
HEATER AND AIR CONDITIONING 1A-65
Fig.
92—Chevrolet Four-Season Ducts
Installation
Reverse
assembly.
the removal procedure to reinstall the duct
Left Outlet Duct
Removal
1.
Remove the two parking brake lever bracket to
dash brace attaching screws and move the lever and
cable so they will not interfere with the duct
removal.
2.
Remove the screw and lock washer attaching the duct
outer bracket to the hinge pillar support.
3.
Remove the screws and lock washers attaching the
duct assembly to the dash brace bracket.
4.
Carefully pull the outer end of the duct downward,
detaching the courtesy light from its bracket.
5. Loosen the screws clamping the outlet duct to dis-
tributor assembly flexible tubing at the outlet duct.
The outlet duct may now be removed from beneath
the instrument panel.
6. The duct extension assembly and the deflector as-
sembly may be removed, if desired, as seen in
Figure 95.
Installation
The duct assembly is installed by reversing the re-
moval instructions.
Center Outlet Duct
Removal
1.
Remove the right and left console trim panels.
2.
Remove the radio receiver.
3.
Remove the electric clock.
4.
Remove the knobs, nuts and bezels from the two
air conditioning controls above the clock, AIR COND.
PULL and COLD IN-HOT PULL.
5. Carefully pull the outlet duct and control cables
loose from the rear of the center console and work
it down and out from under the dash. The left hand
control cable runs through the left hand flexible
tubing and may be left in the tubing after it is dis-
engaged from the duct. The right hand control cable
must also be pulled from the duct assembly as the
duct is removed.
6. The center deflector barrel assembly may now be
removed if necessary. Snap off the hairpin clips to
remove the barrel and spacer washers.
Installation
Reverse the removal procedure for installation.
AIR DISTRIBUTOR ASSEMBLY
Removal
1.
Drain the cooling system radiator.
2.
Remove the heater hoses from the core pipes and
remove the cover attaching nuts and cover surround-
ing the core pipes.
3.
Remove the glove compartment assembly and the
glove compartment door.
NOTE:.
See "Section 1 - Body" for removal
and installation of body items.
4.
Remove the right kick pad.
5. Remove the right and left center console trim panels.
6. Remove the radio receiver assembly.
7. Remove the defroster duct.
CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-67
Fig.
94—Camaro Four-Season Ducts
Heater and Air Distributor Assembly
Removal
rfooo
1.
Disconnect battery ground cable.
2.
Drain radiator (do not purge refrigerant system).
3.
Disconnect all connectors attached to the Comfortron
wiring harness which are on the engine side of the
firewall. Push the wiring harness grommet through
the firewall to the rear.
4.
Disconnect the four vacuum hoses coming from the
underdash through the large firewall grommet. Push
the hose grommet through the firewall to the rear.
5.
Remove the nuts from the heater and air distributor
case studs which project through the firewall from
the dash side.
6. Disconnect the heater hoses from the core tubes.
Under Dash
1.
Remove glove box assembly.
2.
Remove the dash center face plate, ash tray assem-
bly, and any radio and/or tape equipment.
3.
Remove the Comfortron control assembly mounting
screws and lower the control unit.
4.
Remove the vacuum line from the kick pad valve
diaphragm.
5.
Disconnect all harness connectors between the Com-
fortron harness and the rest of the dash wiring.
6. Remove the air distributor duct which supplies the
dash outlets.
7.
Remove the screws attaching the heater and air
distributor to the firewall.
8. Pull the assembly rearward then down to remove
from the dash. Pull the Comfortron wiring harness
and vacuum hose assembly through the firewall.
Installation
1.
Place the entire case assembly with wiring, vacuum
hoses,
and control assembly into the car on the floor.
2.
Pass the underhood wiring harness and vacuum hose
harness as far as possible through the appropriate
firewall holes.
3.
Lift the assembly up into position and pass the case
studs through the firewall mounting holes. Attach
the case to the firewall with the mounting screws.
4.
Mount the dash outlet air distributor duct to the face
of the case.
CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-73
Fig.
105—Comfortron Control Head
10.
Introduce R-12 vapor at cylinder (room) temperature
and pressure.
11.
Leak test all fittings and connections and give partic-
ular attention to a leak test at the compressor shaft
seal if compressor has not been leak tested on the
bench.
12.
Complete system processing and charge system.
