1953 JEEP DJ clock

D

HURRICANE
F4
ENGINE
against the hub of the crankshaft pulley.
Timing

gears are accessible for inspection or replacement

with
the
engine
installed in the vehicle after re­ moving the radiator, belt drive pulley, and timing
cover.

Should
it be necessary to replace the timing gears, attention must be given to the end float of both
the camshaft and crankshaft and to the running

clearance
of both gears. It is also advisable to
check
both the oil jet and oil passage to the
crank­

shaft front bearing to be sure that they are clear.

D-55.
Inspection and
Repair

Check
the general condition of both gears and
inspect for evidence of excessive wear. Replace
excessively worn or damaged gears. Inspect the
cover and replace if bent or damaged. It is recom­ mended that the crankshaft oil seal in the cover
be replaced when the cover is removed to ensure a
good
seal around the crankshaft. To replace this

seal
with the
engine
in the vehicle
requires
removing
the radiator and water pump.

D-56.
Valves, Springs, and Guides

The
exhaust valves seat on the top of the cylinder

block
with the
stems
extending down through
replaceable valve guides. The exhaust valves are actuated by the camshaft through exhaust valve
tappets. The exhaust valve springs are assembled

and
locked on the lower end of the exhaust valve
stems. The retaining locks are the split type, which
fit in a recess on the valve
stems
and into the taper

in
the valve spring retainers.

Adjustment
of exhaust valves is by means of the
adjusting
screw threaded into the upper end of the
exhaust valve tappets. An exhaust valve rotator used as a valve spring retainer is installed on the
lower end of the exhaust valve.
This
valve rotator,
known
as "Roto Cap", is a spring-loaded
ball

bearing
device. On each lift, or opening stroke of
a
valve, the rotator
gives
the valve a slight positive
clockwise rotation.

The
intake valves operate in valve
guides
in the
cylinder
head and are actuated by rocker arms.

The
rocker arms are actuated by valve push rods

and
the intake valve tappets. The intake valve
springs,
the intake valve spring retainers, and the

intake
valve spring retainer locks make up the

remainder
of the valve operating parts. An intake
valve spring retainer oil seal which encircles the

upper
end of the intake valve
between
the valve
locks and the upper end of the valve spring re

tainer,
controls the passage of oil along the valve
stem and guide.

Note:
When
engine
trouble indicates defective
valves as a possible source of trouble, also check

all
vacuum line connections for possible leaks.

D-57.
Inspection of Valves, Springs,
and
Guides

Clean
the valves on a wire wheel, making sure that

all
carbon is removed from the top and the under­
side of the heads and that all gum and varnish
deposits
are removed from the stems.
Polish
the valve
stems
with steel wool or crocus

cloth.
Visually
inspect all valves for warpage,

cracks,
or excessive burning and discard if one of

these
conditions exists. Replace any worn, pitted,

or
corroded valves that cannot be cleaned with a
wire
brush.
Replace any valves when
seats
are pitted, burned, or corroded so badly that they
cannot be cleaned up with a light refacing on a valve refacing machine.

Replace
valves with marks of scoring or abrasion visible on the stem. Replace any valves with bent

stems
which
will
be apparent when the valve is
mounted in the valve refacing machine.

Note:
Use only hard-face exhaust valves for
replacement.

Examine
the
stems
of valves which employ the
ball
bearing rotators.
Wear
marks around the
cir­

cumference of the
stems
indicates that the valve is
rotating satisfactorily.
Vertical
heavy pressure

areas
indicate that the valve is not rotating and the valve spring retainer (Roto
Cap)
should be replaced

if
at fault.
Check
the diameter of the valve stem at two or three places along the length of the stem

with
a micrometer. The intake valve stem diameter is .3733" to .3738" [9,482 a
9,495
mm.]. The
exhaust valve stem diameter is .371" to .372"
[9,423
a
9,449
mm.].

Note:
Exhaust
and intake valve springs are

similar
in appearance. They must not be inter­
changed as they have different spring
charac­

teristics.

Wash
the valve springs thoroughly in solvent.

Visually
examine the springs and replace any that

are
deformed or obviously damaged. Examine for

corrosion
from moisture or acid etching which might
FIG.
D-19—TESTING
VALVE
SPRING

1—
Torque
Wrench

2—
Spring
Testing
Fixture

3—
Valve
Spring
54

D

HURRICANE
F4
ENGINE

FIG.
D-40—TIMING
GEARS Be
sure
to install a new rubber oil
seal
ring on each

intake
valve stem before installing the retainer

locks.
With
the retainer and spring compressed position a
seal
ring
on the valve stem just above the

lock
recess, then install the locks and release the
spring.

