1967 CHEVROLET CAMARO belt

HEATER
AND AIR
CONDITIONING
1A-13

AIR CONDITIONING

INDEX

Page

General Description
1A-13

Four-Season System
1A-13

Controls
1A-16

Comfortron System
. 1A-18

System Components
lA-19

Controls
1A-20

Universal System
. .
1A-21

Chevy
n
All-Weather System
•
1A-21

Corvette Four-Season System
. 1A-22

General Information
. . . 1A-26

Precautions
in
Handling R-12
1A-26

Precautions
in
Handling Refrigerant Lines
1A-28

Maintaining Chemical Stability
in the

Refrigeration System
1A-28

Gauge
Set 1A-29

Charging Station
IA-29

Leak Testing
the
System
1A-29

Vacuum Pump
1A-30

Availability
of
Refrigerant-12
. . 1A-30

Compressor
Oil 1A-31

Compressor Serial Number
1A-31

Inspection
and
Periodic Service
1A-31

Pre-Delivery Inspection
1A-31

6,000 Mile Inspection
1A-32

Periodic Service
, 1A-32

Installing Gauge
Set to
Check System Operation
....
1A-32

Performance Test
1A-32

Performance Data lA-r33

Comfortron System Operational Test
1A-33

Chevrolet Comfortron Tester
1A-34

Complete System Checks
1A-35

Maintenance
and
Adjustments ......
1A-37

Evaporator Comtrol Valve (POA)
.
1A-37
Page

Thermostatic Switch
1A-37

Expansion Valve
1A-41

Engine Idle Compensator
. . .
1A-42

Evacuating
and
Charging Procedures
1A-42

Purging
the
System
1A-42

Evacuating
and
Charging
the
System
1A-43

Checking
Oil . 1A-43

Component Replacement
and
Minor Repair
1A-45

Refrigerant Line Connections
1A-45

Repair
of
Refrigerant Leaks
1A-46

Preparing System
for
Replacement
of

Component Parts
. 1A-46

Foreign Material
in the
System
.
1A-47

Condenser
.
1A-48

Receiver-Dehydrator
1A-48

Evaporator
1A-49

Expansion Valve
1A-57

Evaporator Control Valve (POA)
1A-59

Thermostatic Switch
or
Blower Switch
. .
1A-59

All Weather-Pull Cable
1A-61

Blower Assembly
1A-62

Air Inlet Valve
.
1A-64

Blower
and
Evaporator Assembly
1A-64

Air Distributor Assembly
and
Outlet Ducts ...... 1A-64

Comfortron Automatic Control Components
1A-66

Collision Procedure lA-70

Four-Season Heater Components
1A-73

Comfortron Heater Components
. . . 1A-75

Compressor
1A-76

Wiring Diagrams
1A-78

Special Tools
.
1A-84

GENERAL DESCRIPTION

Four
air
conditioning systems
are
covered
in
this

section. They are:

1.
The
Four-Season System (Chevrolet, Chevelle,

Camaro and Corvette).

2.
The Comfortron System (Chevrolet).

3.
The All Weather System (Chevy n).

4.
The Universal System (Chevrolet, Chevelle, Chevy
n,

Camaro)

Underhood components (that
is, the
compressor,
con-

denser
and
receiver-dehydrator)
are
much
the
same
in

type,
location
and
method
of
attachment
on all of
the

above systems. The six-cylinder reciprocating compres-

sor
is
bracket-mounted
to the
engine
and
belt driven

from
the
crankshaft pulley.
The
condenser
is
mounted

ahead
of the
engine cooling radiator
and the
receiver-

dehydrator
is
mounted
in
the refrigerant line downstream

of
the
condenser.
All
cooling system components
are

connected by means
of
flexible refrigerant lines.

Evaporator size
and
location differ from system
to

system
as do
methods
of
temperature control
and air

supply
and
distribution.

FOUR-SEASON SYSTEM

The Four-Season system used
in the
Chevrolet,

Chevelle, Camaro,
and
Corvette vehicles
may be
iden-

tified
by the
fact that
it
uses
an
evaporator pressure

control known
as the POA
(Pressure Operated Absolute)

suction throttling valve.
Both
the
heating
and
cooling functions
are
performed

by this system.
Air
entering
the
vehicle must pass

through
the
cooling unit (evaporator)
and
through
(or

around)
the
heating unit,
in
that order, and the system
is

thus referred to
as a
''reheat" system.

The evaporator provides maximum cooling
of the air

passing through
the
core when
the air
conditioning sys-

tem
is
calling
for
cooling.
The
control valve acts in the

system only
to
control
the
evaporator pressure
so
that

minimum possible temperature
is
achieved without core

freeze-up.
The
valve
is
preset,
has no
manual con-

trol,
is
automatically altitude compensated,
and non-

repairable.