FUSES
A fuse, located in the junction block protects the entire
air conditioning system except for the blower when op-
erating at high speed.
A second fuse, to protect the high speed blower circuit,
is located in the electrical wiring between the horn relay
and the Air Conditioner relay (except Universal). The
Universal unit has a fuse in the line between the ignition
switch and the Air Conditioner blower switch. See the
specification page for the proper replacement fuse.
FOUR SEASON HEATER COMPONENTS
Corvette
The heater components of the system are, in general,
much the same as those of the standard Corvette heater.
Heater hoses carry the engine coolant to the heater core,
located in the air distributor duct beneath the instrument
panel.
A significant difference is that in the Corvette Air
Conditioning System there is no flow through the heater
core until the COOL IN-HOT PULL knob is pulled out.
This movement opens the vacuum switch on the air
distributor assembly and allows vacuum to be applied
to the water valve mounted in the engine compartment,
opening the valve. Thus the heater core is unheated
until needed, at which time it receives full flow of the
engine coolant. Air passing through the core receives
maximum heat which is tempered by mixing with un-
heated air before entering the passenger compartment.
Heater Core
Replacement
The heater core in the Corvette Air Conditioning
System is removed in the same manner as the core in
the Corvette heater. The distributor assembly must first
be removed from under the dash as covered previously
in this section before the core can be removed and
replaced.
Water Valve
Installation of the water valve is illustrated in Figure
113.
An inoperative valve must be replaced.
Chevrolet
Heater Core
Removal
1.
Disconnect battery ground cable.
2.
Drain radiator
3.
Remove right front fender and skirt assembly.
Fig.
106—Comfortron Temperature Dial Adjustment
Fig.
107—Amplifier Removal
CHEVROLET CHASSIS SERVICE MANUAL

HEATER AND AIR CONDITIONING 1A-74
Fig.
108—Comfortron Power Servo Installation
4.
Disconnect heater' hoses from heater core (at
firewall).
5. Remove glove box door.
6. Remove glove box interior.
7. Disconnect right, left, and center air conditioning
outlet hoses from distributor duct.
8. Remove air distributor duct from heater
housing.
9. Disconnect hose and cable clamps from heater
housing.
10.
Remove the remaining three heater housing stud
retaining nuts (engine compartment) and one upper
retaining screw (inside vehicle).
11.
Pull the unit away from the firewall and out of the
car.
ADJUSTMENT
SCREW
Fig.
109—Mode Shift Vacuum Diaphragm
Fig. 110'—Compressor Mount—L-6 Engines (Typical)
12.
Remove heater.housing cover from heater housing.
13.
Remove heater core from heater housing cover by
removing four (4) retaining screws and two "U"
clamps.
14.
Remove heater core.
Installation
1.
Replace core in case using a non hardening sealer.
Attach the core clamps and retaining screws.
2.
Attach the heater housing cover to the housing.
3.
Position the unit against the firewall and attach
it with the retaining screw at the top of the case.
4.
Attach the sheet metal nuts to the case studs which
project through the firewall to the engine side.
5. Connect the control cables to the control doors and
case.
6. Attach the air distributor duct to the case.
7. Connect the left, right, and center outlet hoses.
8. Replace the glove box assembly.
9. Connect heater hoses to core tubes.
10.
Replace fender assembly.
11.
Fill cooling system and connect battery cable.
Camaro
Lower Heater Hose
Removal
1.
Drain radiator.
2.
Remove side mouldings and retainers.
3.
Remove lower fender attaching bolts.
4.
Remove skirt to fender and skirt to reinforcement
bolts.
5. pry the skirt away from the fender flange and away
from the firewall. Block the skirt (four inchlengtti
of 2 x 4) clear of the lower hose and proceed with
the hose replacement.
Installation
1.
Connect the hose.
2.
Remove the block, move the skirt into position and
install all attaching bolts.
3.
Replace fender attaching bolts and mouldings.
4.
Refill cooling system.
CHEVROLET CHASSIS SERVICE MANUAL

CORVETTE BODY 1B-30
Fig*
66—Front
Body Construction
6. Panel - Front Fender Lower
1.
Panel - Hood
2.
Panel - Cowl Upper F. Front
3.
Panel - Front Fender Upper 7. Bonding Strip
4.
Bonding Strip - Front Fender 8. Panel - Radiator Grille
Upper to Lower
5.
