1967 CHEVROLET CAMARO ECO mode

BRAKES 5-12

VIEW B

Fig.
21—Parking Brake System-Chevy II

2.
Remove return spring at equalizer.

3.
Remove equalizer check nut, and separate cable

stud from equalizer.

4.
Remove clamp from underbody guide bracket. (Con-

vertible models only, also remove clamp from guide

bracket at underbody support.)

5. Remove cable retainer from underbody bracket.

6. Compress expanded conduit locking fingers at toe

pan,
remove cable ball from idler lever, and with-

draw cable from car.

Installation

1.
Position cable ball and conduit tip through cutout

in toe pan.. Make sure conduit locking fingers are

fully expanded and secured in cutout, then position

cable ball in idler lever clevis.

2.
Present parking brake lever to one notch.

3.
P}ace retainer in conduit groove so that conduit

end is secure in underbody bracket.

4.
Position cable in guide bracket(s) and secure cable

in bracket with clamp(s).

5. Place one check nut on cable stud and insert stud

into equalizer, then place second check nut on stud.

6. Connect cable return spring.

7. Adjust parking brake as outlined in this section.
8. Connect positive battery cable.

Rear Cable

Removal

1.
Place parking brake lever in released position.

2.
Disconnect front cable return spring at equalizer.

3.
Remove check nut from front cable stud, withdraw

stud from equalizer, and remove equalizer from

rear cable.

4.
Remove retainers from grooves in rear cable con-

duit, and remove cable from bracket.

5. Remove cable from center body bumper bracket

and spring clip at shock absorber lower mount.

6. Back off rear service brakes sufficiently to allow

for drum removal.

7. Remove both rear wheels and drums.

8. Remove secondary brake shoe return spring.

9. Remove secondary brake shoe hold-down spring

and pin.

10.
Remove cable end from parking brake actuating

lever.

11.
Compress expanded conduit locking fingers at flange

plate entry hole and withdraw cable.

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES 5-17

mended shoe and lining assemblies. Otherwise,

serious fade or failure may occur.

1.
Inspect new linings and make certain there are no

nicks or burrs on bonding material on shoe edge

where contact is made with brake flange plate or

on any of the contact surfaces.

NOTE: Keep hands clean while handling brake

shoes.
Do not permit oil or grease to come in

contact with linings.

2.
If working on rear brakes, lubricate parking brake

cable.

3.
On rear brakes only, lubricate fulcrum end of park-

ing brake lever and the bolt with brake lube, then

attach lever to secondary shoe with bolt, spring

washer, lock washer and nut. Make sure that lever

moves freely.

4.
Before installation make certain the adjusting screw

is clean and lubricated properly.

NOTE: Loose adjustment may occur from an

adjusting screw that is not properly operating.

If the lubrication in the adjusting screw as-

sembly is contaminated or destroyed, the ad-

justing screw should be thoroughly cleaned and

lubricated.

5.
Connect brake shoes together with adjusting screw

spring, then place adjusting screw, socket and nut

in position.

CAUTION: Make sure the proper adjusting

screw is used ("L" for left side of vehicle,

"R"
for right side of vehicle). The star wheel

should only be installed with the star wheel

nearest to the secondary shoe and the adjusting

screw spring inserted to prevent interference

with the star wheel.
6. On rear wheels connect parking brake cable to lever.

7.
Secure the primary brake shoe (short lining—faces

forward) first with the hold-down pin and spring

using a pair of pliers. Engages shoes with the wheel

cylinder connecting links.

8. Install and secure the actuator assembly and second-

ary brake shoe with the hold-down pin and spring

using a pair of needle nose pliers. On rear wheels

position parking brake strut and strut spring.

9. Install guide plate over anchor pin.

10.
Install the wire link.

NOTE: Do not hook the wire link over the

anchor pin stud with the regular spring hook

tool. This may damage the cylinder boot seals.

Fasten the wire link to the actuator assembly ;

first, then place over the anchor pin stud by

hand while holding the adjuster assembly in the

full down position.

11.
Install actuator return spring.

NOTE: Do not pry actuator lever to install re-

turn spring. Ease it in place using the end of a

screw driver or other suitable flat tool.

12.
If old brake pull back (return) springs are nicked,

distorted or if strength is doubtful, install new

springs.

