1967 CHEVROLET CAMARO set clock

HEATER AND AIR CONDITIONING 1A-3

linkage of this lever which will provide partial airflow

only to the defroster duct and which should be used for,

all normal defogging operations.

CORVETTE

Heater components are attached to the dash panel on

the right side of the vehicle with the air inlet assembly

on the engine side and the heater and air distributor

assemblies beneath the instrument panel within the pas-

senger compartment.

The heater operates on outside air only with the blower

receiving its air flow from the cowl vent plenum

chamber.

No water valve is utilized in the system. Therefore,

water flows through the heater core constantly while

the engine is running, keeping the core at maximum

temperature at all times.

Airflow through the system is shown in Figure 1.

Controls

Two knobs control all heater operations:

The FAN-TEMP knob is rotated to turn the blower

on and off and control blower speed and is pulled out

as desired to regulate heater temperature.

The AIR-DEF knob is the air on-and-off control as

well as the defroster control.

Temperature Damper: Door

At the heart of the heater operation is the temperature

damper door. Air from the blower follows parallel paths

through the distributor duct, with one path passing

through the heater core and the other path bypassing the

core.

The temperature damper door is placed in the duct

so that, when closed, the path of the heated air leaving

the heater core is blocked while the ambient air path

remains open. Positive closing of this door when no

heat is being called for is assured by a cam assembly

at the door operating lever. As the FAN-TEMP knob

is pulled out, the damper door is opened accordingly,

allowing varying proportions of heated air to mix with

the unheated airflow, thus providing heater outlet tem-

perature control. With the knob pulled fully out the
Fig.
4—Heater Controls (Corvette)

ambient air path is blocked and all airflow passes

through the heater core. Final heater output temperature

is dependent upon the proportion of heated and ambient

air blended together according* to the setting of the

temperature damper door.

Air and Defrost Damper Doors

Beyond the temperature damper door are the air door

and the defroster door, both operated through a single

bowden cable by the AIR-DEF knob. The first half of the

travel of this knob opens the AIR door allowing the

airflow to pass into the interior of the car through the

floor distributor openings. Pulling the AIR-DEF knob

fully out causes the defroster door to open, diverting

this airflow to the defroster ducts for defogging, de-

frosting or deicing operations.

NOTE: Since this knob is the air on-or-off

control, it should be pulled at least halfway out

before turning on the blower.

Fan Control

Rotate the FAN-TEMP knob to operate the three-

speed blower, increasing the velocity of the air through

the heater. The fully counter-clockwise position of the

knob is the off position. Turn clockwise to the desired

blower speed; fully clockwise for high blower speed.

COMPONENT REPLACEMENT AND REPAIR

CHEVROLET, CHEVELLE, AND CAMARO

Blower Assembly

Removal

1.
Disconnect battery ground cable.

2.
Unclip heater hoses from fender skirt.

3.
(Chevrolet and Camaro) Remove right front fender

and skirt assembly. (See Section 11 of the Service

Shop Manual)

(Chevelle) Move the vehicle front wheels to the

extreme right turn position. Remove all right front

fender retaining bolts. Allow the skirt to drop and

rest on top of the tire. To gain maximum clearance

for access to the blower motor attaching screws, a

block of wood may be wedged between the fender

lower flange and the top of the fender skirt. Position

the wood block so that the rear portion of the skirt

will be forced down and inboard. (See Figure 7.)
4.
Disconnect the blower motor wire at the motor

flange.

5.
Remove the motor to case mounting screws and re-

move motor. Pry the flange gently if the sealer acts

as an adhesive.

6. Remove the blower wheel retaining nut and separate

blower and motor.

Installation

1.
Assemble the blower wheel to the motor with the

open end of the blower away from the motor.

2.
Place the assembly into the case and replace the

mounting screws. Connect the blower motor wire to

the motor.

3.
(Chevrolet and Camaro) Replace the fender and

skirt assembly.

(Chevelle) Replace the fender skirt.

4.
Clip the heater hoses to the fender skirt and connect

the battery ground cable.

