1967 CHEVROLET CAMARO lock

SECTION
1A

HEATER
AND AIR
CONDITIONING

CONTENTS
OF
THIS SECTION

Heater

Air Conditioning
Page

1A-1

1A-13

HEATER

GENERAL DESCRIPTION

CHEVROLET, CHEVELLE,
AND
CAMARO

Components
of the
Chevrolet, Chevelle,
and
Camero

heaters
are
attached
to the
firewall
on the
right side
of

the vehicle. The blower
and air
inlet assembly and water

hoses
are
located on the engine side
of
the firewall while

the heater core and distributor duct
are on the
passenger

side.

The heater operates
on
outside
air
only with
the

blower receiving
its
airflow from
the
cowl vent plenum

chamber.

Since
the
unit
has no
water valve, water circulation

keeps
the
core
hot at all
times.
Air
passing through
the

core receives maximum heat from
the
core.

In operation, three levers control
all
heater opera-

tions.
The
AIR-FAN lever
is a
combination control;

moving
the
lever half-way opens
the
AIR door
(by
means

of
a
bowden cable)
to
supply outside
air to the
three

speed blower. Further movement
of the
lever operates

the blower.
The
other levers depend on bowden cables
to

operate
the
diverter doors located
in the
distributor

duct
to
control heater output and operation.

At
the
heart
of
the heater operation
is the
temperature
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 door, operated
by the
TEMPERATURE
con-

trol lever,
is
placed
in the
duct
so
that when
it
closes
off

the path from
the
heater core,
it
allows ambient airflow

through
the
unheated path.
In the
opposite position only

heated airflow
is
allowed. Final heater output tempera-

ture
is
dependent upon
the
proportion
of
heated
and

unheated
air
blended together according
to the
setting
of

this temperature door.
To
insure positive closing
of
this

door when
the
heat lever
is in the off
position,
a cam

lock device
is
utilized
in the
control linkage
of the

Chevelle heater only.

Just beyond
the
temperature damper door
is the Air

door, operated
by the
AIR-FAN control lever, which
is

the
air
on-or-off control. This door will
be
open when-

ever
the
heater blower
is in
operation.

The defroster door, operated
by the
DEFROSTER

lever, acts
to
divert
the
heated
air
flow
up
through
the

defroster ducts
for
de-fogging, defrosting
or
de-icing

operations.

Figures
1 and 2
illustrate airflow through
the
heater.

BLOWER

DEFROSTER

OUTLET

DASH

PANEL

OUTSIDE
AIR
FROM

COWL PLENUM DUCT

HEATER

OUTLET

DOOR

DOOR

Fig.
1
— Heater
Air
Flow (Chevrolet, Chevelle, Corvette, Camaro)

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-2

DEFROSTER-q

DOOR
v-

HEATER
OUTLET
DEFROSTER
OUTSIDE
AIR
FROM PLENUM

OUTLETS
""•—

,
BLOWER
« 1

/ y

r J

\

AIR
DUQ

•*-——

DOOR
—-**

X J

HEAT
DOOR
HEATER

CORE

Fig. 2-Heater Schematic (Chevy 11)

CHEVY
II

Heater components are located under the instrument

panel in the passenger compartment. Hot water hoses

from the engine are routed to the fire wall to the heater

core pipes. The blower motor receives outside air from

the cowl vent plenum chamber through the adapter as-

sembly. The air enters the heater core chamber where

it either bypasses or passes through the core depending

on the position of the temperature door, controlled by

the TEMPERATURE lever on the instrument panel.

Temperature control is achieved by adjusting the position

of this door to vary the proportion of heated and unheated

air introduced to the car interior. As the air flow is

drawn out of the heater core chamber (in the desired

proportion of hot and cold), it enters the blower where

it is thoroughly mixed, assuring a uniform temperature.

The distributor guides the air flow through either the

floor outlet or the defroster outlets depending on the

setting of the DEFROSTER lever on the instrument

panel. The AIR-FAN lever is the air OFF control as

well as the blower control.

CONTROLS

Control Assembly (Chevrolet, Chevelle, Camaro,

and Chevy II)

Air-Fan Lever

Since the heater makes use of outside air only, this

lever serves as an "air on or off" control by actuating

a damper in the distributor assembly downstream ("up-

stream" in the Chevy n heater) from the blower assem-

bly. With the lever in the half-way position, this damper

will be open to allow airflow into the vehicle. Moving the

lever further will actuate the three-speed (LOW-MED-

HIGH) fan lever which controls the blower motor and

determines the volume and force of the air flowing

through the heater core into the car.

Temperature Lever

Through its bowden cable, this lever controls the
positioning of the temperature door in the distributor

duct. This door allows airflow through either the heater

core (full RIGHT) or the bypass duct around the heater

core (full LEFT). Because the water temperature is con-

stant, this knob acts as an air mixture control, control-

ling temperature by varying the proportions of heated

and unheated air blended in the heater distributor duct.

