1953 JEEP CJ check engine

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

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

F2
F2-26.
Anti-Backfire
Valve

The
anti-backfire valve removal requires discon­ necting the
hoses
and bracket to
engine
attaching
screws.

F2-27.
Air Distribution Manifold and
Injection
Tubes

The
air distribution manifolds can be removed
from the cylinder heads without removing the

cylinder
head assemblies. Disconnect the air delivery
hose
from the pump at
the distribution manifold inlet (check valve).
Loosen the distribution manifold
tube
attaching nuts from the cylinder head and carefully work the
distribution manifold away from the cylinder head.

The
air injection
tubes
can be removed from the
cylinder
head with head on the
engine.
Insert
an easy-out through the
boss
opening on the

cylinder
head
into
the injection
tube
and twist
the
tube
out gradually. Some interference to re­ moval may be encountered due to normal carbon
build-up on the tubes. Injection
tubes
removed in
this manner should be replaced.
The
injection
tubes
used are all of the same diam­
eter and length.

F2-28.
REQUIRED EQUIPMENT

Each
station licensed to perform repair and main­ tenance on the Exhaust Emission Control System
must be equipped with that equipment necessary
for major
engine
tune-up analysis which shall in­ clude at least the following or equivalent:
Ignition Analyzer Oscilloscope
Ammeter
Ohmmeter
Voltmeter
Tachometer 2 Vacuum Gauges
Pressure
Gauge (0-10 psi.)

Cam
Angle Dwell Meter
Ignition Timing
Light

Engine
Exhaust Combustion Analyzer Compression Tester

F2-29.
REPLACEMENT PARTS

Parts
necessary to repair and/or maintain the Ex­
haust Emission Control System are available through any Jeep
SALES
CORPORATION
ware­
house.

F2-30.
WARRANTY
All
parts of the Exhaust Emission Control System
are
covered by the Manufacturer's
Warranty
as stated in the
Warranty
Service and 'Jeep' Quality
Maintenance Plan booklet. 157

F2
EXHAUST EMISSION CONTROL SYSTEMS
F2-3L
EXHAUST EMISSION CONTROL SYSTEM
DIAGNOSIS
GUIDE

Pump Noisy
Hoses Touching Other Parts of Engine or Body (Hood).

Note:
The Air Pump is not completely noiseless.

Under
normal conditions, pump
noise
rises in pitch as
engine
speed
increases. It is desirable to allow
for normal break-in wear of the pump prior to re­
placement for
excessive
noise.
Pump Seized
Replace pump.
-
do not pry on housing.
Leak
In Hose

Check
for leaks; using
soap
and water, tighten clamps or replace
hoses.

Pump Inoperative
Loose Belt — tighten belt
-

Filter
Plugged — replace.

Exhaust
Backfire

Check
for vacuum leaks — correct as necessary.
Check
anti-backfire valve — replace as necessary
Induction System Backfire

Verify
engine
timing and distributor dwell.
Verify
accelerator pump charge.

F2-32.
EXHAUST EMISSION CONTROL SYSTEM MAINTENANCE CHART

Efficient
performance of the Exhaust Emission very important that all of the maintenance require-

Control
System is
dependent
upon precise main-
ments
are performed with extreme care at the
tenance. As indicated in the following chart, it is specific interval indicated.
Thousands of miles* or

OPERATION
number of months whichever occurs first 2 6 12 18 24 30
Inspect engine-driven
belts
for condition and tension R R
Replace positive crankcase ventilation valve
(PCV)
R R

Check
for free operation of exhaust manifold heat control valve O O O O O

Clean
carburetor air cleaner — Oil Bath O O O O O
Replace carburetor air cleaner
element
— Dry Type O
Check
heated air system O O

Engine
tune-up O O

Check
engine
timing R O O O
Adjust
carburetor idle
speed
and mixture R O O O

Perform
factory-recommended road
test
for evaluation of overall performance and handling O O O O O

R
— Required Services O — Recommended Services

*
Miles Kilometers
2,000
—
3,200

6,000
—
9,600

12,000
—
19,200 18,000
—
28,800
24,000
—
38,400
30,000
—
48,000

F2-33.
GENERAL SPECIFICATIONS
Air
Pump Belt Tension 60 lb.

