1967 CHEVROLET CAMARO check engine

ENGINE 6-27

and spark plug shields.

4.
Remove exhaust manifold flange nuts, then lower ex-

haust pipe assembly (hang exhaust pipe from frame

with wire).

5.
Bend french lock tabs (fig. 3V), remove end bolts

then remove center bolts and remove manifold from

engine.

NOTE: A 9/16 thin-wall 6 point socket, sharp-

ened at the leading edge, then started on the head

of the bolt and tapped in place with a hammer,

simplifies bending of french locks.

Installation

1.
Clean mating surfaces on manifold and head, then

install manifold in position and install center bolts.

2.
Install end bolts with french locks under them.

3.
Torque center bolts to specifications, then torque end

bolts to specifications, and bend french lock tabs to

lock end bolts.

4.
Using a new flange gasket install exhaust pipe to

manifold flange.

5.
On 396 and 427 cu. in. engines, clean and install

spark plugs using new gaskets. (Torque spark plugs

to specifications.)

6. Install and connect Delcotron.

7.
Connect the battery ground cable.

8. Start engine and check for leaks.

ROCKER ARM COVER

Removal

1.
Remove air cleaner.

2.
Disconnect crankcase ventilation hoses (as required).

3.
Disconnect temperature wire from rocker arm cover

clips.

4.
Remove rocker arm cover.

CAUTION: DO NOT pry rocker arm cover

loose. Gaskets adhering to cylinder head and
Installation

1.
.Clean gasket surfaces on cylinder head and rocker

arm cover with degreaser then, using a new gasket,

install rocker arm cover and torque bolts to

specifications. .

2.
Connect crankcase ventilation hoses (if disconnected).

3.
Connect temperature wire at rocker arm cover clips.

4.
Install air cleaner.

VALVE MECHANISM

Removal

1.
Remove rocker arm covers as outlined.

2.
Remove rocker arm nuts, rocker arm balls, rocker

arms and push rods.

NOTE: Place rocker arms, rocker arm balls

and push rods in a rack so they may be rein-

stalled in the same location.

Installation and Adjustment

NOTE: Whenever new rocker arms and/or

rocker arm balls are being installed, coat bear-

ing surfaces of rocker arms and rocker arm

balls with Molykote or its equivalent.

1.
Install push rods; Be sure push rods seat in lifter

socket.

2.
Install rocker arms, rocker arm balls and rocker

arm nuts.

3.
Adjust valves when lifter is on base circle of cam-

shaft lobe as follows:

With Hydraulic Valve
Lifters

2L.
Crank engine until
mark on torsional damper

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

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

tion. This may be determined by placing fingers

on the number 1 cylinder valve as the mark on the

rocker arm cover may be sheared by bumpii

end of rocker arm cover rearward with palm

hand or a rubber mallet.

Fig.
3V - Exhaust Manifold French Locks
Fig.
4V - Valve Adjustment (Hydraulic)

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 6-31

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 6-33

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

ENGINE 6-36

Fig.
23V - Installing Crankshaft Sprocket

(283,
327
and
350)

8* Draw camshaft sprocket onto camshaft, using the

three mounting bolts. Torque to bolt specifications.

9. Lubricate timing chain with engine oil.

10.
Install crankcase front cover and torsional damper

as outlined.

CAMSHAFT

Measuring Lobe Lift

NOTE: Procedure is similar to that used for

checking valve timing. If improper valve opera-

tion is indicated, measure the lift of each push

rod in consecutive order and record the

readings.

1.
Remove valve mechanism as outlined.

2.
Position indicator with ball socket adapter on push

rod (fig. 26V).

3.
Rotate the crankshaft damper slowly in the direction

of rotation until the lifter is on the heel of the cam

lobe.
At this point, the push rod will be in its lowest

position.
Fig.
25V- Installing Timing Chain

Fig.
24V - Installing Crankshaft Sprocket

(396 and 427)
Fig.
26V - Measuring Camshaft Lobe Lift

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-37

Fig.
27V—Removing Camshaft

4.
Set dial indicator on zero, then rotate the damper

slowly, or attach an auxiliary starter switch and

"bump" the engine over, until the push rod is in the

fully raised position.

CAUTION: The primary distributor lead must

be disconnected from the negative post on the

coil and the ignition switch must be in the on

position. Failure to do this will result in a dam-

aged grounding circuit in the ignition switch.

5.
Compare the total lift recorded from the dial indica-

tor with specifications.

6. Continue to rotate the crankshaft until the indicator

reads zero. This will be a check on the accuracy of

the original indicator reading.

7.
If camshaft readings for all lobes are within specifi-

cations, remove dial indicator assembly.

8. Install and adjust valve mechanism as outlined.

Removal

1.
Remove valve lifters as outlined.

2.
Remove crankshaft front cover as outlined.

3.
Remove grille as outlined in Section 13.

4.
Remove fuel pump push rod as outlined * in Sec-

tion 6M.

5.
Complete camshaft removal as follows:

CAUTION: All camshaft journals are the same

diameter and care must be used in removing

camshaft to avoid damage to bearings.

Remove camshaft sprocket to camshaft bolts then

remove sprocket and timing chain together. Sprocket

is a light fit on camshaft. If sprocket does not come

off easily a light blow on the lower edge of the

sprocket (with a plastic mallet) should dislodge the

sprocket.

Install two 5/16" - 18 x 4" bolts in camshaft bolt

holes then remove camshaft (fig. 27V).

Installation

NOTE: Whenever a new camshaft is installed
CONVERTER

BOLT AREA -

DEPRESSED

SYNCHROMESH
RING

GEAR

TRANS.,

AUTOMATIC

Fig.
28V - Flywheel Installation (Typical)

coat camshaft lobes with Molykote or its

equivalent.

1.
Lubricate camshaft journals with engine oil and in-

stall camshaft.

2.
Install timing chain on camshaft sprocket. Hold the

sprocket vertical with the chain hanging down, and

orient to align marks on camshaft and crankshaft

sprockets. Refer to Figure 20V.

3.
Align dowel in camshaft with dowel in hole in cam-

shaft sprocket then install sprocket on camshaft.

Refer to Figure 25V.

4.
Draw the camshaft sprocket onto camshaft using the

mounting bolts. Torque to specifications.

5.
Lubricate timing chain with engine oil.

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

7.
Install grille as outlined in Section 13.

8. Install crankcase front cover as outlined.

9. Install valve lifters as outlined.

FLYWHEEL

Removal

With transmission and/or clutch housing and clutch

removed 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.

28V).

NOTE: On Automatic Transmission equipped

engines, the flywheel must be installed with the

flange collar to transmission side (fig. 33V).

ENGINE MOUNTS

Engine mounts (fig. 34V) are the nonr adjustable type

and seldom require service. Broken or deteriorated

mounts should be replaced immediately, because of the

added strain placed on other mounts and drive line

components.

Front Mount Replacement

1.
Remove nut, washer and engine mount through-bolt.

2.
Raise engine to release weight from mount.

3.
Remove mount from engine.

CHEVROLET CHASSIS SERVICE 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