radiator CHEVROLET CAMARO 1967 1.G Chassis Owner's Guide

ENGINE 6-22

the camshaft gear (fig. 15L).

7.
Remove the camshaft and gear assembly by pulling it

out through the front of the block.

NOTE: Support camshaft carefully when re-

moving so as not to damage camshaft bearings.

Installation

1.
Install the camshaft and gear assembly in the engine

block, being careful not to damage camshaft bearings

or camshaft.

2.
Turn crankshaft and camshaft so that the valve tim-

ing marks on the gear teeth will line up (fig. 15L).

Push camshaft into position. Install camshaft thrust

plate-to-block bolts and torque to specifications.

3.
Check camshaft and crankshaft gear run out with a

dial indicator (fig. 16L). The camshaft gear"run out

should not exceed,.004" and the crankshaft gear run

out should not exceed
.003".

4.
If gear mm out is excessive, the gear will have to be

removed and any burrs cleaned from the shaft or the

gear will have to be replaced.

5.
Check the backlash between the timing gear teeth

with a dial indicator (fig. 17L). The backlash should

not be less than .004" nor more than .006".

6. Install fuel pump as outlined in Section 6M.

7.
Install grille as outlined in Section 13.

8. Install crankcase front cover as outlined.

9. Install radiator as outlined in Section 13.

10.
Install valve lifters as outlined.

TIMING GEARS

Replacement

With camshaft removed, crankshaft gear may be re-

moved using Tool J-8105 (fig. 18L). To install crankshaft

gear use Tool J-5590 (fig. 19L). For camshaft gear re-

placement, refer to Section 6, "Camshaft Disassembly"

of the Overhaul Manual.
Fig.
18L
- Removing Crankshaft Gear

Fig.
19L- Installing Crankshaft Gear

FLYWHEEL

Removal

With transmission and/or clutch housing and clutch re-

moved from engine, remove the flywheel.

Installation

1.
Clean the mating surfaces of flywheel and crankshaft

to make certain there are no burrs.

2.
Install flywheel on crankshaft and position to align

dowel hole of crankshaft flange and flywheel (fig.

20L).

NOTE: On Automatic Transmission equipped

engines, the flywheel must be installed with the

flange collar to transmission side (fig. 20L).

3.
Install bolts and torque to specifications.

SYNCHROMESH
CONVERTER

BOLT AREA -

DEPRESSED
•RING

GEAR

TRANS.,

AUTOMATIC

Fig. 17L
—
Checking Timing Gear Backlash
Fig. 20L r Flywheel Installation (Typical)

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-25

refer to Section 6 of the Chassis Overhaul Manual.

Because of the interchangeability and similarity of

many engines, engine sub-assemblies and engine parts,

regardless of which passenger vehicle they are used in,

typical illustrations and procedures are used except
where specific illustrations or procedures are necessary

to clarify the operation. Although illustrations showing

bench operations are used, most single operations, when

not part of a general overhaul, should be performed (if

practical) with the engine in the vehicle.

COMPONENT REPLACEMENT AND ADJUSTMENT

ENGINE ASSEMBLY

Removal

• .1. Drain cooling system and engine oil.

2.
Remove air cleaner and disconnect battery cables at

battery.

3.
Remove hood as outlined in Section 11.

4.
Remove radiator and shroud as outlined in Sec-

tion 13.

5. Remove fan blade and pulley as outlined in Sec-

tion 6K.

6. Disconnect wires at:

• Starter solenoid

• Delcotron

• Temperature switch

• Oil pressure switch

• Coil

7. Disconnect:

• Accelerator linkage at pedal lever.

• Exhaust pipes at manifold flanges.

• Vacuum line to power brake unit at manifold (if

so equipped),

• Power steering pump lines at pump end (if so

equipped).

• Fuel line (from tank) at fuel pump.

• Engine cooler lines (if so equipped).

• Oil pressure gauge line (if so equipped).

8. Raise vehicle and place on jack stands.

9. Remove propeller shaft.

NOTE:
If plug for propeller shaft opening

in transmission is not available, drain

transmission.