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-21

"De-Fog"
Position

In the event that the front windshield should require

removal of a fogging condition, the owner at his option

may direct air to the windshield. The "De-Fog" position

directs part of the air to the windshield while retaining a

certain amount through the floor outlets. The temper-

ature of the air remains the same as it was prior to the

control being placed in the "De-Fog" position. Five

blower speeds are available. The temperature of the air

and the blower speed are selected by the automatic

controls and are dependent upon the in-car temperature.

"De-Ice" Position

The "De-Ice" position provides full heat with "Hi"

blower directing the entire airflow to the windshield to

melt ice. The automatic controls are completely defeated

and as a result, full heat with "Hi" blower are the only

conditions that can be received. The system will turn on

immediately in this position even though the engine

coolant might be cold.

General Information

Three start up conditions can be achieved with

Comfortron.

Weather

Cold
Method of Starting System

System starts as soon as engine coolant is

hot.

Hot System starts immediately when AC is

required.

Any System starts immediately in "De-Ice"

position.

UNIVERSAL SYSTEM

A self-contained unit, the dealer installed Universal

System operates on recirculated air only and entirely

independent of the vehicle heater. Recirculated inside air

is drawn into the unit, passed through the evaporator core

and into the car through the adjustable outlets in the

evaporator case. The entire unit mounts compactly

beneath the dash. Temperature control is by means of a

thermostatic switch.

The compressor used with the Universal System is

identical to that used for the Four-Season system except

for displacement. Underhood components are similar in

placement to the Four-Season system.

Controls

Universal system controls are the AIR knob controlling

the three speed blower motor switch and the TEMP knob

which controls the setting of the thermostatic switchi

Switch adjustment is covered elsewhere in this section.

When operating this system the Heater must be fully off.

CHEVY II ALL-WEATHER SYSTEM

The Chevy n All-Weather Air Conditioning System,

Figure 33, operates in conjunction with the heater to

provide a complete air conditioning system operating on

either outside air, recirculated air or a combination of

both. The cooling unit attaches to the heater distributor

and utilizes the heater blower. Several controls allow
full use of either the heating or cooling features of the

system. During marginal weather, it is possible to pro-

vide heated air at floor level and cooled air at breath

level.

A schematic view of the air conditioning underdash

components is provided in Figure 34 to aid in under-

standing airflow and control operation.

The evaporator assembly, located in the passenger

compartment attached directly to the heater distributor,

contains the evaporator core, expansion valve, thermo-

static switch and the air conditioning "ON" knob. The

thermostatic switch, utilized as the cooling control, feels

the temperature of the cooled air leaving the evaporator

core and turns the compressor on and off in accordance

with cooling needs. Refrigerant lines connect the evap-

orator assembly to the other system components located

in the engine compartment.

The six cylinder air conditioning compressor, com-

pletely field serviceable, is bracket-mounted to the

engine and is belt driven from the crankshaft pulley. A

muffler assembly, designed to eliminate compressor

pulsations is an integral part of the compressor con-

nector block. The condenser is mounted on the radiator

support just ahead of the engine radiator. The receiver-

dehydrator, with its sight glass, is located on the right

fender skirt.

Controls

Control of the air conditioning system is achieved

through the use of the heater control on the instrument

panel as well as the two knobs located on the air condi-

tioning unit itself (fig. 35).

Air Conditioning "ON" Knob

Labeled "Pull for Air Cond.", this knob diverts air-

flow from the floor distributor and through the air condi-

tioning unit. Initial movement of this knob also actuates a

switch, located at the damper door, which energizes the

compressor clutch thus putting the system into operation

and under the control of the thermostatic switch.

Temp-Cool Knob

This knob controls the thermostatic switch. Turn the

knob clockwise for more cooling, counter-clockwise for

less cooling.

Air Lever

This lever actuates the damper within the assembly

which chooses between recirculated air or outside air.

Fig.
31-Universal Air Conditioning Unit

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR. CONDITIONING 1A-24

Fig. 35-Controls-AII Weather (Chevy II)

The heater components of the system are similar to

the standard Corvette heater with hoses routing engine

coolant to and from the heater core. A vacuum operated

shutoff valve assures that no coolant will pass through

the heater core until the system calls for heat.

