stop start CHEVROLET CAMARO 1967 1.G Chassis Workshop Manual

LUBRICATION 0-14

SAE 5W-30 oils may be used during periods when

temperatures of 32° and below are to be expected.

Types of Oils

In service, crankcase oils may form sludge and varnish

and under some conditions, corrosive acids unless pro-

tected against oxidation.

To minimize the formation of these harmful products

and to assure the use of oil best suited for present day

operating conditions, automobile manufacturers have de-

veloped a series of sequence tests designed to evaluate

the ability of any oil to properly lubricate automobile

engines.

It is recommended that only those oils which are

certified by their suppliers as meeting or exceeding the

maximum severity requirements of these sequence tests

(or GM Standard 4745-M) be used in Chevrolet engines.

Certified sequence tested oils will be described as such

on their containers.

Maintaining Oil Level

The oil gauge rod is marked "Full" and "Add Oil."

These notations have broad arrows pointing to the level

lines.
The oil level should be maintained between the

two lines, neither going above the "Full" line nor under

the "Add Oil" line. DO NOT OVERFILL. After operating

vehicle allow a few minutes for oil to return to crankcase

before checking oil level.

Check the oil level frequently and add oil when

necessary.

Oil and Filter Change Intervals

NOTE:
Under prolonged dusty driving condi-

tions,
it is recommended that these operations

be performed more often.

OIL

To insure continuation of best performance, low main-

tenance cost and long engine life, it is necessary to

change the crankcase oil whenever it becomes contami-

nated with harmful foreign materials. Under normal

driving conditions draining the crankcase and refilling

with fresh oil every 60 days or every 6000 miles which-

ever occurs first, is recommended.

It is always advisable to drain the crankcase only after

the engine has become thoroughly warmed up or reached

normal operating temperature. The benefit of draining is,

to a large extent, lost if the crankcase is drained when

the engine is cold, as some of the suspended foreign

material will cling to the sides of the oil pan and will not

drain out readily with the cold, slower moving oil.

OIL FILTER

Change engine oil filter every 6000 miles or every 6

months, whichever occurs first.

NOTE:
For Vehicles in heavy duty operation

involving continuous start-stop or prolonged idl-

ing, engine oil should be changed after 2500-

3000 miles of operation. The filter should be

changed after 5000-6000 miles of operation.
Crankcase Dilution

Probably the most serious phase of engine oil deterio-

ration is that of crankcase dilution which is the thinning

of the oil by fuel vapor leaking by pistons and rings and

mixing with the oil and by condensation of water on the

cylinder walls and crankcase.

Leakage of fuel, or fuel vapors, into the oil pan occurs

mostly during the "warming up" period when the fuel is

not thoroughly vaporized and burned. Water vapor enters

the crankcase through normal engine ventilation and

through exhaust gas blow-by. When the engine is not

completely warmed up, these vapors condense, combine

with the condensed fuel and exhaust gases and form acid

compounds in the crankcase.

As long as the gases and internal walls of the crank-

case are hot enough to keep water vapor from con-

densing, no harm will result. However, when the engine

is run in low temperatures moisture will collect and

unite with the gases formed by combustion resulting in

an acid formation. The acid thus formed is likely to

cause serious etching or pitting which will manifest itself

in excessively rapid wear on piston pins, camshaft

bearings and other moving parts of the engine, oftentimes

causing the owner to blame the car manufacturer or the

lubricating oil when in reality the trouble may be traced

back to the character of fuel used, or a condition of the

engine such as excessive blowby or improper carburetor

adjustment.

Automatic Control Devices to Minimize

Crankcase Dilution

All engines are equipped with automatic devices which

aid greatly in minimizing the danger of crankcase

dUution.

The thermostat, mounted in the cylinder head water

outlet, restricts the flow of water to the radiator until a

predetermined temperature is reached, thus minimizing

the length of time required to reach efficient operating

temperature, reducing the time that engine temperatures

are conducive to vapor condensation.

A water by-pass is included in the cooling system,

utilizing a hole in the front of, the cylinder block. This

allows a limited circulation of coolant, bypassing the

thermostat until thermostat opening temperatures are

reached. This system provides a uniform coolant tem-

perature throughout the engine, eliminating localized

hot-spots, improving exhaust valve life, provides fast

warmrup of lubricating oil and fast temperature rise in

the coolant which provides fast heater operation in cold

weather.

A thermostatic heat control on the exhaust manifold

during the warming up period, automatically directs the

hot exhaust gases against the center of the intake mani-

fold, greatly aids in proper vaporization of the fuel.

