engine JEEP CHEROKEE 1995 Service Manual PDF

Low coolant level can cause thermostat pellet to be
suspended in air instead of coolant. This will cause
thermostat to open later, which in turn causes higher
coolant temperature. Air trapped in cooling system
also reduces amount of coolant circulating in heater
core resulting in low heat output.
DEAERATION
As the engine operates, any air trapped in cooling
system gathers under the radiator cap. The next time
the engine is operated, thermal expansion of coolant
will push any trapped air past radiator cap into the
coolant reserve/overflow tank. Here it escapes to the
atmosphere into the tank. When the engine cools
down the coolant, it will be drawn from the reserve/
overflow tank into the radiator to replace any re-
moved air.
DRAINING COOLING SYSTEM
ALL MODELSÐEXCEPT XJ WITH 4.0L
6-CYLINDER ENGINE
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR
DRAINCOCK WITH SYSTEM HOT AND UNDER
PRESSURE. SERIOUS BURNS FROM COOLANT
CAN OCCUR.
DO NOT WASTE reusable coolant. If the solution
is clean, drain the coolant into a clean container for
reuse.
DO NOT remove the radiator cap when draining
the coolant from the reserve/overflow tank. Open the
radiator draincock and when the tank is empty, re-
move the radiator cap. The coolant does not have to
be removed from the tank unless the system is being
refilled with a fresh mixture.
(1) Drain the coolant from the radiator by loosen-
ing the draincock.
(2) Drain coolant from engine as follows:
(a) On 2.5L 4-cylinder engines (all models) by re-
moving drain plug at left rear side of block.
(b) On 4.0L 6-cylinder engines by removing the
drain plug or coolant temperature sensor on the
left side of the block (Fig. 19).
XJ MODELS WITH 4.0L 6-CYLINDER ENGINE
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR
DRAINCOCK WITH SYSTEM HOT AND UNDER
PRESSURE. SERIOUS BURNS FROM COOLANT
CAN OCCUR.
DO NOT WASTE reusable coolant. If the solution
is clean, drain the coolant into a clean container for
reuse.
(1) Remove radiator pressure cap.(2) For access to radiator draincock, remove radia-
tor grille mounting screws and remove grill. Refer to
Group 23, Body for procedures.
(3) Attach one end of a 24 inch long X 1/4 inch ID
hose to the radiator draincock. Put the other end into
a clean container. Open draincock and drain coolant
from radiator.
(4) Drain coolant from engine by removing the
drain plug and coolant temperature sensor on left
side of block (Fig. 19).
REFILLING COOLING SYSTEM
YJ MODELS
(1) Remove draining hose. Tighten the radiator
draincock and the cylinder block drain plug(s).
(2) Fill system using a 50/50 mixture of water and
antifreeze. This is described in the Coolant section of
this group. Fill the radiator to the top and install the
radiator cap. Add sufficient coolant to the reserve/
overflow tank to raise the level to the FULL mark.
(3) Operate the engine with both the radiator cap
and reserve/overflow tank cap in place. After the en-
gine has reached the normal operating temperature,
shut the engine off and allow it to cool.
(4) Add coolant to the reserve/overflow tank as
necessary.Only add coolant when the engine is
cold. Coolant level in a warm engine will be
higher due to thermal expansion.
XJ MODELS
(1) Tighten the radiator draincock and the cylinder
block drain plug(s). If removed, install coolant tem-
perature sensor (4.0L 6-cylinder engine).
(2) Fill system using a 50/50 mixture of water and
antifreeze as described in the Coolant section of this
Fig. 19 Draining CoolantÐ4.0L 6-Cylinder Engine
JCOOLING SYSTEM SERVICE PROCEDURES 7 - 21

group. Fill radiator to top and install radiator cap.
Add sufficient coolant to reserve/overflow tank to
raise level to FULL mark.
(3) With heater control unit in the HEAT position,
operate engine with radiator cap in place.
(4) After engine has reached normal operating
temperature, shut engine off and allow it to cool.
(5) Add coolant to reserve/overflow tank as neces-
sary.Only add coolant when the engine is cold.
Coolant level in a warm engine will be higher
due to thermal expansion.