13.
Hook springs in shoes using Tool J-8049 by in-

stalling the primary spring from the shoe over the

anchor pin and then spring from secondary shoe

over the wire link end.

14.
Pry shoes away from backing plate and lubricate

shoe contact surfaces with a thin coating of brake

lube (fig. 29).

CAUTION:

facings.
Be careful to keep lubricant off

Fig.
29—Backing Plate Contact Surfaces
15.
After completing installation, make certain the actu-

ator lever functions easily by hand operating the

self-adjusting feature (fig. 30).

1.6. Follow the above procedure for all wheels.

17.
Adjust the service brakes and parking brake as

outlined under "Maintenance and Adjustments" in

this section.

Metallic Linings

Metallic brake linings which use special heat resistant

brake springs are available as an option. Service opera-

tions are the same as for standard brakes; however,

when new linings are installed, the linings should be

seated as described below.

NOTE: Brake shoes with metallic linings re-

quire specially finished brake drums (honed to a

20 micro-inch finish). Metallic linings are not

recommended for service replacement on ve-

hicles with standard brake drums that have not

been honed to specified finish.

Seating Metallic Linings

After the brakes have been adjusted, the following

recommended "lining seating" is as follows:

1.
Make six to eight stops from 30 MPH with moderate

pedal pressure to aid in seating and to mbdulate

any tendency to dive.

CHEVROLET CHASSIS SERVICE MANUAL

SECTION 6

ENGINE

CONTENTS
OF
THIS SECTION

Page

Engine Tune Up
6-1
Torque Sequence

Engine Mechanical
(In
Line)
6-12
Special Tools
. .

Engine Mechanical (V8)
6-24
Page

6-39

6-40

ENGINE TUNE UP

INDEX

Page

General Description
. 6-1

Mechanical Checks and Adjustments
6-1

Spark Plug Removal
6-1

Test Compression
6-1

Service and Install Spark Plugs
6-2

Service Ignition System
6-3

Service Battery
and
Battery Cables
6-5

Service Delcotron
and
Regulator
6-5

Service
Fan
Belt
6-5

Service Manifold Heat Valve
6-5

Tighten Manifold
6-5

Service Fuel Lines
and
Fuel Filter ..........
6-6

Service Cooling System
6-6

Check and Adjust Accelerator Linkage
6-6

Service Crankcase Ventilation
6-6

Service
Air
Injection Reactor System
6-6

Choke Adjustment
6-7
Page

Instrument Cheek-Out
6-7

Instrument Hook-Up.
. 6*7

Check and Adjust Dwell
6-7

Check Dwell Variation
6-7

Check and Adjust Timing
6-8

Adjust Idle Speed
and
Mixture
6-8

Additional Checks and Adjustments
. 6-8

Testing Crankcase Ventilation Valve
. 6-8

Testing Cranking Voltage
6-8

Cylinder Balance Test
. 6-8

Battery
6-8

Ignition
; 6-8

Carburetor
6-11

Fuel Pump
6-11

Cooling System
. 6-11

Cylinder Head Torque and Valve Adjustment
..... 6-11

GENERAL DESCRIPTION

The engine tune up
is
important
to the
modern automo-

tive engine with
its
vastly improved power and perform-

ance.
The
higher compression ratios, improved electri-

cal systems
and
other advances
in
design, make today1 s

engines more sensitive
and
have
a
decided effect
on

power, performance and fuel consumption.

It
is
seldom advisable
to
attempt
a
tune up
by
correc-

tion
of one or two
items only. Time will normally
be

saved
and
more lasting results assured
if the
technician

will follow
a
definite
and
thorough procedure
of
analysis

and correction
of all
items affecting power, performance

and economy.

The tune
up
will
be
performed
in
two parts.
The
first

part will consist
of
visual and mechanical checks and
ad-

justments;
the
second part will consist
of
an instrument

checkout that
can be
performed with
any one of the
units
of service equipment available
for
this purpose. Always

follow
the
instructions provided
by the
manufacturer
of

the particular equipment
to be
used.

Additional checks
and
adjustments
are
included
in the

latter part
of
this section
for use as
required. Many
of

these operations
can be
used
to
isolate and correct trou-

ble located during
the
tune up. Where conditions
are
UB-

covered requiring major corrective action, refer
to the

appropriate section
of
this manual
or the
Passenger

Chassis Overhaul Manual
for
detailed service informa-

tion.

