1967 CHEVROLET CAMARO turn

ELECTRICAL-BODY AND CHASSIS 12-68

-7«3« R.H. DR. JAMB.SW.

C_18W-^{|>R.H. COURT

es RADIO CONN.

c5£ siHp INST. PANEL

COMPT. LAMP

ALL EXCEPT

(13100-400)

HEATER

CONTROL

HTR. CONTROL

LAMP

IGNITION SW.

LGT.

R. TURN IND.

INST.'CL. LP.
HEATER

RESISTOR

18 OR

20 Y

12 PPL/W

12 R

12 P

20 DG

14BRN

12 BRN

24 BRN/W

14
OR

20 GY
12 PPL/W

12 R

12 P

24 BRN/W

14
OR

BRK. ALARM

IND.

HI BEAM

IND.
LP.

GEN. IND. LP.

TEMP. IND. LP

INST* CL. LP.

OIL PRESS

IND.
LP.

HORN BUTTON

TO TRAFFIC

HAZARD SW.

20DBL
INST. CL. LP.

INST. CL. LP.

18 LBL

18 B

18DBL

r—20
BRN

20 OR
20
OR

20 PPL

4 LBL

20 DG

12 R

18 OR

BODY HARNESS

18 W—O-18W
^-20 BRN

20 LG

20 Y

20 DG
L.H. DR. JAMB SW.

20 LG

20 Y

20 DG

Fig.
Ill - Instrument Panel and Cluster — CheveNe

CHEVROLET CHASSIS SERVICE MANUAL

BUMPERS 14-3

required to position the bumper at the correct

mounted height. ,

3.
Tighten all mounting bolts securely and connect li-
cense plate lamp wiring. On Caprice models, con-

nect back-up lamp wiring. Lower vehicle.

GENERAL DESCRIPTION-CHEVELLE

The new front bumper is of a one piece design with the

parking and turn signal lamp assemblies attached to each

outboard end of the bumper.
The rear bumper is also of a one piece design with

provisions for rear gas fill. The back-up lamp assem-

blies are attached near the center of the bumper.

SERVICE OPERATIONS

FRONT BUMPER ASSEMBLY

Removal

1.
Raise and support front of vehicle.

2.
Disconnect parking lamp wiring. -

Fig.
3 - Front Bumper Assembly - Chevelle

Disassembly

1.
Remove bolts attaching braces and brackets to

bumper.

2.
Remove bolts from each parking lamp assembly and

remove parking lamps from bumper.

Assembly

Attach both parking brake lamp assemblies to front

bumper and tighten bolts firmly. Assemble the front

bumper parts by following the disassembly procedure in

reverse order. Except for the parking lamp attachments,

install all bolts loosely; do not tighten any bolts until all

bolts are installed.

Installation

1.
Position the front bumper on the frame horns align-

ing holes in brackets and braces with those in the

frame.

2.
Loosely install bolts, lock washers, and nuts. Note

that eight sided adjustment washer (fig. 3) is placed

in the tab of each mounting bracket. Dial tjie adjust- .

ment washers in the tabs as required to position the

bumper at the correct mounted height.

3.
Tighten all mounting bolts securely, connect the

parking lamp wiring, and lower front of vehicle.
3.
Remove bolts retaining the bumper brackets and

braces to the frame.

4.
Remove bumper assembly from vehicle.

ADJUSTMENT

WASHER

Fig.
4-Rear Bumper Assembly - Chevelle

REAR BUMPER ASSEMBLY (Fig. 4)

Removal

1.
Raise rear end of vehicle.

2.
Disconnect rear license plate lamp and back-up lamp

wiring.

3.
Remove bolts, located behind license plate door, at-

taching face bar reinforcement to frame.

4.
Remove four bolts retaining bumper brackets and

braces to frame.

5. Remove bumper from vehicle.

Disassembly

1.
Remove license plate lamp and back-up lamps from

bumper.

2.
Remove brackets and braces at each end of bumper.

3.
Remove license plate door.

4.
Remove rivets attaching bracket at center of bumper.

Assembly

Attach license plate lamp and back-up lamp assemblies

to bumper; tighten bolts firmly. Assemble the bumper

parts by following the disassembly procedure in the re-

verse order. Except for the license plate lamp and back-

up lamp attachments, install all bolts loosely; do riot

CHEVROLET CHASSIS SERVICE MANUAL

BUMPERS 14-4

tighten any bolts until all bolts have been installed.