An automatic choke reduces the danger of raw or

unvaporized fuel entering the combustion chamber and

leaking into the oil reservoir.

An.
efficient crankcase ventilating system drives off

fuel vapors and aids in the evaporation of the raw fuel

and water which may find its way into the oil pan.

CRANKCASE BREATHER CAP

Clean and re-oil at every oil change..

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-19

Transducer

The transducer will produce a vacuum output that is

completely adjustable by varying the input voltage which

is provided by the amplifier. An increase in the applied

voltage results in a reduced vacuum output.

Power Servo

The power servo receives a vacuum signal from the

transducer, and it is capable of assuming any position

that is called for by the sensors, amplifier, and trans-

ducer. The power servo performs the following functions:

1.
Positions the temperature mix door via the tern-

perature door link. The position of this door~"de-

termihes the portions of hot and cold air being

blended and discharged into the car.

2.
Operates the power servo vacuum valve which de-

termines the air flow paths for heating and air

conditioning.

3.
Contains a printed circuit board which controls the

blower speed. The power servo position determines

the blower speed, but the control lever switch can

override the blower program depending upon the

customer's preference.

4.
Contains the "Hi" blower delay thermistor and the

"master delay thermistor".

Outside Air Diaphragm

When there is no vacuum applied to the hose, the out-

side air door is closed under spring tension. With the

door closed, air is taken from the inside of the auto-

mobile and re-circulated. Applying vacuum to the dia-

phragm opens the door for outside air.

Mode Door Diaphragm

Located behind the duct work, the mode door diaphragm

directs the air flow out either the air conditioning outlets,

the heater floor outlet, or both the heater and air con-

ditioning outlets. This is a push-pull type diaphragm

actuated by vacuum through two hoses and controlled by

the power servo vacuum switch.

Defroster Door

The defroster door is in the defog position until vacuum

is applied to the actuator to obtain either full heat or full

de-ice position.

High Blower Delay Thermistor

The high blower delay thermistor is located on the

power servo housing under the power servo vacuum valve

and printed circuit board assemblies. The function of the

thermistor is to operate the blower at a reduced speed

when the control is in the HI FRONT position until the

residual cold air is discharged from the duct work. This

function occurs when the blower first comes "on" in cold

weather.

Vacuum Tank

During heavy acceleration, the vacuum supply from
the carburetor drops. The vacuum tank, using a^ check

valve, stores vacuum so that under these conditions

vacuum will be available for the Comfortron.

Thermal Vacuum Valve (Hot Water Vacuum Switch)

When engine coolant temperature reaches 75°F, the

valve opens and supplies vacuum to the outside air door

if the system is calling for outside air.

Master Delay Thermister

This thermistor delays the initial operation of the

blower when the system is in the heat mode. In cold

weather this allows outside ram air to flow through the

system thereby purging the cold air in the ducts gradually

until the coolant reaches about 105°F. Then, the termis-

tor passes enough current to energize the master delay

relay which powers the blower at about nine volts.

Vacuum Relay Valve

This relay valve will shut off transducer vacuum to the

power servo whenever the vacuum from the engine intake

manifold falls below the vacuum in the power servo

supply line (engine stopped or operating at low manifold

vacuum). This causes the power servo to be held in

position when the vacuum supply falls too low to maintain

servo control.

Vacuum Bleeder

A vacuum bleeder insures that the outside air door will

close (diaphragm will bleed down) after the system has

been shut down. This prevents outside air from entering

when starting the system on a cold day before the engine

coolant temperature reaches 75°F.

Sun—Ambient Sensor

The sun-ambient sensor measures the temperature of

the air entering the air intake grille in front of the wind-

shield. The sensor is exposed to sun light so that it can

lower the in-car temperature slightly when the sun

is shining.

Ambient Switch

The ambient switch operates the air conditioning com-

pressor clutch. When the outside temperature is above

40° F. the switch will be closed and the compressor will

be running. This switch is included as| part of the sun-

ambient sensor assembly, but operates independently.

Resistor Assembly

The blower resistors are located in the evaporator

housing. The printed circuit board switch in the power

servo determines which of the resistors is being used,

and as in conventional systems, the resistors control the

blower speed.

System Operation

When starting the Comfortron System in cold weather,

the following sequence of events occurs:

1.
Initially the system is inoperative. In LO FRONT

position the master delay thermistor is warming

(self-heating because current is flowing through it)

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-43

LOW PRESSURE

CONTROL
HIGH PRESSURE

CONTROL

3

VACUUM

CONTROL
4

FREON

CONTROL

Fig,
56—Charging Station Controls

3.
When the pressure is reduced to below 100 pounds

on the high pressure gauge, open the low pressure

gauge valve and continue discharging until all re-

frigerant has been released. Close both gauge valves.