The heater core will be hot
at
all times since no water

valve
is
present
in
the system.

System operation
is as
follows (See Figure 24 and 25):

Air, either outside
air or
recirculated
air
enters
the

system
and is
forced through
the
system by the blower.

As
the air
passes through
the
evaporator core,
it

receives maximum cooling
if
the
air
conditioning controls

are calling
for
cooling. After leaving
the
evaporator,

the
air
enters
the
Heater
and Air
Conditioner Selector

Duct Assembly where,
by
means
of
manually operated

diverter doors,
it is
caused
to
pass through
or to
bypass

the heater core
in the
proportions necessary
to
provide

the desired outlet temperature. Conditioned airflow then

enters
the
vehicle through either
the
floor distributor

duct
or the
dash outlets. Remember that the heater core

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-31

FIVE
AMP

TIME DELAY

FUSE

CORD
TO

110
AC
SOURCE
PUMP

INLET
PUMP DISCHARGE

OUTLET

Fig.
44—Vacuum Pump

the use of weighing equipment necessary with the larger

drum. The single can Valve J-6271 can be used for com-

pleting the charge and for miscellaneous operations such
Fig.
45-R-12 Disposable Cans

as flushing. The valves are installed by piercing the top

seal of the cans.

Evacuating and charging procedures later in this sec-

tion will make use of the J-8393 Charging Station which

uses the 25 lb. drum of refrigerant.

COMPRESSOR OIL

Special refrigeration lubricant should be used in the

system. It is available in 1 quart graduated bottles

through Parts Stock. This oil is as free from moisture

and contaminants as it is possible to attain by commercial

processes. This condition should be preserved by im-

mediately capping the bottle when not in use.

See "Air Conditioning System Capacities" for the

total system oil capacity.

Due to the porosity of the refrigerant hoses and con-

nections, the system refrigerant level will show a definite

drop after a period of time. Since the compressor oil is

carried throughout the entire system mixed with the

refrigerant a low refrigerant level will cause a dangerous

lack of lubrication. Therefore the refrigerant charge in

the system has a definite tie-in with the amount of oil

found in the compressor and an insufficient charge may

eventually lead to an oil build-up in the evaporator.

COMPRESSOR SERIAL NUMBER

The compressor serial number is located on the serial

number plate on top of the compressor. The serial num-

ber consists of a series of numbers and letters. This

serial number should be referenced on all forms and

correspondence related to the servicing of this part.

INSPECTION AND PERIODIC SERVICE

PRE-DELIVERY INSPECTION

1.
Check that engine exhaust is suitably ventilated.

2.
Check the belt for proper tension.

3.
With controls positioned for operation of the system,

operate the unit for ten minutes at approximately

2000 rpm. Observe the clutch pulley bolt to see that

compressor is operating at the same speed as the
clutch pulley. Any speed variation indicates clutch

slippage.

Before turning off the engine, check the sight glass

to see that the.unit has a sufficient Refrigerant

charge. The glass should be clear, although during

milder weather it may show traces of bubbles. Foam

in.
the flow indicates a low charge. No liquid visible

indicates no charge.

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-32

5.
Check hose clamp connections. If clamp screw torque

is less than 10 lb. in., retighten to 20-25 lb. in. Do

not tighten to new hose specifications or hose leak-

age may occur.

6. If there is evidence of an oil leak, check the com-

pressor to see that the oil charge is satisfactory.

7.
Check the system controls for proper operation.

6000 MILE INSPECTION

1.
Check unit for any indication of a refrigerant leak.

2.
If there is an indication of an oil leak, check the

compressor proper oil charge.

3.
Check sight glass for proper charge of Refrigerant-

12.

4.
Tighten the compressor brace and support bolts and

check the belt tension.

5.
Check hose clamp connections as in step 5 above.

6. Check thermostatic switch setting (Universal and

All-Weather Systems.)

PERIODIC SERVICE

• Inspect condenser regularly to be sure that it is not

plugged with leaves or other foreign material.

Fig.
46—Compressor Connector Block—Typical
• Check evaporator drain tubes regularly for dirt or

restrictions.

• At least once a year, check the system for proper

refrigerant charge and the flexible hoses for brittle-

ness,
wear or leaks.

• Every 6000 miles check sight glass for low refriger-

ant level.

• Check belt tension regularly.

• Every week - during winter months or other periods

when the system is not being operated regularly- run

the system, set for maximum cooling, for 10 or 15

minutes to insure proper lubrication of seals and

moving parts.