Installation

1.
Position bumper bracket and brace on the frame

aligning holes in frame with those in bracket and

brace.

2.
Loosely install bolts, lock washers and nuts. Note
that eight sided adjustment washers (fig. 4) are

placed at the inside surface of each rear frame

channel. Dial washers as required to position

bumper at correct height.

Tighten all mounting bolts securely, connect back-up

lamp and license plate lamp wiring, and lower rear

of vehicle.

GENERAL DESCRIPTION-CHEVY II

The front and rear bumpers are of a one piece design

with the parking and turn signal assemblies attached to

each outboard end of the front bumper.

SERVICE OPERATIONS

FRONT BUMPER ASSEMBLY (Fig. 5)

Removal

1.
Raise front end of vehicle.

2.
Disconnect parking lamp wiring.

3.
Remove bolts retaining bumper brackets and braces

to frame.

4.
Remove bumper assembly from vehicle.

Disassembly

1.
Remove bolts securing parking lamp assemblies and

remove parking lamps from vehicle.

2.
Remove bolts attaching braces and bumper brackets

to bumper face bar.

Assembly

Referring to Figure 5, assemble brackets and braces

and install parking lamps to face bar. Install all bolts

loosely—do not tighten any bolts until all bolts have been

installed.

Installation

1.
Position assembled bumper on frame extensions,

aligning holes in extension with holes in brackets and

braces.

2.
Install bolts, lock washers, and nuts; tighten

securely.
3.
Connect parking lamp wiring and lower front end of

vehicle.

REAR BUMPER ASSEMBLY (Fig. 6)

Removal

1.
Disconnect license plate lamp wire at connector.

2.
Raise vehicle from floor. From forward side and

underside of rear crossmember, remove mounting

bolts retaining the bumper brackets to the vehicle.

3.
Remove bumper assembly from vehicle.

Disassembly

1.
Remove license plate lamp.

2.
Remove, bolts attaching each bracket to bumper.

Check condition of seal; replace if necessary.

Assembly

1.
Position brackets on face bar as shown in Figure 6

and install mounting bolts; tighten nuts securely.

2.
Install license plate lamp.

Instalfation

1.
Position bumper assembly on vehicle, aligning tapped

holes in bracket with- slotted holes in rearward face

of rear crossmember and install bolts loosely.

2.
Align slotted hole in bracket with tapped hole in

lower flange of rear crossmember and install bolt

loosely.

3.
Adjust entire bumper assembly so that the distance

Fig.
5 - Front Bumper Assembly - Chevy
Fig.
6 - Rear Bumper Assembly - Chevy

CHEVROLET CHASSIS SERVICE MANUAL

ACCESSORIES 15-2

GENERAL DESCRIPTION

The Cruise Master is a speed control system which

employs engine manifold vacuum to power the throttle

Servo unit. The Servo moves the throttle when speed

adjustment is necessary by receiving a varying amount

of bleed air from the Regulator unit. The Regulator

varies the amount of bleed air through a valve system

which is linked to a speedometer-like mechanism. The

speedometer cable from the transmission drives the

Regulator, and a cable from the Regulator drives the

instrument panel speedometer. The. engagement of the
Regulator unit is controlled by an Engagement Switch

located at the end of the turn signal lever. Two brake

release switches are provided: an Electric Switch dis-

engages the Regulator unit and a Vacuum Switch de-

creases the vacuum in the Servo unit to quickly return

the throttle to idle position.

The operation of each unit of the system and the

operation of the entire system under various circum-

stances is described below. Figure 1 shows the location

of the system components within the vehicle-

COMPONENT OPERATION

ENGAGEMENT SWITCH

This switch, located within the turn signal knob, has

three positions. In the fully released position, the switch

passes current through resistance wire to effect a "hold

in" magnetic field in the Regulator solenoid. This cur-

rent is sufficient only to hold the solenoid in place once

it has been actuated by the "pull in" circuit. Depressing

the button partially allows current to flow to the Regu-

lator solenoid at full voltage which causes the solenoid

to pull in. Depressing the button fully opens the circuit

to both the resistance and standard solenoid feed wires

and the solenoid becomes de-activated.

During vehicle operation the three switch positions

have the following functions:

Released

a. System not engaged: No function of the system

will occur although a small current is flowing

through the solenoid via the resistance wire (at

vehicle speeds over 20 mph).

b.
System engaged: The small current flowing

through the resistance wire is holding the solenoid

in the engaged position.

