1967 CHEVROLET CAMARO turn

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 6-28

damper comes near the "0" mark on the front

cover.
11
the valves are not moving, the engine is

in the number 1 firing position. If the valves

move as the mark comes up to the timing tab, the

.
engine is in number 6 firing position and crank-

shaft should be rotated one more revolution to

reach the number 1 position,

b.
Valve adjustment is made by backing off the ad-

justing nut (rocker arm stud nut) until there is

play in the push rod and then tighten nut to just

remove all push rod to rocker arm clearance.

' this may be determined by rotating push rod with

fingers as the nut is tightened (fig. 4
V).
When

push rod does not readily move in relation to the

rocker arm, the clearance has been eliminated.

The adjusting nut should then be tightened an

additional 1 turn to place the hydraulic lifter

plunger in the center of its travel. No other

adjustment is required.

c. With the engine in the number 1 firing position

as determined above, the following valves may be

adjusted.

Exhaust - 1, 3, 4, 8

Intake - 1, 2, 5, 7

d. Crank the engine one revolution until the pointer

"(X" mark and torsional damper mark are again

in alignment. This is number 6 firing position.

With the engine in this position the following

valve may be adjusted.

Fig.
5V - Valve Adjustment (Mechanical)
Exhaust - 2, 5, 6, 7

Intake
-•
3, 4, 6, 8

With Mechanical Valve
Lifters

a. Crank engine until mark on torsional damper

lines up with center or "0" mark on the timing

tab and the engine is in the number 1 firing posi-

tion. This may be determined by placing fingers

on t£e number 1 cylinder valve as the mark on the

damper comes near the n0" mark on the front

cover. If the valves are not moving, the engine

is in the number 1 firing position. If the valves

move as the mark comes up to the timing tab, the

engine is in number 6 firing position and crank-

shaft should be rotated one more revolution to

reach the number 1 position.

b.
With the engine in the number 1 firing position as

determined above, adjust the following valves to

specifications with a feeler gauge (fig. 5V).

Exhaust - 4, 8

Intake - 2, 7. .

c. Turn crankshaft 1/2 revolution (180°) clockwise

and adjust the following valve to specifications

with a feeler gauge.

Exhaust -3,6

Intake - 1, 8

d. Turn crankshaft 1/2 revolution (180°) clockwise

until the pointer "0" mark and torsional-damper

mark are again in alignment. This is number 6

firing position. With the engine in this position,

adjust the following valves to specifications with

a feeler gauge.

Exhaust -5,7

Intake - 3, 4

e. Turn crankshaft 1/2 revolution (180°) clockwise

and adjust the following valves to specifications

with a feeler gauge.

Exhaust - 1, 2

Intake - 5, 6

f. Readjust valves (hot and running) as outlined

under "Engine Tune Up".

4.
Install rocker arm covers as outlined.

5.
Adjust carburetor idle speed and mixture.

VALVE LIFTERS

Hydraulic valve lifters very seldom require attention;

The lifters are extremely simple in design, readjust-

ments are not necessary, and servicing of the lifters re-

quires only that care and cleanliness be exercised in the

handling of parts.

Locating Noisy Lifters (Hydraulic)

Locate a noisy valve lifter by using a piece of garden

hose approximately four feet in length. Place one end of

the hose near the end of each intake and exhaust valve

with the other end of the hose to the ear. In this manner,

the sound is localized making it easy to determine which

lifter is at fault.

Another method is to place a finger on the face of the

valve spring retainer. If the lifter is not functioning

properly, a distinct shock will be felt when the valve re-

turns to its seat.-*

The general types of valve lifter noise are as follows:

1.
Hard Rapping Noise—Usually caused by the plunger

becoming tight in the bore of the lifter body to such

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-29

an extent that the return spring can no longer push

the plunger back up to working position. Probable

causes are:

a. Excessive varnish or carbon deposit causing ab-

normal stickiness.

b.
(Sailing or "pick-up" between plunger and bore of

lifter body, usually caused by an abrasive piece of

dirt or metal wedging between plunger and lifter

body.

2.
Moderate Rapping Noise--Probable causes are:

a. Excessively high leakdown rate.

b.
Leaky check valve seat.

c. Improper adjustment.

3.
General Noise Throughout the Valve Train-rThis

will, in almost all cases, be a definite indication of

insufficient oil supply, or improper adjustment.

4.
Intermittent Clicking—Probable causes are:

a. A microscopic piece of dirt momentarily caught

between ball seat and check valve ball.

b.
In rare cases, the ball itself may be out-of-round

or have a flat spot.

c. Improper adjustment.

In most cases where noise exists in one or more lifters

all lifter units should be removed, disassembled, cleaned

in a solvent, reassembled, and reinstalled in the engine.

If dirt, corrosion, carbon, etc. is shown to exist in one

unit, it more than likely exists in all the units, thus it

would only be a matter of time before all lifters caused

trouble.

Removal

1.
Remove intake manifold as outlined.

2.
Remove valve mechanism as outlined.

3.
Remove valve lifters.

NOTE: Place valve lifters in a rack so they

may be reinstalled in the same location.

Installation

1.
Install valve lifters.

NOTE: Whenever new valve lifters are being

installed coat foot of valve lifters with Molykote

or its equivalent.

2.
Install intake manifold as outlined.

3.
Install and adjust valve mechanism as outlined.

VALVE STEM OIL SEAL AND/OR VALVE SPRING

Replacement

1.
Remove rocker arm cover(s) as outlined.

2.
Remove spark plug, rocker arm and push rod on the

cylinders to be serviced.

3.
Apply compressed air to the spark plug hole to hold

tl*e valves in place.

NOTE: A tool to apply air to the cylinder is

available through local jobbers or may be manu-

factured. In manufacturing this Tool a AC-46N

Spark Plug or its equivalent is recommended.

This will make the Tool universal for all

Chevrolet engines. Chisel the spark plug as

shown, then drive the porcelain out of the plug

by tapping the center electrode against a hard

block. Using a 3/8" pipe tap, cut threads in the

remaining portion of the spark plug and assem-

ble as shown (fig. 6V).
Fig.
6V - Air Adapter Tool

4.
Using Tool J-5892, to compress the valve spring, re-

move the valve locks, valve cap, and valve spring and

damper (fig. 7V).

5.
Remove valve stem oil seal.

6. Remove as follows:

283, 327 and 350 eu. in.
Engines

a. To replace, set the valve spring and damper,

valve shield and valve cap in place. The close

coiled end of the spring is installed against the

cylinder head.

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

oil seal in the lower groove of the stem, making

sure the seal is flat and not twisted.

NOTE: A light coat of oil on the seal will help

prevent twisting.

Fig.
7V - Compressing Valve Spring

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