Typical illustrations
and
procedures
are
used except

where specific illustrations
or
procedures
are
necessary

to clarify
the
operation. Illustrations showing bench
op-

erations
are
used
for
clarification however
all
operations

can
be
performed
on the
vehicle.

MECHANICAL CHECKS
AND
ADJUSTMENTS

Spark Plug Removal

Remove any foreign matter from around spark plugs
by

blowing
out
with compressed
air,
then disconnect wires

and remove plugs.

Test Compression
(Fig. 1)

The compression check
is
important because
an
engine

with
low or
uneven compression cannot
be
tuned success-
fully.
It is
essential that improper compression
be cor-

rected before proceeding with
the
engine tune
up.

1.
Remove
air
cleaner
and
block throttle
and
choke
in

wide open position.

2.
Hook
up
starter remote control cable
and
insert

compression gauge firmly
in
spark plug port.

CAUTION: Whenever
the
engine
is
cranked

CHEVROLET
C*
IS 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 6-29

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

SECTION 6K

ENGINE COOLING

INDEX

Page

General Description . . . 6K-1

Maintenance and Adjustments 6K-1

Coolant Level 6K-1

Coolant System Checks 6K-1

Periodic Maintenance 6K-2

Cleaning 6K-2

Reverse Flushing 6K-2

Radiator 6K-2
Page

Cylinder Block and Cylinder Head 6K-2

Hot Water Heater 6K-2

Fan Belt . 6K-2

Adjustment ....". 6K-2

Thermostat . 6K-2

Replacement 6K-2

Water Pump. . . . 6K-3

Removal 6K-3

Installation 6K-3

GENERAL DESCRIPTION

A pressure cooling system is provided for on all

models by a pressure type radiator cap (fig. 1). The

pressure type radiator cap used is designed to hold a

pressure above atmospheric pressure in the cooling

system. Excessive pressure is relieved by a valve within

the cap that opens to radiator overflow.

The water pump is a ball bearing, centrifugal vane

impeller type. It requires no care other than to make

certain the air vent at the top of the housing and the drain

holes in the bottom do not become plugged with dirt or

grease. Removal and installation of the water pump is

covered in this section. For overhaul procedures of the

water pump refer to Section 6K of the Passenger Chassis

Overhaul Manual.
For radiator, refer to Section 13 of this manual For

radiator shroud, refer to Section 11 of this manual.

Fig.
I—Pressure Radiator Cap

MAINTENANCE AND ADJUSTMENTS

Coolant Level

The radiator coolant level should only be checked when

the engine is cool, particularly on cars equipped with air

conditioning. If the radiator cap is removed from a hot

cooling system, serious personal injury may result

The cooling system fluid level should be maintained

one inch below the bottom of the filler neck of the radia-

tor when cooling system is cold, or at the bottom of the

filler neck when the system is warm. It is very impor-

tant that the correct fluid level be maintained. The seal-

ing ability of the radiator cap is affected when the cooling

level is too high.

All passenger car cooling systems are pressurized

with a pressure cap which permits safe engine operation

at cooling temperatures of
up
to 247°F.

When the radiator cap is removed or loosened, the

system pressure drops to atmospheric, and the heat

which had caused water temperature to be higher than

212°F, will be dissipated by conversion of water to

steam. Inasmuch as the steam may form in the engine

water passages, it will blow coolant out of the radiator

upper hose and top tank, necessitating coolant replace-

ment Engine operating temperatures higher than the

normal boiling point of water are in no way objectionable

so long as the coolant level is satisfactory when the

engine is cooL

Upon repeated coolant loss, the pressure radiator cap

and seat should be checked for sealing ability. Also, the
cooling system should be checked for loose hose con-

nections, defective hoses, gasket leaks, etc.

Coolant System Checks

1.
Test for restriction in the radiator, by warming the

engine up and then turning the engine off and feeling

the radiator. The radiator should be hot at the top

and warm at the bottom, with an even temperature

rise from bottom to top. Cold spots in the radiator

indicate clogged sections.

2.
Water pump operation may be checked by running the

engine while squeezing the upper radiator hose. A

pressure surge should be felt Check for a plugged

vent-hole in pump.

