JEEP CJ 1953 Service Manual

'Jeep*
UNIVERSAL
SERIES
SERVICE
MANUAL

COOLING
SYSTEM

Contents

SUBJECT
PAR.

GENERAL
.G-l Antifreeze Solutions. .G-l6
Cylinder
Block.
..................
.G-8

Draining
Cooling System............... G-3

Engine
Overheating..
.................
.G-19
Fan
Belt.
......... .........
.G-18
Filling
Cooling System.................
G-2

Inhibited
Coolant Solution .G-l7

Temperature
Sending Unit.
...........
.G-l0

Thermostat
.........................
G-9

RADIATOR
.G-5
Radiator
and Heater Hoses.............
G-7
SUBJECT
PAR.

Radiator
Pressure
Cap.................
G-4

Radiator
Removal and Replacement..... G-6

WATER
PUMP.
. . .G-ll
Water
Pump Disassembly. .............G-13

Water
Pump Inspection.
..............
.G-12

Water
Pump Reassembly.
.............
.G-14

Water
Pump Removal and Replacement. .G-l5

SERVICE
DIAGNOSIS.
.G-20

SPECIFICATIONS
. .G-21

ANTIFREEZE
CHART.
..... ... .G-22

G-l. GENERAL
a.
The satisfactory performance of the Hurricane

F4
engine
is controlled to a great
extent
by the proper operation of the cooling system. The
engine

block is full length water jacketed which prevents
distortion of the cylinder walls. Directed cooling
and
large water holes, properly placed in the cylin­
der head gasket cause more water to flow past the
valve
seats
(which are the
hottest
parts of the

block)
and
carry
the heat away from the valves, giving positive cooling of valves and seats.

Minimum
temperature of the coolant is controlled by a thermostat mounted in the
outlet
passage of
the engine. When the coolant temperature is below
thermostat-rated temperature, the thermostat re­ mains closed and the coolant is directed through
the radiator-bypass
hose
to the water pump. When the thermostat opens, coolant flow is directed to
the top of the radiator. The radiator dissipates the
excess
engine
heat before the coolant is recirculated
through the engine.
The
cooling system is pressurized. Operating pres­
sure
is regulated by the rating of the radiator cap

which
contains a relief valve, b. The Dauntless V-6
engine
efficiency and per­formance is controlled to a great
extent
by proper
operation of the cooling system. The cooling system

does
more than cool the engine. It also directs
the flow of coolant to provide the
best
operating
temperature range for each part of the engine.

In
the Dauntless V-6
engine
coolant is forced by
the water pump into two main passages that run the length of the block on each side (Fig. G-l).
FIG.
G-1—COOLANT
FLOW
THROUGH
THE
DAUNTLESS
V-6
ENGINE

161

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

'Jeep*
UNIVERSAL
SERIES SERVICE
MANUAL

G and
scale, especially when used with a flushing
solution. A cleaning solution should be used to

loosen
the rust and scale before reverse flushing
the cooling system.

Flushing
is accomplished through the system in a direction
opposite
to the normal coolant flow.
This

action causes the water to get behind the corrosion

deposits
and force them out. To do this, remove
the upper and lower radiator
hoses.
Then
attach a
drain
hose
at the top of the radiator. Attach a new
piece of
hose
to the radiator
outlet
at the
bottom
and
insert the flushing gun. Connect the water
hose

to the flushing gun to a water
outlet
and the air
hose
to an air line.
Turn
on the water and when
the radiator is
full,
apply the air in short blasts,
allowing the radiator to
fill
between
blasts.
Con­
tinue this flushing operation until the water runs

clear
through the top
hose.

With
the thermostat removed, attach a leadaway
hose
to the water
hose
inlet. Also attach a length
of new
hose
to the water
outlet
connection at the
top of the engine.
Turn
the water on and
fill
the
water jacket and then apply air in short blasts.
Continue
this flushing until the water runs clear.

Also
do the hot water heater. Remove heater water

outlet
hose
from heater core. Remove inlet from 163

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

'Jeep*
UNIVERSAL SERIES SERVICE
MANUAL

G

FIG.
G-4—PRESSURE TESTING COOLING SYSTEM
1—Pressure Tester C-3499 previous radiator leakage. These
spots
may not be
damp if water only or methyl-alcohol-base anti­ freeze is in the cooling system since such coolants
evaporate readily. An ethylene-glycol-base anti­ freeze shows up existing leaks as it
does
not evapo­
rate.
The radiator may be tested for leaks by using

a
Pressure Tester Tool C-4080, as shown in Fig.