INSTALLING GAUGE SET TO CHECK

SYSTEM OPERATION

Compressor Suction and Discharge Connector

Compressor connector assemblies used on all vehicles

are of the same basic design consisting of the inlet

(suction) and outlet (discharge) connections, gauge fittings

and muffler and, in general, the assemblies differ only in

the location of the gauge fittings.

On Universal and Four-Season Systems the outlet line

extends along side of and toward the front of the com-

pressor and the muffler in the line is bracket mounted to

the compressor body. In all Universal Systems the gauge

fittings for both low and high pressure sides of the sys-

tem are located in the connector body. On Four-Season

Systems the high pressure gauge fitting is located on the

muffler and the low pressure gauge fitting is on the POA

Valve.

The Chevy n All-Weather System compressor con-

nector assembly is similar to the Universal System

connector assembly described above except that the

muffler extends straight out from the connector and

is not bracket mounted to the compressor.

Universal and Chevy II All-Weather System

1.
Install Gauge Adapter (J-5420 or J-9459) onto the

high and low pressure hoses of the gauge set.

2.
With the engine stopped, remove the caps from the

cored valve gauge, connectors on the compressor

fittings block.

3.
Connect the gauge lines with adapters to the threaded

connectors on the compressor fittings block.

Four-Season and Comfortron Systems

Installation of the gauge set onto the Four-Season and

Comfortron systems is accomplished in the same manner

as outlined above except that system performance checks

must be performed with the low pressure hose line and

adapter attached to the fitting on the POA valve. Charging

procedures should be performed with the high pressure

gauge line connected to the high pressure gauge fitting

located on the outlet line muffler and the low pressure

gauge line attached to the POA fitting.

CAUTION: When removing gauge lines from

the compressor fittings block be sure to remove

the adapters from the fittings rather than the

gauge lines from the adapters.

PERFORMANCE TEST

This test may be conducted to determine if the system

is performing in a satisfactory manner and should be

used as a guide by the serviceman in diagnosing trouble

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-71

SUN-AMBIENT

SENSOR AND COMPRESSOR

CLUTCH SWITCH

HIGH BLOWER

DELAY RELAY

THERMAL

VACUUM

VALVE

Fig.
102-Comfortron Underhood Wiring

use when inspecting a damaged vehicle equipped with air

conditioning.

1.
Remove the drive belt. Cut belt off if necessary.

2.
Visually inspect the condenser, receiver-dehydrator,

compressor, mounting brackets, conditioning unit, all

connecting lines, and all controls to determine the

extent and nature of the damage.

a. No repairs, such as soldering, welding or braz-

ing, should be attempted on the condenser be-

cause of its construction. If the vapor passages

in the horizontal tubes or return bends or mani-

folds have been damaged in any way, the con-

denser should be replaced with a new one.

b.
The receiver-dehydrator should be replaced if

there is any evidence of its having sustained

either internal damage or a fracture at any of

the lines or welded joints or if the system has

been exposed to the atmosphere for an undeter-

mined period of time.

c. Examine the compressor for any visible external

damage.

d. The evaporator should be examined for damage

and, if necessary, removed or replaced or the

entire unit processed where damaged or exposed

to the atmosphere.

e. All connecting lines and flexible hoses should be

examined throughout their entire length for dam-

age.
If damaged in any manner, replace with new

lines.
f. Check all controls and connecting wires for

damage and replace with new parts where needed.

g. Check the clutch pulley for proper operation and

freedom from damage.

3.
Install gauge set.

4.
Purge the system. Pressure should not exceed 3 to

5 pounds.

5. Remove the compressor from mounting and remove

the oil test fitting.

6. Pour out the oil into a clean glass container and ex-

amine it for any foreign substance such as dirt,

water, metal particles, etc. If any of these are

present, the compressor and receiver-dehydrator

should be replaced and the other system components

should be flushed with liquid refrigerant.

7. If the oil is clean and free of any harmful substance,

replace oil with Frigidaire Oil available through

Parts Stock.

NOTE:
If the system components have been

replaced or flushed, replace the full charge of

oil. If not, add no more fresh oil than was

drained in Step 6.

8. Charge up the compressor to drum or can pressure

and leak test the compressor seals prior to in-

stallation of compressor.

9. Reinstall the compressor and evacuate the system

by following the Evacuating Procedure.

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-76

Fig.
112—-Heater Core Removal—Four-Season System (Corvette)

3.
Replace the core case into the car as described

under Heater and Air Distributor Assembly.

COMPRESSOR

The same basic six.cylinder reciprocating compressor

is used in all systems.

Two variations of the basic compressor are used. One,

with a displacement of 12.6 cu. in. is used with the Four-

Season System. The second model, having displacement

of 10.8 cu. in. is used with the Universal and All-Weather

Systems.
AH Systems

Removal

1.
Purge the refrigerant from the system.

2.
Remove connector attaching bolt and connector. Seal

connector outlets.