Panel - Front Fender
Lower Rear
Lower
9. Panel - Radiator Grille Upper
- Lower Half
10.
Bonding Strip - Front
Fender Lower Front
to Rear
11.
Bonding Strip - Front Fender
Upper to Radiator Grille
Upper Panel
12.
Reinforcement - Front
Fender
13.
Bonding Strip - Front Fender
Upper Reinforcement
14.
Panel - Radiator Grille Upper -
Upper Half
contour. For deep filling and on vertical surfaces,
several layers may be used, each about 1/2" thick.
4.
Finish the repair by grinding, sanding and painting
in the usual manner, Figure 74.
RESIN KIT
The Resin Repair Kit, for major repairs, contains
resin, hardener, Thixatrope, fiberglass cloth, protecting
creams and mixing utensils. Repairs such as torn panels
and separated joints require the adhesive qualities of the
resin and the reinforcing qualities of the glass fibers.
The following procedure is basic for repairing any
plastic (fiberglass component or panel).
1.
Look for hidden damage. Apply pressure by hand
around the damaged area.
2.
Use paint remover and remove finish from around
damage area. Inspect area again for signs of other
damage.
3.
Grind or file the damaged area to form a "V" at
CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-11
Fig.
18 - Cooling System Pressure Test
Carburetor
Refer to Section 6M to perform adjustments such as
idle vent, float level, pump rod and secondary valve.
Fuel Pump
If the owner has complained of poor high speed per-
formance, the fuel pump may be at fault. Too low a
pump pressure or volume will cause a high speed "miss"
because of lack of fuel delievered to the carburetor,
while too high a pressure will cause carburetor flooding.
Check fuel pump as outlined in Section 6M.
Cooling System
The following test may be performed with pressure
testing equipment available commercially for this pur-
pose.
This test provides an excellent means of detecting
internal or external leaks within the cooling system.
1.
Remove radiator cap.
2.
Apply a test pressure of 3 pounds higher than the ra-
diator cap (fig. 18). i.e. 18 pounds for a 15 pound
cap.
3.
If the pressure will not hold, there is either an
internal or external leak in the system.
Cylinder Head Torque and Valve Adjustment
Retorquing the cylinder head bolts is not necessary
unless a gasket has been replaced, or a leak is suspected.
Valve lash must always be adjusted after the head has
been torqued.
Before adjusting the valve lash, it is extremely impor-
tant that the engine be thoroughly warmed up to normal-
ize the expansion of all parts. This is very important
because during the warm-up period, the valve clearances
will change considerably.
Hydraulic
1.
After the engine has been normalized, remove rocker
arm covers and gaskets.
CAUTION: Do not pry rocker arm cover loose.
Gaskets adhering to cylinder head and rocker
arm cover may be sheared by bumping end of
rocker arm cover rearward with palm of hand
or a rubber mallet.
2.
With the engine running at idle, back off valve rocker
arm nut until the valve rocker arm starts to clatter.
3.
Turn rocker arm nut down slowly until the clatter
just stops. This is the zero lash position.
4.
Turn nut down 1/4 additional turn and pause 10 sec-
onds until engine runs smoothly* Repeat additional
1/4 turns, pausing 10 seconds each time, until nut
has been turned down 1 full turn from the zero lash
position.
NOTE: This 1 turn preload adjustment must be
done slowly to allow the lifter to adjust itself to
prevent the possibility of interference, between
the inlet valve head and top of piston, which
might result in internal damage and/or bent push
rods.
Noisy lifters should be replaced.
5.
Repeat Steps 2, 3 and 4 to adjust the rest of the
valves.
6. Clean gasket surfaces on cylinder heads and rocker
arm covers with degreaser then install rocker arm
covers, using new gaskets, and torque bolts to
specifications.
Mechanical
1.
Normalize the engine.
2.
Remove rocker arm covers and gaskets.
CAUTION: Do not pry rocker arm cover loose.
Gaskets adhering to cylinder head and rocker
arm cover may be sheared by bumping end of
rocker arm cover rearward with palm of hand
or a rubber mallet.
3.
Use a socket wrench on self-locking rocker arm stud
nut and adjust as needed to obtain valve lash (see
tune up chart) measured between rocker arm and
valve stem with a leaf type feeler gauge.
4.
Stop engine, clean gasket surfaces on cylinder heads
and rocker arm covers with degreaser then install
rocker arm covers, using new gaskets, and torque
bolts to specifications.
