1967 CHEVROLET CAMARO check oil

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-46

MAKE ANGULAR CUT

FOR HOSE REMOVAL

LOCATING

BEAD

SEALING

BEADS
LOCATING

BEAD
not to nick or score the sealing beads when

cutting off the hose. Cutting the hose lengthwise

may result in this problem.

Fig.
58—Hose Clamp Connections

NOTE:
Where steel to aluminum connections

are being made, use torque for aluminum tubing.

Hose Clamps (Fig. 58)

When hose clamp connections are encountered special

procedures are necessary for both installation and

removal.

Installation

1.
Coat tube and hose with refrigeration oil.

2.
Carefully insert hose over the three beads on the

fitting and down as far as the fourth, or locating,

bead. Hose must butt against this fourth bead.

CAUTION: Use no sealer of any kind.

3.
Install clamps on hose, hooking the locating arms

over the cut end of the hose.

4.
Tighten the hose clamp screw to 35-42 lb. in.

(except Corvette) 30-38 lb. in. (Corvette). DO NOT

RETORQUE.

Removal

1.
Carefully, with a sharp knife, make an angle cut in

the hose as shown in Figure 58. This should loosen

the hose so that it may be worked off the fitting.

2.
Cut off slit end of hose when reinstalling. Reinstall

as described above.

CAUTION: Use only approved refrigeration

hose. Never use heater hose. Use extreme care
REPAIR OF REFRIGERANT LEAKS

Any refrigerant leaks found in the system should be

repaired in the manner given below:

Leaks at "O" Ring Connection

1.
Check the torque on the fitting and, if too loose,

tighten to the proper torque. Always use a backing

wrench to prevent twisting and damage to the "O"

ring. Do not overtighten. Again leak test the joint.

2.
If the leak is still present, discharge the refrigerant

from the system as described under "Evacuating

and Charging Procedures."

3.
Inspect the ''O" ring and the fitting and replace if

damaged in any way. Coat the "O". ring before re-

installed with refrigerati6n oil and install carefully.

4.
Retorque the fitting, using a backing wrench, and

then add 1/2 to 1 lb. of R-12 to the system and

recheck for leaks.

CAUTION: Do not operate the system with this

small refrigerant charge.

5. Purge the system, thus removing the 1/2 to 1 lb.

installed in Step 4 above.

6. Evacuate and charge the system.

Leaks at Hose Clamp Connection

1.
Check the tightness of the clamp itself and tighten

if necessary. Recheck for leak.

2.
If leak has not been corrected discharge the system

and loosen clamp and remove hose from connection.

Inspect condition of hose and connector. Replace

scored or damaged parts.

3.
Dip end of new hose in refrigerant oil and carefully

reinstall over connector. Never push end of hose

beyond the locating bead. Properly torque the clamp.

4.
Recheck the system for leaks by installing 1/2 to 1

lb.
of R-12 into the system. Do not run compressor.

5. Purge. the system, thus removing the 1/2 to 1 lb.

installed in Step 4 above.

6. Evacuate and charge the system.

Compressor Leaks

If leaks are located around the compressor shaft seal

or shell, replacement of necessary seals should be made

as outlined under "Compressor" in the Chassis Overhaul

Shop Manual.

REFRIGERANT HOSE FAILURE

After a leak or rupture has occurred in a refrigerant

hose, or if a fitting has loosened and caused a consider-

able loss of refrigerant and oil, the entire system should

be flushed and recharged after repairs have been made.

Ji the system has been open to atmosphere for any pro-

longed period of time the receiver-dehydrator should be

replaced.

PREPARING SYSTEM FOR REPLACEMENT

OF COMPONENT PARTS

Air conditioning, like many other things, is farily

simple to service once it is understood. However, there

CHEVROLET CHASSIS SERVICE MANUAL

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-49

CHEVROLET

CHEVELLE

CHEVY II

CAMARO
the last possible moment. Be certain that the

direction of flow is correct before connecting

the pipes.

