coolant temperature CHEVROLET CAMARO 1967 1.G Chassis User Guide

SECTION 6K

ENGINE COOLING

INDEX

Page

General Description . . . 6K-1

Maintenance and Adjustments 6K-1

Coolant Level 6K-1

Coolant System Checks 6K-1

Periodic Maintenance 6K-2

Cleaning 6K-2

Reverse Flushing 6K-2

Radiator 6K-2
Page

Cylinder Block and Cylinder Head 6K-2

Hot Water Heater 6K-2

Fan Belt . 6K-2

Adjustment ....". 6K-2

Thermostat . 6K-2

Replacement 6K-2

Water Pump. . . . 6K-3

Removal 6K-3

Installation 6K-3

GENERAL DESCRIPTION

A pressure cooling system is provided for on all

models by a pressure type radiator cap (fig. 1). The

pressure type radiator cap used is designed to hold a

pressure above atmospheric pressure in the cooling

system. Excessive pressure is relieved by a valve within

the cap that opens to radiator overflow.

The water pump is a ball bearing, centrifugal vane

impeller type. It requires no care other than to make

certain the air vent at the top of the housing and the drain

holes in the bottom do not become plugged with dirt or

grease. Removal and installation of the water pump is

covered in this section. For overhaul procedures of the

water pump refer to Section 6K of the Passenger Chassis

Overhaul Manual.
For radiator, refer to Section 13 of this manual For

radiator shroud, refer to Section 11 of this manual.

Fig.
I—Pressure Radiator Cap

MAINTENANCE AND ADJUSTMENTS

Coolant Level

The radiator coolant level should only be checked when

the engine is cool, particularly on cars equipped with air

conditioning. If the radiator cap is removed from a hot

cooling system, serious personal injury may result

The cooling system fluid level should be maintained

one inch below the bottom of the filler neck of the radia-

tor when cooling system is cold, or at the bottom of the

filler neck when the system is warm. It is very impor-

tant that the correct fluid level be maintained. The seal-

ing ability of the radiator cap is affected when the cooling

level is too high.

All passenger car cooling systems are pressurized

with a pressure cap which permits safe engine operation

at cooling temperatures of
up
to 247°F.

When the radiator cap is removed or loosened, the

system pressure drops to atmospheric, and the heat

which had caused water temperature to be higher than

212°F, will be dissipated by conversion of water to

steam. Inasmuch as the steam may form in the engine

water passages, it will blow coolant out of the radiator

upper hose and top tank, necessitating coolant replace-

ment Engine operating temperatures higher than the

normal boiling point of water are in no way objectionable

so long as the coolant level is satisfactory when the

engine is cooL

Upon repeated coolant loss, the pressure radiator cap

and seat should be checked for sealing ability. Also, the
cooling system should be checked for loose hose con-

nections, defective hoses, gasket leaks, etc.

Coolant System Checks

1.
Test for restriction in the radiator, by warming the

engine up and then turning the engine off and feeling

the radiator. The radiator should be hot at the top

and warm at the bottom, with an even temperature

rise from bottom to top. Cold spots in the radiator

indicate clogged sections.

2.
Water pump operation may be checked by running the

engine while squeezing the upper radiator hose. A

pressure surge should be felt Check for a plugged

vent-hole in pump.

NOTE:
A defective head gasket may allow ex-

haust gases to leak into the cooling system.

This is particularly damaging to the cooling

system as the gases combine with the water to

form acids which are particularly harmful to

the radiator and engine.

3.
To check for exhaust leaks into the cooling system,

drain the system until the water level stands just

above the top of the cylinder head, then disconnect

the upper radiator hose and remove the thermostat

and fan belt. Start the engine and quickly accelerate

several times. At the same time note any appreci-

able water rise or the appearance of bubbles which

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE COOLING 6K-2

are indicative of exhaust gases leaking into the coolr

ing system.

Periodic Maintenance

Periodic service must be performed to the engine cool-

ing system to keep it in efficient operating condition.

These services should include a complete cleaning and

reverse flushing as well as a reconditioning service.

In the course of engine operation, rust and scale ac-

cumulate in the radiator and engine water jacket. The

accumulation of these deposits can be kept to a minimum

by the use of a good rust inhibitor but it should be

remembered that an inhibitor will not remove rust al-

ready present in the cooling system.

Two common causes of corrosion are: (1) air suction--

Air may be drawn into the system due to low liquid level

in the radiator, leaky water pump or loose hose con-

nections; (2) exhaust gas leakage—Exhaust gas may be

blown into the cooling system past the cylinder head

gasket or through cracks in the cylinder head and block.