Adjust
the valve tappets to the proper specified

clearance.
Refer to Par. D-108, and specifications
at the end of this section for specifications and
adjustment procedure.

D-91.
Install
Camshaft
Timing
Gear

Turn
the camshaft or crankshaft as necessary so
that the timing marks on the two gears
will
be
together
after the camshaft timing gear is installed.

Refer
to Fig. D-40.
Install
the woodruff key in the key way on the front end of the camshaft.
Start
the large timing gear on the camshaft with the timing

mark
facing out. Do not drive on the camshaft gear, or the camshaft may
dislodge
the plug at the

rear
of the cylinder block causing an oil leak.
Install
the camshaft gear retaining screw and
torque it 30 to 40 lb-ft. [4,1 a 5,5 kg-m.] drawing
the gear
onto
the camshaft in the process. Standard
running
tolerance
between
the timing gears is .000" to .002" [0 a 0,051 mm.] which should be
checked with a
dial
indicator.

D-92.
Install
Timing
Gear
Oil Jet

Install
the timing gear oil jet in the tapped
hole

in
the front of the cylinder block. Position the oil

hole
in the side of the oil jet so that it
will
direct the

oil
stream against the camshaft driven gear just
ahead
of the point of
engagement
with the
crank­
shaft drive gear.

D-93.
Install
Oil Pump

The
oil pump is driven from the camshaft by means of a
spiral
(worm) gear. The distributor, in

turn,
is driven by the oil pump by means of a

tongue
on the end of the distributor shaft which
engages
a slot in the end of the oil pump shaft.
Because the
tongue
and the slot are both machined off center, the two shafts can be meshed in only
one position. Since the position of the distributor shaft determines the timing of the engine, and is
controlled by the oil pump shaft, the position of the oil pump shaft with respect to the camshaft is

important.

Turn
the crankshaft to bring
together
the timing
marks
on the crankshaft and camshaft gears. See

Fig.
D-4 0.
Install
the oil pump mounting gasket on
the pump.
With
the wider side of the shaft on top
(nearer
the top of the cylinder block), start the

oil
pump drive shaft into the opening in the left side of the cylinder block with the mounting
holes
in
the body of the pump in alignment with the
holes
in
the cylinder block. Insert a long-blade screw­

driver
into the distributor shaft opening in the

opposite
side of the block and
engage
the slot in the oil pump shaft.
Turn
the shaft so that the slot is positioned at what would be roughly the nine-

thirty
position on a clock face. Remove tne screwdriver and, looking down the

distributor
shaft
hole
with a flashlight, observe the position of the slot in the end of the oil pump shaft
to make certain it is properly positioned. Replace the screwdriver and, while turning the screw­

driver
clockwise to guide the oil pump drive shaft
gear into
engagement
with the camshaft gear, press
against the oil pump to force it into position. Remove the screwdriver and again observe the
position of the slot. If the installation was properly made, the slot
will
be in a position roughly equiva­
lent to eleven o'clock position on a clock face with
the wider side of the shaft
still
on the top. If the
slot is improperly positioned, remove the oil pump
assembly and repeat the operation.

Coat
the threads of the capscrews with gasket
cement and secure the oil pump in place with two
lockwasher-equipped capscrews installed through the body of the oil pump and into the cylinder block

and
one lockwasher-capscrew installed through
the oil pump mounting flange.

D-94.
Install
Timing
Gear
Cover

Apply
a thin coat of gasket paste to the timing
gear cover. Position the gasket on the cover and

carefully
locate the cover on the front of the front mounting plate. Attach the cover and timing

indicator
and tighten the bolts.