COOLING SYSTEM CLEANING/REVERSE FLUSHING
CAUTION: The cooling system normally operates at
97-to-124 kPa (14-to-18 psi) pressure. Exceeding
this pressure may damage the radiator or hoses.
CLEANING
Drain cooling system and refill with water. Run en-
gine with radiator cap installed until upper radiator
hose is hot. Stop engine and drain water from sys-
tem. If water is dirty, fill system with water, run en-
gine and drain system. Repeat until water drains
clean.
REVERSE FLUSHING
Reverse flushing of the cooling system is the forc-
ing of water through the cooling system. This is done
using air pressure in the opposite direction of normal
coolant flow. It is usually only necessary with very
dirty systems with evidence of partial plugging.
REVERSE FLUSHING RADIATOR
Disconnect the radiator hoses from the radiator fit-
tings. Attach a section of radiator hose to the radia-
tor bottom outlet fitting and insert the flushing gun.
Connect a water supply hose and air supply hose to
the flushing gun.
CAUTION: The cooling system normally operates at
97-to-124 kPa (14-to-18 psi) pressure. Exceeding
this pressure may damage the radiator or hoses.
Allow the radiator to fill with water. When radiator
is filled, apply air in short blasts allowing radiator to
refill between blasts. Continue this reverse flushing
until clean water flows out through rear of radiator
cooling tube passages. For more information, refer to
operating instructions supplied with flushing equip-
ment. Have radiator cleaned more extensively by a
radiator repair shop.
REVERSE FLUSHING ENGINE
Drain the cooling system. Remove the thermostat
housing and thermostat. Install the thermostat hous-
ing. Disconnect the radiator upper hose from the ra-
diator and attach the flushing gun to the hose.Disconnect the radiator lower hose from the water
pump. Attach a lead away hose to the water pump
inlet fitting.
CAUTION: On XJ models, be sure that the heater
control valve is closed (heat off). This is done to
prevent coolant flow with scale and other deposits
from entering the heater core.
Connect the water supply hose and air supply hose
to the flushing gun. Allow the engine to fill with wa-
ter. When the engine is filled, apply air in short
blasts, allowing the system to fill between air blasts.
Continue until clean water flows through the lead
away hose. For more information, refer to operating
instructions supplied with flushing equipment.
Remove the lead away hose, flushing gun, water
supply hose and air supply hose. Remove the thermo-
stat housing and install thermostat. Install the ther-
mostat housing with a replacement gasket. Refer to
Thermostat Replacement. Connect the radiator
hoses. Refill the cooling system with the correct an-
tifreeze/water mixture.
CHEMICAL CLEANING
In some instances, use a radiator cleaner (Mopar
Radiator Kleen or equivalent) before flushing. This
will soften scale and other deposits and aid the flush-
ing operation.
CAUTION: Be sure instructions on the container are
followed.
TESTING COOLING SYSTEM FOR LEAKS
ULTRAVIOLET LIGHT METHOD
All Jeep models have a leak detection additive
added to the cooling system before they leave the fac-
tory. The additive is highly visible under ultraviolet
light (black light). If the factory original coolant has
been drained, pour one ounce of additive into the
cooling system. The additive is available through the
part's department. Place the heater control unit in
HEAT position. Start and operate the engine until
the radiator upper hose is warm to the touch. Aim
the commercially available black light tool at the
components to be checked. If leaks are present, the
black light will cause the additive to glow a bright
green color.
The black light can be used along with a pressure
tester to determine if any external leaks exist (Fig.
20).
PRESSURE TESTER METHOD
The engine should be at the normal operating tem-
perature. Recheck the system cold if the cause of
coolant loss is not located during warm engine exam-
ination.
7 - 22 COOLING SYSTEM SERVICE PROCEDURESJ

WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING.
Carefully remove the radiator pressure cap from
the filler neck and check the coolant level. Push
down on the cap to disengage it from the stop tabs.
Wipe the inner part of the filler neck and examine
the lower inside sealing seat for nicks, cracks, paint,
dirt and solder residue. Inspect the reserve/overflow
tank tube for internal obstructions. Insert a wire
through the tube to be sure it is not obstructed.
