check engine CHEVROLET CAMARO 1967 1.G Chassis Workshop Manual

ELECTRICAL-BODY
AND
CHASSIS
12-26

•
Low oil
pressure

• High engine temperature

• Defective wiring
or
switch

connector from sender

in block above starter
on

and
at
left front
of
distributor
on V-8
Sending Unit Replacement

1.
Disconnect wiring harness

unit terminal (located

L-6 engines

engines).

2.
Remove sender unit using Tool J-21757
or 12
point

socket, replace with
new
unit
and
check operation.

GENERATOR INDICATOR

1.
Ignition
on,
Engine
not
Running
and
Telltale Light

Off.

• Indicator bulb burned out, replace bulb.

• Open circuit
or
loose connection
in the
telltale

light circuit.

2.
telltale Light Stays
on
after Engine
is
Started.
If indicator light does
not go out at
engine idle

speed, refer
to
Charging Systems under Engine

Electrical, Section
6Y.

TEMPERATURE (COOLING SYSTEM) INDICATOR

The temperature indicator circuit consists
of two re-

motely located units, indicator gauge
and
engine sender

unit.
The
indicator gauge, located
in the
instrument

panel, consists
of a
red light which will indicate
an
over-

heated engine condition.

Engine Sender Unit Replacement

1.
Drain engine cooling system
to a
level below unit.

2.
Remove sender unit (located
in the
inlet manifold

near water pump housing
on V-8
engines and
in the

cylinder head near
an
exhaust port
oh L-6
engines)

and replace with new unit.

3.
Refill cooling system
and
check operation
of
unit.

CHEVELLE INSTRUMENTS AND GAUGES

INDEX

Page

General Description
* *
i2-26

Service Operations
12-26

Instrument Panel
12-26

Instrument Cluster.
12-26

Fuel Gauge and/or Ammeter
12-27

Clock,
i 12-27

Speedometer
12-27
Page

Speedometer Cable
.
. 12-27

Temperature Gauge
12-29

Oil Pressure Gauge
12-29

Indicator Lights.
. 12-29

Oil Pressure Indicator
12-29

Generator Indicator
. . 12-29

• Temperature Indicator
12-29

GENERAL DESCRIPTION

The Chevelle instrument cluster assembly consists
of:

a speedometer;
a
fuel gauge;
a
generator,
an
engine
tem-

perature and an
oil
pressure indicator lamp, and includes

a clock
on
deluxe models.
On
super sport models,
am-

meter, coolant temperature
and oil
pressure gauges
re-

place
the
appropriate indicator lights. Except
for the

speedometer,
all of the
indicator lamps, instruments
and

gauges
of
these clusters may
be
serviced without remov-

ing
the
instrument cluster assembly from
the
vehicle.

In addition
to the
instrument indicator lamps,
a
brake

warning lamp
is
included
in the
cluster
as
standard

equipment.
The
indicator
is
connected
to the
parking
brake
and
brake pressure differential switches
and

serves
a
dual function.
It
lights when the parking brake

is applied
and
also when
the
brake pedal
is
applied,
if a

malfunction should occur
in the
brake system
due to a

loss
of
hydraulic pressure. Servicing
of the
hydraulic

pressure differential switch
is
covered
in
Section
5 of

this manual.

Regular maintenance
is not
required on the instrument

cjLuster
or its
components other than maintaining dean

and tight electrical connections, replacing defective parts

and keeping
the
speedometer cable properly lubricated.

SERVICE OPERATIONS

INSTRUMENT PANEL ASSEMBLY

INSTRUMENT CLUSTER (Figs.
41
thru
44)

Removal

1.
Disconnect battery ground cable.

2.
Remove steering coupling bolt and disconnect steer-

ing shaft from coupling.

3.
Loosen mast jacket lower clamp.

4.
Remove
air
conditioning center distributor duct
(if

so equipped).

5. Remove radio rear support bracket screw.

6. Remove mast jacket upper support clamp and retain-

ing bolts from lower support (refer
to
Section
9,

Steering).
CAUTION: Cover mast jacket
and
parl

brake handle with
a
suitable material
to
prevc

scratching.

7.
Disconnect speedometer cable
at
rear
of
cluster

housing
and
speed warning control knob
at
panel
(if

so equipped).