3.
Disconnect electrical lead to clutch actuating coil.

4.
Loosen brace and pivot bolts and detach belt.

5. Remove the nuts and bolts attaching the compressor

brackets to the mounting bracket.

6. Before beginning any compressor disassembly, drain

and measure oil in the compressor. Check for

evidence of contamination to ..determine if remainder

of system requires servicing. Compressor Servicing

information is located in the Chassis Overhaul

Manual.

Installation

1.
li oil previously drained from the compressor upon

removal shows no evidence of contamination, replace

a like amount of fresh refrigeration oil into the com-

pressor before reinstallatLon. If it was necessary to

service the entire system because of excessive con-

tamination in the oil removed, install a full charge of

"fresh refrigeration oil in the compressor. (See

Checking Compressor Oil Charge under Checking

Oil)

2.
Position compressor on the mounting bracket and

install all nuts, bolts and lock washers.

3.
Install the connector assembly to the compressor

rear head, using new "O" rings.

4.
Connect the electrical lead to the coil and install

and adjust compressor belt.

5. Evacuate and charge the system.

6. Leak test the system and check for proper operation.

Fig.
113—Heater Hoses^-Four-Season System (Corvette)

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-77

Compressor Belt Tension Adjustment

Adjust the compressor belt to the specifications shown

in the Tune-Up chart in the Engine section of this manual.

COMPRESSOR FAILURE

If the compressor has failed mechanically to the ex-
tent that metal chips and shavings are found in it, the

system should be checked for foreign material and

cleaned as described under Foreign Material in the

System.

CHEVROLET CHASSIS SERVICE MANUAL

CORVETTE BODY 1B-29

CUSHION

CUSHION ASNi.^ty** ACCESS

#2 BODY BRACKET

( 67 ONLY)
SHIM

( 37 POSITION).

CUSHION ASM.

( 37)

SHIM

( 67 POSITION)

CUSHION

( 37 ONLY)

#1 BODY BRACKET

Fig.
65—Body Mounts

PRECAUTIONS

Creams are available to protect the skin from a con-

dition known as occupational, or contact dermatitis. This

common type of dermatitis is not contagious. Improved

resin formulas in the approved kits have almost elimi-

nated skin irritation. Cream is supplied with the kit for

men who may have a tendency toward skin irritation

from the resins or dust.

The application of these creams is recommended

whenever the Resin Kit materials are used. Generally,

the cream is not required when the plastic solder kit is

being used. Directions for using the cream is as follows:

a. Wash hands clean. Dry thoroughly.

b.
Squeeze about 1/2 inch (or 1/2 teaspoonful) of

#71 cream into palm of hand.

c. Spread evenly and lightly until cream disappears.

Work cream into cuticle, between fingers and

around wrists.

d. Apply second coat, repeating Steps b and c.

e. Hold hands briefly under cold running water to

set cream.

2.
Remove resin mixture from hands as soon as possi-

ble and imperatively before mixture starts to gel.

This can be observed by the action of the material

being used. Resin may be removed with lacquer

thinner by washing in soap and water.

3.
Respirators are recommended when grinding. Also

some minor skin irritation from glass and powdered

cured resin may be evident. Washing in cold water

will help to minimize.

4.
Use a belt sander with a vacuum attachment for dust

control if possible.
5. Resin mixtures may produce toxic fumes and should

be used in well ventilated areas.

6. Be careful not to get any resin material on clothing.

7. Use the right materials for the job. It is important

to use the approved kits because Chevrolet's rigid

quality standards assure you the right material to

do the job. Other materials available may not meet

the required engineering and safety standards.

8. Keep the materials, utensils and work area clean

and dry. These repairs involve chemical reactions,

and dirt or moisture may upset the chemical bal-

ances and produce unsatisfactory results.

9. Before starting repair operations, look for hidden

damage by applying pressure around the damaged

area, looking for hairline cracks and other breakage.

Check for minor damage at other points in the vehi-

cle such as around exhaust pipes, grille, headlamps

and points of wear or rub. Early repair of this

minor damage may prevent major repair later.

PLASTIC SOLDER
KIT

The Plastic Solder Repair Kit is used for minor re-

pairs on the Corvette body. These materials will produce

an easy, quick and lasting repair in the case of small

cracks, surface imperfections and small holes.

1.
Use paint remover or power sander, and remove

finish from damaged area. Carefully inspect for

other areas requiring repair.

2.
Mix the materials (fig. 72).

3.
Apply the material, using a putty knife or rubber

squeegee, Figure 73. Work the material into the

repair and build the material up to the desired

CHEVROLET CHASSIS SERVICE