G-2.

When
the pressure cap opens, the sudden surge of

vapor
or liquid must blow out through the overflow
pipe. If the overflow pipe is dented or clogged,
the pressure caused by obstruction may cause dam­
age to the radiator or
hose
connections in the cool-
1
FIG.
G-5—RADIATOR PRESSURE
CAP
1—
Pressure
Cap

2—
Overflow
Tube

3—
Pressure
Seal 4—
Vacuum
Release Valve
5—
Radiator
Neck
FIG.
G-6—TESTING RADIATOR PRESSURE
CAP
1—
Radiator
Pressure Cap

2—
Adapter

3—
Pressure
Tester C-3499 ing system. To remove clogging material, run a
flexible wire through the overflow pipe.
G-6.
Radiator Removal
and
Replacement
a.
Drain
the radiator by opening the
drain
cock

and
removing the radiator pressure cap.

b.
Remove the upper and lower
hose
clamps and

hoses
at the radiator.

c.
Remove the four cap screws, lock washers and
flat washers that secure the radiator to the radiator
body support. Remove the radiator.

d.
To replace the radiator, reverse the removal

procedure.

G-7.
Radiator
Hoses
and
Heater Hoses

Air,
heat, and water deteriorate radiator and heater

hoses
in two ways: by hardening or cracking which
destroys flexibility and causes leaks; by softening
and
swelling which produces lining failure and
hose

rupture
and clogging. Examine
hoses
spring and

fall
for possible need of replacement or tightening.

If
hoses
are collapsed, cracked, or indicate a
soft

condition on the inside they should be replaced.
Correct
installation of a new heater
hose
is impor­
tant to prevent contact between the
hose
and the
exhaust manifold. On the
Hurricane
F4 engine the
molded curved end of the
hose
connects to the
hot water intake of the heater; the flexible end to the hot water valve on top of the cylinder head.
On
the Dauntless V-6 engine the heater inlet
hose

is connected to the
rear
of the intake manifold 165

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

G
COOLING SYSTEM
12761

FIG.
G-10—WATER
PUMP—

CROSS-SECTIONAL
VIEW
—
DAUNTLESS
V-6
1—
Hub

2—
—Shaft
and Bearing
3—
Cover

4—
Impeller

5—
Ceramic
Seal
6—
Seal
Assembly front end of the pump body. Position the seal,

washer,
and pump seal on shaft flush against the ground seat in the water pump body. Place the

impeller
on an arbor press and press the long end
of the shaft into the impeller until the end of the shaft is flush with the hub of the impeller. Support
the assembly on the impeller end of the shaft and
press the pulley hub on the shaft until the shaft end is flush with the pulley hub. Move the shaft

in
the pump body to align the retaining wire
grooves
in the bearing and pump body and place
the bearing retaining wire in position.

G-l
5. Water Pump Removal and Replacement — Dauntless V-6 Engine

Drain
the cooling system. Remove the fan belt and remove the cooling fan and pulley from the hub on
the water pump. Disconnect the
hoses
from the
water
pump. Remove the cap screws that secure
the water pump to the timing chain cover; remove
the water pump. Do not disassemble the water

pump;
it is serviceable only as an assembly. When

replacing
the water pump, torque the water pump cap screws 6 to 8 lb-ft. [0,829 a 1,106 kg-m.].

G-16.
Antifreeze Solutions

When
water freezes it expands approximately 9%

in
volume. When water, confined in a cooling sys­
tem, freezes it exerts tremendous pressures causing
serious damage. To prevent freezing, antifreeze can
be added to the water to lower its freezing point.

The
two
types
of antifreeze commonly used today have either a methanol or ethylene glycol base,

and
contain corrosion inhibitors. The only anti­
freeze recommended for the cooling system of

'Jeep'
vehicles is ethylene glycol (permanent type).