Rotor
Ring Screw Torque . 37 lb-in.
Housing Cover Bolt Torque 10 lb-ft. Speed Ratio, Air Pump to Engine
1
\i to 1

F2-34.
EXHAUST EMISSION CONTROL SYSTEM CARBURETOR SPECIFICATIONS

Make
Rochester Model Designation 2G Code Number
7027082
—
7041185

Choke
Manual
Number of Barrels 2

Throttle
Bore... \W [3,65 cm.]
Main
Metering Jet Production .051" - 60° [1,29 mm.]
High
Altitude — over
5000
ft .049" - 60° [1,24 mm.]
—
over
10,000
ft .047" - 60° [1,19 mm.]

Float
Level
Adjustment* 1%," [2,94 cm.]
Float
Drop Adjustment l%" [4,76 cm.]
Pump Rod Adjustment** 1%" [2,94 cm.]
Engine
Idle
R.P.M.
(In Neutral) 650 to 700

Initial
Idle Speed-screw
setting
3 turns in

Initial
Idle Mixture-screw
setting
2 turns out
Dash
Pot Setting. Y%w [3,75 mm.]
*From
air horn gasket to top of float at toe.

**From
air cleaner ring to top of pump rod.
158

'Jeep'
UNIVERSAL SERIES SERVICE
MANUAL

F2
F2-35.
EXHAUST EMISSION CONTOL SYSTEM
DISTRIBUTOR SPECIFICATIONS

Distributor:
Make
Delco-Remy Prestolite Prestolite
Model...
1110376
IAT-4501 or IAT-4502 IAT-4502A

Breaker
Point Gap .016"
[0,406
mm.] .016"
[0,406
mm.] .016"
[0,406
mm.]

Breaker
Arm Tension 19 to 23 oz. [538 a 652 gr.] 17 to 22 oz. [482 a 623 gr.] 17 to 22 oz. [482 a 623 gr.]

Cam
Angle. 29° to 31° 29° + 3° 29° ± 3°

Max.
Auto Advance
(Crankshaft
Degrees). 13° to 15° at 1,950 rpm. 16° (& 1800 rpm. 21° @ 1800 rpm.
26°
@
4200
rpm. (Max.) 32° @
4200
rpm. (Max.)

Max.
Vac. Advance
(Distributor
Degrees) 8° 8° 8°
Condenser Capacity. .18 to .23 mfd. .25 to .28 mfd. .25 to .28 mfd.

Timing:
Crankshaft
5°
(BTC)
@ Idle 5°
(BTC)
© Idle 0°
(TDC)
© Idle

Mark
Location Crankshaft Pulley Crankshaft Pulley Crankshaft Pulley

Firing
Order
1-6-5-4-3-2 1-6-5-4-3-2 1-6-5-4-3-2

F2-36.
SPARK PLUG
GAP

Spark
Plug Gap. .035"
[0,889
mm.]

IMPORTANT
NOTICE
The
Exhaust Emission Systems covered in this publication
meet
State and Federal
requirements for hydrocarbon and carbon
monoxide
emissions.

To
assure continued proper operation,
these
systems
must be inspected regularly,
parts must be replaced at factory-recommended intervals and
engine
tune-up services
performed at intervals specified in the Exhaust Emission Control System Maintenance
charts.

For
the
above
reasons,
these
systems
must not, under any circumstances, be altered
to anything other than required specifications provided in this publication.
Further,

the Exhaust Emission Control System, or any of its components, must not be physi­
cally
altered or modified in any respect.

DATA
TAG

For
the serviceman's guidance, each vehicle equipped with exhaust emission control

will
have data tag permanently affixed to the radiator shroud — in example:

VEHICLE EMISSION CONTROL INFORMATION MODEL V6-225 C.I.D.