D-95.
Install
Pistons and Connecting Rods
Before installing each piston and connecting rod assembly in the cylinder block, generously lubricate
the entire assembly with
engine
oil. Space the ring
gaps
around the piston so that no two
gaps
are
aligned vertically and are not located over the
T-slot
in the piston
skirt.
Insert the assembly in
the correct cylinder with the connecting rod
identifying number toward the camshaft side of
the cylinder block. When installing each assembly, rotate the crankshaft so that the
crankpin
is in
the down position. Fit a piston ring compressor
tightly around the piston rings. Reach up from the
bottom
of the cylinder block and guide the end of
the connecting rod over the crankshaft
journal
as
the piston is tapped down into the cylinder bore

with
hammer handle. 66

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

D
Lubricate
the connecting rod bearing surfaces
generously with
engine
oil and install the bearing
cap with the numbered side matched to the num­
bered side of the connecting rod. Torque the nuts
evenly 35 to 45 lb-ft. [4,8 a 6,2 kg-m.]. The con­
necting rod cap nuts are locked with stamped nuts.

Used
stamped nuts should be discarded and re­
placed with new
ones.
These locking stamped nuts
should be installed with the flat face toward the
connecting rod nut.
Turn
the locking nut finger
tight and then 34
turn
more with a wrench. Refer
to Par. D-36 for detailed information on fitting pistons and rings in the cylinder bores.

D-96.
Install
Crankshaft
Pulley

Align
the keyway in the pulley with the woodruff key installed in the crankshaft. Drive the pulley

onto
the crankshaft and secure it in place with
the crankshaft pulley nut. Insert a block of wood

between
one of the counterweights on the
crank­

shaft and the side of the cylinder block to prevent the crankshaft from turning, then tighten the nut.

D-97.
Install
Oil Pan
Before installing the oil pan, make a final internal
inspection particularly making certain that the
inside of the cylinder block is clean. Apply a thin
coat of gasket paste on the oil pan. Place the new

oil
pan gasket in position. Set the oil pan in posi­
tion on the cylinder block and install the oil pan.
Torque
the attaching
bolts
12 to 15 lb-ft. [1,7 a 2,1

kg-m.].
Install
the oil pan
drain
plug and gasket

and
tighten the plug securely.

D-98.
Install
Cylinder
Head

Make
certain that the entire top of the cylinder

block
assembly, the lower surface of the cylinder

head,
and the cylinder head gasket are clean. Blow

all
dirt
or carbon out of the blind tapped bolt
holes

in
the cylinder block before the cylinder head and gasket are installed. Using aerosol spray sealer

Part
No. 994757, spray a thincoat on both surfaces
of the head gasket, position the new cylinder head gasket with the crimped
edges
of the gasket metal down (See Fig. D-31).
This
gasket position allows a
positive seal along the narrow surfaces of the
cylin­

der
head
between
the combustion chambers and
eliminates the possibility of burning combustion
10102

FIG.
D-41—CYLINDER
HEAD
BOLT
TIGHTENING
SEQUENCE
gases
reaching
an
asbestos
portion of the cylinder
head gasket.
Install
the cylinder head bolts. Tighten

the
bolts
with a torque wrench to 60 to 70 lb-ft. 8,3 a 9,7
kg-m.]
in the sequence shown in
Fig.
D-41.
Do not overlook installing the cylinder head bolt

in
the intake
manifold
directly under the
car­

buretor
opening.

D-99.
Install
Rocker Arm Assembly

a.
Insert
ball
ends of the intake valve push rods through the cylinder head and cylinder block and
seat them in the cupped head of the intake valve
tappets.

b.
Install
the
rocker-arm
assembly on the 'four

rocker-arm-mounting
studs. Align the rocker arms
so that the
ball
ends of the intake valve tappet

adjusting
screws fit into the cup ends of the push
rods.

c.
Install
the four rocker-arm-attaching nuts.
Thread
each nut down evenly in sequence, one

turn
at a time, until the torque is 30 to 36 lb-ft. [4,1 a 5,0 kg-m.].

d.
Cement a new gasket on the rocker arm cover.
Install
the cover placing an oil seal then a flat

washer
and nut on each cover stud. Cement a new gasket on the exhaust valve cover.
Install
the cover and crankcase ventilation fittings using a
new gasket back of the vent cover and new copper
ring
gaskets under the attaching screw heads.