8. Remove instrument panel retaining screws (nine

upper and five lower).
.

9. Working under the console remove four lower retain-

ing screws from instrument cluster housing.

10.
Pull instrument panel assembly from console and
lay

forward on mast jacket.

11.
Disconnect wiring harness, cluster lamps and wiring

CHEVROLET CHASSIS SERVICE MANUAL

ELECTRICAL-BODY AND CHASSIS 12-29

Fig.
43b - Speed Warning Device

TEMPERATURE AND/OR OIL PRESSURE

GAUGE

1.
Disconnect battery ground cable.

2.
Remove ash tray and ash tray retainer.

3.
Disconnect A/C hose from the distributor duct.

4.
Disconnect wiring connectors and lamp bulbs from

rear of gauge.

5. Disconnect oil pressure pipe fitting from rear of oil

pressure gauge.

6. Remove (3) screws retaining gauge assembly to

cluster cover and disengage unit from cover.

7. Remove (4) retaining nuts and remove gauge from

template.

8. To install, reverse removal procedure.

INDICATOR LIGHT REPLACEMENT

To replace any indicator or cluster bulb, unsnap the

proper socket from rear of instrument cluster, remove

and replace bulb, and reinsert unit into rear of cluster

housing.
OIL PRESSURE INDICATOR

If the light does not come on when the ignition switch is

turned on, or if the light comes on and remains on after

the engine is started, one or more the following condi-

tions is indicated:

• Low oil pressure

• Defective wiring or switch

• High engine temperature

Switch Replacement

1.
Disconnect wiring harness connector from sender

unit terminal (located in block above starter on L-6

engines and at left front of distributor on V-8

engines).

2.
Remove sender unit using Tool J-21757, replace with

new unit, and check operation.

GENERATOR INDICATOR

Ignition on, Engine not Running and

Telltale Light Off

1.
Indicator bulb burned out, replace bulb.

2.
Open circuit or loose connection in the telltale light

circuit.

Telltale Light Stays on after Engine is Started

If indicator light does not go out at engine idle speed,

refer to' Charging Systems under Engine Electrical,

Section 6Y.

TEMPERATURE
(COOLING
SYSTEM)
INDICATOR

The temperature indicator circuit, consists of two re-

motely located units, indicator gauge and engine sender

unit. The indicator gauge on all models uses a single

red light to indicate an overheated engine condition.

Engine Sender Unit Replacement

1.
Drain engine cooling system to a level below unit.

2.
Remove sender unit (located in the inlet manifold

near water pump housing on V-8 engines and in the

cylinder head near an exhaust port on L-6 engines)

and replace with new unit.

3.
Refill cooling system and check operation of unit.

CHEVROLET CHASSIS SERVICE MANUAL

ELECTRICAL-BODY AND CHASSIS 12-34

5. To replace, reverse the removal procedure.

SPEEDOMETER REPLACEMENT

1.
Remove instrument cluster as previously described

in this section.

2.
Remove clock set shaft knob.

3.
Remove eight screws securing cluster housing to

bezel trim panel. Separate parts carefully observing

stack up of parts.

4.
Remove two screws securing speedometer head to

rear of cluster housing.

NOTE:
Servicing of the speedometer head

should be performed by an authorized AC Speed-

ometer Service Station.

5. To install, reverse the removal procedure..

SPEEDOMETER CABLE

Replacement or Lubricatibn

1.
Disconnect the speedometer cable from the speed-

ometer head. Remove the old cable by pulling it out

from speedometer end of conduit.

NOTE:
If old cable is broken it may be neces-

sary to remove lower piece from transmission

end of conduit.

2.
Lubricate the lower 3/4 of cable with speedometer

cable lubricant and push the cable into the conduit.

Connect the upper end to the speedometer head and

road test vehicle for proper speedometer operation.

INDICATOR LIGHT REPLACEMENT

To replace any indicator or cluster bulb, unsnap the

proper socket from rear of instrument cluster, remove

and replace bulb, and reinsert unit into rear of cluster

housing.