^r-WIRE RELIEF LUG

1 ^-#2-BLUE WIRE

L'3.BLACK WIRE
X /-TURN SIGNAL LEVER

SWITCH—^
^SN

RETAINING RING-^ %^

BUTTON -^

Fig.
2 - Cruise Master Engagement Switch
Partially Depressed

Full voltage is applied to the solenoid (vehicle speed

over 20 mph) which sets the Regulator to maintain the

vehicle speed at the time of Regulator engagement.

Fully Depressed

No electricity flows to the solenoid and the Regulator

is inactive. This position is used by the driver when he

desires to raise or lower his controlled speed. He may

accelerate to his new speed, press the button fully (Regu-

lator releases previously set speed) and release the but-

ton. Upon releasing the button, it passes through the

partially depressed position and the solenoid is "pulled

in", then into released position which provides "hold in"-

current. The driver may also press the button fully with

no pressure on the accelerator pedal. In this case the

regulator releases control of the throttle which returns

to idle and the car slows. When the button is released

the solenoid is pulled in and held in respectively and the

regulator resumes speed control at the speed of the

vehicle during the moment of button release (at vehicle

speeds over 20 mph).

LOCK
NUT

ORIFICE
TUBE

AND
CONNECTOR

ASSEMBLY

AIR FILTER AND

SOLENOID HOUSING COVER

Fig. 3 - Regulator Unit

CHEVROLET CHASSIS SERVICE MANUAL

ACCESSORIES 15-3

CONTROLLED AIR SUPPLY

FROM REGULATOR
DIAPHRAGM

SPRING

METERING ROD

VARIABLE ORF1CE

ENGINE AAANIFOLD VACUUM

FROM REGULATOR VACUUM VALVE
BEAD CHAIN

VACUUM CHAMBER —*
MOUNTING SCREW

Fig.
4- Servo Unit

BRAKE RELEASE SWITCHES

Two brake release switches are employed in the Cruise

Master System. When the brake pedal is depressed, an

Electric Release Switch cuts off the voltage supplied to

the engagement switch, hence cuts off power to the Regu-

lator unit. The Regulator is then disengaged and requires

Engagement Switch operation to return it to operation.

A Vacuum Release Switch operates simultaneously with

the electric release switch whenever the brake pedal is

depressed. This switch opens a port to atmospheric

pressure which rapidly bleeds down the vacuum in the

Servo unit thereby returning the throttle to the idle

position.

SERVO UNIT

The Servo unit is a vacuum actuated, variable position

diaphragm assembly which operates the carburetor throt-

tle when the system is in operation (fig. 4). It is powered

by engine intake manifold vacuum and operates the throt-

tle linkage via a bead chain. The Servo has two ports on

the sealed side of the diaphragm housing: one is supplied

manifold vacuum, and the other is connected to a variable

air bleed in the Regulator Unit. The vacuum port is

located at the center of the unit and the air bleed port

is near the outer wall. When vacuum is applied to the
center port, atmospheric pressure moves the diaphragm

which pulls on the bead chain opening the carburetor

throttle. As the diaphragm moves, it positions a tapered

needle within an orifice in the vacuum port so that as the

diaphragm moves toward the port, the orifice becomes

smaller; and as it moves away from the port, the orifice

becomes larger.

The air bleed port serves to supply a variable quantity

of air to the diaphragm chamber which causes the dia-

phragm to attain a balanced state (between the force of

the atmospheric pressure to chamber pressure differ-

ential and the force of the diaphragm and throttle return

springs). In operation then, the following events occur:

Vacuum is applied to the center port and the diaphragm

moves toward the port. The tapered needle restricts

the vacuum port more and more as it moves into the

orifice. If no air was allowed to bleed into the chamber,

the diaphragm would move until it contacted the housing,

however, the Regulator meters bleed air into the chamber

and the diaphragm reaches a point at which the air is

bled out of the chamber through the vacuum port orifice

as fast as it enters the air bleed port. If the Regulator

begins to supply less bleed air, (vehicle speed decreas-

ing) the vacuum in the chamber increases and the dia-

phragm moves toward the vacuum port. In so doing, the

tapered needle closes the vacuum port orifice even more

CHEVROLET CHASSIS SERVICE MANUAL

ACCESSORIES 15-4

Fig. 5 - Servo Mounting

and the air bled into the chamber again equals the air

bled out. A balance occurs again with the diaphragm in

a new position. If the Regulator begins to supply more

bleed air, (vehicle speed increasing) the vacuum in the

chamber drops and the diaphragm moves away from the

vacuum port, withdrawing the tapered needle from the

orifice and enlarging it. Since the vacuum orifice is

now larger, the greater quantity of air being bled into

the chamber may be bled out by vacuum and a balance

again occurs with the diaphragm in a new position.

