service Crankcase Ventilation
6-6

Service
Air
Injection Reactor System
6-6

Choke Adjustment
6-7
Page

Instrument Cheek-Out
6-7

Instrument Hook-Up.
. 6*7

Check and Adjust Dwell
6-7

Check Dwell Variation
6-7

Check and Adjust Timing
6-8

Adjust Idle Speed
and
Mixture
6-8

Additional Checks and Adjustments
. 6-8

Testing Crankcase Ventilation Valve
. 6-8

Testing Cranking Voltage
6-8

Cylinder Balance Test
. 6-8

Battery
6-8

Ignition
; 6-8

Carburetor
6-11

Fuel Pump
6-11

Cooling System
. 6-11

Cylinder Head Torque and Valve Adjustment
..... 6-11

GENERAL DESCRIPTION

The engine tune up
is
important
to the
modern automo-

tive engine with
its
vastly improved power and perform-

ance.
The
higher compression ratios, improved electri-

cal systems
and
other advances
in
design, make today1 s

engines more sensitive
and
have
a
decided effect
on

power, performance and fuel consumption.

It
is
seldom advisable
to
attempt
a
tune up
by
correc-

tion
of one or two
items only. Time will normally
be

saved
and
more lasting results assured
if the
technician

will follow
a
definite
and
thorough procedure
of
analysis

and correction
of all
items affecting power, performance

and economy.

The tune
up
will
be
performed
in
two parts.
The
first

part will consist
of
visual and mechanical checks and
ad-

justments;
the
second part will consist
of
an instrument

checkout that
can be
performed with
any one of the
units
of service equipment available
for
this purpose. Always

follow
the
instructions provided
by the
manufacturer
of

the particular equipment
to be
used.

Additional checks
and
adjustments
are
included
in the

latter part
of
this section
for use as
required. Many
of

these operations
can be
used
to
isolate and correct trou-

ble located during
the
tune up. Where conditions
are
UB-

covered requiring major corrective action, refer
to the

appropriate section
of
this manual
or the
Passenger

Chassis Overhaul Manual
for
detailed service informa-

tion.

Typical illustrations
and
procedures
are
used except

where specific illustrations
or
procedures
are
necessary

to clarify
the
operation. Illustrations showing bench
op-

erations
are
used
for
clarification however
all
operations

can
be
performed
on the
vehicle.

MECHANICAL CHECKS
AND
ADJUSTMENTS

Spark Plug Removal

Remove any foreign matter from around spark plugs
by

blowing
out
with compressed
air,
then disconnect wires

and remove plugs.

Test Compression
(Fig. 1)

The compression check
is
important because
an
engine

with
low or
uneven compression cannot
be
tuned success-
fully.
It is
essential that improper compression
be cor-

rected before proceeding with
the
engine tune
up.

1.
Remove
air
cleaner
and
block throttle
and
choke
in

wide open position.

2.
Hook
up
starter remote control cable
and
insert

compression gauge firmly
in
spark plug port.

CAUTION: Whenever
the
engine
is
cranked

CHEVROLET
C*
IS SERVICE MANUAL

ENGINE 6-2

remotely at the starter, with a special jumper

cable or other means, the primary distributor

lead must be disconnected from the negative

post on the coil and the ignition switch must be

in the "ON" position. Failure to do this will

result in a damaged grounding circuit in the

ignition switch.

3.
Crank engine through at least four compression

strokes to obtain highest possible reading.

4.
Check and record compression of each cylinder.

5.
If one or more cylinders read low tor uneven, inject

about a tablespoon of engine oil on top of pistons

in low reading cylinders (through spark plug

port).
Crank engine several times and recheck

compression.

• If compression comes up but does not necessarily

reach normal, rings are worn.

• If compression does not improve, valves are

burnt, sticking or not seating properly.

• If two adjacent cylinders indicate low compres-

sion and injecting oil does not increase compres-

sion, the cause may be a head gasket leak between

the cylinders. Engine coolant and/or oil in cylin-

ders could result from this defect.

NOTE: If a weak cylinder cannot be located

with the compression check, see "Cylinder Bal-

ance Test" under "Additional Checks and Adjust-

ments" in this section.

Service and Install Spark Plugs (Fig. 2)

1.
Inspect each plug individually for badly worn elec-

trodes,
glazed, broken or blistered porcelains and

replace plugs where necessary. Refer to spark plug

diagnosis information presented in Section 6Y for an

analysis of plug conditions.

2.
Clean serviceable spark plugs thoroughly, using an

abrasive-type cleaner such as sand blast. File the

center electrode flat.