Torque
the valve tappet cover nuts 7 to 10 lb-ft. [1,0 a 1,4 kg-m.].
D-100.
Install
Distributor and
Spark
Plugs

To
correctly install the distributor, it
will
be neces­

sary
to place No. 1 piston in the firing position.
To
locate the firing position of No. 1 piston, first

turn
the
engine
until No. 1 piston is moving up on
the compression stroke as indicated by compression

pressure
being forced through the
spark
plug open­

ing.
Turn
the
engine
slowly until the 5° before top
center
mark
on the timing gear cover is in align­
ment with the
mark
on the crankshaft pulley. Oil
the distributor housing where it bears on the
cylin­
der
block and install the distributor. Mount the

rotor
on distributor shaft and
turn
the shaft until
the rotor points towards No. 1
spark
plug terminal
tower position (when cap is installed, about 5
o'clock) with the contact points just breaking.
Move the rotor back and forth slightly until the

driving
lug on the end of the shaft enters the slot cut in the oil pump gear and slide the distributor
assembly down into place. Rotate the distributor body until the contact points are just breaking.
Install
the hold down screw.

Connect
the core
primary
wire to the distributor.

Clean
and adjust the
spark
plugs, setting the elec­

trode
gaps
at .030" [0,762 mm.].
Install
the plugs
to prevent any foreign matter entering the com­
bustion chambers during the remaining operations.
Torque
the
spark
plugs 25 to 30 lb-ft. [3,5 a 4,6

kg-m.].

Install
spark
plug cables, placing them in the dis­

tributor
cap terminal towers starting with No. 1

and
installing in a counter clockwise direction of
the firing order sequence (1-3-4-2). 67

'Jeep9
UNIVERSAL
SERIES
SERVICE
MANUAL

h.
Check
ignition (distributor) timing; reset if
necessary.

i.
Check
carburetor
adjustments; reset if necessary,

j.
With
engine
fully warmed up, tighten cylinder
head and manifold
bolts
and nuts to specified
torque.
Check
cylinder head gaskets and
bolts
for
air
or coolant leaks.

Note:
Tightness of cylinder head
bolts
should be
checked and corrected after 500 to 600 miles [800

a
960 km.] of normal operation.

k.
Check
fan belt tension; adjust if necessary.

I.
Check
for and correct any oil leak, fuel leak or
coolant leak.
D-107.
VALVE
ADJUSTMENT

Proper
valve adjustment is important to prevent
burning
of valves and poor
engine
performance.

This
adjustment consists of obtaining a specified

lash
in the valve mechanism. The exhaust valve
tappets and the intake valve rocker arms should be adjusted to the proper clearance with the
engine

cold (at room temperature). Valve clearance can
be properly adjusted only when the tappet is on the
heel or low portion of the cam.
INTAKE

OPENS

9°
BTC?

FIG.
D-43-
10270

-VALVE
TIMING
D-108. Valve Adjustment Procedure

The
exhaust valve tappets are adjusted by turning
the adjusting screw in or out of the tappet as neces­
sary
to obtain the proper clearance. Where special
wrenches can be obtained, they should be used to facilitate the adjustment. The proper clearance is .016" [0,406 mm.]
between
the end of the adjusting
screw and the
bottom
of the exhaust valve.

Crank
the
engine
over to
close
a valve and check
the clearance with a feeler
gauge.
To adjust, hold
the tappet with one wrench and
turn
the adjusting

screw,
with the other.
Check
and adjust each of
the tappets in proper sequence.

Adjust
each intake valve by adjusting the rocker
arm
screw at the push rod to obtain .018" [0,457 mm.] clearance
between
the rocker arm and the
valve stem with tappet on the heel of the cam.
D-109.
Check
Valve
Timing

To
check the valve timing, carefully set the intake
valve rocker arm adjustment for No. 1 cylinder to .026"
[0,6604
mm.]
between
the rocker arm and the
valve stem. Rotate the crankshaft clockwise until
the piston in No. 1 cylinder is ready for the intake stroke. The intake valve
opens
9° before top center
(BTC).
Note
the distance
between
the
"TC"
and
"5°"
marks on the indicator on the timing gear
cover and estimate the 9° before top center position.
See
Fig.
D-43.
With
the crankshaft in this position, timing is correct if the rocker arm is just tight
against the intake valve stem. Do not overlook resetting the rocker arm adjustment to the correct

running
clearance.
D-110. Positive
Crankcase
Ventilation

Be
sure there are no air leaks at the tube connec­
tions
between
the air cleaner and the oil filler tube,

and
that the oil filler tube cap gasket is in
good

condition. Always keep the cap locked securely in
place. When tuning the
engine
or grinding valves, remove the control valve and clean it thoroughly.
If
the valve is blocked with carbon, the ventilating
system
will
not operate and, should the valve

fail
to seat, it
will
be impossible to make the
engine

idle satisfactorily. Refer to Par. C-6 for servicing.
D-111. Oil
Filter

The
engine
is equipped with a throw-away type

oil
filter.
This
oil filter must be serviced periodi­
cally
as outlined in the
Lubrication
Section. 69