AIR

TO SERVO

VACUUM

TO SERVO
VACUUM

RELEASE

SWITCH

ELEaRIC

RELEASE

SWITCH

Fig.
6- Servo, Regulator and Hose
Fig. 7 - Release Switches and Brackets

REGULATOR

The Regulator is a device which has two primary

functions: First, it is a vacuum switch which, when en-

gaged by the driver, supplies engine manifold vacuum to

the Servo. Second, it meters a small variable quantity

of air to the Servo unit in order to change the carburetor

throttle opening to effect speed control. A secondary

function of the Regulator is to drive the speedometer.

Since the car speed is sensed by a speedometer-like

mechanism within the unit, the speedometer cable from

the transmission drives the Regulator which drives a

second cable (at a one to one ratio) to the speedometer.

The Regulator is electrically engaged and disengaged

through operation of the Engagement Switch and the

Electric Brake Release Switch. It has two sub-assem-

blies which make up the unit: one being the magnetic

speed sensing assembly and the other being the solenoid

actuated vacuum switch, air bleed and filter, and low

limit speed switch assembly (fig. 8 and 9).

Magnetic Speed Sensing Assembly

The speed sensing assembly operates in the same man-

ner as a speedometer unit except that instead of rotating

a needle through an angle proportional to the vehicle

speed, it rotates a rubber drum which is clutched to the

air bleed valve when the system is in operation. The

assembly is driven by the speedometer cable from the

transmission which turns a disk shaped ferrite magnet.

Facing the magnetic disk is the driven brass disk mounted

on a shaft with the rubber drum mounted on the same

shaft. A spiral hairspring connects the shaft to the

housing and allows it to rotate through an angle which is

proportional to car speed. If the car doubled its speed,

the shaft would rotate to twice its previous angle as may

be seen by noting the operation of a speedometer. The

CHEVROLET CHASSIS SERVICE MANUAL

driven disk is sandwiched between the magnetic disk and

a field plate. The field plate forms a returning path for

the magnetic field from the magnetic disk.

The gear drive for the magnetic disk is a 90 degree

nylon gear drive with the driven gear rotating both the

magnetic disK and the speedometer drive cable.

Vacuum Switch, Air Bleed and Filter, and Low

Limit Speed Switch

The end of the shaft from the speed sensing assembly

with the rubber drum extends into the air bleed metering

assembly. This rubber drum has a tang extending from

its surface which allows a set of points to close at a

specific car speed. When the car reaches about 20 mph,

the rubber drum has rotated far enough (moved by the

brass driven disk in the magnetic field) so that its tang

has allowed a spring loaded electrical point to contact

another point. These points are in series with the sole-

noid coil so that under 20 mph, no Regulator operation

is possible.

Surrounding the rubber drum is a "U" shaped spring

clip which is held spread away from the drum by the

nose or cam of the solenoid when the solenoid is in the

relaxed position. The rubber drum and this clip com-

prise the speed clutch of the regulator. When the sole-

noid is energized, the solenoid nose moves toward the

drum and releases the ends of the clip. The clip springs

inward and attaches itself by friction to the drum. Now,
ACCESSORIES 15-5

any change in car speed will rotate the drum and move

the "U" clip just as a speedometer moves its needle.

The top of the MUtf clip is attached to the air bleed valve.

The clip moves a sleeve which slides on the orifice

tube thereby covering and uncovering air ports in the

wall of the tube (the tube inner end is plugged) whenever

car speed changes from the speed at which the solenoid

was energized. The direction of drum rotation is such

that resulting bleed valve operation will cause the Servo

to decrease engine power if the car exceeds the preset

speed and increase engine power if car speed decreases.

The air which passes out the orifice tube enters the

Regulator through the openings in the solenoid housing,

passes through the oil wetted polyurethane filter, and then

enters the orifice tube ports.

When the solenoid is de-energized, the nose retracts

and cams the ends of the "U" clip outward so that it re-

leases the rubber drum.

