1967 CHEVROLET CAMARO lock

HEATER AND AIR CONDITIONING 1A-36

(These tests should be performed with the engine at operating temperature.)

SYSTEM CHECKS

Control

Head

Setting

High

Front

Lo

Front

Lo

Front

Hi

Front

Hi

Front
Tester Settings

Function

Manual

Manual

Manual

Manual

De-ice

65° on

Temp.

Dial

Hi

Front

Hi

Front

Hi

Front
Auto-

Matic

1 1

Auto-

matic

Manual

Manual
Manual

Control

Max.

Heat

Rotate

from

Max.

Heat to

Max.

Cold

150

Max.

Cold

Max.

Cold

Max.

Cold

Max.

Heat

Max.

Heat

Max.

Cold
Voltage

Trans-

ducer

Trans-

ducer

Ampli-

fier

Trans-

ducer

Probe

Probe

Trans-

ducer

Trans.
Tester Should

Indicate:

High Blower

Maximum Heat

Reduced Blower

Speed

Complete series of

blower changes from

Hi to Lo to Hi

again.

AMPLIFIE:

Remove conn, from c

Voltage reading she

Short this lead to grc

Voltage reading she

No voltage change in<

COMPRESSOR C

Cooling System

Operation

DE-ICE i

Assuming rest of

system is operating

normally: Max. Heat

1
to windshield.

SENSOR STR

•—

TRAtfSDtfC

0-3"
Vac. Reading

8 Volts Min.

9"
Min.
Vac.
Reading

0-4 Voltage Reading
If not, check

the following:

Fuse in Slock

In Line Fuse

High Blower

Delay Relay

Duct Delay

Thermistor

High Blower

Delay Sensor

Power Servo

Blower Switch

Resistor

Blower Motor

Wiring Harness

Blower Switch

Master Delay

Thermistor

Master Delay

Relay

Resistor

Power Servo

Blower Motor

CHECK

Resistor

I CHECK
Electrical Diagram

Probe Points:

1-2

8-9

10-21

20

18

19

*
9-46

-r

^2-3
15

16

Checked during

above procedure.

(This is a com-

plete step-by-step

high blower circuit

check which also

checks wiring

harness.)

4

5

6

L2-13

L4

""§2-15

39-46

1
16 1

14

22-40-42-44-15

.ontrol head temperature dial.

>uld be 9 volts minimum,

jund.

>uld be 0 volts,

iicates malfunctioning of amplifier.

JUTCJH CHUCK

Compressor Clutch

(Grille Temp, must

be above 40°.)

IRCUIT

Blower Switch

Master Delay

Relay

Transd

NGCl
ucer

Sensor String

2R CHECK

Transducer voltage

&t Max. Cold

position)

Transducer Ground

Hi Blower Outside

air (air door closed

to car body). Hot air

from heater outlets.

Hi Blower Recirc.

Air (air door open

to car body) cold air

from A/C outlets.
24-25-26-27-28
Voltmete

should re
ad

Battery Voltage

Battery Voltage

Battery Voltage

. Vtinimum
6
volts

Battery Voltage

Minimum
6
volts

Battery Vo]

Batterv Vo]
Ltage

Ltage

Battery Voltage

Batterv Voltage

3a

Bai
:terv Vo

tterv Vo
tage

tage

Minimum
6
volts

Batterv Voltage

Minimum
6
volts

Battery Voltage

Minimum
8
volts

Minimum 8 volts

Minimum 8 volts

Batterv Voltage

Minimum 8 volts

1 III • II »ll. —..• —•— . !!•• 1

Battery Voltage

3-23

20-10-21

38

29-30-31-32-33-

34-35-36

37-38

Defective Power Servo; Leak in Vacuum

System; Temp.; Door Link Disconnected

or Jammed; Defective Vacuum Relay

Valve

Defective Mode Door Diaphragm
Batterv Voltage

Battery Voltage

Zero Voltage

Battery Voltage

Battery Voltage

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

HEATER AND AIR CONDITIONING 1A-45

• A very badly leaking compressor seal.