Chevrolet, Chevelle, Chevy II, and Camaro

Replacement

1.
Remove the receiver inlet and outlet connections and

the two receiver to fender skirt attaching screws.

2.
Carefully remove the receiver-dehydrator from the

vehicle.

3.
Replace the new receiver~dehydrator assembly in

the vehicle and install all attaching screws and re-

frigerant lines.

4.
Add one fluid oz. refrigerant oil, evacuate and charge

the system.

Corvette

Replacement

1.
Purge the system of refrigerant.

2.
Disconnect the "O" ring inlet

hose clamp outlet connection

openings.

3.
Remove the receiver-dehydrator to radiator support

bracket screws (production engine) or receiver-

dehydrator to condenser bracket screws (optional

engine) and remove the unit from the car.

4.
Install the new receiver-dehydrator applying 30 in.

lbs.
torque to the attaching screws.
connection and the

and tape the hose

NOTE:
Do not uncap the new receiver-

dehydrator until the last instant before

installation.

5.

2.

3.

Fig.
63—
Receiver-Dehydrator Mounting (Chevrolet,

Chevelle/ Chevy II, Camaro)
Connect the high pressure lines at the inlet (use a

new "O" ring and torque connection to 13 ft. lbs.)

and outlet (torque screw to 25 in. lbs.).

6. Add one fluid oz. refrigerant oil, evacuate, charge

and check the system.

Sight Glass Replacement-All Vehicles

If damage to the sight glass should occur, a new sight

glass kit should be installed. The kit contains the sight

glass,
seal and retainer. (See Figure 65.)

1.
Purge system.

Remove the sight glass retainer nut using a screw

driver and remove old glass and seal.

Install the new glass and seal and retainer nut, being

careful not to turn the nut past the face of the hous-

ing. To do so may damage the "O" ring seal.

4.
Evacuate and recharge the system.

EVAPORATOR

Chevrolet and Camaro Four-Season System

The evaporator and blower case assembly is designed

so that the core may be removed without the need for

removing the entire unit from the vehicle. Instead,

only the side cover must be removed.

Removal and Installation of Entire Assembly

1.
Remove the inlet line at the expansion valve and the

suction throttling valve outlet connection.

2.
Remove the electrical connector from the blower

motor.

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-50

Fig.
64—Receiver-Dehydrator Mounting (Corvette)

3.

4.

5.

6.
To gain access to the blower motor end of the as-

sembly, remove the fender and skirt.

Remove the assembly to firewall attaching screws.

Remove the entire assembly from the vehicle.

Reverse the above procedure when installing the

assembly into the vehicle.

Core Replacement

1.
Disconnect the connections at the suction throttling

valve inlet and the expansion valve outlet. Remove

the expansion valve bulb from the core outlet line.

Cap all open lines. .

Remove the screws attaching the evaporator cover

to the firewall and to the evaporator assembly and

remove the cover.

Remove the screws attaching the core to the assem-

bly and remove the core.

Reverse the above steps for core replacement.

Add three fluid oz. refrigerant after installing a

new core, evacuate and charge the system.
2.

3.

4.

5.

Comfortron

The evaporator assembly is nearly identical to that
of the Four-Season system, and, with the exception of

additional wiring and vacuum hoses, service procedures

are the same.

Chevelle Four-Season System

Removal

•
1.
Purge the system of refrigerant, then remove the

right fender skirt and the hood hinge. Do not remove

the fender.

2.
Disconnect the high pressure line (between the

receiver-dehydrator and the thermostatic expansion

valve) at the expansion valve, and the suction throt-

tling valve to compressor line at the suction throt-

tling valve. Cap and seal all open lines.

3.
Remove the three screws attaching the duct assembly

to the evaporator housing and the blower assembly.

4.
Remove the bolts attaching the evaporator assembly

to the cowl and carefully pull the assembly from the

vehicle. The duct assembly will be removed at this

time also.