EVACUATING AND CHARGING THE SYSTEM

GENERAL NOTE: La all evacuating procedures

shown below, the specification of 26-28 inches

of Mercury vacuum is used. These figures are

only attainable at or near Sea Level Elevation.

For each 1000 feet above sea level where this

operation is being performed, the specifications

should be lowered by 1 inch. Example: at 5000

ft. elevation, only 21 to 23 inches of vacuum can

normally be obtained.

Whenever the air conditioning system is open for any

reason, it should not be put into operation again until it

has been evacuated to remove air and moisture which

may have entered the system.

The following procedures are based on the use of the

J-8393 Charging Station.

Filling Charging Cylinder

1.
Open control valve on refrigerant drum.

2.
Open valve on bottom of charging cylinder allowing

refrigerant to enter cylinder.

3.
Bleed cylinder valve on top (behind control panel) as

required to allow refrigerant to enter. When re-

frigerant reaches desired level (see "Air Condition-

ing System Capacities"), close valve at bottom of

cylinder and be certain bleed valve is closed

securely.

NOTE: It will be necessary to close bleed valve

periodically to allow boiling to subside to check

level in sight glass.

Installing Charging Station to System

1.
Be certain all valves on charging station are closed.

2.
Connect high pressure gauge line to high pressure

gauge fitting. (See "Installing Gauge Set to Check

System Operations.")
3.
See Figure 56. Turn high pressure control (2) one

turn counter-clockwise (open). Crack open low pres-

sure control (1) and allow refrigerant gas to hiss

from low pressure gauge line for three seconds,

then connect low pressure gauge line to low pressure

gauge fitting.

4.
System is now ready for performance testing.

Evacuating and Charging System

1.
Install charging station as previously described.

Refer to Figure 56 and 57 while performing the

following operation.

2.
Remove Low Pressure gauge line from compressor.

3.
Crack open high (2) and low (1) pressure control

valves, and allow refrigerant gas to purge from

system. Purge slow enough so that oil does not

escape from system along with Refrigerant.

4.
When refrigerant flow stops, connect Low Pressure

gauge line to compressor.

5.
Turn on vacuum pump and open Vacuum Control

Valve (3).

6. With system purged as above, run pump until 28-29

inched of vacuum is obtained. Continue to run pump

for 15 minutes after the system reaches 28-29 inches

vacuum.

7.
If 28-29 inches cannot be obtained, close Vacuum

Control Valve (3) and shut off vacuum pump. Open

Refrigerant Control Valve (4) and allow 1/2 pound of

R-12 to enter system. Locate and repair all leaks.

8. After evacuating for 15 minutes, add 1/2 pound of

R-12 to system as described in Step 7 above. Purge

this 1/2 pound and reevacuate for 5 minutes. This

second evacuation is to be certain that as much con-

tamination is removed from the system as possible.

9. Only after evacuating as above, system is ready for

charging. Note reading on sight glass of charging

cylinder. If it does not contain a sufficient amount

for a full charge, fill to the proper leveL

10.
With High and Low pressure Valves (1 and 2) open,

close Vacuum Control Valve (3) and open Freon

Control Valve (4). Operating the heater and air

conditioner blower with the controls set for cooling

will help complete the charging operation.

NOTE: If the charge will not transfer com-

pletely from the station to the system, close

the high pressure valve at the gauge set, set

the air conditioning controls for cooling, check

that the engine compartment is clear of ob-

structions, and start the engine. Compressor

operation will decrease the low side pressure

in the system.

System is now charged and should be performance

tested before removing gauges.

CHECKING OIL

In the six cylinder compressor it is not recommended

that the oil be checked as a matter of course. Gener-

ally, compressor oil level should be checked only where

there is evidence of a major loss of system oil such as

might be caused by:

• A broken refrigerant hose.

• A severe hose fitting leak.

CHEVROLET CHASSIS SERVICE MANUAL

FRONT SUSPENSION 3-15

4.
Insert Spring Compressor J-
6874-
4-
5 with Adapters

J-6874-8-9 into upp^r spring tower so that lower

MU"
bolt fits into shock absorber mounting holes in

spring seat (fig. 23). Secure the two lower studs to

the spring seat with nuts.

5.
Fit the tool upper pilot to top of spring and compress

spring by tightening upper nut (fig. 24). Compress

spring until screw is bottomed out.

6. Remove lower spring seat retaining nuts, lift spring

and seat assembly from control arm and guide it

down and out through fender skirt (fig. 25).

