1953 JEEP DJ air filter

Dl

DAUNTLESS
V-6
ENGINE
In
addition to the instructions covering operations
for disassembling the
engine
out of the vehicle, special instructions are given to cover different
operations required when disassembly is
done
with
the
engine
installed.

During
disassembly operations, the
engine
should be mounted in a suitable
engine
repair stand.

Where
practicable, modify or adapt an existing re­

pair
stand as necessary to accommodate the
engine.
If
an
engine
repair stand is not used, take care to

perform
disassembly operations in a manner that
will
protect personnel against an accident and the
engine
and its parts against damage.

Dl-6.
Mounting Engine
On
Engine Stand

Refer
to Fig. Dl-4.
a.
With
the
engine
supported by a hoist, remove
the clutch housing and clutch. Match
mark
the flywheel and the clutch cover before disassembly to assure proper reassembly.
b. Position the
engine
on the
engine
stand.
c. Release
some
tension of the hoist cables and secure
engine
to stand.

d.
Make sure the position lock on the
engine
stand
is tight to prevent the
engine
from accidentally
inverting.

e.
Release the hoist cables.
FIG.
D1
-4—ENGINE
MOUNTED
ON
STAND

1—
Spacer
J-8690-6
A—Bolt,
i/2-NC
x 3i/2"

2—
Bolt,
3/a-NC
x 4*/2" 5—Adapter 21316-J 3—
Engine
Mounting Stand
Dl-7.
Remove Intake Manifold
and

Carburetor Assembly

Disconnect crankcase vent
hose,
distributor vacuum

hose,
and fuel line from carburetor. Disconnect two distributor leads from ignition coil. Disconnect

wiring
harness from coolant temperature sending

unit.
Remove ten cap
bolts
which attach intake
manifold to cylinder heads. Remove intake mani­
fold assembly and gaskets from
engine.

Dl-8. Remove Exhaust Manifold
The
engine
has two exhaust manifolds. Remove five attaching screws, one nut, and exhaust mani­
fold from each cylinder head.

Dl-9.
Remove Distributor

Disconnect vacuum
hose
and wiring harness from

distributor.
Disconnect spark plug cables from
spark
plugs. Remove sparks plugs from
engine.
Pull

spark
plug cable retainers from brackets on rocker

arm
covers. Remove mounting screw, retainer

bracket,
and distributor from timing chain cover.
If
timing chain and sprockets are not to be re­
moved from
engine,
note
position of distributor
rotor so that it can be installed in identical position.

Dl-10. Remove
Fuel Pump
Disconnect output fuel line from fuel pump. Re­
move
two mounting bolts, fuel pump, and gasket

from
timing chain cover.

Dl-11.
Remove Alternator
and Fan
Belt

Disconnect wiring harness from alternator. Remove nut and flat washer which fasten alternator to
adjustment bracket. Pivot alternator
inward,
to­

ward
engine
cylinder block, to relieve fan belt
tension. Remove fan belt from pulleys. Remove
two attaching screws, mounting bracket, and alter­ nator from right cylinder head of
engine.

Dl-12.
Remove Cooling
Fan and
Water Pump

Refer
to Fig. Dl-5.
Remove four cap screws, lock washers, cooling fan,

fan
hub, and fan drive pulley from flange of water
pump shaft. Remove nine attaching screws, water
pump, alternator adjustment bracket, and water pump from timing chain cover.

Dl-13.
Remove
Oil
Filter

Unscrew
oil filter from
engine
oil pump.

Dl-14.
Remove Starter Motor

Disconnect wiring harness from starter motor and
solenoid. Remove two attaching screws, starter motor, solenoid, and motor attaching bracket from

engine
flywheel housing and cylinder block.

Dl-15.
Remove
Oil
Pressure Sending Unit

Disconnect wiring harness from oil pressure send­
ing unit. Remove oil pressure sending unit from

engine
cylinder block.

Dl-16.
Remove
Oil
Dipstick

Withdraw
and remove oil level dipstick and dip­

stick
tube
from
engine
cylinder block.

