1967 CHEVROLET CAMARO oil filter

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

ACCESSORIES 15-9

Adjustment- Adjust the bead chain so that it is as tight

as possible without holding the throttle open when the

carburetor is set at its lowest idle throttle position.

When connecting the bead chain (engine stopped) manually

set the fast idle cam at its lowest step and connect the

chain so that it does not hold the idle screw off the cam.

If the chain needs to be cut, cut it three beads beyond the

bead which pulls the linkage.

REGULATOR

Service - A defective regulator, that is one which is not

simply out of adjustment, must be replaced. During re-

placement, check the hoses which connect to the regulator

and replace any which are cracked or deteriorated.

Air Filter

The air filter located in the solenoid cover should be

cleaned and re-oiled at engine oil change intervals.

1.
Snap the solenoid cover off.

2.
Remove the filter and wash it in kerosene or mineral

spirits. Squeeze it dry and wet with SAE 10 engine

oil.
Squeeze out excess oil and reinstall into the

cover.

3.
Attach the cover with neoprene seal to the solenoid

housing. Be certain that the cover fits tightly to the

housing.

One regulator adjustment is possible: Engagement-

Cruising Speed Zeroing (to remove any difference be-

tween engagement and cruising speed).

NOTE:
No regulator adjustment should be

made, however, until the following items have

been checked or serviced:

1.
Bead chain properly adjusted.

2.
All hoses in good condition, properly attached, not

leaking, not pinched or kinked.

3.
Regulator air filter clean and properly oiled.

4.
Electric and vacuum release switches properly

adjusted.

Engagement—Cruising Speed Zeroing

If the cruising speed is lower than the engagement

speed, loosen the orifice tube locknut and turn the tube

outward; if higher, turn the tube inward. Each 1/8 turn

will alter the engagement-cruising speed difference one

mph. Tighten the locknut after adjustment and check the

system operation at 50 mph.

ELECTRICAL SYSTEM CHECK OUT

1.
Check fuse and connector.

2.
Check electric brake switch as follows: Unplug con-

nector at brake switch. Connect ohmmeter at points

A and B on brake switch. The ohmmeter must indi-

cate infinity when the brake pedal is depressed and

continuity when pedal is released. The cruise re-

lease brake switch (electric) is adjusted as is the

standard stop light brake switch. Replace electric

brake switch if needed.

3.
Check engagement switch and connecting wiring as
follows: Unplug push button control connector

(brown, blue, black) at electrical wiring harness con-

nector and perform the following tests. (See Fig-

ure 10)

Test #1
—
Connect ohmmeter between terminal #1 (brown

wire) and terminal #2 (blue wire). Continuity shall be

maintained until switch is depressed all the way in.

Test #2
—
Connect ohmmeter between terminal #1 (brown

wire) and terminal #3 (black). No continuity shall be

shown; however, when the button is depressed halfway,

continuity shall be indicated. When the button is pressed

all the way down, no continuity shall be shown.

Test #3 — Connect ohmmeter between terminal #2 (blue

wire) and terminal #3 (black). Button released, no con-

tinuity; however, when the button is depressed partially

and fully, continuity shall be shown.

4.
Check regulator solenoid coil, low-speed switch, and

wiring harness as follows:

a. Disconnect engagement switch wire harness con-

nector from the main wire harness connector

(brown, blue, and black wires). Connect ohm-

meter
'
between point C (blue wire in main wire

harness) and ground. (Make sure the regulator is

well grounded to chassis.) The ohmmeter should

read 45 ohms ± 2 ohms. If a resistance of

greater value is shown, then disconnect the con-

nector from the regulator and measure the re-

sistance of the blue wire from point C to D. It

should measure 40 ohms. Check the resistance

from point E (vertical bar of terminal forming T)

to ground. It should measure 5 ohms ± 1/4 ohm.

Replace either the wiring harness or solenoid as

needed if greater values are indicated. The black

harness wiring from point F to G should also be

checked for continuity.

ENGAGEMENT SWITCH TEST

BUTTON POSITION

Cruise (released)

Engage (partially depressed)

Trim (fully depressed)
TERMINALS

1 TO 2

closed

Closed

open
1 TO 3

open

closed

open
2 TO 3

open

closed

closed

SERVO AND VACUUM SYSTEM CHECK OUT

To determine the condition of the diaphragm, remove

hoses from power unit and apply 14 inches of vacuum to

either vacuum tube opening (seal the other opening) and

hold in for one minute. The vacuum shall not leak down

more than 5 inches of vacuum in one minute. If leakage

is detected, replace servo. To utilize engine as a vac-

uum source, proceed as follows:

1.
DISCONNECT SERVO $EAD CHAIN and hoses from

servo and connect engine vacuum directly to vacuum

servo fitting (fitting in middle of servo). Seal the

servo unit opening.

2.
Note position of servo diaphragm.

3.
Start engine - the diaphragm should pull in.

4.
Clamp off engine vacuum supply line and check for

leakage. '

The cruise release brake switch (vacuum) and connecting

hoses can likewise be checked using a vacuum pump.

CHEVROLET CHASSIS SERVICE MANUAL