•
ENGINE
AT
NORMAL OPERATING TEMPERATURE

•
LIGHTS
AND ALL
ACCESSORIES
OFF

•
IDLE MIXTURE
.. .
LEAN BEST IDLE

•
IGNITION TIMING
0*
(TDC)
*
SPARK PLUG
GAP 035
•
DWELL
. . . 30* (.016
POINT
GAP) •
IDLE SPEED
. . .
650- 700
RPM
TRANSMISSION
IN
NEUTRAL DURING TUNE
UP

SEE
SERVICE MANUAL FOR ADDITIONAL INFORMATION

THIS VEHICLE CONFORMS
TO U.S. DEPT. OF H.E.W.
REGULATIONS APPLICABLE
TO
1971
MODEL YEAR
NEW
MOTOR VEHICLES
Jeep
CORPORATION
14400
NOTE:
The
above
tag applies to vehicles equipped with Distributor Model
IAT-4502A.

On
vehicles equipped with Distributor Models
1110376,
IAT-4501 and IAT-4502 the tag is the same

except
that Ignition Timing is 5°
T.D.C.

Always
refer to the data tag when checking or re-adjusting ignition timing, idle speed, and idle mixture.
159

COOLING
SYSTEM

14263

FIG.
G-2—COOLING SYSTEM
COMPONENTS
V-6
ENGINE

1—
Radiator
Pressure Cap

2—
Hose
Clamp

3—
Radiator
Hose (Inlet-Upper)
4—
Radiator
Hose (Outlet-Lower) 5—
Bolt
6—
Water
Pump Assembly 7—
Cap
8—Thermostat
By-Pass Hose
g—Water Outlet
Elbow

10—
Gasket

11—
Thermostat
12—
Water
Pump Gasket

13—
Dowel
Pin
14—
Radiator
Shroud (Heavy Duty Cooling) 15—
Pulley

16—
Fan
Spacer
17—
Fan
and Alternator Belt

18—Fan

19—
Lockwasher

20—
Radiator

21—
Drain
Cock
From
these
main passages, the coolant flows around
the
full
length of each combustion chamber.

After
cooling the block, the coolant passes through
ports between the block and each cylinder head.
These
ports direct most of the coolant flow around the exhaust valve area to prevent hot exhaust
gases

from
overheating the exhaust ports.

From
the cylinder heads, the water passes into a
water
manifold between each of the heads and the

water
pump. If the thermostat is closed, the coolant
is ported back to the pump where it is recirculated

back
into the pump and into the engine. After the
coolant heats enough to open the thermostat, the coolant is directed from the water manifold through
a
hose
to the top of the radiator and then through
the radiator which acts as a heat exchanger to cool the fluid. The coolant is then ported through a
hose

from
the bottom of the radiator to the pump, which

recirculates
it back to the engine.

The
cooling system is pressurized. Operating pres­
sure
is regulated by a relief valve in the radiator

cap. The
heater inlet
hose
is connected to a port on
the right bank cylinder head. The outlet
hose
is connected to the heater adapter tube on the water

pump.

c.
It is recommended when using water for coolant
that the cooling system be flushed and checked for leaks twice a year, preferably in the
fall
before
antifreeze is added and in the spring when the antifreeze is drained.

Reverse
flushing
will
aid greatly in removing rust 162

G
COOLING SYSTEM
engine
connections. Insert flushing gun and flush
heater core.
Care
must be taken when applying air
pressure to prevent damage to the heater core.

G-2.
Filling
Cooling System
To
fill
the cooling system, remove the
fill
cap and

fill
the tank to the top. Replace the cap and run
the
engine
at medium speed for approximately one
minute. Remove the cap and recheck the coolant level. Add more coolant if necessary to bring the level back to the top of the tank. If the cooling system is filled when the
engine
is cold, recheck the coolant level after the
engine
has warmed up.
This

will
ensure that the thermostat has opened allow­ ing complete cooling system circulation.

Always
correct any cooling system leaks before installing antifreeze. A corrosion inhibitor should be used in the cooling system to prevent the forma­
tion of rust and scale. A quality brand antifreeze containing a corrosion inhibitor should be used.

When
the antifreeze is drained in the spring, a
corrosion inhibitor should be added with the water.

Note:
Cooling system components for both V6 and

F4
engines
are shown in
Figs.
G-2 and G-3.