• Collision damage to the system components.

As a quick check on compressor oil charge, with the

engine off, carefully crack open the oil drain plug on the

bottom of the compressor. If oil comes out, the com-

pressor has the required amount of oil To further check

the compressor oil charge, should the above test show

insufficient oil, it is necessary to remove the compressor

from the vehicle, drain and measure the oil.

Checking Compressor Oil Charge

1.
Run the system for 10 minutes at 500-600 engine

rpm with controls set for maximum cooling and

high blower speed.

2.
Turn off engine, discharge the system, remove

compressor from vehicle, place it in a horizontal

position with the drain plug downward. Remove the

drain plug and, tipping the compressor back and

forth and rotating the compressor shaft, drain the

oil into a clean container, measure and discard the

oiL

3.
a. If the quantity drained was 4 fluid oz. or more,

add the same amount of new refrigerant oil to

the replacement compressor.

b.
If the quantity drained was less than 4 fluid oz.,

add 6 fluid oz. of new refrigeration oil to the

replacement compressor.

c. If a new service compressor is being installed,

drain all oil from it and replace only the amount

specified in Steps 3a and 3b above.

d. If a field repaired compressor is being installed,

add an additional 1 fluid oz. to the compressor.

4.
In the event that it is not possible to idle the com-

pressor as outlined in Step 1 to effect oil return to

it, proceed as follows:

a. Remove the compressor, drain, measure and

discard the oil.

b.
If the amount drained is more than 1-1/2 fluid

oz.
and the system shows no signs of a major

leak, add the same amount to the replacement

compressor.

c. If the amount drained is less than 1-1/2 fluid oz.

and the system appears to have lost an excessive

amount of oil add 6 fluid oz. of clean refrigeration

oil to replacement compressor, 7 fluid oz. to a

repaired compressor.

If the oil contains chips or other foreign ma-

terial, replace the receiver-dehydrator and flush
or replace all component parts as necessary. Add

the full specified volume of new refrigeration oil

to the system.

5.
Add additional oil in the following amounts for any

system components being replaced.

Evaporator 3 fluid oz.

Condenser . . . . ... . . . . . . 1 fluid oz.

Receiver-Dehydrator ....... 1 fluid oz.

NOTE: When adding oil to the compressor, it

will be necessary to tilt the rear end of the

compressor up so that the oil will not run out

of the suction and discharge ports. Do not set

the compressor on the shaft end.

Adding Oil to the System

The system should be completely assembled and un-

charged before adding oil. Use only uncontaminated

refrigerant oil (525 viscosity) and add as follows:

1.
Connect the low pressure line from the gauge set

to the low pressure gauge fitting on the P.O.A.

valve (Four-Season) or low pressure fitting on the

compressor connector Mock (Universal System).

2.
Connect the high pressure line from the charging

station gauge set to the compressor muffler or high

pressure side of the connector block.

3.
Disconnect the high pressure line from the gauge set,

make certain that the line is clean, and place the

end in a graduated container.

4.
Pour enough refrigerant oil into the container so

that the required volume may be drawn into the

system by the high pressure hose.

5.
Close the high pressure valve at the gauge set,

and open the low pressure valve.

6. Operate the vacuum pump to drop the pressure within

the system and cause atmospheric pressure to force

oil through the high pressure line into the system.

When the oil level has dropped the required volume,

pull the line out of the oil container and continue

vacuum pump operation to force the oil contained

in the line into the system.

7.
Shut off the vacuum pump and connect ttye high

pressure line to the gauge set. Open the high

pressure valve and evacuate the system through

the high and low pressure sides of the system.

Complete the charging operation as outlined in Step

10 under "Evacuating and Charging System".

COMPONENT REPLACEMENT AND MINOR REPAIRS

REFRIGERANT LINE CONNECTIONS

"O"
Rings

Always replace the "O" ring when a connection has

been opened. When replacing the "O" ring, first dip it

in refrigeration oil. Always use a backing wrench on

"O"
ring fittings to prevent the pipe from twisting and

damaging the "O" ring. Do not overtighten. Correct

torque specifications are as follows:
Metal

Tube

O.D.