'Jeep*
UNIVERSAL
SERIES
SERVICE
MANUAL

E

FIG.
E-9—LOW-SPEED
SYSTEM

1—
Body
Flange 6—Idle Air Bleed

2—
-Idle
Adjustment Screw Port
7—Air
By-pass
3—
Idle
Port 8—Economizer

4—
Idle
Well
9—Metering Rod Jet
5—
Low
Speed Jet 10—Idle Adjustment Screw
in
Pars.
"A"
through
"D";
however, because of the

Idle
Limiter
Cap,
the idle mixture screw
CANNOT

be adjusted in the counter-clockwise
(rich)
direc­
tion. The adjustment is made from the
rich
stop

position and the mixture screw is turned in (clock­
wise) approximately %
turn
to
"Lean
Best
Idle."
Refer
to Fig. E-6.

The
"Lean
Best
Idle"
method of idle
setting
is as
follows:

a.
Any scheduled service of ignition system should precede this adjustment.

b.
Connect tachometer or vacuum
gauge
to
engine.

c.
Warm
up
engine
and stabilize temperatures.

d.
Adjust
engine
idle to
speed
desired, using throt­tle idle
speed
adjusting screw.
e. Carburetors without Idle
Limiter
Cap
turn
idle
mixture
screws out (counterclockwise) until a
loss

of
engine
speed
is indicated; then slowly
turn
mix­
ture
screw in (clockwise
-leaner)
until maximum

speed
(RPM) is reached. Continue turning in (clockwise) until
speed
begins
to drop;
turn
mixture
adjustment back out (counterclockwise
-rich)
until
maximum
speed
is just regained at a "lean as
possible" mixture adjustment.

E-15.
High-Speed System

Fuel
for part-throttle and full-throttle operation
is supplied through the high-speed system shown

in
Fig. E-10. A metering rod and metering rod

jet
control the amount of fuel admitted through the nozzle for high-speed operation. The lower
end of the metering rod is calibrated in size to

accurately
meter the fuel required. As the rod
|
13346

FIG.
E-10—HIGH-SPEED
SYSTEM

1—Nozzle 7—Pump Diaphragm
Spring

2
—Metering
Rod 8—Diaphragm Assembly

3—
Pump
Lifter
Link
9—Chamber

4—
Metering
Rod Arm Assembly
10—Metering
Rod Jet 5—
Diaphragm
Shaft
11—Carburetor
Casting

6—
Upper
Pump Spring 12—Carburetor Bore is automatically raised and lowered in the jet,
the opening in the jet is varied in size to supply
fuel
proportionate to the requirements through the
higher
speed
and power range. The metering rod
is both mechanically and vacuum controlled and is
attached to the metering rod arm assembly.
During
part-throttle operation, vacuum in chamber

pulls
diaphragm down, holding metering arm
assembly against pump lifter
link.
Movement of the metering rod is controlled by the
pump lifter
link
which is attached to the carburetor
throttle shaft. At all
times
vacuum in the chamber
is strong
enough
to overcome the tension of pump

diaphragm
spring. Upper pump spring serves as

a
bumper upon deceleration and as a delayed
action spring upon acceleration. Under any operat­ ing condition, when the pump diaphragm spring
overcomes vacuum in the chamber, the metering

rod
will
move
toward the wide throttle (power) position.

Note:
Nozzle is pressed in and should not be
removed.

E-16.
Metering Rod Adjustment

Check
metering rod adjustment each time the

carburetor
is reassembled. Before adjustment is
made, be sure that the flat of metering rod arm
is parallel to the flat of pump lifter
link
as shown
(Fig.
E-10.).
With
the throttle valve
seated
in
car­

buretor
bore, press down on the upper end of
diaphragm
shaft until the diaphragm
bottoms

in
the vacuum chamber. The metering rod should
now
seat
on casting with the metering rod
arm
flat against the pump lifter
link.
If the meter­
ing rod
does
not
seat
on the casting (check by 115

Fl
EXHAUST EMISSION CONTROL SYSTEMS

12793

FIG.
Fl-1—HURRICANE
F4-134
ENGINE EXHAUST EMISSION CONTROL SYSTEM
1—
Anti-Backfire
Diverter
Valve

2— Air
Pump

3—
Pump
Air
Filter
Injection
Tube(s)
(Inside
Manifold)

5—Air
Delivery
Manifold
6—
Check
Valve
Ignition
timing must be set at 0 or at top dead
center.

