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