1967 CHEVROLET CAMARO length

BRAKES 5-21

brake fluid. Coat the primary and secondary seals

on the secondary piston with clean brake fluid. Insert

the secondary piston spring retainer into the sec-

ondary piston spring. Place the retainer and spring

down over the end of the secondary piston until the

retainer locates inside of the lips of the primary

cup.

10.
Hold the master cylinder with the open end of the

bore down. Push the secondary piston into the bore

until the spring seats against the closed end of the

bore.

11.
Position the master cylinder in a vise with the

open end of the bore up. Coat the primary and

secondary seal on the primary piston with clean

brake fluid. Push the primary piston assembly,

spring end first, into the bore of the master cylinder*

Hold the piston down and snap the lock ring into

position in the small groove in the I.D. of the bore.

12.
Push the primary piston down to move the secondary

piston forward far enough to clear the stop screw

hole in the bottom of the front fluid reservoir. Install

the stop screw.

13.
Install reservoir diaphragm in the reservoir cover

and install the cover on the main cylinder. Push

bail wire into position to secure the reservoir cover.

Installation

1.
Assemble the push rod through the push rod retainer,

if it has been disassembled.

2.
Push the retainer over the end of the main cylinder.

Assemble new boot over push rod and press it down

over the push rod retainer. Slide new mounting

gasket into position.

3.
Secure .the main cylinder to the firewall with mount-

ing bolts.

4.
Connect the push rod clevis to the brake pedal with

pin and retainer.

5. Connect the brake lines to the main cylinder.

6. Fill the main cylinder reservoirs to the levels

shown in Figure 8. Bleed the brake system as out-

lined in this section.

7. K necessary, adjust the brake pedal free play as

outlined in this section.

WHEEL CYLINDER (Fig. 33)

The wheel cylinder boots should be removed from a

cylinder body only when they are visibly damaged or

leaking fluid. Wheel cylinders having torn, cut, or heat-

cracked boots should be completely overhauled.

Removal

1.
Raise vehicle and place on jack stands.

Fig.
33-Chevelle Wheel Cylinder—Exploded View

1.
Push Rod Boot 6. Spring

2.
Piston 7. Piston Cup

3. Piston Cup 8. Piston

4.
Housing 9. Push Rod Boot

5. Fluid Inlet
2.
Remove wheel and tire assembly. Back off brake

adjustment, if necessary, and remove drum.

3.
Disconnect brake system hydraulic line from

cylinder.

4.
Remove brake shoe pull back springs.

5. Remove screws securing wheel cylinder to flange

plate. Disengage cylinder push rods from brake

shoes and remove cylinder.

NOTE:
On Chevrolet, it is necessary to re-

move the anchor pin which holds the front wheel

cylinder to flange plate to remove the front

wheel cylinder.

Disassembly

1.
Remove boots from cylinder ends with pliers and

discard boots.

2.
Remove and discard pistons and cups.

Inspection and Cleaning

NOTE:
Staining is not to be confused with

corrosion. Corrosion can be identified as pits

or excessive bore roughness.

1.
Inspect cylinder bore. Check for staining and corro-

sion.
Discard cylinder if corroded.

2.
Polish any discolored or stained area with crocus

cloth by revolving the cylinder on the cloth sup-

ported by a finger. Do not slide tfce cloth in a

lengthwise manner under pressure.

NOTE:
Before washing parts, hands must be

clean. Do not wash hands in gasoline or oil

before cleaning parts. Use soap and water to

clean hands.

3.
Wash the cylinder and metal parts in Declene or

equivalent.

4.
Shake excess cleaning fluid from the cylinder-. Do

not use a rag to dry the cylinder as lint from the rag

cannot be kept from the cylinder bore surfaces.

5. Check piston for scratches or other visual damage;

replace if necessary.

Assembly (Fig. 33)

1.
Lubricate the cylinder bore and counterbore with

clean brake fluid and insert spring - expander

assembly.

2.
Install new cups with flat surfaces toward outer

ends of cylinder. Be sure cups are lint and dirt free

before insertion. Do not lubricate cups prior to

assembly.

3.
Install new Durex pistons into cylinder with flat

surfaces toward center of cylinder. Do not lubri-

cate pistons before installation.

4.
Press new boots into cylinder counterbores by hand.

Do not lubricate boots prior to installation.

Installation

1.
Position wheel cylinder to brake flange plate. Install

screws and tighten securely.

NOTE:
On Chevrolet front wheels, mount front

wheel cylinders to the brake flange plate by

installing the threaded anchor pin through the

wheel cylinder housing and tighten to 130 lb. ft.