The cam lock device at the damper door operating

lever (Chevelle only) may be adjusted as follows: Loosen

the two attaching screws. Place the cam in the closed

position and insert a pin through holes provided, locking

the cam in this position. Rotate the entire assembly

toward the closed position. Hold closed with some force

and tighten attaching screws. Remove the locking pin.

Defrost Lever

The defrost lever controls the position of the damper

(or deflector) door located in the heater and defroster

assembly. In the "off" position full airflow will go to

the floor duct for car heating purposes. In the "de-ice"

position the diverter door will drop down and divert

almost all the airflow to the defroster duct. (This posi-

tion will seldom be needed except for extreme de-icing

requirements). A "detent" position is built into the

Fig. 3—Heater Control Panel (Chevrolet Shown as Typical)

CHEVROLET CHASSIS SERVICE MANUAL

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-26

clockwise for medium and high blower speed, as

desired. Low blower speed is automatic during

cooling operations.

4.
"Def-Pull". This knob should be pushed fully in.

Additional Cooling Hints

1.
The center barrel outlet in the dash may be rotated

to deflect air as desired or used to act as a shut off

door.

2.
The right and left ball outlets may be rotated to

deflect air in the direction desired. Each outlet has

a shut off valve operated by a knob approximately

4 in. inboard. When the knob is horizontal, the valve

is open.

3.
There are two (2) additional outlets in the bottom of

the ducts approximately 6" inboard from the valve

knobs. A rotating cover will open these outlets to

provide cool air for the feet if desired.

4.
When first entering a very warm car, open the

windows for a few minutes until the interior of the

car has cooled off.
Heating

1.
"Air Pull-Fan". Pull this knob fully out. Rotate

the knob clockwise for low, medium or high blower

speed as desired. If just a small amount of heat is

desired, leave the fan on low or medium speed and

regulate the temperature with the "Cool In-Hot Pull"

knob.

2.
"Air Cond-Pull". This knob should normally be

pushed fully in. However, during cool, damp days

it is possible, by pulling this knob fully out, to de-

humidify the air by passing it through the evaporator

core before reheating to the desired outlet

temperature.

3.
"Cool In-Hot Pull". Pull this knob out as far as

necessary to provide the temperature desired.

4.
"Def-Pull". Pull this knob all the way out for

maximum defrosting or de-icing. When the knob is

partly out, a portion of the hot air is used for de-

frosting and the balance is discharged through the

heater outlet.

GENERAL INFORMATION

In any vocation or trade, there are established proce-

dures and practices that have been developed after many

years of experience. In addition, occupational hazards

may be present that require the observation of certain

precautions or use of special tools and equipment. Ob-

serving the procedures, practices and precautions of

servicing refrigeration equipment will greatly reduce the

possibilities of damage to the customers' equipment as

well as virtually eliminate the element of hazard to the

serviceman.

PRECAUTIONS IN HANDLING REFRIGERANT-12

Refrigerant-12 is transparent and colorless in both the

gaseous and liquid state. It has a boiling point of 21.7^

below zero and, therefore, at all normal temperatures

and pressures it will be a vapor. The vapor is heavier

than air and is noninflammable, nonexplosive, non-

poisonous (except when in contact with an open flame)

and noncorrosive (except when in contact with water).

The following precautions in handling R-12 should be

observed at all times.

• All refrigerant drums are shipped with a heavy metal

screw cap. The purpose of the cap is to protect the

valve and safety plug from damage. It is good .prac-

tice to replace the cap after each use of the drum.

• If it is ever necessary to transport or carry a drum

or can of refrigerant in a car, keep it in the luggage

compartment. Refrigerant should not be exposed to

the radiant heat from the sun for the resulting in-

crease in pressure may cause the safety plug to

release or the drum or can to burst..

• Drums or disposable cans should never be subjected

to high temperature when adding refrigerant to the

system. In most instances, heating the drum or can

is required to raise the pressure in the container

higher than the pressure in the system during the

operation. It would be unwise to place the drum on a

gas stove, radiator or use a blow torch while pre-

paring for the charging operation, for a serious ac-

cident can result. Don't depend on the safety
plug - many drums have burst when the safety plug

failed.' Remember, high pressure means that great

forces are being exerted against the walls of the

container. A bucket of warm water, not over 125°F,

or warm wet rags around the container is all the heat

that is required.

• Do not weld or steam clean on or near the system.

Welding or steam cleaning can result in a dangerous

pressure buildup in the system.

• When filling a small drum from a large one, never

fill the drum completely. Space should always be

allowed above the liquid for expansion. If the drum

were completely full and the temperature was in-

creased, hydraulic pressure with its tremendous

force would result.