Cleaning

A good cleaning solution should be used to loosen the

rust and scale before reverse flushing the cooling

system. There are a number of cleaning solutions avail-

able and the manufacturer's instructions with the particu-

lar cleaner being used should always be followed.

An excellent preparation to use for this purpose is GM

Cooling System Cleaner. The following directions for

cleaning the system applies only when this type cleaner

is-used.

1.
Drain the cooling system including the cylinder block

and then close both drain plugs.

2.
Remove thermostat and replace thermostat housing.

3.
Add the liquid portion (No. 1) of the cooling system

cleaner.

4.
Fill the cooling system with water to a level of about

3 inches below the top of the overflow pipe.

5. Cover the radiator and run the engine at moderate

speed until engine coolant temperature reaches 180

degrees.

6. Remove cover from radiator and continue to run the

engine for 20 minutes. Avoid boiling.

7. While the engine is still running, add the powder

portion (No. 2) of the cooling system cleaner and

continue to run the engine for 10 minutes.

8. At the end of this time, stop the engine, wait a few

minutes and then open the drain cocks or remove

pipe plugs. Also remove lower hose connection.

CAUTION: Be careful not to scald your hands.

NOTE:
Dirt and bugs may be cleaned out of

the radiator air passages by blowing out with air

pressure from the back of the core.

Reverse Flushing

Reverse flushing should always be accomplished after

the system is thoroughly cleaned as outlined above.

Flushing is. accomplished through the system in a direc-

tion opposite to the normal flow. This action causes the

water to get behind the corrosion deposits and force

them out.

Radiator

1.
Remove the upper and lower radiator hoses and re-

place the radiator cap,

2.
Attach a lead-away hose at the top of the radiator.
3.
Attach a new piece of hose to the radiator outlet

connection and insert the flushing gun in this hose.

4.
Connect the water hose of the flushing gun to a water

outlet and the air hose to an air line.

5. Turn on the water and when the radiator is full, turn

on the air in short blasts, allowing the radiator to

fill between blasts of air.

CAUTION: Apply air gradually as a clogged

radiator will stand only a limited pressure.

6. Continue this flushing until the water from the lead-

away hose runs clear.

Cylinder Block and Cylinder Head

1.
With the thermostat removed, attach a lead-away

hose to the water pump inlet and a length of new hose

to the water outlet connection at the top of the engine.

NOTE:
Disconnect the heater hose when re-

verse flushing engine.

2.
Insert the flushing gun in the new hose.

3.
Turn on the water and when the engine water jacket

is full, turn on the air in short blasts.

4.
Continue this flushing until the water from the lead-

away hose runs clear.

Hot Water Heater

1.
Remove water outlet hose from heater core pipe.

2.
Remove inlet hose from engine connection.

3.
Insert flushing gun and flush heater core. Care must

be taken when applying air pressure to prevent

damage to the core.

Fan Belt

Adjustment

1.
Loosen bolts at Delcotron slotted bracket.

2.
Pull Delcotron away from engine until desired ten-

sion reading is obtained with a strand tension gauge.

Refer to Section 6, "Engine Tune-Up".

3.
Tighten all Delcotron bolts securely.

Thermostat

The thermostat consists of a restriction valve actuated

by a thermostatic element. This is mounted in the hous-

ing at the cylinder head water outlet above the water

pump,
thermostats are designed to open and close at

predetermined temperatures and if not operating properly

should be removed and tested as follows.

Replacement

1.
Remove radiator to water outlet hose.

2.
Remove thermostat housing bolts and remove water

outlet and gasket from thermostat housing (fig. 2).

3.
Inspect thermostat valve to make sure it is in good

condition.

4.
Place thermostat in hot water 25° above the temper-

ature stamped on the thermostat valve.

5. Submerge the valve completely and agitate the water

thoroughly. Under this condition the valve should

open fully.

6. Remove the thermostat and place in water 10° below

temperature indicated on the valve.

7. With valve completely submerged and water agitated

thoroughly, the valve should close completely.

8. If thermostat checks satisfactorily, re-install, using

a new housing gasket.