Dl-17.
Remove Crankshaft Pulley

Remove six attaching screws and crankshaft pulley

from
crankshaft vibration damper. 80

'Jeep*
UNIVERSAL
SERIES
SERVICE
MANUAL

Dl
Dl-65.
Rocker Arm Cover Cleaning
and Inspection

a.
Clean
both rocker arm covers with suitable
cleaning solvent and dry thoroughly.

b.
Inspect each rocker arm cover visually for

scratches,
bends, dents, and tears. Replace cover

if
unserviceable.

Dl-66.
Timing Chain
and
Sprocket Inspection

Inspect
the timing chain and both sprockets for
damage or excessive wear. Replace unserviceable
parts.

Dl-67.
Timing Chain Cover Cleaning and Inspection

a.
Clean
the timing chain cover with suitable clean­
ing solvent and dry with compressed air.

b.
Inspect the cover visually for breaks,
cracks,
and
other damage.
With
a straightedge, check cylinder
block, water pump, and oil pump faces for bends

and
distortion.

c.
Install
oil pump gears in oil pump cavity of
timing gear cover.
With
a straightedge and feeler
gauge,
check gear and clearance. Refer to Fig.

Dl-30.
Clearance
should be
between
.0023"
[0,0584

mm.] and .0058"
[0,1358
mm.]. If it is lower
than
.0018" [0,0457 mm.], inspect thrust surfaces
of cover which touch gears for wear.

d.
Replace the timing chain cover if unserviceable.
FIG.
Dl-30—CHECKING
OIL
PUMP
GEAR

END
CLEARANCE

1—
Feeler
Gauge
2—
Straight
Edge

3—
Pump
Body
4—
Pump
Gears
Dl-63.
Oil Pump Cleaning and
Inspection

a.
Clean
gears with suitable cleaning solvent and

dry
thoroughly. Inspect for wear, scoring, and other damage. Replace either or both gears if unservice­
able.

b.
Remove the oil pressure relief valve cap, spring

and
plunger. Refer to Fig. Dl-31. Oil filter bypass
valve plunger and spring are staked in place and should not be removed. 12719

FIG.
Dl-31—OIL
PUMP
PRESSURE
RELIEF
VALVE

1—
Valve
Cap
2—
Gasket

3—
Spring

4—Valve
5—
Oil
Pump
Cover
c.
Wash valve parts thoroughly. Inspect the relief
valve plunger for wear or scoring.
Check
the spring to see that it is not worn or collapsed. Replace any
relief
valve spring that is questionable. Thoroughly

clean
the screen staked in the cover.

d.
Insert the relief valve plunger into its bore in
the cover. The plunger should have no more clear­ ance than an easy slip fit. If there is any perceptible
sideways movement, the plunger and/or the cover should be replaced.
e.
Check
oil filter bypass valve plunger for
cracks,

nicks,
or warping. The plunger should be flat and free of nicks or scratches.
f.
Lubricate
and install pressure relief valve plung­
er
and spring in bore of oil pump cover.
Install

cap and gasket. Torque cap to 30 to 40 lb-ft. [4,1 a 5,5 kg-m.]. Do not over-tig1 n.

Note:
Pressure relief valve cap has no tapped
hole

for installation of oil pressure switch.

H1
-69.
Crankshaft Vibration
Damper
Inspection

Inspect
the crankshaft vibration damper for
cracked,
broken, distorted, or otherwise damaged
condition. If damaged, replace.

Dl-70.
Crankshaft Pulley Inspection

Inspect
the crankshaft pulley for damage or exces­
sive wear. Replace if visibly worn or damaged.

Dl-71.
ENGINE REASSEMBLY

The
engine
assembly procedure in the following
paragraphs
is given in the sequence to be followed
when the
engine
is being completely overhauled.
Individual
inspection,
repair,
and fitting operations
previously covered in detail are made throughout
the assembly procedure. The assembly procedure
does
not cover accessories. If a new cylinder block
fitted with pistons is used, many of the operations

will
not be required.

Mount
the cylinder block in an
engine
repair stand.
If
an
engine
stand is not available, perform the
following assembly operation in a manner designed to protect personnel against an accident, and the
engine
and its parts against damage. 95

'Jeep*
UNIVERSAL SERIES SERVICE
MANUAL

E

FUEL
SYSTEM
Contents

SUBJECT
PAR.