Four control knobs surrounding the clock on the in-

strument panel center console provide full control of the

heating and cooling functions of the air conditioning

system.
The general arrangement of the system components

is pictured in Figure 37 while a schematic view of the

system will be found in Figure 36.

Controls Corvette

Four control knobs, grouped around the clock on the

instrument panel central console, provide full control

of the heating and cooling functions of the Corvette Air

Conditioning System. Each of the knobs, through a bowden

cable, operates one of the air diverter doors in the air

distributor assembly. In addition, the AIR COND.-PULL

knob operates the compressor switch; blower speeds are

controlled by turning the AIR PULL knob; and the heater

hot water valve vacuum switch is actuated by the COOL

IN-HQT PULL knob.

Air Conditioning "ON" Knob

The "AIR COND. PULL" knob controls the positioning

of the air diverter door which routes conditioned air

through either the dash diffuser ducts or the floor dis-

tributor outlets. Movement of this knob (hence, movement

of the selector door) also controls' the compressor

switch. When the door is positioned to send air through

the dash outlets the compressor is automatically turned

on to place the cooling system in operation and the fan

is turned on to LOW speed.

Blower Switch and Air Selector

The AIR PULL-FAN knob operates the selector door

in the right hand plenum chamber and may be set to allow

full outside air, full inside air, or a mixture of the two to

DEFROSTER DOOR

OPERATED BY

DEFROSTER KNOB
AIR CONDITIONING DOOR

OPERATED BY

AIR COND. PULL KNOB
BLOWER

OPERATED

BY TURNING

AIR KNOB

AIR DOOR

OPERATED

BY PULLING

AIR KNOB

OUTSIDE

AIR

CONTROLS

HEAT DOOR

OPERATED BY

COOL IN-HOT PULL

KNOB

L.H. OUTLET
CENTER

OUTLET
R.H. OUTLET
AIR COND.

PULL
COOL IN

HOT PULL

AIR PULL

LO-MED-HI
DEFROSTER

PULL

Fig.
36—Corvette Four-Season System Schematic

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-40

THERAAAL VACUUM

VALVE
TO ENGINE

VACUUM

SOURCE

VACUUM STORAGE

TANK

OUTSIDE AIR

DIAPHRAGM

MODE

DIAPHRAGM

VACUUM

RELAY
BLACK

DEFOG-DEICE

DIAPHRAGM

GREEN

BLACKj ||
|
BROWN

CONTROL

VALVE

Fig.
50—Comfortron Vacuum Diagram

are fused which will lead to evaporator freeze-up.

Replace the switch.

• If the compressor does not operate regardless of

the position of the knob a loss of the power

element charge is indicated provided that it has

been established that power is supplied to the

switch. This, of course, results in no cooling.

Replace the switch.

• Check the screw threads for stripped or other-

wise damaged threads.

Adjusting Switch

H, after checks above, the switch seems to be operating

properly,

follows:
adjust for proper setting if necessary, as
1.
(Chevy II All-Weather) Turn the outer air deflector

in the face plate so that the attaching screws may

be removed; Then remove the control knobs, bezels

and the thermostatic switch. (Universal) remove the

face plate retaining screws. Pull the faceplate away

from the case when ready to turn the switch adjusting

screw.

2.
Vehicle must be set up as in Step 2 above.

3.
The suction side of the system, read on the low

pressure gauge, should pull down to the pressure

shown in the chart in Performance Test under the

ambient temperature at the time the switch is being

set.

4.
If the low side pulls down lower than the prescribed

pressure at the end of each cooling cycle, turn the

adjusting screw (See Figure 54) clockwise in single

CHEVROLET CHASSIS SERVICE MANUAL

HEATER
AND AIR
CONDITIONING
1A-41

OUTLET

1

TO EXPANSION
^

VALVE
TO
OIL

BLEED LINE

^ INLET

Fig.
51—Evaporator Pressure Control Valve—POA

turn increments until
the
suction pressure rises
to

the correct pressure.

5.
If the
pressure
is
more than
it
should
be,
turn the

adjusting screw counter-clockwise until
the
proper

pressure
is
reached.