10.
Disconnect:

• Shift linkage at transmission.

• Speedometer cable at transmission.

• Transmission cooler lines (if so equipped).

11.
On synchromesh equipped vehicles, disconnect clutch

linkage at cross-shaft then remove cross-shaft en-

gine bracket.

12.
Remove rocker arm covers as outlined, then attach

engine lifting adapter at the proper cylinder head bolt

locations.

13.
Remove front mount bolts.

14.
Attach lifting device and raise engine to take weight

off front mounts, then remove rear mount bolts.

15.
Raise engine to take weight off rear mount, then re-

move crossmember.

NOTE:
On Chevrolets it will be necessary to

remove mount from transmission before cross-

member can be removed.

16.
Remove engine-transmission assembly from vehicle

as a unit.

17.
Remove transmission (and clutch):
Synchromesh Transmission

a. Remove clutch housing cover plate screws.

b.
Remove bolts attaching the clutch housing to en-

gine block then remove transmission and clutch

housing as a unit.

NOTE:
Support the transmission as the last

mounting bolt is removed, and as it is being

pulled away from the engine (to prevent damage

to clutch disc).

c. Remove starter and clutch housing rear cover

plate.

d. Loosen clutch mounting bolts a turn at a time (to

prevent distortion of clutch cover) until the spring

pressure is released. Remove all bolts, clutch

disc and pressure plate assembly.

Automatic
Transmission

a. Lower engine, secured by the hoist, and support

engine on blocks.

b.
Remove starter and converter housing underpan.

c. Remove flywheel-to-converter attaching bolts.

d. Support transmission on blocks.

e. Remove transmission-to-engine mounting bolts.

f. With the hoist attached, remove blocks from the

engine only and slowly guide the engine from the

transmission.

18.
Mount engine in stand.

Installation

1.
Attach lifting device to engine and remove engine

from engine stand.

2.
Install transmission (and clutch):

Synchromesh Transmission

a. Install the clutch on flywheel as outlined in Sec-

tion 7.

b.
Install clutch housing rear cover and starter.

c. Install transmission and clutch housing as out-

lined in Section 7.

d. Install clutch housing cover screws and tighten

securely.

Automatic
Transmissions

a. Position engine adjacent to the transmission and

align the converter with the flywheel.

b.
Bolt transmission to engine, then raise engine and

transmission assembly and install flywheel to

converter attaching bolts.

c. Install converter housing underpan and starter.

3.
Tilt and lower engine and transmission assembly into

the chassis as a unit, guiding engine to align front

mounts with frame supports.

4.
Install front mount bolts and torque to specifications.

5. Raise engine enough to install rear crossmember,

then install crossmember, install rear mount, lower

engine and torque rear mount to specifications.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-26

6. Remove lifting device and lifting adapter then install

rocker arm covers as outlined.

7.
On synchromesh equipped vehicles, install clutch

cross-shaft engine bracket, then adjust and connect

clutch as outlined in Section 7.

8. Connect:

• Speedometer cable.

• Shift linkage at transmission.

• Transmission cooler lines (if so equipped).

9. Install propeller shaft.

10.
Remove jack stands and lower vehicle.

11.
Connect: \ '

Power steering pump lines (if so equipped).

Vacuum line to power brake unit (if so equipped).

Exhaust pipes at manifold flanges.

Accelerator linkage at pedal lever.

Fuel line at fuel pump.

Engine cooler lines (if so equipped).

Oil pressure gauge lines (if so equipped).

12.
Connect wires at:

Coil

Oil pressure switch

Temperature switch

Delcotron

Starter solenoid

13.
Install pulley, fan blade and fan belt as outlined in

Section 6K.

14.
Install radiator and shroud as outlined in Section 13.

15.
Install and adjust hood as outlined in Section 11.

16.
Connect battery cables.

17.
Fill with coolant, engine oil and transmission oil,

then start engine and check for leaks.

18.
Perform necessary adjustments and install air

cleaner.

INTAKE MANIFOLD

Removal

1.
Drain radiator and remove air cleaner.

2.
Disconnect:

Battery cables at battery.