GENERAL
E-1 Dash

FUEL
EVAPORATIVE EMISSION
?*^r
CONTROL SYSTEM
..E-2
Canister
.E-3 . Demand Valve E-4

Fuel
Tank.
.E-5
Inspection Test. E-8
Sealed Gas Cap. E-7

Servicing
System E-9
Vapor
Separator or Expansion
Tank
E-6

CARBURETOR
—
HURRICANE F4 ENGINE.
. .
......
..... ,. . .E-10 Accelerating Pump System.............. .E-19 Accelerating Pump Maintenance E-20

Carburetor
Reassembly
E-2
2

Carburetor
Disassembly E-21
Choke
System E-17
Dash
Pot Adjustment E-44

Fast
Idle Adjustment E-18
Float
Adjustment E-12
Float
System. E-ll
High-Speed System . .E-15
Idle
Adjustment .E-14

Low-Speed
System . E-13
Metering Rod Adjustment E-16

CARBURETOR
~r
DAUNTLESS V-6 ENGINE
.E-25
Accelerator Pump Adjustment E-41 Accelerator Pump System. . E-30

Air
Horn Body Assembly E-39
Air
Horn Body Removal and Disassembly.
E-33

Carburetor
Cleaning and Inspection E-36
Carburetor
Removal E-32
Choke
System E-31

Curb-Idle
Speed and Mixture Adjustment. .E-42

E-1. GENERAL
The
fuel system of the Jeep Universal vehicle,
whether equipped with a Hurricane F4 or Daunt­

less
V-6 Engine,
consists
of the fuel tank, fuel lines, fuel pump, carburetor and
air
cleaner.
Fig. E-1, E-2.
Vehicles equipped with a
Fuel
Evaporative
Emis­

sion Control System
also
include a
non-vent

pressure and vacuum
sensitive
gas cap, a liquid
expansion and vapor separator tank, a carbon filled vapor
storage
canister, and a vapor purge line. Service information pertaining to the
Fuel
Evap­

orative Emission Control System is outlined in

Par.
E-2 through
E-9.
Refer to Figs. E-3 and E-4.
The
most
important
attention
necessary to the fuel
system is to
keep
it clean and free from water. It should be periodically inspected for leaks.

CAUTION—Whenever
a vehicle is to be stored for

an
extended
period, the fuel system should be com­

pletely
drained, the
engine
started and allowed to
run
until the carburetor is emptied.
This
will
avoid
oxidization of the fuel, resulting in the formation of
SUBJECT
PAR.
Pot Adjustment .E-44

nal
Carburetor Adjustments.........E-40

Idle
Adjustment
.
E-43 System . . .E-26

Bowl
Body Assembly E-38

Fuel
Bowl Body Disassembly E-34

Idle
System E-27

Main
Metering System E-28
Power System . E-29
Throttle
Body Assembly .E-37

Throttle
Body Removal, and Disassembly. .E-35

FUEL
PUMP
—
HURRICANE F4 ENGINE.
E-45, 54, 60

Cleaning
and Inspection.............
.E-57,
63 Disassembly E-46, 56, 62
Installation E-59, 65
Reassembly
.E-47,
58, 64
Removal
E-55, 61

Testing.
E-49, 50, 51, 52, 53, 66

Vacuum
Pump E-48

FUEL
PUMP
—
DAUNTLESS V-6 ENGINE
E-67
Removal
E-68

AIR CLEANER
—
CARBURETOR
E-69
ACCELERATOR
LINKAGE
.E-70

FUEL
TANK
AND
LINES
E-71
Float
Unit . .E-76
Fuel
Lines E-77
Fuel
Tank
. . .E-72

Fuel
Tank
Cap E-75

Fuel
Tank
Installation. E-74
Fuel
Tank
Removal E-73

SERVICE
DIAGNOSIS
E-78

SPECIFICATIONS.
E-79
gum in the units of the fuel system. Gum formation
is similar to hard varnish and may cause the fuel
pump valves or the carburetor
float
valve to be­
come
stuck or the filter screen blocked. Acetone or commercial fuel system cleaners
will
dissolve

gum formation. In
extreme
cases
it
will
be necessary
to dissassemble and clean the fuel system. In
most

cases, however, a
good
commercial fuel system sol­
vent
used in accordance with the manufacturer's
instructions or one pint [0,6 ltr.] of
acetone
placed
in
the fuel tank with
about
one gallon [4,5 ltr.]
of
gasoline
will
dissolve
any
deposits
as it
passes

through the system with the
gasoline.