G-3. Draining
Cooling System

To
completely
drain
the cooling system, open the

drain
in the
bottom
of the radiator and also a

drain
on the right side of the cylinder block on the
Hurricane
F4 engine. The Dauntless V-6
engine

has two
drain
plugs, one located on each side of the cylinder block. Both plugs must be removed to
completely
drain
the cooling system.
Remove the radiator cap to break any vacuum
that may have developed.

Should
the cooling solution be lost from the system

and
the
engine
become
overheated do not
refill

the system immediately but allow the
engine
to cool or
refill
slowly while the
engine
is running. If
cold solution is poured into the radiator while the

engine
is overheated there is danger of cracking the

cylinder
block and/or cylinder head.
G-4.
Radiator Pressure
Cap

All
radiators are equipped with pressure caps which
reduce evaporation of cooling solution and make the
engines
more efficient by permitting slightly
higher operating temperatures. When operating
properly,
the pressure cap permits pressure build-up

in
the cooling system during periods of severe heat

load.
This
pressure increases the boiling point of the coolant and thus reduces overflow losses. The

effectiveness
of the cap is limited by its opening
pressure and the boiling point of the coolant (see
note
below). The pressure cap employs a spring-
loaded, rubber-faced pressure seal which presses against a seat in the radiator top tank. Spring pres­

sure
determines the opening pressure of the valve.

A
typical pressure cap is shown in Fig. G-5.

Note:
Refer to cooling system specifications (Par.

G-21)
for opening (relief) pressure when the ve­
hicle is equipped with either the
Hurricane
F4
or
Dauntless V-6 engine. If a new cap is required, always install a cap of the same type and pressure
rating
specified. It should never be altered or re­
placed by a plain cap.

A
vacuum release valve (Fig. G-5) is employed to
prevent undesirable vacuum build-up when the system
cools
down. The vacuum release valve is
held against its seat under light spring pressure.

Vacuum
in the system is relieved by the valve
which
opens
at V2 to 1 psi. [0,035 a 0,07 kg-cm2]

vacuum.
A pressure tester can be used to check and
test
the vacuum pressure rate (see Fig. G-6).
Although the mechanism of the pressure cap re­ quires no maintenance, the cap should be inspected
periodically for cleanliness and freedom of opera­ tion. The pressure cap gasket and radiator filler neck seat should also be inspected to be sure they

are
providing a proper seal. If the rubber face of
the valve is defective, a new cap should be installed.
Filler
neck reseating
tools
are commercially
avail­
able to correct minor
defects
at the surface of the seat. Follow instructions of the reseating tool manu­

facturer.

To
remove the radiator pressure cap when the
engine
coolant temperature is high or boiling, place

a
cloth over the pressure cap and
turn
counter­ clockwise about Vi
turn
until the first (pressure release)
stop
is reached. Keep the cap in this posi­
tion until all pressure is released.
Then
push cap
down and
turn
still
further until cap can be re­ moved. To install the pressure cap, place it in posi­
tion and
turn
it clockwise as far as it
will
go.

Caution:
Use extreme care in removing the radiator
pressure cap. In overheated systems, the sudden release of pressure can cause a steam flash and this

flash,
or the
loosened
cap can cause serious personal

injury.

G-5.
RADIATOR

Maintenance of the radiator consists of keeping
the exterior of the radiator core clean, the interior free from rust and scale, and the radiator free from

leaks.
Check
the cooling system fluid level and for
leaks each
2000
miles
[3.200
km.] or every 30
days, whichever occurs first.
This
exterior of the

radiator
core should be cleaned and the radiator inspected for leaks each
6000
miles
[9.600
km.]
of normal service of the vehicle. Cleaning should be performed by blowing out with air stream or water stream directed from the
rear
of the radiator.

Visual
inspection is not sufficient as the accumula­ tion of small particles of foreign material on core
surfaces can restrict cooling without closing the core openings.