Fl-10.
Exhaust Manifold

The
exhaust manifold is provided with a
boss
that is drilled and tapped at each cylinder to accept the

air
delivery manifold and injection tubes.

Fl-11.
MAINTENANCE

Efficient
performance of the exhaust emission con­
trol
system is dependent upon precise maintenance.
In
addition to the air pump and connecting
hoses

and
tubes, this system's efficiency is dependent
upon special carburetor calibration, distributor cen­

trifugal
advance curve and ignition timing setting

which
must be adjusted at 0 or top dead center.

Road
test
is a factory recommended optional serv­ ice every
6,000
miles
[9,600
km.] to evaluate over­

all
performance.

The
following procedure is recommended to assist
in
diagnosing performance and/or emission level
problems that are peculiar to
Exhaust
Emission

Control
System equipped vehicles.

Fl-12.
Carburetor

Check
carburetor number for proper application. (Specifications are listed at the end of this section)

Check
the dash pot and adjust as required.

Proper
carburetor idle mixture adjustment is im­
perative for
best
exhaust emission control.
The
idle adjustment should be made with the en­
gine
at normal operating temperature and air
cleaner
in place. Adjust the throttle
stop
screw to
idle the
engine
at specified RPM. All lights and accessories must be turned off.

Fl-13.
Carburetor
Idle
Setting
NOTE:
The idle mixture adjustment procedure for
the late model
YF-4941S
and
YF-6115S
Carter
Carburetor
equipped with the
External
Idle
Mix­

ture
Limiter
Cap is the same as outlined below
in
Pars.
"A"
through
"D";
however, because of the

Idle
Limiter
Cap,
the idle mixture screw
CANNOT

be adjusted in the counter-clockwise
(rich)
direc­
tion. The adjustment is made from the
rich
stop
position and the mixture screw is turned in (clock­
wise) approximately %
turn
to "Lean Best
Idle."
Refer
to Section E, Fig. E-6.

The
"Lean
Best
Idle"
method of idle setting is as follows:

a.
Any scheduled service of ignition system should
precede this adjustment. 144

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

Fl
b. Connect tachometer to
engine.

c.
Warm
up
engine
and stabilize temperatures.

d.
Adjust
engine
idle to
speed
desired, using throt­
tle idle
speed
adjusting screw.

e.
Carburetors without Idle
Limiter
Cap turn idle mixture screws out (counterclockwise) until a
loss

of
engine
speed
is indicated; then, slowly turn mix­
ture screw in (clockwise-leaner) until maximum

speed
(RPM) is reached. Continue turning in (clockwise) until
speed
begins
to drop; turn mixture
adjustment back out (counterclockwise-richer) un­

til
maximum
speed
is just regained at a "lean as
possible" mixture adjustment.

Fl-14.
Distributor

Check
the distributor number for proper appli­
cation.
Check
the distributor cam dwell angle and
point condition and adjust to specifications or re­ place as required. (Specifications listed at the end
of this section)
Check
ignition timing and set at

0°
or
TDC.

Fl-15.
Anti-iackfire
Diverter Valve

The
anti-backfire valve remains closed
except
when
the throttle is closed rapidly from an
open
position.

To
check the valve for proper operation, accelerate
the
engine
in neutral, allowing the throttle to
close

rapidly.
The valve is operating satisfactorily when
no exhaust system backfire occurs. A further check
to determine whether the valve is functioning can be made by removing from the anti-backfire valve
the large
hose
Which
connects to the check valve.
Accelerate the
engine
to allow the throttle to
close

rapidly.
The valve is operating satisfactorily if a
momentary interruption of rushing air is audible.

Fl-16.
Check Valve

The
check valve prevents the reverse flow of ex­
haust
gases
to the pump in the
event
the pump
should, for any reason,
become
inoperative or should exhaust pressure ever
exceed
pump pressure.

To
check this valve for proper operation, remove the air supply
hose
from the pump at the
distri­

bution manifold.
With
the
engine
running, listen for exhaust leakage at the check valve which is
connected to the distribution manifold.