OIL PRESSURE INDICATOR

If the light does not come on when the ignition switch
is turned on, or if the light comes on and remains on

after the engine is started, one or more of the following

conditions is indicated:

• Low oil pressure

• High engine temperature

• Defective wiring or switch

Switch Replacement

1.
Disconnect wiring harness connector from sender

unit terminal (located in block above starter on

L-6 engines and at left front of distributor on V-8

engines).

2.
Remove sender unit, replace with new unit, and

; check operation.

GENERATOR INDICATOR

1.
Ignition on, engine not running and telltale light off.

a. Indicator bulb burned out, replace bulb.

b.
Open circuit or loose connection in the telltale

light circuit.

2.
Telltale light stays on after engine is started.

a. If indicator light does not go out at engine idle

speed, refer to Charging Systems under Engine

Electrical, Section 6Y.

TEMPERATURE (COOLING SYSTEM) INDICATOR

The temperature indicator circuit consists of two re-

motely located units, indicator gauge and engine sender

unit. The indicator gauge on all models uses a single

red light to indicate an overheated engine condition.

Engine Sender Unit Replacement

1.
Drain engine cooling system to a level below unit.

2.
Remove sender unit (located in the inlet manifold

near water pump housing on V-8 engines and in the

cylinder head near an exhaust port on L-6 engines)

and replace with new unit.

3.
Refill cooling system and check operation of unit.

CORVETTE INSTRUMENTS AND GAUGES

INDEX

Page

General Description ., 12-34

Service Operations . 12-35

Instrument Cluster ., 12-35

Fuel Gauge 12-35
Speedometer/Tachometer Service. 12-35

Temperature Gauge 12-35

Ammeter/Oil Pressure Gauges 12-35

GENERAL DESCRIPTION

All Corvette instruments and gauges are conveniently

located in the dash-mounted cluster. The entire cluster

is removable to permit servicing of the various instru-

ments and gauges. The indicator and cluster illuminating

bulbs may be replaced without removing the cluster from

the panel.
Regular maintenance is not required on the instrument

cluster or its components other than maintaining clean

and keeping the speedometer and tachometer cables

properly lubricated.

CHEVROLET CHASSIS SERVICE MANUAL

ELECTRICAL-BODY AND CHASSIS 12-35

SERVICE OPERATIONS

INSTRUMENT CLUSTER

REMOVAL AND INSTALLATION (Fig. 49)

1.
Remove mast jacket assembly. Refer to Section 9

for removal procedures.

2.
Disconnect tachometer drive cable at distributor.

3.
Disconnect the headlamp panel control switch from

instrument cluster.

4.
Remove lighting switch as outlined in this section.

10 10-A 1112 13

14
15 16 17 18 19

Fig.
49- Instrument Cluster Connections

1.
Cluster Illuminating

Bulbs

2.
Direction Signal Indicator

Bulb L.H.

3. Direction Signal Indicator

BulbR.H.

4.
Headlamp Actuating Motor

Indicator

5. Headlamp Hi Beam

Indicator

6. Parking Brake Alarm

Indicator

7. Ground Lead Attaching

Point

8. Temperature Indicator
"1"

Terminal
9.

10.

10A.

11.

12.

13.

14.

]5.

16.

17.

18.

19.

20.

21.
Temperature Indicator "S"

Terminal

Ignition Switch Receptacle

ignition Switch Illuminating

Bulb

Oil Pressure Indicator

Tachometer

Lighter Receptacle

Trip Odometer

Wiper Switch Receptacle

Speedometer

Ammeter "Gen" Terminal

Ammeter "Battery" Terminal

Lighting Switch Receptacle

Fuel Gauge
"1"
Terminal

Fuel Gauge "S" Terminal

5. Remove the ignition switch. Refer to Section 6Y

for removal procedure. Then disconnect ignition

switch lamp support at instrument panel.

6. Disconnect oil pressure line at oil pressure gauge

then remove the lead wires from ammeter, wiper

switch and cigarette lighter. Disconnect trip odom-

eter at mast jacket support.

7. Remove the instrument cluster-to-dash retaining

screws and pull cluster assembly slightly forward

to obtain clearance for removal of speedometer

cable, tachometer cable, cluster ground wire, fuel

gauge lead wires and remaining indicator and cluster

illuminating lamps.

8. To install cluster in dash panel, reverse removal

procedure.