E-2.
FUEL
EVAPORATIVE EMISSION CONTROL SYSTEM

Description and Operation

•
Refer to Figs. E-3 and E-4.

The
Fuel
Evaporative Emission Control System
is
designed
to reduce fuel vapor emission that 109

'Jeep*
UNIVERSAL
SERIES
SERVICE
MANUAL

E

FIG.
E-3—FUEL EVAPORATIVE EMISSION CONTROL SYSTEM- HURRICANE F4 ENGINE
A—Side
View

1—
Charcoal Canister
2— Purge
Line

3—
Fuel
Tank
4—
Fuel
Filler
Hose 5—
Non-Vented
Gas Cap
B—Plan
View

6—
Vapor
Separator
or Expansion Tank 7—
Fuel
Gauge

8—
Fuel
Line-to-Fuel Pump

9—
p.C.V.
Crankcase
Valve

10—Fuel
Pump

crankcase
vent system. The charcoal canister in­
corporates an integral demand valve
which
regu­

lates
vapors entering the canister as
well
as a
limit
fill
valve
to control air trapping during tank
fill.
The
Fuel
Evaporative Emission Control System
incorporates the following new or modified parts:

E-3.
Canister
The canister used for the vapor control system has
provisions for containing activated charcoal gran­ ules. The material used for the canister body is a

special,
fuel resistant, heat stabilized nylon. At the top of the canister there is the demand valve which
has connections; one vents the vapor to the canister
while the other connection joins the canister to the purge system. These
tubes
enter the canister on

opposite
sides of a baffle which permits uniform
vapor distribution throughout the canister. The
bottom
of the canister is fitted with a filter element
that allows fuel tank venting to atmosphere after vapors are trapped in the activated charcoal.

E-4.
Demand Valve

The
demand valve is integral with the canister. It
is essenitally a combination pressure regulator and

vacuum
relief valve.
This
valve regulates the rate
of vapor
flowing
from the fuel tank into the canister.
The
valve consists of a housing, a spring loaded
diaphragm,
a diaphragm cover, and a vacuum

relief
valve. The operation of the unit is such that
as tank vent pressure increases the diaphragm lifts,
permitting vapor to enter the canister. The pres­
sure
under which this occurs is 4" to 6"
H2O.
This

action regulates the flow of vapors into the canister
under severe soak and operation conditions (temp, changes), but generally prohibits the flow of vapor 111

'Jeep*
UNIVERSAL
SERIES
SERVICE
MANUAL

E
there is a relief valve that
opens
to reduce high
(dangerous) pressures in the fuel tank. In con­

junction
with the pressure relief valve there is a
vacuum
relief valve to
stop
collapse of the fuel

tank
in case of a plugged system or failure of the demand valve. When replacing the gas cap, the
same type must be used as originally installed.

E-8.
System Inspection Test

The
fuel emission vent system should be checked

carefully
to ensure the absence of any leaks to the
atmosphere of either liquid or vapor which might
affect the accuracy, safety, or performance of the control system.

To
assure that the sealed system has been properly

installed,
the following
test
procedure has been
developed.
Disconnect the vent line from the fuel tank system
to the activated charcoal canister, induce l/i p.s.i.
air
pressure. If this pressure can be maintained for

a
few seconds the vent system is assured to be sealed. DO NOT add air pressure to the canister
because damage can occur to the demand valve if
care
is not taken.

E-9.
Servicing the System

Periodic
Maintenance — Replace carbon canister filter at
12,000
miles
[19,200
km.] or 12 month in­tervals (more
often
for operation in dusty areas).

This
is the only regular maintenance service

required.