6. After adjusting
the
switch, install the capillary to
its

normal position
and
observe
the
operation
of the

system
for
several minutes. Then
if
the operation
is

satisfactory remove the gauge
set,
replace the switch

and reinstall the face plate onto the evaporator case.

EXPANSION VALVE

A malfunction
of the
expansion valve will
be
caused

by
one of the
following conditions: valve stuck open,

valve stuck closed, broken power element,
a
restricted

screen
or an
improperly located
or
installed power

element bulb.
The
first three conditions require valve

replacement.
The
last two may be corrected by replacing

the valve inlet screen
and by
properly installing
the

power element bulb.

Attachment
of the
expansion valve bulb
to the
evap-

orator outlet line
is
very critical.
The
bulb must be

attached tightly
to the
line
and
must make good contact

with
the
line along
the
entire length
of
the bulb. A loose
bulb will result
in
high
low
side pressures and poor

cooling.
On
bulbs located outside
the
evaporator case

insulation must be properly installed.

The external equalizer line shown
in
Figure
55 is
not

used
in the
Custom
and
Chevy
II
All-Weather systems.

Indications
of
expansion valve trouble provided by the

Performance Test are
as
follows:

VALVE STUCK OPEN
OR
BROKEN POWER

ELEMENT

Noisy Compressor.
•

No Cooling
-
Freeze
Up.

VALVE STUCK CLOSED
OR
PLUGGED SCREEN

Very Low Suction Pressure.

No Cooling.

Fig.
52-P.O.A. Valve Installed
Fig.
53—Thermostatic Switch Removal

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 3-6

Fig.
8 - Caster and Camber Adjustments - Chevy

To adjust for caster and camber, loosen the upper sup-

port shaft to crossmember nuts, add or subtract shims as

required and retighten nuts.

NOTE:
Caster and camber can be adjusted in

one operation.

Caster and camber specifications will be found in the

last section of this book.

Chevrolet and Chevy II

The caster angle is adjusted by turning the two niits at

the front of the lower control arm strut rod (figs. 7 and

8).
Shortening this rod will increase caster. Lengthen-

ing will decrease caster.

Camber angle is adjusted by loosening the lower con-

trol arm pivot bolt and rotating the cam located on this

pivot. This eccentric cam action will move lower control

arm in or out, thereby varying camber.

Steering Axis Inclination Adjustment

"Camber" is the outward tilt of the wheel and "steering

axis inclination" is the inward tilt of the knuckle. Cam-

ber cannot be changed without changing steering axis

inclination. Correct specifications willbe found at the

end of this section. If, with the camber correctly ad-

justed, the steering axis inclination does not fall within

the specified limits the knuckle is bent and should be

replaced.

If a new knuckle is installed, caster, camber and toe-in

must be readjusted.

Toe-In Adjustment

Toe-in, the inward pointing of both front wheels, is

checked with the wheels in the straight ahead position. It

is the difference of the distance measured between the

extreme front and the distance measured between the ex-

treme rear of both front wheels. Correct toe-in specifi-

cations will be found at the end of this section.
NOTE:
Toe-in must be adjusted after caster

and camber adjustment.

A. If the equipment being used measures the toe-in of

each wheel individually:

1.
Set the steering gear on the high point, mark 12

o'clock position on the steering shaft and position

the steering wheel for straight ahead driving.

2.
Loosen the clamp bolt at each end of each tie rod

and adjust to the total toe-in as given in the speci-

fications at the end of this book.

B.
If a tram gauge is being used, proceed as follows:

1.
Set the front wheels in the straight ahead position.

2.
Loosen the clamp bolts on one tie rod and adjust

for the proper toe-in as given in the specifications

at the end of this book.

3.
Loosen the clamp bolts on the other tie rod. Turn

both rods the same amount and in the same direc-

tion to place the steering gear on its high point and

position the steering wheel in its straight ahead

position.