The solenoid also operates a vacuum switch simul-

taneously with the clutching and declutching of the "U"

clip.
The vacuum switch supplies the Servo unit with

manifold vacuum. The solenoid operated vacuum valve

slides over two ports in the Regulator wall. One port

is connected to manifold vacuum and the other is con-

nected to the center port of the Servo unit. When the

solenoid is de-energized, the valve closes the manifold

vacuum port and opens the Servo port to the inside of

the regulator case. When the solenoid is energized, the

valve connects the Servo port to the manifold vacuum

AAAGNET

SPEED CUP

FIELD PLATE

HAIRSPRING
TO SPEEDOMETER

MAGNET HOUSING

ASSEMBLY
ORIFICE TUBE &

CONNECTOR ASSEM.
CONTROL

VALVE

CLUTCH

SPRING

LOW LIMIT

SPEED SWITCH

RUBBER

DRUM

VACUUM PORT

TO SERVO

INPUT CONNECTION

SOLENOID COIL

SOLENOID AND CLUTCH

HOUSING ASSEMBLY
VACUUM PORT

TO ENGINE

VACUUM VALVE

UNLOCKING CAM

•SOLENOID PLUNGER

AIR FILTER

SIDE VIEW SECTION

REGULATOR DISENGAGED
END VIEW SECTION

ENGAGED

Fig.
8 - Regulator-Cross Section '

CHEVROLET CHASSIS SERVICE MANUAL

ACCESSORIES
15-6

port thereby supplying vacuum to the Servo unit.

During system operation
the
following events occur:

1.
Car
speed below
20
mph—no function
of the
unit

because
the
rubber drum
has
not rotated
far
enough

to close
the
solenoid points.
No
energizing current

can flow through the solenoid coil.

2.
Car
speed above
20
mph—The tang
on the
rubber

drum
has
closed
the
solenoid points
and
current
is

flowing through
the 40 ohm
resistance wire
to the

solenoid coil. This current
is
not sufficient to "pull

in", the solenoid.

3.
Driver partially presses Engagement Switch—full

voltage flows through
the
solenoid
to
pull
it
into

operation. Solenoid
cam
tension
on the "U"
clip
is

released and the clip grips the rubber drum. Simul-

taneously the vacuum switch operates; applying man-

ifold vacuum
to the
Servo unit which tightens
the

throttle chain. When
the
driver releases pressure

from
the
accelerator pedal
the
unit will position the

throttle
to
maintain the speed
at
the time
of
solenoid
operation.

Driver releases
the
Engagement Switch—current

flows
to the
solenoid through
the 40
ohm wire and

since the solenoid is "pulled in", the reduced current

flow
is
sufficient to hold
it
in position.

The
car
begins
to
ascend
a
hill—car speed drops

slightly (very slightly) and the magnetic force on the

driven disk
of the
speed sensor
is
decreased.
The

disk rotates slightly
(as
would
a
speedometer shaft

because
of
hairspring tension) turning
the
rubber

drum. Since
the "U"
clip
is
gripping
the
drum,
it

moves
the
slide which COVERS
the air
bleed ports

more. With less air bleeding into the Servo, greater

vacuum exists
in it
and the diaphragm moves toward

the vacuum port opening
the
throttle wider.
The

tapered needle moves into the orifice further and the

diaphragm balances
in a
new position with the wider

throttle opening.
Car
speed
has
been maintained

automatically.

1.
Speedometer Cable

Adapter (From

Transmission)

2.
Gasket

3. Speedometer Cable

Adapter
(To

Speedometer)

4.
Adapter
and
Magnet

Housing

5. Rotating Magnet

6. Helical Ramp
7. Field Plate Adjusting

Pinion

8. Adjusting Pinion

Locating Spring

9. Brass Magnetically

Driven Disk

10.
Field Plate

11.
Hair Spring

12.
Hair Spring Keeper

13.
Rubber Drum

Tang
14.
Rubber Drum

1$.
"U"
Shaped Clutch

Spring

16.
Air
Bleed Sleeve

17.
Orifice Tube

18.
Orifice

19.
Orifice Tube Locknut

20.
Clutch
and
Solenoid

Housing

21.
Vacuum Supply Port

(To Servo)
22.
Vacuum Port (To

Intake Manifold)

23.
Vacuum Valve Slide

24.
Solenoid Coil

25.
Solenoid Plunger

Return Spring

26.
Solenoid Cover Gasket

27.
Air Filter

28.
Solenoid Cover

29.
Air Inlets

Fig.
9-
Regulator
-
Exploded

CHEVROLET CHASSIS SERVICE MANUAL