3.
Inspect each spark plug for make and heat range. All

plugs must be of the same make and number.

4.
Adjust spark plug gaps to specifications using a

round feeler gauge.
PORCELAIN

INSULATOR

INSULATOR CRACKS

OFTEN OCCUR HERE

CENTER ELECTRODE

[FILE FLAT WHEN

ADJUSTING GAP-

[DO NOT BEND!
(PROPER GAP)

(BEND TO ADJUST GAP)

CAUTION:

adjust gap.
Fig.
2 - Spark Plug Detail

Never bend the center electrode to

Always adjust by bending ground or

side electrode.

If available, test plugs with a spark plug tester.

Inspect spark plug hole threads and clean before in-

stalling plugs. Corrosion deposits can be removed

with a 14 mm. x 1.25 SAE spark plug tap (available

through local jobbers) or by using a small wire brush

in an electric drill. (Use grease on tap to catch

chips.)

ADJUST DWELL

ANGLE SETTING OR

POINT OPENING

Fig.
1 - Checking Compression
Fig.
3 - Distributor (In Line)

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE
6-3

(ROUND) Y~~fll^H

CENTRIFUGAL
A ^k

ADVANCE--jflgKpl

MECHANISM
UB|

CAM
KSK^2

LUBRICATOR
VlSMi

REPLACEMENT
^BK

-^ADJUST
SQUARELY

AND
JUST

TOUCHING
LOBE

OF
CAM
/ROTOR

HBB
__

I^BH^F
?
(SOUARE)

^K^ I /—
CAM

jKft^J / LUBRICATOR

H^T^
CAUTION!

QV NEVER
OIL

•L-^
CAM LUBRICATOR-

REPLACE
WICK

WHEN
NECESSARY
LATERAL

MISALIGNMENT
PROPER

LATERAL ALIGNMENT

Fig.
4- Distributor (V8)

CAUTION: Use extreme care
-when
using tap to

prevent cross threading. Also crank engine sev-

eral times to blow out any material dislodged

during cleaning operation.

7. Install spark plugs with new gaskets and torque to

specifications.

NOTE:
The following are some of the

greatest causes of unsatisfactory spark plug

performance.

•
Installation of plugs with insufficient torque to

fully seat the gasket.

•
Installation of the plugs using excessive torque

which changes gap settings.

•
Installation of plugs on dirty gasket seal.

•
Installation of plugs into corroded spark plug hole

threads.

8^ Connect spark plug wiring.

Service
Ignition System

1.
Remove distributor cap, clean cap and inspect for

cracks, carbon tracks and burned or corroded ter-

minals. Replace cap where necessary.

2.
Clean rotor and inspect for damage or deterioration.

Replace rotor where necessary.

3.
Replace brittle, oil soaked or damaged spark plug

wires.
Install all wires to proper spark plug. Proper

positioning of spark plug wires in supports is impor-

tant to prevent cross-firing.

4.
Tighten all ignition system connections.

5. Replace or repair any wires that are frayed, loose or

damaged.
Us
CORRECT
LATERAL MISALIGNMENT BY

j BENDING
FIXED CONTACT SUPPORT

[NEVER
BEND BREAKER LEVER

Fig.
5 - Point Alignment

Magnetic
Pulse(Breakerless)
Distributor

There are no moving parts in the ignition pulse ampli-

fier, and the distributor shaft and bushings have perma-

nent type lubrication, therefore no periodic maintenance

is required for the magnetic pulse ignition system. Refer

to Section 6Y for an analysis of problems and/or repair

procedures encountered on the Transistorized (Magnetic

Pulse) ignition system.

Standard
(Breaker Point) Distributor
(Figs.
3 or 4)

1.
Check the distributor centrifugal advance mechanism

by turning the distributor rotor in a clockwise direc-

tion as far as possible, then releasing the rotor to

see if the springs return it to its retarded position.

If the rotor does not return readily, the distributor

must be disassembled and the cause of the trouble

corrected.

2.
Check to see that the vacuum spark control operates

freely by turning the movable breaker plate counter-

clockwise to see if the spring returns to its retarded

position. Any stiffness in the operation of the spark

control will affect the ignition timing. Correct any

interference or binding condition noted.

3.
Examine distributor points and clean or replace if

riecessary.

DO
NOT SUCK

IN
TOO MUCH

ELECTROLYTE

TAKE
READING

AT
EYE LEVEL

Fig.
6 - Testing Specific Gravity of Battery

CHEVROtET
CHASSIS SERVICE MANUAL