NOTE:
A defective head gasket may allow ex-

haust gases to leak into the cooling system.

This is particularly damaging to the cooling

system as the gases combine with the water to

form acids which are particularly harmful to

the radiator and engine.

3.
To check for exhaust leaks into the cooling system,

drain the system until the water level stands just

above the top of the cylinder head, then disconnect

the upper radiator hose and remove the thermostat

and fan belt. Start the engine and quickly accelerate

several times. At the same time note any appreci-

able water rise or the appearance of bubbles which

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE COOLING 6K-2

are indicative of exhaust gases leaking into the coolr

ing system.

Periodic Maintenance

Periodic service must be performed to the engine cool-

ing system to keep it in efficient operating condition.

These services should include a complete cleaning and

reverse flushing as well as a reconditioning service.

In the course of engine operation, rust and scale ac-

cumulate in the radiator and engine water jacket. The

accumulation of these deposits can be kept to a minimum

by the use of a good rust inhibitor but it should be

remembered that an inhibitor will not remove rust al-

ready present in the cooling system.

Two common causes of corrosion are: (1) air suction--

Air may be drawn into the system due to low liquid level

in the radiator, leaky water pump or loose hose con-

nections; (2) exhaust gas leakage—Exhaust gas may be

blown into the cooling system past the cylinder head

gasket or through cracks in the cylinder head and block.

Cleaning

A good cleaning solution should be used to loosen the

rust and scale before reverse flushing the cooling

system. There are a number of cleaning solutions avail-

able and the manufacturer's instructions with the particu-

lar cleaner being used should always be followed.

An excellent preparation to use for this purpose is GM

Cooling System Cleaner. The following directions for

cleaning the system applies only when this type cleaner

is-used.

1.
Drain the cooling system including the cylinder block

and then close both drain plugs.

2.
Remove thermostat and replace thermostat housing.

3.
Add the liquid portion (No. 1) of the cooling system

cleaner.

4.
Fill the cooling system with water to a level of about

3 inches below the top of the overflow pipe.

5. Cover the radiator and run the engine at moderate

speed until engine coolant temperature reaches 180

degrees.

6. Remove cover from radiator and continue to run the

engine for 20 minutes. Avoid boiling.

7. While the engine is still running, add the powder

portion (No. 2) of the cooling system cleaner and

continue to run the engine for 10 minutes.

8. At the end of this time, stop the engine, wait a few

minutes and then open the drain cocks or remove

pipe plugs. Also remove lower hose connection.

CAUTION: Be careful not to scald your hands.

NOTE:
Dirt and bugs may be cleaned out of

the radiator air passages by blowing out with air

pressure from the back of the core.

Reverse Flushing

Reverse flushing should always be accomplished after

the system is thoroughly cleaned as outlined above.

Flushing is. accomplished through the system in a direc-

tion opposite to the normal flow. This action causes the

water to get behind the corrosion deposits and force

them out.

Radiator

1.
Remove the upper and lower radiator hoses and re-

place the radiator cap,

2.
Attach a lead-away hose at the top of the radiator.
3.
Attach a new piece of hose to the radiator outlet

connection and insert the flushing gun in this hose.

4.
Connect the water hose of the flushing gun to a water

outlet and the air hose to an air line.

5. Turn on the water and when the radiator is full, turn

on the air in short blasts, allowing the radiator to

fill between blasts of air.

CAUTION: Apply air gradually as a clogged

radiator will stand only a limited pressure.

6. Continue this flushing until the water from the lead-

away hose runs clear.

Cylinder Block and Cylinder Head

1.
With the thermostat removed, attach a lead-away

hose to the water pump inlet and a length of new hose

to the water outlet connection at the top of the engine.

NOTE:
Disconnect the heater hose when re-

verse flushing engine.

2.
Insert the flushing gun in the new hose.

3.
Turn on the water and when the engine water jacket

is full, turn on the air in short blasts.

4.
Continue this flushing until the water from the lead-

away hose runs clear.

Hot Water Heater

1.
Remove water outlet hose from heater core pipe.

2.
Remove inlet hose from engine connection.

3.
Insert flushing gun and flush heater core. Care must

be taken when applying air pressure to prevent

damage to the core.