Spring Seat Replacement (Fig. 26)

1.
Release spring tension and disconnect spring com-

pressor from spring seat.

2.
Install new spring seat to spring compressor.

Installation

1.
If spring is to be replaced, install new spring into

tool and compress spring until screw is bottomed

out.

NOTE: Spring coil ends must be against spring

stops in upper and lower seats.

2.
Lift spring and tool assembly into place and position

so that the upper spring stop is inboard.

NOTE: Locating tab on upper spring seat may

be flattened before reinstalling spring.

3.
Install lower spring seat to control arm and torque

nuts as shown in the Specifications.

4.
Loosen spring compressor until spring is properly

seated in upper spring tower and remove.

5.
Install shock abosrber as outlined under Shock Ab-

sorber—Installation in this section.

Corvette

Removal

1.
With car on suitable hoist or jack, (support vehicle

by frame so control arms may swing free) remove

wheel and tire assembly, stabilizer bar and shock

absorber. Loosen the lower ball joint to steering

knuckle nut, and the' two lower control arm cross

shaft bushing bolts.

2.
Place Tool J-6874-1 across top of sixth coil (ap-

prox.),
then loosely secure Tool J-6874-2 to the up-

per shoe, with attaching capscrews and lock washers.

The upper shoe "V" notch and lower shoe raised land

should contact spring.

3.
Insert Tool J-6874 up through center of spring and

attach to upper and lower shoe assembly.

4.
Position spacers under shock absorber mounting hole

and against bottom of lower control arm. Install

special bearing washer and Tool J-6874-5. Locate

bearing against spacer and large washer against

bearing. Feed screw up through large washer bear-

ing and spacer and thread into Tool J-6874 and

tighten snugly (fig. 22).

5.
Center shoe assembly on spring and tighten screw

until a very slight compression is placed on spring

(fig. '22). Then firmly tighten down the two cap-

screws securing the upper and lower shoes to lock

these shoes to spring.

6. Turn head of screw until spring is compressed just

enough to clear the spring tower, then remove the

lower ball joint to steering knuckle nut (fig. 22).
NOTE: It may be necessary to assist the

spring out of the spring tower with a pry bar or

a similar tool.

7.
Disconnect the lower ball joint from the steering

knuckle and lower the control arm with the com-

pressed spring. Immediately release compression

on spring by backing off long screw. Release spring

and tool and withdraw spring.

CAUTION: The spring force under compres-

sion is very large. Exercise every safety pre-

caution when performing this operation to see

that individuals and materials subject to damage

are removed from the path of the spring when

the control arm is being lowered. Also, the

compressed spring
be relaxed immedi-

ately after lowering the control arm to reduce

the time of exposure to the large compressive

force.

Installation

1.
Position spring with closely coiled end up. Place

Tool J-6874-1 across the top of the sixth coil (ap-

prox.) then loosely secure Tool J-6874-2 to the

upper shoe with attaching capscrews and lock wash-

ers.
The upper shoe MV" notch and lower shoe

raised land should contact spring.

2.
Insert Tool J-6874 up through center of spring and

attach to upper and lower shoe assembly with bolt

and nut.

3.
Set spring in its seat on the lower control arm.

4.
Position spacers centrally under shock absorber

mounting hole and against bottom of lower control

arm. Install bearing, large washer and Tool

J-6874-5.
Locate bearing against spacer and large

washer against bearing. Feed the screw up through

large washer, bearing and spacer and thread into

yoke rod. Tighten snugly, but do not start to draw

down yet

5.
Center the shoe assembly on the spring and tighten

the lag screw until a very slight compression is

placed on spring, then firmly tighten down the two

capscrews securing the upper and lower shoes. This

will lock the shoes to the coil spring.

6. Turn head of screw until spring is compressed just

enough to clear the spring tower.

NOTE: It may be necessary to assist the

spring into the spring tower with a pry bar or

similar tool.

7.
Immediately install the lower ball joint into steering

knuckle and secure in place with attaching nut.

8. Release compression on spring and at the same time

use a drift to guide the coil spring into its proper

seat. End of coils must be 3/8" from coil stops in

spring seat.

9. Tighten the lower ball joint to steering knuckle nut

and lock with cotter key.

10.
Install shock absorber and stabilizer bar.

11.
Install wheel, tire and drum assembly.

12.
Remove car from hoist or jack stands.

13.
Tighten the two lower control cross shaft bushing

bolts to 45-55 lbs. ft. torque.