FUEL GAUGE

The gasoline fuel gauge circuit consists of an electri-
cal indicator in the instrument cluster and a float-

controlled rheostat in the fuel tank.

Since the fuel gauge consists of two remotely located

units and connecting wires, it is sometimes difficult to

determine which unit is at fault when the gauge fails to

operate properly. Cluster removal is necessary to re-

place the fuel gauge.

NOTE:
Be sure to check gas gauge fuse in fuse

panel before attempting to trouble shoot for

inoperative gauge or tank sending unit.

SPEEDOMETER AND/OR TACHOMETER

Removal and Installation

Cluster must be removed from vehicle to service

speedometer head assembly (see Cluster Removal pro-

cedure)
.
With cluster removed from vehicle:

1.
Remove five screws securing cluster back panel to

cluster assembly; separate the parts carefully.

CAUTION: Care must be used to avoid marring

instrument cluster face.

2.
Remove two screws securing speedometer or ta-

chometer head to cluster back panel; carefully re-

move speedometer or tachometer head.

NOTE:
Servicing of speedometer or tachom-

eter head should be performed by an authorized

AC service station.

3.
Reverse above procedure to install speedometer.

Cable Replacement or Lubrication

1.
Disconnect the. cable from the speedometer or ta-

chometer head. Remove the old cable by pulling it

out from speedometer end of conduit.

NOTE:
If old cable is broken it may be nec-

essary to remove lower piece from transmission

or distributor end of conduit as applicable.

2.
Lubricate the lower 3/4 of cable with
AC
speedom-

eter cable lubricant and push the cable into the con-

duit. Connect the upper end to the speedometer or

tachometer head and road test vehicle for proper

operation.

TEMPERATURE GAUGE

The temperature indicator requires very little service

other than testing for malfunctioning and replacing de-

fective units. Cluster must be removed to service tem-

perature gauge.

Do not attempt to repair either the engine unit or the

gauge. When installing new engine unit, do not use

thread compound on unit threads, as this will increase

electrical resistance of unit and cause faulty reading

on gauge.

AMMETER OR OIL PRESSURE GAUGE

The ammeter or oil pressure gauge requires very

little attention other than keeping ammeter terminals

clean and tight. If the oil pressure control line should

become restricted it should be blown out or replaced.

Cluster must be removed to service these gauges.

HftVKI MANUAL

ELECTRICAL-BODY AND CHASSIS 12-38

Fig.
52 - Instrument Cluster Lighting

1
• Cluster Lamp

2.
* High Beam Indicator

3. Oil Pressure Indicator

4.
L.H. Directional Indicator

5. Generator indicator
6. R.H. Directional indicator

7. Temperature Indicator

8. Printed Circuit

9. Chassis Harness Connector

10,
Brake Warning Indicator

2.
Remove sender unit.

3.
Replace with new unit and check operation.

GENERATOR INDICATOR

1.
Ignition on, engine not running and indicator light off:

•Indicator bulb is burned out, replace bulb.

•Open circuit or loose connection in the indicator

light circuit.
2.
Indicator light stays on after engine is started:

•Ti indicator light does not go out at engine idle

speed, refer to Charging System Tests in Section

6Y, Engine Electrical.

TEMPERATURE (COOLING SYSTEM) INDICATOR

The temperature indicator circuit consists of two re-

motely located units, indicator lamp and sending unit.

The "indicator lamp, located in the instrument cluster

CHfVROtEr CHASM SfXVICf

ELECTRICAL-BODY AND CHASSIS 12-40

Fig.
54 - Seat Separator Instrument Console

consists of a single red light which will indicate an over-

heated engine condition.

Engine Sender Unit Replacement

1.
Drain engine cooling system to a level below unit.
2.
Remove sender unit (located in cylinder head near

an exhaust port on L-6 engines and in the inlet mani-

fold near water pump housing on V-8 engines).

3.
Replace unit, refill cooling system and check opera-

tion of unit.

DIRECTIONAL SIGNAL

Directional signal assemblies provide as standard pro-

duction equipment a lane changing feature and hazard

warning system on all model applications. Two different

design switches are used as shown in Figure 55. Major

difference between the two units is that one type has can-

celling and detent springs which are serviceable, other-

wise both units are not repairable and must be replaced

as an assembly in service.

