1967 CHEVROLET CAMARO drain bolt

ENGINE 6-16

5.
Adjust ignition timing and carburetor idle speed and

mixture.

VALVE STEM OIL SEAL AND/OR VALVE SPRING

Replacement

1.
Remove rocker arm cover as outlined.

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

cylinder(s) to be serviced.

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

the 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 ^>lug and assem-

ble as shown (fig. 3L).

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

move the valve locks, valve cap, valve shield and

valve spring and damper (fig. 4L).

5.
Remove the valve stem oil seal.

6. 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.

Compress the spring with
Too^
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.

7.
Install the valve locks and release the compressor

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.

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

specifications.

9. Install and adjust valve mechanism as outlined.

CYLINDER HEAD ASSEMBLY

Removal

1.
Remove manifold assembly as. outlined.

2.
Remove valve mechanism as outlined.

3.
Drain cooling system (block).

4.
Remove fuel and vacuum line from retaining clip at

water outlet then disconnect wires from temperature

sending units.

5.
Disconnect upper radiator hose at water outlet hous-

ing and battery ground strap at cylinder head.

6. Remove coil (L6 engines only).

7.
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
matter and free of nicks or heavy scratches.

Cylinder bolt threads in the block and threads

on the cylinder head bolt must be cleaned. (Dirt

will affect bolt torque.) Do not use gasket sealer

on composition steel asbestos gasket.

Fig. 3L -
AIF
Adapter Tool

1.
Place the gasket in position over the dowel pins with

the bead up.

2.
Carefully guide cylinder head into place over dowel

pins and gasket.

3.
Coat threads of cylinder head bolts with sealing com-

pound and install finger tight.

4.
Tighten cylinder head bolts a little at a time in the

sequence shown on the torque sequence chart until

the specified torque is reached.

5.
Install coil (if removed).

6. Connect upper radiator hose and engine ground strap.

7.
Connect temperature sending unit wires and install

fuel and vacuum lines in clip at water outlet.

8. Fill cooling system.
•

9. Install manifold assembly as outlined.

10.
Install and adjust valve mechanism as outlined.

Fig.
4L
- Compressing Valve Spring

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-17

Fig.
5L
-
Engine Blocked for Pan Removal

NOTE: Do not install rocker arm cover.

11.
Start engine and allow warm up then retorque cylin-

der head
as
outlined in Step 4 and readjust valves as

outlined under Engine Tune Up.

OIL PAN

Removal

Chevrolet
and Camaro

1.
Disconnect battery positive cable.

2.
Remove through bolts from engine front mounts.

3.
Drain radiator, then disconnect upper and lower ra-

diator hoses at radiator.

4.
Remove fan blade as outlined in Section 6K.

5.
Raise vehicle then drain engine oil.

6. Disconnect and remove* starter.

7.
On
vehicles equipped with automatic transmission,

disconnect transmission cooler lines at transmission

and remove converter housing underpan.

8. Disconnect steering
rod at
idler lever then swing

steering linkage for oil pan clearance.

9. Rotate crankshaft until 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. 5L), 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.

Cfievel/e

1.
Remove enginfe from vehicle as outlined.

2.
Place engine on jack stands, one at each front mount

and one at transmission extension.

CAUTION: Leave engine lift attached
to
en-

gine.
Do not remove all weight
of
engine from

engine lift.

3.
On
vehicles equipped with automatic transmissions

remove converter housing underpan.

4.
Remove starter.

5.
Remove oil pan and discard gaskets and seals.
Chevy//

1.
Disconnect battery positive cable.

2.
Drain engine oil.

3.
Disconnect then remove starter.

4.
Disconnect-steering idler arm bracket at right hand

frame rail and swing steering linkage down for pan

clearance.

5.
On L6 engines, remove front crossmember.

NOTE:
On
station wagon
let
stabilizer
bar

hang while removing crossmember.
"

6. Remove oil pan and discard gaskets and seals.

Installation

1.
Thoroughly clean all gasket sealing surfaces.

NOTE: Use
a
new pan gasket set.

2.
Install rear seal in rear main bearing cap.

3.
Install front Seal on crankcase front cover pressing

tips into holes provided in cover.

4.
Install side gaskets on cylinder block (fig. 6L).

5.
Complete installation as follows:

Life

1
i

If ^
jfp^;.^3p
>\~^^ \s3^^r' -'••'•'-^^Hll

|^=-5p|:*iil^
mm

Fig.
6L
-
Pan Gaskets and Seals

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-19

OIL SEAL (REAR MAIN)

Replacement

The rear main bearing oil seal can be replaced (both

halves) without removal of the crankshaft.

NOTE:
Always replace the upper and lower

seal as a unit. Install with the lip facing toward

the front of the engine.

1.
With the oil pan removed, remove the rear main

bearing cap.

2.
Remove oil seal from the groove by lifting the end

tab (fig. 7L) then clean seal groove.

3.
Lubricate the lip and O.D. of a new seal with engine

oil. Keep oil off the parting line surface. Insert

seal in cap and roll it into place with finger and

thumb,
using light pressure so beads on seal O.D.

are not cut by seal groove at cap parting line. Be

sure tabs on seal are properly located in cross

grooves.

4.
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. 8L).

NOTE:
Always clean crankshaft surface re-

moving all foreign deposits before installing a

new seal. Also clean seal groove.

5. Lubricate the lip and O.D. of a new seal with engine

oil. Keep oil off the parting line surface. Gradually

push with a hammer handle, while turning crank-

shaft, until seal is rolled into place. (Similar to in-

stalling a main bearing.) Be careful that seal bead

on O.D. is not cut. Compress seal towards crank-

shaft as much as possible.

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

torque to specifications. Be sure cross seal tabs

are in place and properly seated.

CRANKSHAFT PULLEY AND HUB

(Chevy II with L4 Engine)

Removal

1.
Drain radiator and disconnect upper and lower radi-

ator hoses at radiator.

2.
Remove radiator core as outlined in Section 13.

3.
Remove fan belt. Remove crankshaft pulley from

pulley hub.

4.
Install puller Tool J-6978 to pulley hub with two

3/8"
x 2" and one 5/16" x 2" bolts and remove hub

then remove puller tool.

Installation

1.
Coat oil seal contact area on hub with engine oil

position hub over crankshaft and key and start hub

into position with a mallet. Using Tool J-5590 drive

onto crankshaft until it bottoms against crankshaft

gear.

NOTE:
Crankshaft extends slightly through hub

and a tool is necessary to drive hub completely

into bottomed position.

2.
Install pulley onto hub.

NOTE:
There are two 3/8" holes and one

5/16" hole that must be matched on hub in order
Fig.
9L - Removing Torsional Damper

to properly position timing mark.

3.
Install fan belt and adjust using strand tension gauge.

4.
Install radiator as outlined in Section 13.

TORSIONAL DAMPER

Removal

1.
Remove radiator core, as outlined in Section 13.

2.
Remove fan belt and (if so equipped) accessory drive

pulley and belt.

3.
Install Tool J-6978 to damper and turn puller screw

to remove damper (fig. 9L). Remove tool.

Installation

1.
Coat front cover oil seal contact area of damper with

engine oil.

CAUTION: It is necessary to use installer

Tool J-22197 to prevent the inertia weight sec-

Fig.
10L - Installing Torsional Damper

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 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