1/4

3/8

1/2

5/8

3/4
Thread and

Fitting

Size

7/16

5/8

3/4

7/8

1-1/16
Steel

Tubing

Torque*

13

33

33

33

33
Alum.

Tubing

Torque*

6

12

12

20

25

* Pound Feet

CHEVROLET CHASSIS SERVICE

HEATER AND AIR CONDITIONING 1A-47

are certain procedures, practices and precautions that

should be followed to prevent costly repairs, personal

injury or damage to equipment. For this reason it is

strongly recommended that the preceding information in

this section be studied thoroughly before attempting to

service the sytem.

Great emphasis must be placed upon keeping the sys-

tem clean. Use plugs or caps to close system components

and hoses when they are opened to the atmosphere. Keep

your work area clean.

In removing and replacing any part which requires

unsealing the refrigerant circuit the following operations,

which are described in this section, must be performed

in the sequence shown.

1.
Purge the system by releasing the refrigerant to the

atmosphere.

2.
Remove and replace the defective part.

3.
Evacuate and charge the system with R-12.

CAUTION: Always wear protective goggles

when working on refrigeration systems. Goggles

J-5453 are included in the set of air conditioning

special tools. Also, beware of the danger of

carbon monoxide fumes by avoiding running the

engine in closed or improperly ventilated

garages.

FOREIGN MATERIAL IN THE SYSTEM

Whenever foreign material is found in the system,

it must be removed before restoring the system to

operation.

In the case of compressor mechanical failure, perform

the following operations:

1.
Remove the compressor.

2.
Remove the receiver-dehydrator and discard me

unit.

3.
Flush the condenser to remove foreign material

which has been pumped into it.

4.
Disconnect the line from the receiver-dehydrator

at the inlet connection of the expansion valve. Inspect

the inlet screen for the presence of metal chips

or other foreign material. If the screen is plugged,

replace it. Reconnect the line to the expansion

valve.

5. Install a new receiver dehydrator.

6. Install the replacement compressor.

7. Add the necessary quantity of oil to the system (one

fluid ounce because of receiver-dehydrator replace-

ment plus the quantity needed for the replacement

compressor—see Checking Compressor Oil Charge

under Checking Oil.

8. Evacuate and charge the system.

9. Check system performance.

CONDENSER

Chevrolet

Replacement

1.
Remove the hood catch and hood catch - grille

support.

2.
With the system purged of refrigerant, disconnect

the inlet and outlet hose clamp connections and the

condenser to radiator support attaching screws.

3.
Remove the condenser from the vehicle.
NOTE:
If it is to be reused, cap or tape the

receiver-dehydrator inlet and outlet connections

at once.

4.
Install new condenser, position the assembly and

install the radiator support to condenser attaching

screws and replace all line connections.

5. Replace the hood catch and grille support and its

attaching bolts.

6. Replace the hood catch.

7. Evacuate, charge and check the system. Add one

fluid oz. refrigerant oil after installing a new

condenser.

Chevelle and Camaro

Replacement

1.
Remove the hood lock catch support and catch.

2.
With the system purged of refrigerant, disconnect

the inlet and outlet hose clamp connections and the

condenser to radiator support attaching screws.

3.
Remove the condenser from the vehicle.

NOTE:
Cap or tape the inlet and outlet con-

nections at once.

4.
Install new condenser, position the assembly and in-

stall the radiator support to condenser attaching

screws and replace all line connections.

5. Evacuate, charge and check the system. Add one

fluid oz. refrigerant oil after installing a new

condenser.

Chevy II

Replacement

1.
Purge the refrigerant from the system.

Fig.
59—Condenser Mounting (Chevrolet and Chevelle)

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-48

Fig.
60-Condenser Mounting (Chevy II)

2.
Remove the bumper, bumper filler panel, grille,

grille support, hood lock catch support and catch as

described in Section 11, "Chassis Sheet Metal".