Canister
Filter
Replacement — Disconnect
hoses

from
top of canister, remove canister from mount
-

t
FIG.
E-5—CARBURETOR—
F4 ENGINE,
EARLY
MODEL
1—
Choke
Clamp
Bracket

2—
Choke
Shaft and
Lever
Assembly

3—
Fuel
Inlet
Elbow

4—
Bowl
Vent Tube 5—
Idle
Air Adjusting
Needle
6—
Throttle
Lever
and Shaft Assembly
7—
Idle
Speed Adjusting Screw
8—
Fast
Idle Connector Rod ing bracket. Remove cover from
bottom
of canister
by pulling it down to
disengage
clips. Remove and
discard
polyurethane filter element
(squeeze
ele­

ment out from under retainer bar).
Install
new
filter by squeezing element under retainer bar and positioning it evenly around entire
bottom
of
canister with
edges
tucked under canister lip, snap

bottom
cover in place, reinstall canister on bracket

and
reconnect
hoses.

Vapor
line
hoses
used in this system are made of

special
rubber material.
Bulk
hoses
are available for
parts
service.
Ordinary
rubber
hose
should not be
used to service vapor lines as they are subject to deterioration and may clog the system.
Liquid

vapor separators or expansion tanks and canisters

are
serviced as complete units only.
Canister
air filters, however, are serviced separately.

E-10.
CARBURETOR
—
HURRICANE
F4
ENGINE

A
single-barrel manual choke, down-draft carbure­
tor (Fig. E-6) is used on the
Hurricane
F4 engine.
The
carburetor is internally vented by a tube
opening located in the air horn body of the
car­

buretor.
This
opening is connected by a rubber
tube to the air
outlet
horn of the air cleaner thus
allowing only filtered atmospheric pressure air
to enter the float chamber for balance pressure
of the carburetor fuel.

Note:
A carburetor with a specific flow character­

istic
is used for exhaust emission control. The
carburetor
is identified by a number, and the correct

carburetor
must be used, when replacement is
necessary.

Early
production models
CJ-3B,
CJ-5,
CJ-5A,
CJ-6,
and
CJ-6A
have a
Carter
YF-938SD
carbure­
tor superseding the earlier
YF-938SC,
YF-938SA,

or
YF-938S
models.

Note."
Conversion kits for changing earlier models
to SD models are available. See Par E-23. It is recommended that when a carburetor is converted
that a tag be fashioned stamped with the new model number and installed under one of the air

horn
screws.
Look
for such a tag to determine if
the carburetor has previously been converted.

Carburetors
listed above are all in the same YF
series and have only minor differences. Descriptions
and
repair procedures given in the following
para­
graphs apply equally to all
YF-series
carburetors.
YF-series
carburetors employ manual and vacuum
control of the metering rod and accelerator pump.
The
carburetor controls and vaporizes the fuel
through five separate systems: float system, low-
speed system, high-speed system, choke system,

and
accelerating-pump system. A description of the function and operation of each system provides an over all description of the carburetor.

For
identification, the series designation is stamped
on the body under the name
Carter
and the model
designation is stamped on a flange protruding
from
the body.

Note:
When checking for carburetor icing causes,
also check the vacuum-pump-to-manifold vacuum
line connector. 113

'Jeep9
UNIVERSAL
SERIES
SERVICE
MANUAL

E
exterior moving parts of a carburetor are
often

responsible for unsatisfactory performance.
For
this

reason,
efficient carburetion depends upon careful cleaning and inspection while servicing.

a.
Thoroughly clean carburetor castings and metal
parts
in carburetor cleaning solvent.

Caution:
Accelerator pump plunger and any fiber

or
rubber parts should never be immersed in
car­

buretor
cleaner. Wash pump plunger in cleaning
solvent.

b.
Blow out all passages in the castings with com­
pressed air. Dry all parts with compressed air.

Make
sure all jets and passages are clean. Do
not use wire to clean fuel passages or air bleeds.

c.
Check
inlet valve
needle
and seat for wear. If

wear
is noted, the assembly must be replaced.

d.
Check
float hinge pin for wear and check float
for damage.

e.
Check
throttle and choke shaft bores for wear

and
out-of-round.
f. Inspect idle mixture adjustment
needles
for
burrs
or
grooves; replace if damaged.
g. Inspect cup of accelerator pump plunger; re­
place if damaged, worn, or hardened. Inspect pump

well
in bowl for wear or scoring.

h.
Check
filter screens for
dirt
or lint.
Clean,
and

if
they remain
clogged,
replace.

i.
If for any reason parts have
become
loose
or
damaged in the cluster assembly, the assembly
must be replaced.