Fl-17.
Air
Pump

Check
for proper drive belt tension with belt tension
gauge
W-283. The belt strand tension should be

50-60
pounds on a belt with previous service, meas­

ured
on the
longest
accessible span
between
two pulleys. When installing a new belt, adjust the
tension to
60-80
pounds tension. DO NOT PRY
ON
THE DIE
CAST
PUMP
HOUSING.

To
check the pump for proper operation, remove the air
outlet
hose
at the pump.
With
the
engine

running,
air discharge should be
felt
at the pump

outlet
opening. The pump
outlet
air pressure, as determined by the relief valve, is preset and is not
adjustable.

The
air pump
rear
cover assembly, housing the pressed in inlet and discharge tubes, and the pres­
sure relief valve are the only pump
components

recommended for service replacement. These parts
are
to be replaced only when damaged as a result
of handling or in the
event
the relief valve was
tampered with.

Fl-18.
Carburetor
Air
Cleaner

Every
6000
miles
[9,600
km.] clean the inside
sur­

face at the sump and
refill
to indicated oil level with
SAE
40 or 50
engine
oil
above
32 F; SAE 20

below
32 F. Wash filter
element
in kerosene and

drain.
Reassemble the air cleaner.

More
frequent cleaning and replacement is advis­ able when the car is operated in dusty areas or on
unpaved roads. Accumulated dirt restricts air flow,
reducing fuel
economy
and performance.

Fl-19.
REMOVAL
PROCEDURES

The
following paragraphs
give
the procedures for removing the major units of the Exhaust Emission

Control
System and the required equipment
needed.

Fl-20.
Air
Pump

Loosen
the air pump adjusting strap to facilitate

drive
belt removal. Remove the air pump air dis­
charge hose(s) and air filter attachment. Separate
the air pump from its mounting bracket. At time of installation, torque tighten the air pump mount­ing
bolts
to
30-40
lbs-ft. [4,15 a 5,53 kg-m.]. Adjust
the belt strand tension to
50-60
pounds on a belt
with previous service and
60-80
pounds on a new
belt.

Fl-21.
Anti-Backfire
Diverter Valve

The
anti-backfire diverter valve removal requires disconnecting the
hoses
and bracket to
engine
at­
taching screws.

Fl-22.
Air
Distribution
Manifold
and
Injection Tubes

In
order to remove the air distribution manifold
without bending the tubing, which could result in
fractures
or leakage, it is necessary to remove the
exhaust manifold as an assembly from the
engine.

After
the exhaust manifold assembly is removed
from
the
engine,
place the manifold in a vise and

loosen
the air distribution manifold
tube
retaining nuts at each cylinder exhaust port. Tap the injec­
tion
tubes
lightly to allow the air distribution mani­
fold to be pulled away partially from the exhaust manifold. The stainless steel injection
tubes
in the
exhaust manifold may have
become
partially fused
to the air distribution manifold and, therefore, may
require
application of heat to the joint in order to
separate. While applying heat to the joint, rotate
the injection
tubes
with pliers being careful not to
damage the
tubes
by applying excessive force.

At
time of installation, the air injection
tubes
must
be positioned into the exhaust manifold prior to
placing the exhaust manifold assembly on the en­ gine.

Note:
Two different length injection
tubes
are used.

The
shorter length injection
tubes
must be inserted into cylinders 1 and 4. 145

F2
EXHAUST EMISSION CONTROL SYSTEMS
the throttle
stop
screw to idle the
engine
at 650
to 700 rpm.

F2-17. Carburetor Idle Setting
The
"Lean
Best
Idle"
Method of Idle Setting is as
follows:

a.
Any scheduled service of ignition system should
precede this adjustment

b.
Connect tachometer to engine.

c.
Warm
up
engine
and stabilize temperatures.

d.
Adjust
engine
idle to speed desired, using throt­
tle idle speed adjusting screw.
e.
Turn
idle mixture screws out (counterclockwise)

until
a
loss
of
engine
speed is indicated; then slowly
turn
mixture screws in (clockwise-leaner)
until
maximum speed (rpm) is reached. Continue

turning
in (clockwise) until speed begins to drop;

turn
mixture adjustment back out (counterclock­
wise-richer)
until maximum speed is just regained

at
a "lean as possible" mixture adjustment.