Fan Belt

Adjustment

1.
Loosen bolts at Delcotron slotted bracket.

2.
Pull Delcotron away from engine until desired ten-

sion reading is obtained with a strand tension gauge.

Refer to Section 6, "Engine Tune-Up".

3.
Tighten all Delcotron bolts securely.

Thermostat

The thermostat consists of a restriction valve actuated

by a thermostatic element. This is mounted in the hous-

ing at the cylinder head water outlet above the water

pump,
thermostats are designed to open and close at

predetermined temperatures and if not operating properly

should be removed and tested as follows.

Replacement

1.
Remove radiator to water outlet hose.

2.
Remove thermostat housing bolts and remove water

outlet and gasket from thermostat housing (fig. 2).

3.
Inspect thermostat valve to make sure it is in good

condition.

4.
Place thermostat in hot water 25° above the temper-

ature stamped on the thermostat valve.

5. Submerge the valve completely and agitate the water

thoroughly. Under this condition the valve should

open fully.

6. Remove the thermostat and place in water 10° below

temperature indicated on the valve.

7. With valve completely submerged and water agitated

thoroughly, the valve should close completely.

8. If thermostat checks satisfactorily, re-install, using

a new housing gasket.

9. Refill cooling system.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE FUEL 6M-4

Fig.
3C-Fuel Level Sight Plug

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

ment panel.

3.
Loosen choke cable clamp 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.

5. Install air cleaner.

Float Adjustment

Ho/fey (Model 4150
Center
Inlet & Model 2300)

1.
Remove air cleaner then remove the fuel level sight

plugs (Fig. 3c)

2.
With parking brake on, and transmission in neutral,

start the engine and allow it to idle.

3.
With the car on a level surface, the fuel level should

be on a level with the threads at the bottom of the

sight plug port (plus or minus 1/32 inch).

NOTE:
No float drop adjustment is required

on this carburetor.

4.
If necessary to adjust (either or both bowls), loosen

inlet needle lock screw and turn the adjusting nut

clockwise to lower or counter-clockwise to raise

fuel level, then tighten lock screw.

NOTE:
1/6 turn of adjusting nut equals ap-

proximately 1/16" fuel level change.

5. Allow a minute for fuel level to stabilize then re-

check the level at sight plug.

6. Readjust, if necessary, until proper level is obtained,

then install sight plug and air cleaner.

NOTE:
To assure proper secondary float level

setting it is advisable to accelerate primary

throttles slightly and hand operate secondary
throttle. This assures a stabilized secondary

fuel level.

Additional Adjustments

The following adjustments may be made without re-

moving the carburetor from the engine. For procedure

refer to Section 6M of the Overhaul Manual under the

carburetor being serviced.

Rochester BV

• Float

• Idle Vent

• Choke Rod (Fast Idle)

• Choke Vacuum Break

• Choke Unloader

Rochester 2GV

• Float

• Accelerator Pump

• Idle Vent

• Choke Rod (Fast Idle)

• Choke Vacuum Break

• Choke Unloader

• Secondary Throttle Opening

• Secondary Throttle Lockout

Rochester 4MV

• Float

• Accelerator Pumj)

• Idle Vent

• Air Valve

• Choke Rod

• Choke Vacuum Break

• Choke Unloader

• Air Valve Lockout

• Secondary Opening

• Secondary Lockout

Carter YF

• Float

• Idle Vent

• Choke Rod (Fast Idle)

• Choke Vacuum Break

• Choke Unloader

Holley 4160 and 4150
(Except End
Inlet)

• Float

• Air Vent Valve

• Accelerator Pump

• Choke Vacuum Break

• Choke Unloader

Holley 2300 and 4150
(End
Inlet)

• Air Vent Valve (except 2300)

• Accelerator Pump

• Choke Vacuum Break

• Choke Unloader

Removal

Flooding, stumble on acceleration and other perform-

mance complaints are, in many instances, caused by the

presence of dirt, water, or other foreign matter in the

carburetor. To aid in diagnosing the cause of the com-

plaint, the carburetor should be carefully removed from

the engine without draining the fuel from the bowl.

The contents of the fuel bowl may then be examined for

contamination as the carburetor is disassembled.

1.
Remove air cleaner and gasket.

2.
Disconnect fuel and vacuum lines from carburetor.

CHEVROLET CHASSIS SERVICE MANUAL