Inspect the cams on the outside part of the filler
neck. If the cams are bent, seating of pressure cap
valve and tester seal will be affected. Replace cap if
cams are bent.
Attach pressure tester 7700 (or an equivalent) to
the radiator filler neck (Fig. 21).Operate the tester pump to apply 124 kPa (18 psi)
pressure to the system. If the hoses enlarge exces-
sively or bulge while testing, replace as necessary.
Observe the gauge pointer and determine the condi-
tion of the cooling system according to the following
criteria:
²Holds Steady: If the pointer remains steady for
two minutes, there are no serious coolant leaks in
the system. However, there could be an internal leak
that does not appear with normal system test pres-
sure. Inspect for interior leakage or do the Internal
Leakage Test. Do this if it is certain that coolant is
being lost and no leaks can be detected.
²Drops Slowly: Shows a small leak or seepage is oc-
curring. Examine all connections for seepage or slight
leakage with a flashlight. Inspect the radiator, hoses,
gasket edges and heater. Seal any small leak holes
with a Sealer Lubricant or equivalent. Repair leak
holes and reinspect the system with pressure ap-
plied.
²Drops Quickly: Shows that a serious leakage is oc-
curring. Examine the system for serious external
leakage. If no leaks are visible, inspect for internal
leakage. Large radiator leak holes should be repaired
by a reputable radiator repair shop.
INTERNAL LEAKAGE INSPECTION
Remove the engine oil pan drain plug and drain a
small amount of engine oil. Coolant, being heavier
than engine oil, will drain first. Another way of test-
ing is to operate the engine and check for water glob-
ules on the engine oil dipstick. Also inspect the
automatic transmission oil dipstick for water glob-
ules. Inspect the automatic transmission fluid cooler
for leakage. Operate the engine without the pressure
cap on the radiator until thermostat opens.
Attach a pressure tester to the filler neck. If pres-
sure builds up quickly, a leak exists as a result of a
faulty cylinder head gasket or crack in the engine.
Repair as necessary.
WARNING: DO NOT ALLOW PRESSURE TO EX-
CEED 124 KPA (18 PSI). TURN THE ENGINE OFF.
TO RELEASE THE PRESSURE, ROCK THE TESTER
FROM SIDE TO SIDE. WHEN REMOVING THE
TESTER, DO NOT TURN THE TESTER MORE THAN
1/2 TURN IF THE SYSTEM IS UNDER PRESSURE.
If there is no immediate pressure increase, pump
the pressure tester until the indicated pressure is
within the system range. Vibration of the gauge
pointer indicates compression or combustion leakage
into the cooling system.
WARNING: DO NOT DISCONNECT THE SPARK
PLUG WIRES WHILE THE ENGINE IS OPERATING.
Fig. 20 Leak Detection Using Black LightÐTypical
Fig. 21 Pressurizing SystemÐTypical
JCOOLING SYSTEM SERVICE PROCEDURES 7 - 23

CAUTION: Do not operate the engine with a spark
plug shorted for more than a minute. The catalytic
converter may be damaged.
Isolate the compression leak by shorting each
spark plug to the cylinder block. The gauge pointer
should stop or decrease vibration when spark plug
for leaking cylinder is shorted. This happens because
of the absence of combustion pressure.
COMBUSTION LEAKAGE TEST (WITHOUT
PRESSURE TESTER)
DO NOT WASTE reusable coolant. If the solution
is clean, drain the coolant into a clean container for
reuse.
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR
DRAINCOCK WITH THE SYSTEM HOT AND UNDER
PRESSURE. SERIOUS BURNS FROM COOLANT
CAN OCCUR.
Drain sufficient coolant to allow for thermostat re-
moval. Refer to Thermostat Replacement. Disconnect
the water pump drive belt.
Disconnect the upper radiator hose from the ther-
mostat housing. Remove the housing and thermostat.
Install the thermostat housing.
Add coolant to the radiator to bring the level to
within 6.3 mm (1/4 in) of the top of the thermostat
housing.
CAUTION: Avoid overheating. Do not operate the
engine for an excessive period of time. Open the
draincock immediately after the test to eliminate
boil over of coolant.