Upper radiator and heater hose at manifold.

Accelerator linkage at pedal lever.

Fuel line at carburetor. ;

Wires at temperature sending switch and coil

(both sides).

Power brake hose at carburetor base.

Spark advance hose at distributor.

Crankcase ventilation hoses (as required).

3.
Remove distributor cap and mark rotor position with

chalk. Remove distributor clamp and distributor,

then position distributor cap rearward clear of

manifold.

4.
Remove coil.

5.
Remove manifold-to-head attaching bolts, then re^

move manifold, (with carburetor on) from engine and

discard gaskets and seals.

6. If manifold is to be replaced,,transfer:

Carburetor and carburetor mounting studs.

Temperature sending switch.

Water outlet and thermostat (use new gasket).

Heater hose adapter.

Choke coil.

Installation

1.
Clean gasket and seal surfaces of manifold, cylinder
heads and block.

2.
Install manifold end seals on block as shown (fig.

2V).

3.
Install side gaskets on cylinder heads using sealing

compound around water passages (fig. 2V).

4.
Install manifold bolts, and torque to specifications in

the sequence outlined on the Torque Sequence Chart.

5.
Install coil.

6. Install distributor with the rotor pointing at the chalk

mark, then install distributor cap.

NOTE:
If the crankshaft has been rotated while

the distributor was removed, time distributor to

number 1 cylinder as outlined in Section 6Y.

7.
Connect:

Battery cables at battery.

Upper radiator and heater hose at manifold.

Accelerator linkage at pedal lever.

Fuel line at carburetor.

Wires at temperature sending switch and coil

(both sides)!

Power brake hose at carburetor base.

Spark advance hose at distributor.

Crankcase ventilation hoses (as required).

Fill with coolant, start engine, check for leaks and

adjust timing and carburetor idle speed and mixture.

EXHAUST MANIFOLD

Removal

NOTE:
If equipped with "Air Injection Reactor

System", remove air manifold and tubes as out-

lined in Section 6T.

1.
Disconnect battery ground cable.
-

2.
Disconnect and remove Delcotron (as required).

3.
On 396 and 427 cu. in. engines, remove spark plugs

Fig. 2V - Intake Manifold Gasket and Seal Location

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-30

c". Install the valve locks and release the compres-

sor tool making sure the locks seat properly in

the upper groove of the valve stem.

NOTE: Grease may be used to hold the locks

in place while releasing the compressor tool.

396 and 427
cu.
in.
Engines

a. Install new valve stem oil seal (coated with oil)

in position over valve guide.

b.
Set the valve spring and damper and valve cap in

place.

c. Compress the spring with Tool J-5892 and install

the valve locks, then release the compressor tool,

making sure the locks seat properly in the groove

of the valve stem.

NOTE: Grease may be used to hold the locks

in place while releasing the compressor tool.

7.
Install spark ,plug, using a new gasket, and torque to

specifications. -

8. Install and adjust valve mechanism as outlined.

CYLINDER HEAD ASSEMBLY

Removal

1.
Remove intake manifold as outlined.

2.
Remove exhaust manifolds as outlined.

3.
Remove valve mechanism as outlined.

4.
Drain cooling system (block).

5.
Remove cylinder head bolts, cylinder head and gas-

ket. Place cylinder head on two blocks of wood to

prevent damage.

Installation

CAUTION: The gasket surfaces on both the

head and the block must be clean of any foreign

ttter and free of nicks or heavy scratches.

Under bolt threads in the block and threads on

Pie cylinder head bolt must be cleaned. (Dirt

will affect bolt torqueT)

1.
On engines using a STEEL gasket, coat both sides of

a new gasket with a good sealer, spread the sealer

thin and even. One method of applying the sealer that

will assure the proper- coat is with the use of a paint

roller. Too much sealer may hold the beads of the

gasket away from the head or block.

CAUTION: Use no sealer on engines using a

composition STEEL ASBESTOS gasket.

2.
Place the gasket in position over the dowel pins with

the bead up.