3.
Disconnect connectors at condenser inlet and outlet

tubes and remove screws attaching refrigerant line

holding clips to the condenser baffle.

4.
Remove bolts attaching condenser through radiator

' support and slide condenser to the left and out of

vehicle.

5. Reverse these steps to reinstall new condenser.

6. Evacuate and charge the system. Add one fluid oz.

of refrigerant oil after installing a new condenser.

Corvette

Replacement (Production Engine)

1.
Remove the hood from the car, first scribing the

hinge attachment location.

2.
Purge the system of refrigerant.

Fig.
61—Condenser Mounting (Cdrnaro)
Fig.
62—Condenser Mounting (Corvette)

3.
Disconnect the inlet line connection at the condenser

inlet and the outlet line at the receiver-dehydrator.

Cap the receiver-dehydrator immediately.

4.
Remove the screws attaching the condenser to the

radiator support and carefully lift the unit from the

car.

5. Remove the receiver-dehydrator from the old con-

denser and install it, using a new "O" ring, on the

new condenser.

6. Set new condenser in place on the radiator support

and install the attaching screws, torquing them to

20 lbs. ft.

7. Make the inlet and outlet connections, using new

"O"
rings, and torque 13 lbs. ft.

8. Evacuate, charge and check the system. Add one

fluid oz. of refrigerant oil after installing a new

condenser.

Replacement (Optional Engine)

Replacement procedure remains much the same for the

installation supplied with the optional engine except for

the location of the receiver-dehydrator. Follow the steps

given above except that the outlet line must be removed

at the receiver outlet. (See Figure 64.)

RECEIVER-DEHYDRATOR

The receiver-dehydrator should be replaced if it has

been damaged through an accident or if it leaks or be-

comes restricted or clogged. Do not attempt to repair

the receiver-dehydrator.

The receiver-dehydrator is merely a moisture collect-

ing device and a refrigerant storage area and is the least

likely component of the system to cause a malfunction.

If at any time when examining the compressor oil,

moisture is found or there is an indication of moisture

at the expansion valve needle, the receiver-dehydrator

should be replaced as follows (fig. 63):

NOTE:
If the receiver-dehydrator is to be re-

used, cap the inlet and outlet connections

immediately. When installing a receiver-

dehydrator, do not uncap the connections until

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-54

Fig.
71-Wiring-AH Weather (Chevy II)

1.
Loosen the lock screws and remove the two control

knobs from the front of the evaporator unit. Then

use a suitable spanner wrench to remove the two

nuts beneath the control knobs.

2.
Remove the screws (located in the outer ball outlets)

attaching the face plate.to the evaporator case. Then

remove the face plate and, reaching through this

opening, carefully remove the plug attaching the

thermostatic switch capillary tube to the evaporator

core.

3.
Turning the unit over, remove the screws attaching

the back cover and gasket to the case and remove

the cover and gasket.

4.
From the top of the case, remove the screws attach-

ing the evaporator core brackets to the case.

5.
Carefully draw the core and expansion valve assem-

bly out of the case.

NOTE: The air conditioning "on" door bowden

cable, which extends through the core, will also

be removed at this time.

6. Remove the expansion valve power element from

the low pressure line.
7.
Disconnecting the high pressure and low pressure

lines from the valve, remove the valve from the

core.

8. At this point either the expansion valve, evaporator

core or both may be replaced.

a. If replacing the expansion valve, use new etO"

rings and make the connections carefully to

eliminate possible refrigerant leaks. Position

the power element bulb so that it lies flush with

the low pressure line and has the insulating

material properly in place.

b.
If the evaporator core is to be replaced, it will

be necessary to remove the air conditioning

door bowden cable from the core and install it

in the same location in the replacement core.

If no passage has been provided for this purpose

in the replacement core, a pointed instrument

such as a pencil may be forced through core

vanes at the proper location to provide the re-

quired opening. Also remove the spacer bracket,

nut and screw from the inlet and outlet pipes of

the evaporator core and place them in a like

position on the replacement core.

CHEVROLET CHASSIS SERVICE MANUAL