F2-18. Distributor
The
ignition distributor used with the
Exhaust
Emission
Control
System is the same as that used
on
engines
without
Exhaust
Emission
Control.
Check
the distributor cam dwell angle and point
condition.
Check
ignition timing and adjust to specifications shown on the last
page
of this section.

F2-19.
Anti-Backfire
Valve

The
anti-backfire valve remains closed except when
the throttle is closed rapidly from an open position.
To
check the valve for proper operation, accelerate
the
engine
in neutral, allowing the throttle to close

rapidly.
The valve is operating satisfactorily when
no exhaust system backfire occurs. A further check
to determine whether the valve is functioning can
be made by removing from the anti-backfire valve
the large
hose
which connects the valve to the

pump.
With
a finger placed over the open end of
the
hose
(not the valve), accelerate the
engine
and allow the throttle to close rapidly. The valve is
operating satisfactorily if a momentary air rushing
noise is audible.

F2-20.
Check
Valve

The
check valves in the lines to the air distribution manifolds prevent the reverse flow of exhaust
gases

to the pump in the event the pump should, for

any
reason,
become
inoperative or should exhaust

pressure
ever exceed pump pressure.

To
check this valve for proper operation, remove the air supply
hose
from the pump at the check

valve.
With
the
engine
running, listen for exhaust
leakage at the check valve which is connected to
the distribution manifold.

F2-21.
Air
Pump

Check
for proper drive belt tension with belt tension
gauge
W-283. The belt strand tension should be 60 pounds measured on the
longest
accessible span
between two pulleys. DO NOT PRY ON THE

DIE
CAST
PUMP
HOUSING. To
check the pump for proper operation, remove
the air
outlet
hose
at the pump.
With
the
engine

running,
air discharge should be felt at one of
the pump
outlet
openings. The pump
outlet
air
pressure,
as determined by the relief valve, is preset
and
is not adjustable.

The
air pump
rear
cover assembly, housing the pressed in inlet and discharge tubes, and the pres­
sure
relief valve are the only pump components
recommended for service replacement. These parts
are
to be replaced only when damaged as a result
of handling or in the event the relief valve was
tampered with.

F2-22.
Intake Manifold

Intake
manifold leaks must not be overlooked. Air
leakage at the intake manifold may be compen­
sated for by
richer
idle mixture setting, however, this
will
usually cause uneven fuel-air distribution
and
will
always result in
loss
of performance and
exhaust emission control. To check for air leakage
into the intake manifold, apply kerosene or naph­
tha,
on the intake manifold to cylinder head joints

and
observe whether any changes in
engine
rpm

occur.
If an air leak is indicated, check the mani­
fold to cylinder head bolt torque. The correct torque is 25-35 lbs. ft. [3,46 a 4,84 kg-m.]. If the

leak
is
still
evident,
loosen
the manifold assembly

and
torque-tighten the bolts evenly.
Start
from the center and use proper torque values. Replace the
manifold
gasket if the leak
still
exists.
Clean
both
mating surfaces and check for
burrs
or other ir­

regularities.

Always
torque the bolts evenly to the specified
torque value to prevent warpage.

F2-23.
Carburetor
Air
Cleaner
—Oil
Bath

Every
6,000
miles [9,600 km.] disconnect attach­

ing
hoses
and unscrew the wing nut from the top
of the air cleaner and lift it off the carburetor.

Lift
the cover and filter element off the oil sump.

Clean
the inside surface of the sump and
refill
to

indicated
oil level with SAE 40 or 50
engine
oil
above 32 F; SAE 20 below 32 F.
Wash
filter element in kerosene and
drain.
Reassemble the air

cleaner
and install on carburetor.

More
frequent cleaning and replacement are advis­ able when the car is operated in dusty areas or on

unpaved
roads. Accumulated
dirt
restricts air flow,
reducing
fuel economy and performance.

F2-24.
REMOVAL PROCEDURES
The
following paragraphs
give
the procedures for removing the major units of the exhaust emission
control
system and the required equipment needed.

F2-2S.
Air
Pump

Loosen
the air pump mounting bracket bolts. Re­ move the air pump air hose(s). Separate the air pump from its mounting bracket. At time of install­
ation,
torque tighten the air pump mounting bolts
to
30-40
lbs.-ft [4,15 a 5,53 kg-m.].
Adjust
the
belt strand tension to 60 pounds. 156