NOTE: If a suitable adjustable jack-stand is

CHEVROLET CHASSIS SERVICE MANUAL

REAR SUSPENSION AND DRIVE LINE 4-7

tioned vertically in the torque arm before ap-

plying pressure to the puller screw.

5.
Remove shim and bearing spacer from spindle

support.

6. Note size of shim used. If dial indicator reading

was more than
.008",
select a shim thinner by the

amount needed to bring end play within limits. If

dial indicator reading was less than
.001",
select a

shim thicker by the amount needed to bring end play

within limits.

NOTE: Shims are available in thicknesses from

.097"
to .148" in increments of
.003".

EXAMPLE: Bearing end play reading obtained

on dial indicator was
.011",
.003" over limit.

Bearing shim removed from spindle measures

.145".
New shim installed measures .139", .006"

smaller. End play is now decreased by .006" and

is
.005",
which is within the .001" to .008" limit.

7.
After determining shim thickness, install bearing

spacer and shim on spindle. Position spindle in

spindle support.

8. Press inner bearing race and roller assembly on

spindle as follows.

a. Position Tool J-4731 over spindle and against

bearing inner race.

b.
Position washer and spindle nut on spindle and

proceed to tighten nut until bearing is forced on

spindle sufficiently to allow spindle drive flange

to be installed (fig. 13). Remove spindle nut,

washer and Tool
J-4731.
Discard nut and use a

new one for final assembly.

9. Position drive flange over spindle, making sure

flange is aligned with spindle splines. Install washer
Fig.
13—Installing Drive Spindle to Support (Corvette)

and nut on spindle then tighten nut to specifications

and install cotter pin. If specified torque does not

permit cotter pin insertion, tighten nut to next flat.

10.
Seat spindle support outer seal in bore by using

screw driver, or other suitable tool, to press against

metal portion of seal.

11.
Install brake disc and caliper. Refer to Section 5

for details of brake disc and caliper installation.

12.
Install axle drive shaft, wheel and tire assembly,

adjust camber cam to original position and torque

all components to specifications.

COMPONENT PARTS REPLACEMENT

(Chevrolet, Chevelle, Chevy II and Camaro)

COIL SPRING

Chevrolet

Removal

To remove either or both rear coil springs proceed

as follows.

1.
Raise rear of vehicle and place jack stands under

frame. Support vehicle weight at rear, using either

a jack or post of twin-post hoist under axle.

2.
Remove both rear wheels from vehicle.

3.
With the car supported as in Step 1, so that the rear

springs are compressed by weight of vehicle; per-

form the following:

a. Disconnect both rear shock absorbers from the

anchor pin lower attachment.

b.
Loosen the upper control arm(s) rear pivot bolt

(do not remove the nut).

C. Loosen both the left and the right lower control

arm rear attachment (do not disconnect from axle

brackets).

d. Remove the rear suspension tie rod from the

stud on the axle tube.

4.
At the lower seat of both rear coil springs, slightly

loosen the nut on the bolt that retains the spring and

seat to the control arm. When the nut has been

backed off the maximum permissible, all threads of
the nut should still be engaged on the bolt.

CAUTION: Under ,no condition should the nut,

at this time, be removed from the bolt in the

seat of either spring.

5.
Slowly lower the support (jack or hoist post) that has

been in place under the rear axle, thereby allowing

the axle to swing down, carrying the springs out of

their upper seat and providing access for spring

removal.

6. Remove the lower seat attaching parts from each

spring, then remove the springs from the vehicle

(fig. 14).

Installation

1.
Position the springs in their upper seat so that end

of top coil is 3/8" ± 1/8" from end of stop. Install

the lower seat parts on the control arm, with the nut

finger tight on the spring retainer bolt.

NOTE: Omit the lock washer under the special

high carbon bolt, so that sufficient bolt thread

will be available to start the nut. The lock

washers will be installed later (in Step 4).

2.
By alternately raising the axle slightly and then

re-snugging the nut on each spring lower seat bolt,

move the axle upward until vehicle weight is fully

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES
5-31

POWER BRAKES

INDEX

General Description 5-31

Maintenance
and"
Adjustments 5-31

Inspection . ... 5_31

Lubrication 5-31

Bleeding Instructions . . . 5.31

Air Cleaner Service . . . , 5.31
Page

Component Replacement 5-31

Power Brake Cylinder ......* 5-31

Removal . . 5-31

Disassembly and Assembly See Overhaul Manual

Installation . . . . 5-31

GENERAL DESCRIPTION

The Power Brake Unit is a self-contained hydraulic

and vacuum unit, utilizing manifold vacuum and atmos-

phere pressure for its power.