Radiator
leakage occasionally results from cor­
rosion perforation of the metal but most leakage results from mechanical failure of soldered joints
when too much strain has been put on the joint.
Fractures
occur most
often
at the joint where the
radiator
inlet and
outlet
pipes are attached to the

tanks.
When the seams break, the entire soldered

joint
is
exposed
and can corrode, but breakage
rather
than corrosion is the
primary
cause of seam
leakage. Examine the radiator carefully for leaks before and after cleaning. Cleaning may uncover points of leakage already existing but plugged with
rust.
White, rusty, or colored leakage stains indicate 164

G
COOLING SYSTEM and
the outlet
hose
is connected to the water pump
housing.
When
installing a new hose, clean the pipe connec­
tions and apply a thin layer of nonhardening seal­
ing compound. Hose clamps should be properly
located over the connections to provide secure fastening. The pressurized cooling system pressure

can
blow off improperly installed hoses.

G-8.
Cylinder
Block

Any
coolant leaks at the engine block water joints

are
aggravated by pump pressure in the water

jacket
and by pressure developed in the cooling system when the pressure cap is in place.
Small
leaks showing up only as moist
spots
often
cannot
be detected when the engine is hot except by the
appearance of rust, corrosion, and dye stains where
leakage evaporated. Also, expansion and contrac­ tion of the engine block resulting from extreme
temperature changes can aggravate leaks. For
these

reasons, when checking for coolant leaks inspect
the block when it is cold and while the engine is

running.
A
leaking
drain
cock or plug that cannot be stopped

leaking
by tightening should be replaced.
Leaking

core-hole expansion plugs should be replaced.
If
tightening gasketed joints
will
not correct leak­
age, install new gaskets. Use a sealing compound
where recommended.

G-9.
Thermostat
a.
The cooling system of the engine is designed
to provide adequate cooling under most adverse conditions. However, it is necessary to employ
some

device to provide quick warming and to prevent
overcooling during normal operation. Automatic
control
of engine operating temperature is provided
by a water flow control thermostat installed in the
water
outlet of the
Hurricane
F4 engine. The ther­
mostat is a heat-operated valve. It should always
be maintained in working order and the vehicle
should never be driven without one installed as there would then be no control of engine tempera­

ture.
The temperature at which the thermostat
opens
is preset and cannot be altered.

b.
The thermostat on the
Hurricane
F4 engine is
located in a housing on the top front of the cylinder

head.
On the Dauntless V-6 engine it is located
in
the thermostat housing of the air intake manifold.

The
standard engine thermostat for the
Hurricane

F4
and Dauntless V-6 engine has a normal rating
of
190°F.
[87.8°C]
and should begin to open at

a
coolant temperature between
180°F.
[82°C]
to
192°F.
[89°C]
and be fully open at
202°F.
[94°C.].
See Fig. G-7 for method of testing.

When
the thermostat is not operating properly, the engine may
run
too hot or too cold. Overheating

may
damage the thermostat so that its valve
will

not function properly, and a cold engine
will
not achieve
full
efficiency.
Rust
can also interfere with
thermostat operation. To
test
the thermostat, place

it
in water heated approximately
25°F.
[17°C]
above the temperature stamped on the thermostat

valve.
Submerge the bellows completely and agitate
the water thoroughly. The valve should open fully.
Next, place the thermostat in water heated approxi-
FIG.
G-7—THERMOSTAT
TEST

mately 10°F.
[11°C]
below the temperature
stamped on the thermostat valve. Submerge the bellows completely and agitate the water thorough­
ly.
The valve should close completely. If the ther­
mostat fails either of
these
tests, it should be re­ placed with a new one of the same type and rating.

G-10. Temperature
Sending Unit

The
sending unit incorporates a temperature sens­ ing element that when it is surrounded by cold engine coolant, the unit provides the highest resist­
ance in the temperature
gauge
indicator
circuit.
Resultant
low current flow in the circuit causes the

indicator
on the instrument panel to read at the low (C) end of the
gauge.
As engine coolant tem­

perature
increases, the resistance of the unit is
decreased allowing an increased current flow in
the
circuit,
making the instrument panel
gauge

register in proportion to the temperature of the engine coolant.