Note:
Use ijew gaskets whenever the carburetor
is disassembled.

E-37.
Throttle Body Assembly
a.
Install
idle mixture adjustment
needles
and
springs in throttle body. Tighten finger-tight, then
unthread
one
turn
as a preliminary adjustment
setting.

Caution:
Do not force idle mixture adjustment
needles
against
seats
or damage may result.

b.
Invert
fuel bowl body and place new throttle
body gasket on bowl. Fasten throttle body to bowl
body with three screws and lockwashers; tighten

securely.

E-38.
Fuel
Bowl Body Assembly

a.
Drop steel discharge check
tall
of accelerator
pump into discharge hole.
Install
pump discharge

spring
and T-shaped retainer. Stake retainer in
place.

Note:
Top of retainer must be flush with flat

surface
of fuel bowl body.

b.
Install
two inserts in main well. Align surface
on lip of insert with flat surface in recess on top
of main well.
Install
venturi cluster with gasket,

and
tighten mounting screws evenly and securely.

Be
certain that center screw is fitted with fiber gasket, and that a special smooth shank screw is
used.
c.
Install
two main metering jets, power valve
gasket and power valve.

d.
Install
small aluminum inlet check
ball
in ac­

celerator
pump inlet at
bottom
of pump well. In­

sert
pump return spring into well, and center by
pressing spring downward with finger.

e.
Install
pump inlet screen in
bottom
of fuel

bowl.

E-39.
Air
Horn Body
Assembly

a.
Install
choke lever and collar on choke shaft.

Prong
on choke lever must face away from air

horn
body and be on top of choke trip lever.
b.
Install
choke shaft and lever assembly into the

air
horn. Choke rod
hole
in the choke lever must
face fuel inlet side of carburetor.

c.
Install
choke valve plate in choke shaft so that
letters RP
will
face upward in finished carburetor.
Install
two new valve plate attaching screws, but
do not tighten securely until valve plate is centered.

To
center choke valve plate on choke shaft, hold
choke valve tightly closed, then slide choke shaft

inward
to obtain approximately .020" [0,508 mm.]

clearance
between
choke trip lever and choke lever

and
collar assembly. Tighten choke valve screws

securely,
and stake lightly in place. Choke valve

will
be perfectly free in all positions when installed
correctly.

d.
Insert
outer accelerator pump lever and shaft as­ sembly into air horn body, with lever pointing to­

ward
choke shaft.
Install
inner pump arm, with plunger
hole
inward,
and tighten set screw securely.
Position pump plunger assembly on inner pump
arm,
with pump shaft pointing
inward,
and install

retainer.

e.
Install
needle
seat screen on inlet valve seat. In­

stall
seat and gasket in air horn body. Tighten seat
securely with a wide-blade screwdriver.
f.
Install
power piston into vacuum cavity.
Lightly
stake piston retainer washer in place. Piston should

travel
freely in cavity.
g.
Install
air horn gasket on air horn body, fitting
gasket over guide pin.

h.
Attach inlet valve
needle
to float.
Carefully

position float and insert float hinge pin. Drop tang
at
rear
of float arm downward toward air horn.

i.
Install
fuel inlet fitting, if removed.

j.
With
air horn assembly inverted, measure the distance from the air horn gasket to top of float
at toe \%£f [27,78 mm.] for standard carburetors

and
\%i [29,36 mm.] for exhaust emission control
equipped carburetors, as shown in Fig. E-23. Use
float level
gauge
J-5127-2. Bend float arm as re­

quired
to adjust float level.

k.
With
air horn body held upright, measure dis­
tance from gasket to
bottom
of float
pontoon
at outer end. Use a l7/s" [47,625 mm.] float drop

gauge.
Bend float tang, as required, to adjust float

drop.
See Fig. E-24.