9. Refill cooling system.

CHEVROLET CHASSIS SERVICE 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
12-36

CAMARO INSTRUMENTS AND GAUGES

INDEX

Page

General Description
12-36

Service Operations
12-36

Instrument Cluster
. . . 12-36

Instrument Lamps
12-36

Printed Circuit
12-36

Fuel Gauge
12-37

Tachometer
. . 12-37

Seat Separator Instrument Console
12-37
Page

Fuel Gauge
12-37

Ammeter
12-37

Temperature Gauge
12-37

Oil Pressure Gauge
. 12-37

Fuel Warning Unit
12-37

Clock.
... 12-37

Oil Pressure Indicator
12-37

Generator Indicator
12-38

Temperature Indicator
12-38

GENERAL DESCRIPTION

The standard Camaro instrument cluster assembly con-

sists
of two
circular units which house
the
speedometer

and fuel gauge assemblies.
The oil
pressure, left-hand

directional
and
brake warning indicators
are
located
in

the face
of the
speedometer bezel while generator,
tem-

perature
and
right-hand directional indicators are grouped

with
the
fuel gauge unit.
The
high beam indicator
is

located between
the
cluster bezels.

A special instrumentation package
is
available with
the

eight-cylinder engine
and
center floor console combina-

tion.
The
special cluster includes:
a
clock; coolant

temperature,
oil
pressure, fuel
and
ammeter gauges,

mounted forward
on the
seat separator console;
a ta-

chometer
in the
right circular housing
of the
dash
in-

strument cluster; and
a low
fuel level indicator replacing

the
oil
pressure indicator lamp
in the
instrument cluster.

The instruments
and
gauges,
may be
serviced only

after
the
instrument cluster
is
removed from
the
vehicle.

Indicator
and
cluster lamps except
for the
high beam

indicator
may be
replaced without removing
the
cluster

assembly. Partial cluster removal
is
necessary when

replacing
the
high beam indicator due
to its
proximity
to
the upper brace
rod
anchor plate.
The
bulbs
are in-

stalled
in
plastic sockets which lock into
the
cluster

housing and make contact with
the
printed circuit.

A
low
level fuel warning system
is a
special feature

available with
the
floor console gauge pack. This
sys-

tem includes
an
indicator lamp
in the
dash cluster and
a

semi-conductor unit senses
the
change
in
electrical
re-

sistance
of the
fuel system circuitry
as
variations
in

fuel level occur.
The
sensing device
is
replaced
as a

unit
if
found defective.

The brake warning light serves
a
dual purpose.
It

functions
as an
indicator when
the
parking brake
is ap-

plied
and
also
if
there
is a
malfunction (loss
of
hydraulic

pressure)
in the
brake system. Switches which provide

the signal
to
operate
the
light
are
located
at the
parking

brake assembly
and at the
brake master cylinder
in the

hydraulic lines. Service
of the
brake pressure differ-

ential switch unit
is
covered
in
Section
5 of
this manual.

Regular maintenance
is not
required on
the
instrument

cluster
or its
components other than maintaining clean,

tight electrical connections, replacing defective parts

and keeping
the
speedometer properly lubricated.

SERVICE OPERATIONS

INSTRUMENT CLUSTER (Figs.
50
thru
53)

Removal
and
Installation

1.
Disconnect battery ground cable.

2.
Remove mast jacket lower support screws
at toe
pan.

3.
Remove mast jacket upper support bolts
and
allow

steering wheel
to
rest
on
seat cushion.

CAUTION: Both supports must
be
detached
to

prevent distortion
of
mast jacket.

4.
Remove cluster attaching screws from face
of
panel

and partially remove assembly from console opening.

5. Reaching behind cluster assembly, disconnect speed-

ometer cable, speed warning device
(if so
equipped
-

Fig.
51) and
chassis harness connector
at
rear
of

panel.

6. Remove assembly from console opening to
a
suitable

bench area
for
required service operations.

7.
To
install, reverse removal procedure.

INSTRUMENT CLUSTER LAMP REPLACEMENT

1.
Turn bulb holder counterclockwise
and
pull
out to

remove from
the
cluster housing.
2.
Pull bulb straight out
to
remove from socket.

3.
Press replacement bulb inward
to
lock
in
socket.

4.
Insert lamp assembly into housing, with lugs
on

holder entering notches
in
housing,
and
turn clock-

wise
to
lock
in
place.

PRINTED CIRCUIT REPLACEMENT

1.
Remove instrument cluster
as
previously described

in this section.

2.
Remove
all
cluster illuminating and indicator lamps

from housing.

3.
Remove fuel gauge terminal nuts
or
tachometer
re-

taining nuts securing printed circuit
to
housing.

4.
Remove four
hex
head screws retaining printed
cir-

cuit
to the
cluster housing
and
remove circuit from

housing.

5.
To
install, reverse removal procedure.

CAUTION:
The
retaining screws
are
part
of

the grounding circuit
and
must
be
installed
to

provide proper connections
for the
printed
eir-

cuit.

CHEVROLET CHASSIS SERVICE MANUAL