To
test
the sending unit, first run the engine until

it
has had time enough to warm up.
If
no reading is indicated on the
gauge,
check the
sending unit to
gauge
wire by removing the wire

from
the sending unit and momentarily grounding
the wire. If the
gauge
now indicates, the sending

unit
is faulty. If the
gauge
still
does
not indicate, the wire is defective.
Repair
or replace the wire,

a.
Hurricane
F4 Engine.

The
thermo-couple coolant temperature sending
unit
is mounted in the right
rear
of the cylinder head (Fig. G-8) and is connected by a single wire
to the dash unit of the instrument cluster. 166

'Jeep*
UNIVERSAL
SERIES
SERVICE
MANUAL

FIG.
G-8—TEMPERATURE SENDING UNIT- HURRICANE
F4
ENGINE
1—Temperature
Sending Unit

b.
Dauntless V-6 Engine.

The
thermo-couple coolant sending unit is mounted
in
the left
rear
area of the intake manifold and is
connected by a single wire to the dash unit of
the instrument cluster.

G-ll.
WATER PUMP

a.
Hurricane
F4 Engine.

The
water pump on the
Hurricane
F4
engine
is a

centrifugal
impeller type of large capacity to
cir­

culate water in the entire cooling system. The double row
ball
bearing (Fig. G-9), is integral with
the shaft and is packed at assembly with a special
high melting point grease which
will
last the life of
the bearing. The bearing is sealed to retain the
lubricant
and prevent
dirt
and dust from entering.

The
bearing and shaft are retained in the water
pump body by the bearing retaining wire. The
water
seal bears against the ground seat on the
pump body and the inside of the impeller, maintain­
ing a constant pressure against both and preventing

water
leakage. A
drain
hole
in the
bottom
of the
pump body precludes any water
seepage
past the

seal
from entering the bearing.
The
impeller and the pulley hub are pressed on
the shaft under high pressure,
b.
Dauntless V-6 Engine.

A
centrifugal-type water pump, shown in
Fig.
G-10,

circulates
coolant through the Dauntless V-6
engine

and
its cooling system.
This
pump is mounted on
the timing chain cover.
Similar
to the
engine
cooling
fan
mounted on its hub, the pump is driven through
a
V-belt from the crankshaft pulley.

Coolant
enters the water pump at its center.
Centri­

fugal force then forces coolant radially outward, through vanes of the pump impeller, and backward
through two discharge passages in the timing chain cover. These passages conduct an equal amount of
coolant to each cylinder bank water jacket.
This

water
pump has a sealed double row
ball
bearing
and
a ceramic water seal, neither of which can be

serviced.
In
event
of bearing or water seal failure, the entire water pump assembly must be replaced.
G-l2.
Water
Pump Inspection

Check
the water pump for leaks, and excessive end play or
looseness
of the shaft in the pump. A

quick
way to check is to work the fan blades up
and
down by hand. If any play is noticed, this
indicates that the bearings are rough. Rough bear­ings should be checked to see if the water pump
should be replaced or rebuilt.

G-13.
Water Pump
Disassembly
—
Hurricane
F4
Engine

•
Refer to Fig. G-9.

a.
Remove the fan belt, fan blades, and fan pulley.

b.
Remove the
bolts
attaching the water pump
to the block. Remove the pump.

c.
Remove the bearing retainer spring.

d.
Remove the pump impeller and pulley with a suitable puller.

e.
Remove the pump seal, bearing and shaft, and

bearing
slinger.

G-l4.
Water Pump Reassembly
—
Hurricane
F4
Engine

•
Refer to Fig. G-9.
Before assembling the water pump, examine water
seal
seat in the pump body and should it be rough,

install
a new pump body.

To
reassemble the unit, insert the long end of the shaft into the pump body from the front end until
the outer end of the bearing is flush against the

FIG.
G-9—WATER
PUMP-
HURRICANE
F4
ENGINE

1—
Fan
and Pump Pulley
2—
Bearing
and Shaft

3—
Bearing
Retainer Spring

A—Pipe
Plug 5—
Pump
Body
6—
Seal
Washer 7—
Pump
Seal
8—
Impeller

9—
Gasket
167