C.
After the adjustment has been made:

1.
a. Chevrolet—Position inner tie rod clamp bosses

forward to 90° down to avoid stabilizer link bolt

interference.

b.
Chevelle—Position the tie rod clamp bosses

down to 45?° forward to avoid interference.

c. Chevy II--Position the outer tie rod clamp

bosses forward and not more than 45° up or

down from horizontal to avoid interference.

Inner clamps forward and vertical.

d. Corvette--Position inner tie rod clamps with

bolt horizontal and down. Position outer clamps

with bolt vertical and to the rear.

e. Camaro—Position inner tie rod clamps with

open end of clamp and slot in line. Position

relative to ground unimportant. Position outer

clamps with bolt top and 30° either side of ver-

tical. Position relative to slot unimportant.

RIDING HEIGHT AND COIL SPRING SAG

The following check will quickly determine whether or

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE
6-3

(ROUND) Y~~fll^H

CENTRIFUGAL
A ^k

ADVANCE--jflgKpl

MECHANISM
UB|

CAM
KSK^2

LUBRICATOR
VlSMi

REPLACEMENT
^BK

-^ADJUST
SQUARELY

AND
JUST

TOUCHING
LOBE

OF
CAM
/ROTOR

HBB
__

I^BH^F
?
(SOUARE)

^K^ I /—
CAM

jKft^J / LUBRICATOR

H^T^
CAUTION!

QV NEVER
OIL

•L-^
CAM LUBRICATOR-

REPLACE
WICK

WHEN
NECESSARY
LATERAL

MISALIGNMENT
PROPER

LATERAL ALIGNMENT

Fig.
4- Distributor (V8)

CAUTION: Use extreme care
-when
using tap to

prevent cross threading. Also crank engine sev-

eral times to blow out any material dislodged

during cleaning operation.

7. Install spark plugs with new gaskets and torque to

specifications.

NOTE:
The following are some of the

greatest causes of unsatisfactory spark plug

performance.

•
Installation of plugs with insufficient torque to

fully seat the gasket.

•
Installation of the plugs using excessive torque

which changes gap settings.

•
Installation of plugs on dirty gasket seal.

•
Installation of plugs into corroded spark plug hole

threads.

8^ Connect spark plug wiring.

Service
Ignition System

1.
Remove distributor cap, clean cap and inspect for

cracks, carbon tracks and burned or corroded ter-

minals. Replace cap where necessary.

2.
Clean rotor and inspect for damage or deterioration.

Replace rotor where necessary.

3.
Replace brittle, oil soaked or damaged spark plug

wires.
Install all wires to proper spark plug. Proper

positioning of spark plug wires in supports is impor-

tant to prevent cross-firing.

4.
Tighten all ignition system connections.

5. Replace or repair any wires that are frayed, loose or

damaged.
Us
CORRECT
LATERAL MISALIGNMENT BY

j BENDING
FIXED CONTACT SUPPORT

[NEVER
BEND BREAKER LEVER

Fig.
5 - Point Alignment

Magnetic
Pulse(Breakerless)
Distributor

There are no moving parts in the ignition pulse ampli-

fier, and the distributor shaft and bushings have perma-

nent type lubrication, therefore no periodic maintenance

is required for the magnetic pulse ignition system. Refer

to Section 6Y for an analysis of problems and/or repair

procedures encountered on the Transistorized (Magnetic

Pulse) ignition system.

Standard
(Breaker Point) Distributor
(Figs.
3 or 4)

1.
Check the distributor centrifugal advance mechanism

by turning the distributor rotor in a clockwise direc-

tion as far as possible, then releasing the rotor to

see if the springs return it to its retarded position.

If the rotor does not return readily, the distributor

must be disassembled and the cause of the trouble

corrected.

2.
Check to see that the vacuum spark control operates

freely by turning the movable breaker plate counter-

clockwise to see if the spring returns to its retarded

position. Any stiffness in the operation of the spark

control will affect the ignition timing. Correct any

interference or binding condition noted.

3.
Examine distributor points and clean or replace if

riecessary.

DO
NOT SUCK

IN
TOO MUCH

ELECTROLYTE

TAKE
READING

AT
EYE LEVEL

Fig.
6 - Testing Specific Gravity of Battery

CHEVROtET
CHASSIS SERVICE MANUAL