Due to the integral design relationship of the signal

switch and the energy absorbing steering column, refer-

ence should be made to Steering, Section 9 of this manual
whenever any service operations are performed on the

steering column. The directional signal switch replace-

ment procedures covered in this section are intended to

supplement the detail service operations outlined in Sec-

tion 9.

Special note should be taken of the fact that different

signal flasher units are used in Chevrolet models depend-

ent on the number of lamps to be operated. The hazard

warning unit, even though an integral component of the

directional switch assembly, requires the installation of

an additional flasher unit in the fuse panel capable of op-

CHEVROtET CHASSIS SERVICE MANUAL

ELECTRICAL-BODY AND CHASSIS 12-60

....
£
VALVE ASSEMBLY

mm

BROWN
*yr

RED '
WATER

INTAKE

PORT

|f|i

Wjjm WATER

|HP DISCHARGE

W PORTS

WASHER

PUMP

ASSEMBLY

Fig.
102 - Washer Pump Assembly

5. Remove gear mechanism from the gear box and slide

spacer washer (No. 9) off the gear assembly eccen-

tric shaft.

6. Slide the drive plate and shaft assembly (No.. 11) out

of the gear, assembly, remove the lock and drive

pawls (Nos. 12 and 13) and remove the coil spring

(No.
14).

Reassembly

1.
Assemble lock and drive pawls to the shaft and drive

plate assembly as shown in Figure 99.

2.
Install the assembled parts from Step 1 in the gear

and eccentric shaft as shown in Figure 100.

3.
Connect the coil tension spring between the lock and

drive pawls (fig. 100).
4.
Reinstall spacer washer on the eccentric shaft of the

gear.

5. Reinstall gear mechanism in the housing as shown in

Figure 101.

6. Reassemble the parts removed in Steps 1 through 4

under drive gear disassembly.

The washer pump and/or valve assembly (fig. 102) may

be removed from the wiper assembly as a unit; therefore

it is- not necessary to remove the. wiper assembly from

the vehicle if only the washer pump and/or valve assem-

bly requires service.

WASHER PUMP SECTION

PUMP REPLACEMENT

. To replace the washer pump assembly proceed as

follows:

1.
Raise vehicle hood and remove engine distributor

shielding and distributor cap.

2.
Remove lead wires from washer pump and disconnect

ground wire from screw retained connector; discon-

nect hoses from valve unit.

3.
Remove four screws which secure the washer pump

assembly to the gear box.

a* The water inlet and outlet valve assembly is

serviced as a unit if required; also the rotor cam

is serviced separately.

4.
Install washer pump and cover assembly so that the

slot in the washer pump cam fits over the pin on the

wiper unit drive plate.

5. Install the four washer pump to gear box retaining

screws, position ground lug under lower screw.

6. Connect valve inlet and outlet hoses, attach ground

lead and washer pump lead wires.

7. Install engine distributor cap and shielding.

8. Lower hood and check operation of wiper unit.

SPECIAL TOOLS

J-21932

BEZEL NUT REMOVER

Fig.
103 - Special Tools

CHEVROLET CHASSIS SERVICE MANUAL

SECTION 13

RADIATOR AND GRILLE

INDEX

Page Page

General Description 13-1 Repairs 13-4

Radiator and Shroud-All Vehicles (Except Corvette) . . . . 13-1 Installation 13-4

Removal 13-1 Grille Assembly - Chevy II 13-4

Installation 13-1 Removal . 13-4

Radiator and Fan Shroud - Corvette . . . . 13-1 Repairs 13-5

Fan Shroud Replacement 13-1 Installation . 13-5

Aluminum Radiator 13-1 Grille Assembly - Corvette 13-5

Copper Radiator . 13-1 Removal . . . . 13-5

Grille Assembly - Chevrolet 13-2 Installation ....*... 13-5

Removal 13-2 Grille Assembly - Caxnaro 13-5

Repairs 13-3 Removal 13-5

Installation 13-3 Repairs . 13-6

Grille Assembly - Chevelle 13-3 Installation . . 13-6

Removal 13-.Q

GENERAL DESCRIPTION

Radiator assemblies are attached by cap screws either the radiator and shroud are basically the same for each

to the radiator support or radiator shroud, depending on vehicle,

the engine installation of each vehicle. The Camaro fan

Shroud is mounted in two bottom slots and secured by one NOTE: Refer to the Fisher Body Service Man-

bolt at the top. Removal and installation procedures for ual for Body, Section IX for Sheet Metal, Section

14 for Bumpers, and Section 1A for Air Condi-

tioning information when required.