To secure, peen over the flat washer on the

anchor pin.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-7

Tune Up should be checked whenever the Air Injection

Reactor System seems to be malfunctioning. Particular

care should be taken in checking items that affect fuel-air

ratio such as the crankcase ventilation system, the car-

buretor and the carburetor air cleaner. Carburetors and

distributors for engines with the Air Injection Reactor

System are designed, particularly, for these engines;

therefore, they must not be interchanged with or replaced

by a carburetor or distributor designed for an engine

without the Air Injection Reactor System.

Choke Adjustment (Fig. 11)

With Remote Choke

1.
Remove air cleaner and check to see that choke

valve and rod move freely.

2.
Disconnect choke r*od at choke lever.

Check choke adjustment as follows:

On all except 275 hp 327 cu. in. engines, hold

choke valve closed and pull rod up against stop. The

top of choke rod end should be 1/2 - 1 rod diameter
4.

5.
above top of hole in choke valve lever.

On 275 hp 327 cu. in. engines, hold choke valve

closed and push rod down against stop on thermostat

bracket. The top of the choke rod should be 1/2 - 1

rod diameter below the top of the hole in the choke

lever.

If necessary, adjust rod length by bending rod at off-

set. (Bend must be such that rod enters choke lever

hole freely and squarely.)

Connect rod at choke lever and install air cleaner.

3.
With Manual
Choke

1.
Remove air cleaner.

2.
Push hand choke knob in to within 1/8" of instrument

panel.

3.
Loosen choke cable at carburetor bracket and adjust

cable through the clip until the choke valve is wide

open.

4.
Tighten cable clamp at carburetor bracket and check

operation of choke valve to ensure full closed and

wide open positions.

INSTRUMENT CHECK-OUT

Instrument Hook Up

Connect vacuum gauge, dwell meter, tachometer and

timing light as recommended by the manufacturer of the

equipment being used.

Check and Adjust Dwell

1.
Start engine then ch^ck ignition dwell.

.2.
If dwell is not within specifications, adjust dwell as

follows:

V8 ENGINES

• With engine running at idle, raise the adjustment

screw window-and insert an Allen wrench in the

socket of the adjusting screw (fig. 12).

• Turn the adjusting screw as required until a dwell

reading of 30° is obtained. A 2° variation is al-

lowable for wear.

• Close access cover fully to prevent the entry of

dirt into the distributor.

NOTE: If a dwell meter is not available, turn
adjusting screw clockwise until engine starts to

misfire, then turn screw one-half turn in the op-

posite direction to complete adjustment.

IN LINE ENGINES

• Remove distributor cap and recheck point setting.

If dwell is still not within specifications check the

distributor as outlined in Section 6Y.

Check Dwell Variation

Slowly accelerate engine to 1500 rpm and note dwell

reading. Return engine to idle and note dwell reading. If

dwell variation exceeds specifications, check for worn

distributor shaft, worn distributor shaft bushing or loose

breaker plate.

WINDOW

"HEX" TYPE

WRENCH

Fig.
12 - Setting Point Dwell (V8)
Fig.
13 - Ignition Timing Marks

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-15

2.
Install rocker arms, rocker arm balls and rocker

arm
nuts.
\
Tighten rocker arm nuts until all lash is

eliminated. .

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

shaft lobe as follows:

a. Mark distributor housing, with chalk, at each cyl-

inder position (plug wire) then disconnect plug

wires at spark plugs and coil and remove distri-

butor cap and plug wire assembly (if not previ-

ously done).

b.
Crank engine until distributor rotor points to

number one cylinder position and breaker points

are open. Both valves on number one cylinder

may now be adjusted.

c. Back out adjusting nut until lash is felt at the push

rod then turn in adjusting nut until all lash is re-

moved. This can be determined by checking push

rod side play while turning adjusting nut (fig. 2L).

When play has been removed, turn adjusting nut

in one full additional turn (to center lifter

plunger).

d. Adjust the remaining valves, one cylinder at a

time,
in the same manner.

4.
Install distributor cap and spark plug wire assembly.

5.
Install rocker arm cover as outlined.

6. Adjust carburetor idle speed and mixture.

VALVE LIFTERS

Hydraulic valve lifters very seldom require attention.

The lifters are extremely simple in design readjustments

are not necessary, and servicing of the lifters requires

only that care and cleanliness be exercised in the han-

dling of parts.