Start the engine and accelerate rapidly three times
(to approximately 3000 rpm) while observing the
coolant. If internal engine combustion gases are leak-
ing into the cooling system, bubbles will appear in
the coolant. If bubbles do not appear, there is no in-
ternal combustion gas leakage.
COOLANT RESERVE/OVERFLOW SYSTEM
The system works along with the radiator pressure
cap. This is done by using thermal expansion and
contraction of the coolant to keep the coolant free of
trapped air. It provides:
²A volume for coolant expansion and contraction.
²A convenient and safe method for checking/adjust-
ing coolant level at atmospheric pressure. This is
done without removing the radiator pressure cap.
²Some reserve coolant to the radiator to cover mi-
nor leaks and evaporation or boiling losses.
As the engine cools, a vacuum is formed in the
cooling system of both the radiator and engine. Cool-ant will then be drawn from the coolant tank and re-
turned to a proper level in the radiator.
The coolant reserve/overflow system consists of a
radiator mounted pressurized cap, a plastic reserve/
overflow tank (Figs. 22, 23 or 24), a tube (hose) con-
necting the radiator and tank, and an overflow tube
on the side of the tank.
Fig. 22 Reserve/Overflow TankÐYJ Models
Fig. 23 Reserve/Overflow TankÐXJ ModelsÐExcept
Right Hand Drive
7 - 24 COOLING SYSTEM SERVICE PROCEDURESJ

(4) When checking for vacuum leaks.
WARNING: IF VEHICLE HAS BEEN RUN RECENTLY,
WAIT AT LEAST 15 MINUTES BEFORE REMOVING
RADIATOR CAP. WITH A RAG, SQUEEZE RADIATOR
UPPER HOSE TO CHECK IF SYSTEM IS UNDER
PRESSURE. PLACE A RAG OVER THE CAP AND
WITHOUT PUSHING DOWN, ROTATE CAP
COUNTER-CLOCKWISE TO THE FIRST STOP. AL-
LOW FLUID TO ESCAPE THROUGH OVERFLOW
HOSE INTO COOLANT RESERVE/OVERFLOW
TANK. SQUEEZE RADIATOR UPPER HOSE TO DE-
TERMINE WHEN PRESSURE HAS BEEN RE-
LEASED. WHEN COOLANT AND STEAM STOP
BEING PUSHED INTO TANK AND SYSTEM PRES-
SURE DROPS, REMOVE RADIATOR CAP COM-
PLETELY.
PRESSURE TESTING RADIATOR CAPS
Remove cap from radiator. Be sure that sealing
surfaces are clean. Moisten rubber gasket with water
and install the cap on pressure tester (tool 7700 or
an equivalent) (Fig. 26).
Operate the tester pump and observe the gauge
pointer at its highest point. The cap release pressure
should be 83-to-110 kPa (12-to-16 psi). The cap is sat-
isfactory when the pressure holds steady. It is also
good if it holds pressure within the 83-to-110 kPa
(12-to-16 psi) range for 30 seconds or more. If the
pointer drops quickly, replace the cap.
CAUTION: Radiator pressure testing tools are very
sensitive to small air leaks, which will not causecooling system problems. A pressure cap that does
not have a history of coolant loss should not be re-
placed just because it leaks slowly when tested
with this tool. Add water to tool. Turn tool upside
down and recheck pressure cap to confirm that cap
needs replacement.
INSPECTION
Visually inspect the pressure valve gasket on the
cap. Replace cap if the gasket is swollen, torn or
worn. Inspect the area around radiator filler neck for
white deposits that indicate a leaking cap.
RADIATORS
GENERAL INFORMATION
All radiators are down flow types except XJ models
equipped with 4.0L 6-cylinder engines. Radiators in
XJ models equipped with the 4.0L 6-cylinder engine
are the cross flow type. Plastic tanks are used on all
radiators.
CAUTION: Plastic tanks, while stronger than brass,
are subject to damage by impact, such as
wrenches.
If the plastic tank has been damaged, the plastic
tank and/or o-rings are available for service repair.
Tank replacement should be done by qualified per-
sonal with proper equipment.
RADIATOR COOLANT FLOW CHECK
The following procedure will determine if coolant is
flowing through the cooling system.