Methanol
base antifreeze evaporates with the water
when the vehicle is operated at warmer tempera­
tures and requires more attention to avoid
loss
of
protection. Ethylene glycol base antifreeze seldom
evaporates at normal operating temperatures.

Methanol
solution is injurious to vehicle finishes.
Should
any be spilled on the vehicle, it should be
washed off immediately with a
good
supply of cold water without wiping or rubbing. Under ordi­

nary
conditions, ethylene glycol is not injurious to
vehicle finishes.

Warning.*
Drinking
ethylene glycol antifreeze or its
solutions can be harmful or fatal. Do not use anti­
freeze containers for
food
or beverages.

A
table in Par.
G-2
2
gives
the protection obtained
by the addition of various amounts cf ethylene glycol.
Before installing antifreeze, inspect the cooling sys­
tem to be sure it is clean, leak-proof, and otherwise

in
proper operating condition.
Drain
the cooling system, see Par. G-3. Pour in 3 quarts [3 ltr.] of

clean
water, add the required quantity of anti­ freeze, then add clean water to within 1" [2,54 cm.] of the top of the overflow pipe to allow for expan­
sion when hot. Run the
engine
until it is
warm.

Then
recheck the solution level.
Check
the anti­
freeze protection with a hydrometer reading.

G-l7.
Inhibited Coolant Solutions

All
'Jeep5 vehicles equipped with either the
Hur­
ricane
F4 or Dauntless V-6
engine
should use only

inhibited
year-round, permanent-type
engine
cool­
ant
solutions that are formulated to withstand two

full
calendar years of normal operation without

draining
or adding inhibitors. The
engine
cooling
system should be completely drained and the
rec­
ommended coolant installed every two years. Be-
fo
a
installing the permanent-type solution, inspect the cooling system to be sure it is clean, leakproof,

and
in proper operating condition.

Note:
Water alone, methanol, or alcohol-type anti­
freeze is definitely not recommended for 'Jeep*
Vehicles.

G-l8.
Fan Belt

The
fan, water pump, generator or alternator are
driven
by a V-belt. The drive of the V-belt is on
the side of the V. A fan belt that is too tight
will

cause
rapid
wear of the alternator or generator and
water
pump bearings. If the belt is too
loose,
it may
slip
preventing the water pump from properly cool­
ing the
engine
or the generator or alternator from
properly
charging the electrical
circuit.
Use fan belt
tension
gauge
Tool W-283 to properly adjust belt.

The
fan belt is properly adjusted when it can be
deflected Vi" [13 mm.] with strong thumb pres­

sure
applied midway
between
the fan and alter­

nator
pulleys.
Check
this adjustment and inspect the condition of the fan belt at each
engine
lubri-
168

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

G
cation period. It is
good
preventive maintenance to
replace a badly frayed, worn or cracked fan belt
before it breaks in operation.

To
replace the fan belt,
loosen
the attaching
bolts

at each generator or alternator brace-to-engine mounting and pivot the alternator or generator to­

ward
the
engine
to gain slack needed to install the new belt Remove the old belt. Position the new
belt over the fan pulley, over the crankshaft pulley,
then over the generator or alternator pulley.
Pull
the generator or alternator away from the
engine

until
belt tension is
firm.
Then tighten the generator

or
alternator mounting
bolts
and check the tension
as indicated above. Reset the generator or alternator as necessary for correct belt tension.
Finally,
torque
the generator or alternator mounting
bolts
25 to 35 lb-ft. [3,4 a 4,8 kg-m.].

Note:
On the Dauntless V-6
engine
when adjusting
the fan belt tension, the alternator mounting
bolts

should be torqued 30 to 40 lb-ft. [4,14 to 5,53

kg-m.].
If a fan belt tension
gauge
(W-283) is
avail­

able, proper tension should be 80 pounds [36,2 kg.].