3.
Carefully guide cylinder head into place over dowel

pins and gasket.

4.
Coat threads of cylinder head bolts with sealing

compound and install finger tight.

5.
Tighten cylinder head bolts a little at a time in the

sequence shown on the torque sequence chart until

the specified torque is reached.

6. Install the exhaust manifold as outlined.

7.
Install the intake manifold as outlined.

8. Install and adjust the valve mechanism as outlined.
OIL
PAN

Removal

Chevrolet
and Camaro

1.
Disconnect battery positive cable.

2.
Disconnect distributor cap from distributor (to pr-e-

vent breaking distributor cap when engine is raised).

3.
Drain radiator, then disconnect lower radiator hose

at water pump and remove oil dip stick and tube

(where necessary). '

4.
Remove fan blade.

5.
Raise vehicle then drain engine oil;

6. Remove through bolts from engine front mounts.

Disconnect and remove starter.

7.
On vehicles equipped with automatic transmissions,

remove converter housing underpan.

8. Disconnect steering rod at idler lever then swing

steering linkage 4pwn for oil pan clearance.

9. Rotate crankshaft untii timing mark on torsional

damper is at 6:00 o'clock position.

10.
Using a suitable jack, and a block of wood to prevent

damaging oil pan, raise engine "enough to insert 2" x

4"
wood blocks under engine mounts (fig. 8V), then

lower engine onto blocks.

NOTE: If 2" x 4" wood blocks are cut 5-1/2"

long they can be used on all Chevrolet engines.

The 5-1/2" length up for In-line engines and the

4"
side up for V8 engines.

11.
Remove oil pan and discard gaskets and seals.

NOTE: -On the 396 and 427 cu. in. engine, the

oil pan has three 1/4" x 20 attaching bolts at ,

crankcase front cover. One located at each

corner and one at lower center.

Chevelle

1.
Remove engine from vehicle as outlined.

2.
Lower engine onto jack stands, one at each front

Tnaount and one at transmission extension.

CAUTION: Leave engine lift attached to en-

gine.
Do not remove all weight of engine off

engine lifET

3.
Remove starter.

4.
On vehicles equipped with automatic transmission

remove converter housing underpan.

5.
Remove oil pan and discard gaskets and seals.

Fig.
8V - Engine Blocked for Pan Removal

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-31

Chevy II

1.
Disconnect battery positive cable.

2.
Drain engine oil.

3.
Disconnect and remove starter.

4 Disconnect steering idler arm bracket at right hand

frame rail and swing steering linkage down for pan

clearance.

5.
Disconnect* exhaust pipes at manifolds and allow

pipes to hang free.

6. Remove oil pan and discard gaskets and seals.

Corvette

1.
Disconnect battery positive cable then remove oil

dipstick and tube.

2.
Raise and support vehicle then drain engine oil.

3.
Remove starter and flywheel underpan.

4.
Disconnect steering linkage idler at frame and lower

the linkage.

5.
Remove oil pan and discard gaskets and seals.

6. On Hi-Performance engines, the oil baffle must

be removed before additional operations can be

performed.

NOTE: On the 427 cu. in. engine, the oil pan

has three 1/4" x 20 attaching bolts at crankcase

front cqver. One located at each corner and one

at lower center.

Installation

1.
Thoroughly clean all gasket sealing surfaces.

NOTE: Use a new pan. gasket set.

2.
Install side gaskets on pan rails, using.gasket sealer

as a retainer.

3.
Install rear oil pan seal in groove in rear main

bearing cap with ends (fig. 9V) butting side gaskets.

4.
Install oil pan front seal in groove in .crankcaee front

cover, with ends butting side gaskets.

5.
If crankshaft was rotated while £>an was off, place

timing mark at 6:00 o'clock position.

6. Install oil pan and torque bolts to specifications.

NOTE: On 396 and 427 cu. in. engines, start

three 1/4" x 20 bolts into crankcase front cover

before tightening, any other pan bolts.