Fig.
19
- Oil Deflector Clips Installed
CHEVROLET CHASSIS SERVICE MANUAL

ENGINE
6-12
ENGINE
MECHANICAL
IN LINE
INDEX
Page
General Description . „ 6-12
Component Replacement and Adjustment 6-12
.Engine Assembly 6-12
Removal 6-12
Installation 6-13
Manifold Assembly 6-14
Removal . 6-14
Installation 6-14
Rocker Arm Cover . 6-14
Removal 6-14
mstallation . . . 6-14
Valve Mechanism
......
1 6-14
Removal 6-14
Installation and Adjustment . 6-14
Valve Lifters
..............
6-15
Locating Noisy Lifters
„.;....
6-15
Removal
.'.*...•
6-15
Installation . 6-15
Valve Stem Oil Seal and/or Valve Spring . 6-16
Replacement . 6-16
Cylinder Head Assembly . 6-16
Removal 6-16
Installation . 6-16
Oil Pan . » 6-17
Removal . . . ; . . 6-17
Installation
.........
. 6-17
Oil Pump . 6-18
Page
Removal . 6-18
Installation . 6-18
Oil Seal (Rear Main) . 6-19
Replacement 6-19
Crankshaft Pulley and Hub 6-19
Removal 6-19
Installation 6-19
Torsional Damper 6-19
Removal 6-19
Installation 6-19
Crankcase Front Cover . 6-20
Removal . 6-20
Installation 6-20
•
Oil Seal (Front Cover) 6-20
Replacement 6-20
Camshaft 6-21
Measuring Lobe Lift . ... .
.-.••.-.
6-21
Removal 6-21
Installation 6-22
Timing Gears
..••••.............••• 6—22
Replacement
6-22
Flywheel
6-22
Removal
* 6-22
Installation
6-22
Engine
Mounts
6-23
Replacement
(Front)
6-23
Replacement
(Rear)
. 6-23
GENERAL DESCRIPTION
The
In
Line engines
(fig. 1L)
covered
in
this section
are
the 1H3 cu. in. L4, the 194,
230
and
250
cu. in. L6,
regardless
of
which passenger vehicle they
are
used
in.
This section covers
the
removal
and
installation
of en-
gine assemblies;
the
removal, installation
and
adjustment
of some sub-assemblies
and
replacement
of
some
com-
ponents.
For
service
to all
components
and
sub-assem-
blies (after removal)
and
removal
of
some sub-assem-
blies,
refer
to
Section
6 of the
Chassis Overhaul Manual.
Because
of the
interchangeability
and
similarity
of
many engine sub-assemblies
and
engine parts, regardless
of which passenger vehicle they
are
used
in,
typical illus-
trations
and
procedures
are
used except where specific
illustrations
or
procedures
are
necessary
to
clarify
the
operation. Although illustrations showing bench opera-
tions
are
used, most single operations, when
not
part
of a
general overhaul, should
be
performed
(if
practical) with
the engine
in the
vehicle.
COMPONENT REPLACEMENT
AND
ADJUSTMENT
ENGINE ASSEMBLY
Removal
1.
Drain cooling system
and
engine
oil.
2.
Remove
air
cleaner
and
disconnect battery cables
at 7.
battery.
3.
Remove hood
as
outlined
in
Section 11.
4.
Remove radiator
and
radiator shroud
as
outlined
in
Section 13.
5.
Remove
fan
blade
and
pulley
as
outlined
in
Section
6K.
6. Disconnect wires
at:
• Starter Solenoid
8.
• Delcotron
9.
Temperature Switch
Oil Pressure Switch
Coil
Disconnect:
Accelerator linkage
at
manifold bellerank.
Exhaust pipe
at
manifold flange.
.
Fuel line (from tank)
at
fuel pump.
Vacuum line
to
power brake unit
at
manifold
(if
so equipped).
• Power steering pump lines
at
pump
end (if so
equipped).
Raise vehicle
and
place
on
jack stands.
Remove propeller shaft.
CHEVROLET CHASSIS SERVICE MANUAL

ENGINE 6-14
b.
Bolt transmission to engine, then raise engine and
transmission assembly and install flywheel to
converter attaching bolts.
c. Install converter
housing*
underpan and starter.
3.