I.
Carefully
place air horn body on fuel bowl
body, making certain that the accelerator pump
plunger is properly positioned in the pump well.
Lower
the cover gently, straight down; install air 123

FUEL
SYSTEM
|
11893

FIG.
E-29—FUEL
AND
VACUUM
PUMP—F4
ENGINE,
EARLY
MODELS

1—
Cover
Screw
2—
Lockwasher

3—
Diaphragm
Spring
4—
Spring
Seat 5—
Diaphragm
and Rod
6—
Oil
Seal 7—
Valve
Assembly
8— Body
9—
Rocker
Arm Pin Spring
10—
Fuel
Diaphragm
11—
Oil
Seal Retainer
12—
Diaphragm
and Rod 13—
Valve
Retainer
14—
Cover
15—
Gasket

16—
Screen

17—
Bow!

18—
Bail
19—
Gasket

20—
Screw
21—
Rocker
Arm Spring
22—
Link
Spacer
23—
Rocker
Arm

24—
Washer

25—
Body
fuel. The diaphragm can start and
stop
many
times
in
each mile of vehicle operation, but the pump
actuating lihkage is always in operation while the

engine
is running. The fuel pump incorporates a
pulsator and pulsator chamber to dampen the
effect

of pump pressure pulsations on the carburetor

needle
valve.
This
prevents high fuel level in the

reservoir
that would result from the
needle
being

jarred
away from its seat. Also, operating
economy
would be affected because a high fuel level usually results in an over-rich mixture.

The
actuating linkage has its own spring to ensure
continuous contact of the lever to the camshaft
eccentric.

This
fuel pump has a sediment bowl and filtering
screen which is attached to the top of the pump by
a
wire clamp and thumb nut. The screen and sedi­
ment bowl should be cleaned at least twice yearly
to prevent trouble due to a blocked screen or water
freezing. The bowl should be washed and wiped

dry
and the screen dried and then cleaned with a
stiff
brush.
When reassembling the bowl make cer­
tain
that the cork gasket is not broken; reverse it
and
position it flat on the seat, then install the
bowl and tighten the thumb nut securely. After
cleaning, start the
engine
and carefully inspect the
bowl for leakage.

E-46.
Disassembly
Remove the cover plate, gasket, and screen or
bowl clamp, sediment bowl, gasket and screen if so equipped.
Mark
the two castings with a file to
ensure positioning in the same relation upon
assembly. Remove the screws attaching the fuel cover to the pump body. Remove the cover,

diaphragm,
and spring. Remove rocker arm pin,
rocker
arm, and rocker arm spring. Remove the
valve plate screw and separate the valve plate

retainer,
valve gaskets, and valves.

Clean
all parts in cleaning solvent and blow out

with
compressed air. Valves should not be removed

from
the valve housing assembly.
Check
all parts
to see that
they
have not
been
cracked or broken
and
that screw threads have not
been
stripped or
cross threaded. Refer to Par. E-49 for fuel pump
testing. 126

'Jeep'
UNIVERSAL
SERIES
SERVICE
MANUAL

E
E-47.
Reassembly

•
Refer to Fig. E-29.
Install
the valve gaskets, valves, valve retainer and
secure them with the valve retainer screws. Make
sure that the inlet and
outlet
valves are in their proper positions. Place the diaphragm spring re­
tainer in position on the diaphragm
pull
rod
and
install diaphragm spring. Position the
dia­

phragm assembly in pump
body
and attach the
cover to pump body, with file marks aligned, with
the six attaching screws. Do not draw the screws
up tight.
Install
rocker arm spring, rocker arm

pin
washers, rocker arm and rocker arm pin.
With

rocker
arm positioned on the diaphragm rod, draw
the six pump
body
screws up evenly and securely.
Install
the filter screen, cork gasket and sediment
bowl and secure them firmly with the thumb screw
on the bowl clamp.

E-48.
Vacuum
Pump

The
double-action fuel pump resembles two single-
action pumps placed one
above
the other. A single
fuel pump rocker arm actuates the two separate diaphragms. One diaphragm is part of the fuel
delivery pump and operates as described in Par.
E-45.
The other diaphragm is part of the vacuum
pump and operates as described here.