This unit permits the use of a low brake pedal as well

as less pedal effort than is required with the conventional

(nonpower) hydraulic brake system. Only two external
line connections are necessary -
one
a vacuum connection

from manifold to check valve located on front shell; the

other, a hydraulic connection from the main cylinder

outlet directly into the hydraulic system. The unit is

mounted on the engine side of the fire wall and directly

connected to the brake pedal.

MAINTENANCE AND ADJUSTMENTS

INSPECTIONS

1.
Check vacuum line and vacuum line connections as

well as vacuum check valve in front shell of power

unit for possible vacuum loss.

2.
Inspect all hydraulic lines and connections at the

wheel cylinders and main cylinder for possible

hydraulic leaks.

3.
Check brake assemblies for scored drums, grease

or brake fluid on linings, worn or glazed linings,

and make necessary adjustments.

4.
Check brake fluid level in the hydraulic reser-

voirs.
The reservoirs should be filled to the levels

shown in Figure 8.

5. Check for loose mounting bolts at main cylinder and

at power section.

6. Check air cleaner filter in power piston extension

and replace filter if necessary.

7. Check brake pedal for binding and misalignment

between pedal
-and
push rod.

LUBRICATION

The power brake unit is lubricated at assembly and
needs no further lubrication other than maintaining

normal reservoir fluid level. The reservoir should be

filled as described in this section.

BLEEDING INSTRUCTIONS

The power system may be bled manually or with a

pressure bleeder as outlined in this section. Use only

GM
Supreme 11 Brake Fluid or equivalent. Do not use the

power assist while bleeding. The engine should not be

running and the vacuum reserve should be reduced to

zero by applying the brake several times before starting

the bleeding procedure.

AIR CLEANER SERVICE

Servicing of the air cleaner is recommended and the

element replaced when restriction becomes severe

enough to affect power brake response. At any other

time, if cleaning of the filter is felt necessary, it should

be shaken free of dirt or washed in soap and water and

thoroughly dried.

COMPONENT REPLACEMENT

POWER BRAKE CYLINDER

Removal

1.
Remove vacuum hose from vacuum check valve.

2.
Disconnect hydraulic lines at main cylinder.

Disconnect push rod at brake pedal assembly.

Remove nuts and lock washers securing power unit

to fire wall, and remove power unit from engine

compartment.
3.

4.

NOTE:
Chevy

to fire wall.
has a three stud attachment

Repair procedures for the power cylinder are outlined

in the Brake Section of the Overhaul Manual-for service
of the main cylinder refer to applicable portion of

"Standard Brakes" in this manual.

Installation

1.
Mount the power brake assembly in place and install

the attaching nuts and lock washers.

2.
Attach vacuum line to check valve.

3.
Secure hydraulic lines to main cylinder.

4.
Attach push rod to brake pedal assembly, and check

operation of stop light.

5. Bleed brakes as outlined in this section.

CAUTION: After replacing the unit on the vehi-

cle,
start the engine and allow vacuum to build

up before applying the brake.

CHEVROLET CHASSIS SERVICE

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
6-8

Check
and
Adjust Ignition Timing
(Fig. 13)

1.
Disconnect
the
distributor spark advance hose
and

plug
the
vacuum source opening.

2.
Start engine
and run at
idle speed
(see
tune
up
chart).

3.
Aim
timing light
at
timing
tab.

NOTE:
- The
markings
on the
tabs
are in 2°

increments
(the
greatest number
of
markings
on

the
"A"
side
of the "O"). the "O"
markings
is

TDC
of
#1 cylinder
and all
BTDC settings fall
on

the
"A"
(advance) side
of "O".

4.
Adjust
the
timing
by
loosening
the
distributor clamp

and
,
rotating
the
distributor body
as
required, then

tighten
the
clamp.

5.
Stop engine
and
remove timing light
and
reconnect

the spark advance hose.

Adjust Idle Speed
and
Mixture
(Fig. 14)
(Except when

equipped with
Air
Injection Reactor System)

1.
As a
preliminary adjustment, turn idle mixture

screws lightly
to
seat
and
back
out 2
turns.

CAUTION:
Do not
turn idle mixture screw

tightly against seat
or
damage
may
result.

2.
With engine running
at
operating temperature (choke

wide open) adjust idle speed screw
to
bring idle

speed
to
specified
rpm
(automatic transmission
in
drive, manual transmission
in
neutral).

3.
Adjust idle mixture screw
to
obtain highest steady

idle speed
(1/4
turn
out
from lean roll).

4.
Repeat Steps
2 and 3 as
needed
for
final adjustment.

5.
Shut down
the
engine, remove gauges
and
install
air

cleaner.