G-l
9. Engine Overheating

An
engine
will
not be damaged by high coolant
temperatures unless the coolant boils. The pres­

surized
cooling system on the 'Jeep' vehicles raises the boiling point of the coolant solution. Should
overheating be encountered, and the fault is be­
lieved to be in the cooling system check for the
following:

a.
Proper coolant level. See
Filling
Cooling Sys­
tem Par. G-2.
b. Poor air flow.
Check
for dirty radiator core. (See Radiator Par. G-5).
Check
for faulty belt
pulley operation, worn or
loose
fan belt, or dam­ aged fan.
Clean,
repair, replace or adjust as neces­

sary.

c. Foaming coolant.
Check
for air leaks at water
pump,
hose
connection and filler cap. Tighten, re­

pair
or replace as necessary.

d.
Surging or "after boil".
Check
pressure cap and
replace if valves or gasket are faulty.
e.
External
leaks.
Check
the following for leaks:
Hoses and clamps, water pump, radiator, head gas­
ket, core plugs and drain cocks, as well as the cylin­ der head or block for
cracks.

f.
Internal
leaks.
Check
for faulty head gasket,
cracked
cylinder head or block.
g. Poor coolant flow.
Check
hose
condition, water pump, fan belt, and repair or replace as necessary. Inspect block for rust or scale, and clean and flush
the system, if necessary.

h.
Check
the temperature
gauge.
169

G
COOLING SYSTEM G-20.
SERVICE DIAGNOSIS

SYMPTOMS
PROBABLE REMEDY

Overheating:
Lack
of Coolant Refill radiator
Thermostat inoperative . Replace thermostat
Water
pump inoperative. Overhaul or replace
Incorrect
ignition or valve timing. Set
engine
timing
Excessive piston blowby Check pistons, rings and cylinder walls
Fan
belt
broken or badly worn Replace
belt

Radiator
clogged
Reverse flush and clean
Air
passages
in core
clogged
Clean with water and air pressure
Excessive carbon formation. Remove carbon from cylinder head(s) Muffler
clogged
or
bent
exhaust
pipe
Replace damaged part

Loss
of Cooling
Liquid:
Loose
hose
connections
Tighten
connections

Damaged
hose
Replace
hose

Leaking
water pump Overhaul or replace

Leak
in radiator Remove and repair
Leaky
cylinder head
gasket
Replace
gasket
Crack
in cylinder block. Small crack can be closed with
Radiator
or Block Sealer

G-21. COOLING SYSTEM SPECIFICATIONS

Radiator
Cap:
Relief
Pressure

Vacuum
Valve Release.
Thermostat:
Rating

Starts to Open

Fully
Open

Water
Pump:
Type.

Drive

Radiator:

Type

Cooling System Capacity: Without Heater

With
Heater..

Fan:
Number of Blades Diameter

Drive
Belt: Angle of V

Length
Width
HURRICANE
F4
7 and 15 psi. [0,5 kg-cm2 and 1,05 kg cm2]
lA to 1 psi. [0,04 a 0,07 kg-cm2]

190°F.
[87,8°C]
180°F.
[82°C]

202°F.
[94°C]

Centrifugal
V-Belt

Tube
8s Fin
11 qt. [10,4 ltr.] 12 qt. [11,5 ltr.]
15" [38 cm.]
38°

42%" [108 cm.] [1,74 cmJ
DAUNTLESS
V-6 15 psi. [1,05 kg-cm2]
1 psi. [0,07 kg-cm2]

190°F.
[87,8°C]
180°F.
[82°C]

202°F.
[94°C]

Centrifugal
V-Belt

Tube
& Fin
9 qt. [8.5 ltr.]
10 qt. [9,4 ltr.]
4

\SbA"
[39,7 cm.]

38°

43.92"
[111,5
cm.] Vg"
[0.952
cm.] G-22. ANTIFREEZE CHERT

Quarts
i
Quarts
Ethylene Glycol

U.S.
Imperial
Liters
Fahr.
Cent.

10-Quart
System

2
m
2

16°
-
8.8°

3
2V2
2%
4°

-15.5°

4
3H
-12°

-24.4°

5 4M -34°

-36.6°

6
5

5Vs
-62°

-52.2°

11-Quart
System

2 2

18° -
7.6°

3 2H
2%
8°

-13.3°

4
3%
-
6°

:
-21.10

5 4M 4M -23°

-30.5°

6
5

SVs
-47°

-43.8°

12-Quart
System

2
1 m 2 1

19° ;
- 7.2°

3
2*A
10°
!
-12.2°

4
I
3H
3M 0°
;
-17.7°

5 !
4M 4^ :
-15°

s
-26.1°

6 1 5
5%
-34°

-36.6°
170