1967 CHEVROLET CAMARO air condition

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 5-15

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 5-22

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 5-23

Fig.
34—Brake Drum Access Hole

2.

Install brake drum, aligning tang with wheel hub

(fig. 18).

3.
Install wheel and tire assembly.

. 4. Make final brake adjustment as outlined in this

section and check brake operation.

BRAKE PIPE DISTRIBUTION AND SWITCH

ASSEMBLY (Fig. 2)

Removal

1.
Disconnect battery cable.

2.
Disconnect electrical lead from switch assembly.

3.
Place dry rags below the switch to absorb any fluid

spilled during removal of switch.

4.
Disconnect four hydraulic lines from connections
at switch. If necessary, loosen line connections at

main cylinder to loosen lines. Cover open line ends

with clean, lint-free material to prevent foreign

matter from entering the system.

5.
Remove mounting screw and remove switch from

vehicle.

Installation

1.
Make sure new switch is clean and free of dust and

lint. If any doubt exists, wash switch in Declene,

or equivalent, and dry with air.

2.
Place switch in position and secure to bracket with

mounting screw.

3.
Remove protective material from open hydraulic

brake lines and connect lines to switch. If necessary,

tighten brake line connections at main cylinder.

4.
Connect switch electrical lead.

5.
Connect battery cable.

6. Bleed the brake systems as outlined in this section.

CAMARO PRESSURE REGULATOR VALVE

(AIR CONDITIONED MODELS ONLY)

Removal (Fig. 3)

1.
Place dry rags below valve to absorb any fluid

spilled during removal of valve.

2.
Disconnect hydraulic brake lines from both sides

of switch. Cover open line ends with clean, lint-free

material to prevent foreign matter from entering

the system.

3.
Remove mounting screw and remove switch from

vehicle.

Installation

1.
Make sure new valve is clean and free of dust and

lint. If any doubt exists, wash valve in Declene, or

equivalent, and dry with air.

2.
Place valve in position and secure to frame side

rail with mounting screw.

3.
Remove protective material from open hydraulic

brake lines and connect lines to each side of valve.

4.
Bleed brake system as outlined in this section.

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
6-3

(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

ENGINE 6-6

CHOKE VALVE

COMPLETELY

CLOSED

PULL UPWARD ON

ROD TO END OF

TRAVEL

BEND ROD

TO ADJUST
ROD IN BOTTOM

OF SLOT

BOTTOM OF

ROD SHOULD

EVENWITH

TOP OF

HOLE
CHOKE VALVE

CLOSED

BOTTOM OF

ROD SHOULD

BE EVEN WITH

TOP OF HOLE

TOP OF ROD

SHOULD BE EVEN

WITH BOTTOM

OF HOLE (CHOKE

CLOSED)

^..BEND ROD TO

ADJUST

_PULL DOWNWARD

ON ROD TO CON-

TACT STOP

L6 (TYPICAL)

V8 327-275 HP

V8 350-295 HP
BEND ROI

TO ADJUST

PULL UPWARD ON

ROD TO CONTACT

STOP ON BRACKET

ALL V8 (EXCEPT 327-275 HP

AND 350-295 HP)

Fig.
11 - Remote Choke Adjustment

sequence outlined on Torque Sequence Chart. A slight

leak at the intake manifold destroys engine performance

and economy.

Service Fuel Lines and Fuel Filter

1.
Inspect fuel lines for kinks, bends or leaks and cor-

rect any defects found, • • •

2.
Inspect filter and replace if plugged.

NOTE:
If a complaint of poor high speed per-

formance exists on the vehicle, fuel pump tests

described in Section 6M should be performed.

Service Cooling System

1.
Inspect cooling system for leaks, weak hoses, loose

hose clamps and correct coolant level, and service

as required.

NOTE:
A cooling system pressure test, as de-

scribed in "Additional Checks and Adjustments"

in this section, may be performed to detect

internal or external leaks within the cooling

system.

Check and Adjust Accelerator Linkage

1.
Disconnect accelerator rod at carburetor throttle

lever.

2.
Hold carburetor throttle lever in wide position.

3.
Pull accelerator rod to wide open position. (On ve-

hicles equipped with automatic transmission, pull

through detent).

4.
Adjust accelerator rod to freely enter hole in carbu-

retor throttle lever.'

NOTE:
Accelerator linkage is outlined in de-

tail in Section 6M.
5. Connect accelerator rod at throttle lever.

Service Crankcase Ventilation (Fig. 10}

All engines have either "Positive" or "Closed Positive"

ventilation systems utilizing manifold vacuum to draw

fumes and contaminating vapors into the combustion

chamber where they are burned. Since it affects every

part of the engine, crankcase ventilation is an important

function and should be understood and serviced properly.

In both "Positive" and "Closed Positive" ventilation,

air is drawn through the engine, (through a regulating

valve) into the manifold, drawing' crankcase vapors and

fumes with it to be burned. "Positive" ventilation uses a

vented-meshed cap for clean air intake to the engine,

while . "Closed Positive" ventilation system draws the

clean air from the carburetor air cleaner and has a

nonvented oil filler cap.

1.
Ventilation valve may be checked as outlined under

"Additional Checks and Adjustments".

2.
Inspect for deteriorated or plugged hoses.

3.
Inspect all hose connections.

4.
On closed positive ventilation systems, remove flame

arrestor and wash in solvent then dry with com-

pressed air.

Service Air Injection Reactor System

Inspect air injection reactor system for evidence of

leaks,
deteriorated hoses, cracked air manifolds or tubes

and loose hose clamps. Inspect air injection pump belt

condition and tension. Make all necessary repairs as

outlined in "Section 6T".

Because of the relationship between "Engine Tune Up"

and "Unburned Exhaust Gases", the condition of Engine

CHEVROLET CHASSIS SERVICE MANUAL