7.
Complete installation as follows:

Chevrolet
and Camaro

a. Using a suitable jack (and a block of wood to pre-

vent damaging oil pan) raise engine enough to re-

move 2" x 4" wood blocks, then lower engine.

b.
On vehicles equipped with automatic transmission

install converter housing underpan.

c. Install through bolts in engine front mounts.

d. Install and connect starter. Connect steering rod

at idler lever.

e. Lower vehicle and install fan blade.

f. Cbnnnect lower radiator hose, then install oil dip

stick tube and dip stick.

g. Connect distributor cap and battery positive

cable.

h. Fill radiator with coolant and fill engine with oil,

then start engine and check for leaks.

Chevelle

a. On vehicles equipped with automatic transmission
Fig.
9V - Oil Pan Gasket and Seal Location

install converter housing underpan.

b.
.Install starter.

c. Install, engine as outlined.

Chevy II

a. Connect exhaust pipe to manifold flange using new

packing seals.

b.
Connect steering idler arm bracket.

c. Connect starter wires..

d. Connect battery cable.

e. Fill with oil, start engine and check for leaks.

Corvette

a. Connect steering linkage.

b.
Install oil dip stick tube and dip stick then con-

nect battery cables.

c. Fill engine with oil, then start engine and check

for leaks.

OIL PUMP

Removal

1.
Remove oil pan as outlined.

2.
Remove pump to rear main bearing cap bolt and re-

move pump and extension shaft.

Installation

1.
Assemble pump and extension shaft to rear main

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-32

Fig.
1GV - Removing Oil Seal (Lower Half)

bearing cap, aligning slot on top end of extension

shaft with drive tang on lower end of distributor

drive shaft.

2.
Install pump to rear bearing cap bolt and torque to

specifications.

NOTE:
Installed position of oil pump, screen

is with bottom edge parallel to oil pan rails.

3.
Install oil pan as outlined.

OIL SEAL (REAR MAIN)

Replacement

The rear main bearing oil seal can be replaced (both

halves) without removal of the crankshaft.
Fig.
12V - Removing Torstonal Damper

NOTE:
Always replace the upper and lower

seal as a unit.. Install with the lip facing toward

the front of the engine.

With the oil pan and oil pump removed, remove the

rear main bearing cap.

Remove oil seal from the groove by prying from the

bottom with a small screw driver (fig. 10V).

Lubricate the lip of a new seal with engine oil. Keep

oil off the parting line surface as this is treated with

glue. Insert seal in cap and roll it into place with

finger and thumb, using light pressure so seal tangs

at parting line do not cut bead on back of seal.

To remove the upper half of the seal, use a small

hammer to tap a brass pin punch on one end of seal

until it protrudes far enough to be removed with

pliers (fig. 11V).

NOTE:
Always wipe crankshaft surface clean

before installing a new seal.
1.

2.

3.

5.

Fig.
1IV - Removing Oil Seal (Upper Half)
Lubricate the lip of a new seal with engine oil. Keep

oil off the parting line surface as this is treated with

glue. Gradually push with a. hammer handle, while

turning crankshaft, until seal is rolled into place.

(Similar to installing a main bearing.) Be careful

that seal tangs at parting line do not cut bead on back

of seal.

6. Install the rear main bearing cap (with new seal) and

torque to specifications.

TORSIONAL DAMPER

Removal

1.
Remove fan belt, fan and pulley as outlined in Sec-

tion 6K.

2.
Remove the radiator and shroud as outlined in Sec-

tion 13.

NOTE:
If additional operations such as cam-

shaft removal are not being performed, the radi-

ator will not have to be removed
.on
Chevrolets

and Corvettes equipped with 396 and 427 cu. in.

engines.

. 3. On Corvettes equipped with 427 cu. in. engines, re-

move engine front mount through-bolts and raise

front of engine enough for torsional damper to clear

frame crossmember.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-33

Fig.
13V - Installing TorsionaI Damper (283, 327 and 350)

4.
Remove accessory drive pulley, then remove tor-

sional damper retaining bolt (if so equipped).

5. Install Tool J-6978 to torsional damper and turn

puller screw to remove damper from crankshaft

(fig. 12V).