• Discharging large quantities of R-12 into a room can

usually be done safely as the vapor would produce

no ill effects, however, in the event of an accidental

rapid discharge of the system it is recommended

that inhalation of large quantities of R-12 be avoided.

This caution is especially important if the area con-

tains a flame producing device such as a gas heater.

While R-12 normally is nonpoisonous, heavy con-

centrations.. of it in contact with a live flame will

produce a toxic gas. The same gas will also attack

all bright metal surfaces.

• Protection of the eyes is of vital importance! When

working around a refrigerating system, an accident

may cause liquid refrigerant to hit the face. If the

eyes are protected with goggles or glasses, no

serious damage can result. Just remember, any

R-12 liquid that you can touch or that touches you is

at least 21.7"F. below zero. The eyeballs can't take

much of this temperature. If R-12 liquid should

strike the eyeballs, here is what to do:

1.
Keep calm.

2.
Do not rub the eyes! Splash the affected area with

quantities of cold water to gradually get the tem-

perature above the freezing point. The use of min-

eral, cod liver or an antiseptic oil is important in

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-29

time as possible will be required to perform the

operation. Don't leave the system open any longer

than is necessary.

• Finally, after the operation has been completed and

the system sealed again, air and moisture should be

evacuated from the system before recharging.

GAUGE SET

The gauge set (fig. 41) is used when purging, evacua-

ting, charging or diagnosing trouble in the system. The

gauge at the left is known as the low pressure gauge.

The face is graduated into pounds of pressure and, in

the opposite direction, in inches of vacuum. This is the

gauge that should always be used in checking pressures

on the low pressure side of the system. When all parts of

the system are functioning properly the refrigerant

pressure on the low pressure side never fails below 0

pounds pressure. However, several abnormal conditions

can occur that will cause the low pressure to fall into a

partial vacuum. Therefore, a low pressure gauge is

required.

The high pressure gauge is used for checking pres-

sures on the high pressure side of the system.

The connection at the left is for attaching the low

pressure gauge line and the one at the right the high

pressure gauge line. The center connector is common to

both and is for the purpose of attaching a line for adding

refrigerant, discharging refrigerant, evacuating the sys-

tem and other uses. When not required, this line or

connection should be capped.

NOTE:
Gauge fitting connections should be in-

stalled hand tight only and the connections leak

tested before proceeding.

The hand shutoff valves on the gauge manifold do not

control the opening or closing off of pressure to the

gauges. They merely close each opening to the center

connector and to each other. During most diagnosing

and service operation, the valves must be closed. The

only occasion for opening both at the same time would be

to bypass refrigerant vapor from the high pressure to

the low pressure side of the system, or in evacuating

both sides of the system.

CHARGING STATION

The J-8393 Charging Station is a portable assembly of

a vacuum pump, refrigerant supply, gauges, valves, and

most important, a five (5) pound metering refrigerant

charging cylinder. The use of a charging ey'inder elim-

inates the need for scales, hot water pails, etc.

The chief advantage of this unit is savings. A very

definite savings in refrigerant and time can be obtained

by using this unit. Since the refrigerant is metered into

the system by volume, the correct amount may be added

to.
the system and charged to the customer. This, coupled

with the fact that the unit remains "plumbed" at all times

and thus eliminates loss of refrigerant in purging of

lines and hooking-up, combines to enable the operator to

get full use of all refrigerant purchased by the

dealership.

All evacuation and charging equipment is hooked to-

gether in a compact portable unit (fig. 42) which brings

air conditioning service down to the basic problem of

hooking on two hoses, and manipulating clearly labeled

valves.
Fig.
42—System Charging Station

This will tend to insure that the job will be done without

skipping operations. As a result, you can expect to save

time and get higher quality work, less chance of an over

or undercharge, or comeback.

The pump mount is such that the dealer may use his

own vacuum pump. The gauges and manifold are in com-

mon use. Thus a current air conditioning dealer can use

the equipment on hand and avoid duplication.

LEAK TESTING THE SYSTEM

Whenever a refrigerant leak is suspected in the system

or a service operation performed which results in dis-

turbing lines or connections, it is advisable to test for

leaks.
Common sense should be the governing factor in

performing any leak test, since the necessity and extent

of any such test will, in general, depend upon the nature

of the complaint and the type of service performed on

the system. It is better to test and be sure, if in doubt,

than to risk the possibility of having to do the job over

again.

NOTE:
The use of a leak detecting dye within

the system is not recommended because of the

following reasons:

1.
Refrigerant leakage can exist without any oil leakage.

In this case the dye will not indicate the leak, how-

ever, a torch detector will.

2.
The addition of additives, other than inhibitors, may

alter the stability of the refrigeration system and

cause malfunctions.

3.
Dye type leak detectors which are insoluble form a

curdle which can block the inlet screen of the ex-

pansion valve.

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