Adjust Idle Speed
and
Mixture
(Fig. 14)
(With
Air

Injection Reactor System)

The recommended adjustment procedure
for Air
Injec-

tion Reactor System equipped engines
is as
follows:

1.
As a
preliminary adjustment, turn idle mixture

screws lightly
to
seat
and
than back
out 3
turns.

CAUTION:
Do not
turn idle mixture screw

tightly against seat
or
damage
may
result.

2.
With engine running
at
operating temperature, choke

wide open,
and
parking brake applied, adjust idle

specified idle speed (automatic

"drive"-manual transmission
in
to

in
screw

transmission

"neutral").

;3.
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.

4.
Repeat Steps
2 and 3 as
needed
for
final adjustments.

ADDITIONAL CHECKS
AND
ADJUSTMENTS

Testing Crankcase Ventilation Valve
(Fig. 15) 0

1.
Connect tachometer
and
vacuum gauge
as for
idle

speed
and
mixture adjustment.

2.
Set
parking brake, start engine
and
adjust idle speed

and mixture.

3.
Disconnect ventilation hose
at
valve, block opening
of

valve
and
read engine
rpm
change.

4.
A
change
of
less than
50 rpm
indicates
a
plugged

ventilation valve
-
replace
the
valve.

Cylinder Balance Test
(Fig. 16)

It
is
often difficult
to
locate
a
weak cylinder.
A com-

pression test,
for
example, will
not
locate
a
leaky intake

manifold,
a
valve
not
opening properly
due to a
worn

camshaft,
or a
defective spark plug.

With
the
cylinder balance test,
the
power output
of one

cylinder
may be
checked against another, using
a set of

grounding leads. When
the
power output
of
each cylinder

is
not
equal,
the
engine will lose power
and run
roughly.

Perform
a
cylinder balance test
as
follows:

1.
Connect
the
tachometer
and
vacuum gauge.

2.
Start engine
and run at 1500 rpm.

3.
Ground large clip
of
grounding leads
and
connect
in-

dividual leads
to all
spark plugs except
the
pair being

tested.

Divide
the
firing order
in
half
and
arrange
one
half

over
the
other.
The
cylinders
to be
tested together
ap-

pear
one
over
the
other.

L4 Firing Order
V8 Firing Order

1-8-4-3-6-5-7-2

1-6, 8-5, 4-7, 3-2

1-3-4-2
= 1-3

4-2

L6 Firing Order

1-5-3-6-2-4
=
=
1-4. 3-2

1-5-3

6-2-4
1-6, 5-2, 3-4
1-8-4-3

6-5-7-2

4.
Operate engine
on
each pair
of
cylinders
in
turn
and

note engine
rpm and
manifold vacuum
for
each pair.

A variation
of
more than
1
inch
of
vacuum
or 40 rpm

between pairs
of
cylinders being tested indicates that

the cylinders
are off
balance.

Battery

The battery should
be
checked with special testing

equipment
and to the
equipment manufacturers specifica-

tions.
See
Section 6Y
for
complete information
on
battery

tests.

Ignition

The following additional ignition checks
may be
made

with
any of
several pieces
of
equipment available
for un-

covering
the
source
of
engine difficulties.
The
specific

operating instructions
of the
equipment manufacturer

should
be
followed:

Cranking voltage

Ignition switch

Distributor resistance

Secondary resistance

Ignition output
and
secondary leakage

Cranking Voltage
(Fig. 17)

1.
Disconnect coil primary lead
at the
coil negative

terminal
to
prevent engine from firing during

cranking.

2.
Connect voltmeter between primary terminal
of coi|

(resistance wire side)
and
ground.

3.
Operate starting motor.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-11

Fig.
18 - Cooling System Pressure Test

Carburetor

Refer to Section 6M to perform adjustments such as

idle vent, float level, pump rod and secondary valve.

Fuel Pump

If the owner has complained of poor high speed per-

formance, the fuel pump may be at fault. Too low a

pump pressure or volume will cause a high speed "miss"

because of lack of fuel delievered to the carburetor,

while too high a pressure will cause carburetor flooding.

Check fuel pump as outlined in Section 6M.

Cooling System

The following test may be performed with pressure

testing equipment available commercially for this pur-

pose.
This test provides an excellent means of detecting

internal or external leaks within the cooling system.

1.
Remove radiator cap.

2.
Apply a test pressure of 3 pounds higher than the ra-

diator cap (fig. 18). i.e. 18 pounds for a 15 pound

cap.

3.
If the pressure will not hold, there is either an

internal or external leak in the system.