As
the actuating lever forces the diaphragm upward against spring pressure, air is forced through the

outlet
port
into
the
engine's
intake manifold. On
the return stroke, spring pressure forces the
dia­
phragm downward, creating a
partial
vacuum and
opening the inlet valve. In this manner, air is pumped out of the windshield wiper motor and
into

the intake manifold. When the wiper motor is shut off, manifold vacuum holds the diaphragm against its spring so that the
full
motion of the actuating
lever is not accompanied by a
complete
up-and-
down motion of the diaphragm.

When
the windshield wiper motor is turned on, but manifold vacuum is greater than the vacuum
created by the
booster
pump, air
flows
from the
wiper motor through both valves of the vacuum
booster.
As manifold vacuum drops off as a result
of the
engine
operating under low
speed
and high load, the vacuum created by the vacuum
booster

will
be greater than
engine
intake manifold vacuum

and
the pump
will
operate the wiper motor when the wiper control switch is turned on.

•
Refer to Fig. E-29. Remove the
eight
cover attaching screws and
lockwashers, and remove the cover, diaphragm

spring
and spring seat. Detach the diaphragm rod
from the rocker arm and remove the diaphragm.
The
valve assemblies are pressed
into
the cover

and
body
and lightly staked. They may be removed
with the point of a knife blade. If installing new valves be sure the inlet and
outlet
valves are
correctly positioned and stake them lightly with

a
small punch.
Assemble the vacuum pump in the reverse order
of disassembly, drawing the cover attaching screws up evenly and tightly.
E-49.
Fuel
Pump
Testing

Four
tests
are presented in following paragraphs to
test
for proper operation of the fuel pump. In addi­
tion, check the following:

a.
Check
for secure mounting of the fuel pump.

The
rocker arm may be working the entire pump
up and down, rather than just the pump
dia­

phragms.
b. Remove and clean the fuel sediment bowl.
c.
Check
all fuel lines.
E-50.
Volume
Check

To
measure fuel pump capacity (amount of fuel
delivered in a given time) disconnect the pump-to-

carburetor
line at the carburetor end. Place the

open
end of the line in a suitable container.
Start

the
engine
and operate at normal idle speed.
Delivery
should be one quart U.S. [1 ltr.] within
one minute.

E-51.
Pressure
Check

To
measure fuel pump pressure (force of fuel de­

livery)
disconnect the pump-to-carburetor line
at the carburetor end. Plug a pressure
gauge
and T-fitting
into
the
open
end of this line and
into
the

carburetor.
Start
the
engine
and operate at normal
idle speed. Pressure should be 2J4 to 3% psi.
[0,716
a
0,264
kg-cm2] at 1800 rpm. and at 16"
[406 mm.]
above
the
outlet.

E-52.
Vacuum
Check

To
measure fuel pump vacuum (pull of. the pump
at the inlet side) disconnect the pump-to-fuel-tank
line at the fuel pump. Attach a vacuum
gauge
to the fuel pump inlet.
Start
the
engine,
accelerate to
specified speed, and hold this
engine
speed
while
taking a
gauge
reading. Permissible
gauge
reading
is 8* [203 mm.] of mercury [Hg] at 1200 rpm. and
10j^'
[267 mm.] at 1800 rpm.
E-53.
Vacuum
Booster
Check

To
test
the condition of the vacuum
booster
pump,
disconnect both inlet and
outlet
lines at the pump.

Attach
a vacuum
gauge
to the windshield wiper
connection at the pump.
Start
the
engine,
accelerate
to
2000
rpm., and hold this
engine
speed
while taking a
gauge
reading. Permissible
gauge
reading
is 10* to 14" [254 a 356 cm.] of mercury [Hg].
E-54.'
FUEL
PUMP
(SINGLE-ACTION)
—
HURRICANE
F4
ENGINE
•
Early
Models.
Vehicles with electric windshield wiper motors are
equipped with a single-action fuel pump (Fig.

E-30).
The fuel pump cam lever is activated by an eccentric on the
engine
camshaft. When the
car­

buretor float
needle
valve closes, accumulation of
fuel in the pump
extends
the diaphragm spring.

This
action causes the rocker arm linkage to be­
come
inoperative until the pressure on the
dia­
phragm and spring is reduced. The fuel pump dis­
charge pressure is thus controlled by the diaphragm

spring.
This
provides a steady supply of fuel to the
carburetor
at a fairly constant pressure. 127