Locating Noisy Lifters

Locate a noisy valve lifter by using a piece of garden

Fig.
2L - Valve Adjustment
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

returns 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

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

abnormal stickiness.

b.
Galling or "pickup" 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—This

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, disasssmbled, cleaned

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

If dirt, varnish, 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 valve mechanism as outlined.

2.
Mark distributor housing, with chlak, at each cylin-

der position (plug wire) then disconnect plug wires at

spark plugs and coil and remove distributor cap and

plug wire assembly.

3.
Crank engine until distributor rotor points to number

one position, then disconnect distributor primary lead

at coil and remove distributor.

4.
Remove push rod covers (discard gaskets).

5.
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 push rod covers, using new gaskets, and

torque bolts to specifications.

3.
Install distributor, positioning rotor to number one

cylinder position, then connect primary lead at coil.

4.
Install and adjust valve mechanism as outlined.

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 6-28

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 6-30

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 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 FUEL 6M-3

Idle Speed and Mixture Adjustment (With Air Injection

Reactor System)

The following is the recommended procedure for Air

Injection Reactor System equipped engines.

NOTE: This adjustment should be performed

with engine at operating temperature and parking

brake applied.

1.
Remove air cleaner.

2.
Connect tachometer to engine, then set hand brake

and shift transmission into neutral.

3.
As a preliminary adjustment, turn idle mixture

screws lightly to seat and back out 3 turns.

CAUTION: Do not turn idle mixture screw

tightly against seat or damage may result."

4.
With engine running (choke wide open) adjust idle

speed screw to specified idle speed. (Automatic

transmission in dirve, synchronized transmission in

neutral).

5.
Adjust idle mixture screw (turn in) to "lean roll"

position; then turn screw out 1/4 turn (1/4 turn

rich from "lean roll"). The definition of "lean

roll" point is a 20 to 30 rpm drop in engine speed,

obtained by leaning the idle mixture.

NOTE: On air conditioned vehicles, turn air

conditioning "OFF" on in-line, 283, 327, and'

350 cu. in. engines, and turned "ON" and hot

idle compensator held closed on 396 and 427 cu.

in. engines.

6. Repeat Steps 4 and 5 as needed for final adjustment.

NOTE: If necessary, final adjustment of the
carburetor may be made with air cleaner

installed.

7.
Shut down the engine, remove gauges and install air

cleaner. *

Fast Idle Adjustment

Rochester
4MV and Holley

With fast idle lever on high step of cam and choke valve

open (engine warm) set fast idle to give specified engine

rpm. Adjust sejrew on Rochester 4MV and bend fast

idle lever *pn Holley. .

Choke Adjustment

With Remote Choke (Fig. 2c)

1.
Remove air cleaner and check to see that choke

valve and rod move freely.

2.
Disconnect choke rod at choke lever.

3.
Check choke adjustment as follows:

On all except 275 and 300 h.p. 327 cu. in. engines,

hold choke valve closed and pull.rod up against stop.

The top of choke rod end should be 1/2-1 rod diame-

ter above top of hole in choke valve lever.

On 275 and 300 h.p. 327 cu. in. engines, hold choke

valve closed and push rod down against stop on ther-

mostat bracket. The top of the choke rod should be

1/2-1 rod diameter below the top of the hole in the

choke lever.

4.
If necessary, adjust rod length by bending rod at

offset bend. (Bend must be such that rod enters

choke lever hole freely and squarely).

5.
Connect rod at choke lever and install air cleaner.

With Manual Choke (Carter YF)

1.
Remove air cleaner.

CHOKE VALVE

COMPLETELY

CLOSED

PULL UPWARD ON

ROD TO END OF

TRAVEL

BEND ROD

TO ADJUST
ROD IN BOTTOM

OF SLOT

BOTTOM OF

ROD SHOULD

BE EVEN WITH

TOP OF

HOLE
CHOKE VALVE

CLOSED

BOTTOM OF

ROD SHOULD

BE EVEN WITH

TOP OF HOLE

TOP OF ROD

SHOULD BE EVEN

WITH BOTTOM

OF HOLE (CHOKE

CLOSED)

BEND ROD TO

ADJUST

PULL DOWNWARD'

ON ROD TO CON-

TACT STOP

L6 (TYPICAL)

[

V8 327-275 HP

V8 350-295 HP
BEND ROD

TO ADJUST

PULL UPWARD ON

ROD TO CONTACT

STOP ON BRACKET

ALL V8 (EXCEPT 327-275 HP

AND 350-295 HP)

Fig.
2C—Remote Choke Adjustment

CHEVROLET CHASSIS SERVICE MANUAL