Cylinder Head Torque and Valve Adjustment

Retorquing the cylinder head bolts is not necessary

unless a gasket has been replaced, or a leak is suspected.

Valve lash must always be adjusted after the head has

been torqued.

Before adjusting the valve lash, it is extremely impor-

tant that the engine be thoroughly warmed up to normal-

ize the expansion of all parts. This is very important

because during the warm-up period, the valve clearances

will change considerably.

Hydraulic

1.
After the engine has been normalized, remove rocker

arm covers and gaskets.

CAUTION: Do not pry rocker arm cover loose.
Gaskets adhering to cylinder head and rocker

arm cover may be sheared by bumping end of

rocker arm cover rearward with palm of hand

or a rubber mallet.

2.
With the engine running at idle, back off valve rocker

arm nut until the valve rocker arm starts to clatter.

3.
Turn rocker arm nut down slowly until the clatter

just stops. This is the zero lash position.

4.
Turn nut down 1/4 additional turn and pause 10 sec-

onds until engine runs smoothly* Repeat additional

1/4 turns, pausing 10 seconds each time, until nut

has been turned down 1 full turn from the zero lash

position.

NOTE: This 1 turn preload adjustment must be

done slowly to allow the lifter to adjust itself to

prevent the possibility of interference, between

the inlet valve head and top of piston, which

might result in internal damage and/or bent push

rods.
Noisy lifters should be replaced.

5.
Repeat Steps 2, 3 and 4 to adjust the rest of the

valves.

6. Clean gasket surfaces on cylinder heads and rocker

arm covers with degreaser then install rocker arm

covers, using new gaskets, and torque bolts to

specifications.

Mechanical

1.
Normalize the engine.

2.
Remove rocker arm covers and gaskets.

CAUTION: Do not pry rocker arm cover loose.

Gaskets adhering to cylinder head and rocker

arm cover may be sheared by bumping end of

rocker arm cover rearward with palm of hand

or a rubber mallet.

3.
Use a socket wrench on self-locking rocker arm stud

nut and adjust as needed to obtain valve lash (see

tune up chart) measured between rocker arm and

valve stem with a leaf type feeler gauge.

4.
Stop engine, clean gasket surfaces on cylinder heads

and rocker arm covers with degreaser then install

rocker arm covers, using new gaskets, and torque

bolts to specifications.

Fig.
19
- Oil Deflector Clips Installed

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-23

ENGINE MOUNTS

Engine mounts (fig. 21L) are the non-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

Chevrolet,
Chevelle, and Comoro

1.
Remove nut, washer, spacer then engine mount

through-bolt.

2.
Raise engine to release weight from mount.

3.
Remove mount, stop bracket and frame bracket as-

sembly from crossmember, then remove stop

bracket and mount from frame bracket.

4.
Install stop bracket and new mount on frame bracket,

then install assembly on crossmember.

5.
Lower engine, install through-bolt and tighten all

mount bolts to specified torques.

Chevy II

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

2.
Raise engine to release weight from mount.

3.
Remove bracket-to-mount bolt, then remove mount.

4.
Install new mount on bracket.

5.
Lower engine, install through-bolt and tighten all

mount bolts to specified torques.

Rear Mount Replacement
Chevrolet

1.
Remove crossmember-to-mount bolts.

2.
Raise transmission to release weight from mount.

3.
Remove mount-to-trans mission bolts, then remove

mount and spacer.

4.
Install spacer and new mount on transmission.

5.
While lowering transmission, align and start cross-

member-to-mount bolts.

6. tower transmission and tighten all mounting bolts

to specified torques.

Chevelle and Camaro

1.
Remove crossmember-to-mount bolts.

2.
Raise transmission to release weight from mount.

3.
Remove mount-to-transmission bolts, then remove

mount.

4.
Install new mount on transmission.

5.
While lowering transmission align and start cross-

member-to-mount bolts.

6. Lower transmission and tighten all mounting bolts to

specified torques.

Chevy II

1.
Remove crossmember-to-mount bolts.

2.
Raise transmission to release weight from mount.

3.
Remove mount-to-transmission bolts, then remove

mount.

4.
Install new mount on transmission.

5.
While lowering transmission align and start cross-

member-to-mount bolts.

6. Lower transmission and tighten all mounting bolts

to specified torques.

FRONT

CHEVROLET

REAR

REAR
L4 FRONT

CHEVY II

L6 FRONT

L6 REAR
FRONT

CAMARO

REAR

Fig.
21L- Engine Mounts

CHEVROLET CHASSIS SERVICE MANUAL