Tilt and lower engine and transmission assembly into
the chassis as a unit, guiding engine to align front
mounts with frame supports.
4.
Install front mount through bolts and torque to
specifications.
5.
Raise engine enough to install rear crossmember,
then install crossmember, install rear mount, lower
engine and torque bolts to specifications.
6. Remove lifting device and lifting adapter then install
rocker arm cover as outlined.
7.
On synchromesh equipped vehicles, install clutch
cross shaft engine bracket, then adjust and connect
clutch as outlined in Section 7.
8. Connect:
• Speedometer cable.
• Shift linkage at transmission.
9; Install propeller shaft.
10.
Remove jack stands and lower vehicle.
11.
Connect:
Power steering pump lines (if disconnected).
Vacuum line to power brake unit (if disconnected).
Fuel line at fuel pump.
Exhaust pipe at manifold flange.
Accelerator linkage at manifold bellcrank.
12.
Connect wires at:
Coil
Oil pressure switch
Temperature switch
Delcotron
Starter solenoid
13.
Install pulley, fan blade and fan belt as outlined in
Section 6K.
14.
Install radiator and shroud as outlined in Section 13.
15.
Install and adjust hood as outlined in Section 11.
16.
Connect battery cables.
17.
Fill with coolant, engine oil and transmission oil,
then start engine and check for leaks.
18.
Perform necessary adjustments and install air
cleaner.
MANIFOLD ASSEMBLY
Removal
1.
Remove air cleaner.
2.
Disconnect both throttle rods at bellcrank and re-
move throttle return spring.
3.
Disconnect fuel and vacuum lines at carburetor.
Disconnect choke cable on \A engines.
4.
Disconnect crankcase ventilation hose at rocker arm
cover.
5.
Disconnect exhaust pipe at manifold flange and dis-
card packing.
6. Remove manifold attaching bolts and clamps then
remove manifold assembly and discard gaskets.
7.
Check for cracks in manifold castings.
8. If necessary to replace either intake or exhaust
manifolds, separate them by removing one bolt and
two nuts at center of assembly. Reassemble mani-
folds using a new gasket. Tighten finger tight and
torque to specifications after assembly to cylinder
head. Transfer all necessary parts.
Installation
1.
Clean gasket surfaces on cylinder head and
manifolds*
2.
Position new gasket over manifold end studs on head
and carefully install the manifold in position making
sure the gaskets are in place.
3.
Install bolts and clamps while holding manifold in
place with hand.
4.
Torque bolts to specifications.
NOTE: On L6 engines center bolt and end bolt
torque differ.
5.
Connect exhaust pipe to manifold using a new
packing.
6. Connect crankcase ventilation hose at rocker arm
cover.
7.
Connect fuel and vacuum lines at carburetor.
8. On L4 engines connect choke cable and adjust as out-
lines in Section 6M.
9. Connect throttle rods at bellcrank and install throttle
return spring.
10.
Install air cleaner, start engine, check for leaks and
adjust carburetor idle speed and mixture.
ROCKER ARM COVER
Removal
1.
Disconnect crankcase ventilation hose(s) at rocker
arm cover.
2.
Remove air cleaner.
3.
Disconnect temperature wire from rocker arm cover
clips.
4.
Remove rocker arm cover. '
CAUTION: Do Not pry rocker arm cover loose
Gaskets adhering to cylinder head and rocker
arm cover may be sheared by bumping end of
rocker arm cover rearward with palm of hand or
a rubber mallet.
Installation
1.
Clean gasket surfaces on cylinder head and rocker
arm cover with degreaser then, using anew gasket,
install rocker arm cover and torque bolts to
specifications.
2.
Connect temperature wire at rocker arm cover clips.
3.
Install air cleaner.
4.
Connect crankcase ventilation hoses.
VALVE MECHANISM
Removal
1.
Remove rocker arm cover as outlined.
2.
Remove rocker arm nuts, rocker arm
balls,
rocker
arms and push rods.
NOTE:
Place rocker arms, rocker arm balls
and push rods in a rack so they may be rein-
stalled in the same location.
Installation and Adjustment
NOTE:
Whenever new rocker arms and/or
rocker arm balls are being installed, coat bear-
ing surfaces of rocker arms and rocker arm
balls with Molykote or its equivalent.
1.
Install push rods,
socket.
Be sure push rods seat in lifter
CHEVROLET CHASSIS SERVICE MANUAL