Core Replacement

1.
With the evaporator assembly removed from the

vehicle, remove the expansion valve and its bulb.

2.
Remove the four nuts and bolts holding the two

halves of the evaporator housing together and sepa-

rate the halves.

3.
The evaporator core may now be removed.

4.
Leak test the new core and connections, before in-

stalling the core in the housing, by installing the

expansion valve and all refrigerant lines. Connect an

R-12 cylinder to the low pressure compressor gauge

fitting and charge the system to cylinder pressure,

then leak test.

5. After satisfactorily testing the core, install it into

the housing and reassemble the two sides of the.

housing.

Installation

1.
Remove the right trim pad and the screws attaching

the air conditioning duct to the kick panel. This

should allow the duct to be pulled slightly loose from

the kick panel. If not it may be necessary to loosen

the entire duct to obtain the necessary clearance.

2.
Install the evaporator in the cowl being sure that

the duct assembly is in place between an evaporator

housing and the blower assembly.

3.
Replace all bolts and screws.

4.
Move the interior air conditioning duct until sure

that the duct gasket is properly positioned over the

evaporator housing flange. Proper gasket fit at this

point is of great importance.

5. Replace all refrigerant lines.

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

refrigerant oil after installing a new core.

7. Replace the fender skirt and hood hinge.

Universal System All Vehicles

Core and/or Expansion Valve Replacement

Since repairs should never be made on the evaporator

core, a defective unit must be replaced. Before replacing

the core, however, check to be sure that any leaks pres-

ent are not located at the hose connections or expansion

valve connections.

CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-53

Fig.
70—Wiring and Vacuum Lines—Four-Season (Camaro)

Installation

1.
Connect the expansion valve to the refrigerant pipes.

Attach the capillary bulb to the evaporator.

2.
Attach the evaporator to the- case. Attach the inlet

and outlet pipes clamps.

3.
Assemble the case halves. Insert the capillary tube

from the thermostatic switch between the fins as

shown in Figure . Attach the cover plate to the

case.

4.
Mount the unit to the dash and connect the refrigerant

lines.

5.
Evacuate and charge the system. If a new evaporator

was installed, add three fluid ounces of refrigerant

oil to the system before charging.

6. Test system operation.

Chevy II All-Weather System

Removal

Under
the Hood

1.
Purge the refrigerant from the system.

2.
Remove the refrigerant hoses from the evaporator

inlet and outlet connections extending through the

special grommet in the dash panel and into the

engine compartment.

3.
Remove the screw, nut, spacer bracket and grommet

from the outlet connection pipes.
Within the Car

4.
Remove the glove box, ash tray and ash tray

retainer.

5.
Reach through the glove box door to disconnect the

air conditioning "on" door bowden cable (fig. 75).

6. Remove the two shield attaching screws and shield

(A, fig. 76) which covers the lower right evaporator

bracket-to-blower bracket attaching screw (B, fig.

76),
then remove this screw.

7.
Behind the lower left side of ihe evaporator, remove

the evaporator bracket-to-heater distributor bracket

attaching screw (C, fig. 76).

8. Reaching through the glove box door and ash tray

openings, remove the two nuts and washers (D,

fig.
76) attaching the evaporator assembly studs to

the lower instrument panel flange and reinforcement.

9. Disconnect the drain hoses and carefully pull the

evaporator unit toward the rear of the vehicle.

10.
Disconnect wiring connectors (see fig. 77) as nec-

essary and remove the evaporator unit from the

vehicle.

Gore and/or Expansion Valve Replacement

A defective unit must be replaced since repairs should

never be made on the evaporator core. Before replacing

the core, however, check to be sure that any leaks pres-

sent are not located at the hose connections or expansion

valve connections. The following procedure assumes that

the evaporator unit has been removed from the vehicle

as outlined above.

CHEVROLET CHASSIS SERVICE MANUAL