SERVICE OPERATIONS

RADIATOR
AND
SHROUD—ALL VEHICLES
NOTE: Reach upper two shroud bolts from top,

(EXCEPT CORVETTE)
between hood and radiator support. Reach lower

4 by reaching around front edge of open hood.

Removal

1.
Drain radiator. 4.- Remove shroud carefully (tilt rearward, then lift up

2.
Disconnect inlet and outlet radiator hoses, and Pow- to clear fan blades).

erglide cooler lines if vehicle is so equipped. 5. Reverse procedure to install, fill cooling system and

3.
Remove radiator and shroud attaching screws and lift check for leaks.

radiator and shroud out of vehicle.

Aluminum Radiator

Installation

NOTE:
Refer to Figures 1 through 5 for radi- Removal and Installation

ator fan and shroud assembled positions for each 1. Remove shroud as previously outlined.

vehicle. Reverse removal procedures, fill cool- 2. Disconnect lower raciiator hose at either end.

ing system and check for leaks. 3. Remove radiator upper mount bracket bolts and

bracket, then lift radiator from vehicle.

RADIATOR AND FAN SHROUD-CORVETTE 4. Reverse procedure to install.

Fan Shroud Replacement (Fig. 4) Copper Radiator

1.
Drain radiator and open hood. (Install a bolt in hole

of hood support bracket for safety purposes.) Removal and Installation

2.
Disconnect upper radiator hose and supply tank hose 1. Remove hood panel assembly after scribing bracket

at radiator connection. location.

3.
Remove shroud bolts. 2. Drain radiator and disconnect radiator hoses.

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

ACCESSORIES 15-11

12 VOLTS D.C.
ELECTRIC BRAKE

RELEASE

IGNITION

SWITCH

ENGINE

VACUUM

TRANSDUCER

Fig.
11 - Vacuum and Electrical Diagram

AUTOMATIC LEVEL CONTROL

INDEX

Page

General Description . . 15-11

System Checks and Adjustments 15-13

Service Operation . 15-15

GENERAL DESCRIPTION

A pneumatic level control system that automatically

maintains correct rear trim height of a car under varying

load conditions, the optional automatic level control is

used only in conjunction with the Superlift Shock Absorber

option.

The Superlift Shock Absorber option alone, consists of

the two shock absorbers with pressure lines to a "Tee"

where a ill valve is located, the shocks are inflated

with (or deflated of) compressed air (at any gas station)

to obtain the vehicle level desired with any given load

change.

The automatic leveling system is added to the Superlift

Shock Absorbers and supplies its own compressed air.

The system (fig. 13) consists of a vacuum operated air

compressor with pressure regulator,
and
integral storage

tank, vacuum line to engine, air intake filter, air lines,

and a height control valve.

The COMPRESSOR is a two-stage, vacuum actuated

type, requiring no lubrication. Vacuum supply is taken

from engine carburetor base. High pressure air is
supplied to the reservoir tank by the second stage of

the two-stage compressor. The first stage intake stroke

draws air at atmospheric pressure through a oneway

check valve located in the end of the first stage housing

under the first ^tagei housing cover. On the first stage

compression stroke, the intake valve is closed and the

oneway check valve in the second stage end of the piston

is opened. This allows the air from the first stage

cylinder to flow through the hollow piston into the second

stage cylinder for jhigh pressure compression. The

second stage compression stroke closes the check valve

in the piston and opeijis the check valve in the end of the

second stage housing.

The intake and compression strokes are controlled by a

sliding distributor valive that is actuated through an arm

that is tripped by the piston as it nears the end of each

stroke. Each time the arm actuates the distributor

valve, a different set of holes are covered in the first

stage housing. The distributor valve controls the flow of

intake manifold vacuum and air under atmospheric pres-

CHEVROLET CHASSIS SERVICE MANUAL