6. Remove tool.

Installation

CAUTION: It is necessary to use installer tool

to prevent the inertia weight section from walk-

ing off the hub during installation of damper.

283, 327 and 350 cu. in. Engines

(Except 327-325 HP & 350 HP)

1.
Coat front cover seal contact area (on torsional

damper) with engine oil.

Fig.
14V - Installing Torsional Damper (396 and 427)
2.
Attach damper installer Tool J-22197 to damper.

Tighten fingers of tool to prevent weight from moving

(fig. 13V).

3.
Position damper on crankshaft and drive into position

until it bottoms against crankshaft sprocket (fig.

13V).
Remove installer tool.

4.
Install accessory drive pulley.

5. Install radiator and shroud as outlined in Section 13.

6. Install fan pulley and fan as outlined in Section 6K.

7. Install fan belt and adjust to specifications using

strand tension gauge.

8. Fill cooling system, start engine and check for leaks.

396 and 427
cu.
in.
Engines

1.
Coat front cover seal contact area (on damper) with

engine oil.

2.
Place damper in position over key on crankshaft.

3.
Using Tool J-21058 pull damper onto crankshaft

(fig. 14V).

NOTE:
If engine or radiator has not been re-

moved from the vehicle a 1/2"- 20 x 5" bolt and

a
1/2"-20
nut may be used in place of the bolt

and nut of Tool J-21058.

CAUTION: Install bolt in crankshaft with suffi-

cient thread engagement (min. 1/2").

4.
Remove tool from crankshaft.

5. Install damper retaining bolt and torque to specifica-

tions,
then install accessory drive pulley.

6. Install radiator and shroud as outlined in Section 13.

7. Install fan pulley and fan as outlined in Section 6K.

8. Install fan belt and adjust to specifications using

strand tension gauge.

9. On Corvettes, lower engine and install front mount

through-bolts.

10.
Fill cooling system, start engine and check for leaks.

327
cu.
in. (325 & 350 HP)
Engine

Install damper as outlined for 396 and 427 cu. in. en-

gines,
using a 7/16"-20 x 5" bolt and nut in place of the

bolt and nut furnished with J-21058.

CRANKCASE FRONT COVER

Removal

1.
Remove oil pan as outlined.

2.
Remove torsional damper as outlined.

3.
Remove water pump as outlined in Section 6K.

4.
Remove crankcase front cover attaching bolts and

remove front cover and gasket, then discard gasket

Installation

283, 327 and 350 cu. in.
Engine

1.
Make certain that cover mounting face and cylinder

block front face are clean and flat.

2.
Coat the oil seal with engine oil and using a new

cover gasket, coated with gasket sealer, install cover

and gasket over dowel pins and cylinder block.

3.
Install cover screws and torque bolts to

specifications.

4.
Install water pump as outlined in Section 6K.

5. Install torsional damper as outlined.

6. Install oil pan as outlined.

CHEVROLET CHASSIS SOVKZ MANUAL

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

ENGINE COOLING 6K-3

Fig.
2— Replacing Thermostat
Water Pump

Removal

1.
Drain radiator and break loose the fan pulley bolts.

2.
Disconnect heater hose, lower radiator hose and

by pass hose (as required) at water pump.

3.
Loosen Delcotron and remove fan belt then remove

fan bolts, fan and pulley.

4.
Remove pump to cylinder block bolts and remove

pump from engine.

NOTE:
On in line engines, pull the pump

straight out of the block first, to avoid damage

to impeller.

Installation

1.
Install pump assembly on cylinder block and tighten

bolts securely. Use on new pump to block gasket(s).

2.
Install pump pulley and fan on pump hub and tighten

bolts securely.

NOTE:
A guide stud (5/16"-24 x 1-1/2" bolt

with the head removed) installed in one hole of

the fan hub will aid in aligning hub, pulley and

fan.
Remove stud after starting the remaining

three bolts.

3.
Connect hoses and fill cooling system.

4.
Install fan belt and adjust as previously outlined.

5. Start engine and check for leaks.

CHEVROLET CHASSIS SERVICE MANUAL