If engine is cold, idle engine until normal operating
temperature is reached. Then feel the upper radiator
hose. If hose is hot, the thermostat is open and water
is circulating through cooling system.
RADIATOR CLEANING
The radiator and air conditioning fins should be
cleaned when an accumulation of bugs, leaves etc.
has occurred. Clean radiator fins are necessary for
good heat transfer. With the engine cold, apply cold
water and compressed air to the back (engine side) of
the radiator to flush the radiator and/or A/C con-
denser of debris.
RADIATOR REMOVAL/INSTALLATION
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS, RADIATOR CAP, OR
LOOSEN THE RADIATOR DRAINCOCK WITH THE
SYSTEM HOT AND PRESSURIZED. SERIOUS
BURNS FROM THE COOLANT CAN OCCUR.
DO NOT WASTE reusable coolant. If solution is
clean, drain coolant into a clean container for reuse.
Fig. 26 Pressure Testing Radiator Pressure
CapÐTypical
7 - 26 COOLING SYSTEM SERVICE PROCEDURESJ

WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094) (FIG. 27). SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS. AL-
WAYS WEAR SAFETY GLASSES WHEN SERVICING
CONSTANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps (Fig. 28). If re-
placement is necessary, use only an original equip-
ment clamp with matching number or letter.XJ MODELS WITH 2.5L 4-CYLINDER ENGINE
REMOVAL
(1) Disconnect negative battery cable at battery.
(2) Observe the previousWARNINGS.Remove ra-
diator cap.
(3) Position drain pan under draincock. Open radi-
ator draincock. Drain radiator.
(4) Remove radiator upper and lower hose clamps
(Figs. 27 and 28). Remove hoses.
(5) Remove E-clip from alignment dowel at radia-
tor lower mounting bracket (Fig. 29).
(6) Disconnect coolant reserve/overflow tank hose
from radiator.
(7) Remove four radiator fan shroud mounting
bolts (Fig. 29). Push shroud back against front of en-
gine.
(8) If equipped, disconnect and plug automatic
transmission fluid cooler lines. Refer to Group 21,
Transmission for procedures.
(9) Remove two radiator top mounting bolts (Fig.
29).
(10) (a) If equipped with air conditioning, remove
the radiator grille mounting screws and remove grill.
Refer to Group 23, Body for procedures.
(b) If equipped, remove the air conditioning con-
denser-to-radiator mounting bolt. Use an open end
wrench to remove bottom bolts (Fig. 30).
(11) Lift radiator straight up and out of vehicle.
Take care not to damage radiator fins. When remov-
ing radiator, note position of the rubber seals located
on the top, bottom and sides of radiator (Fig. 29). To
prevent possible overheating, these seals must be in-
stalled to their original positions.
INSTALLATION
(1) Install radiator behind air conditioning con-
denser with bottom alignment dowel inserted into ra-
diator lower mounting bracket (Fig. 29).
(2) Install E-clip to radiator alignment dowel (Fig.
29).
(3) Tighten the four condenser-to-radiator mount-
ing bolts to 6.2 Nzm (55 in. lbs.) torque.
(4) If removed, install radiator grille.
(5) Tighten radiator top mounting bolts to 6 Nzm
(55 in. lbs.) torque.
(6) If equipped, connect automatic transmission
fluid cooler lines to radiator. Refer to Group 21,
Transmission for procedures.
(7) Install the radiator fan shroud.
(8) Connect the coolant reserve/overflow tank hose.
(9) Connect radiator hoses and install hose clamps.
(10) Connect negative battery cable.
(11) Close the draincock.
(12) Fill cooling system with correct coolant.
(13) Install radiator cap.
(14) Check and adjust automatic transmission
fluid level (if equipped).
Fig. 27 Hose Clamp ToolÐTypical
Fig. 28 Clamp Number/Letter Location
JCOOLING SYSTEM SERVICE PROCEDURES 7 - 27

XJ MODELS WITH 4.0L 6-CYLINDER ENGINE
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS OR LOOSEN THE RADIATORDRAINCOCK WITH THE SYSTEM HOT AND PRES-
SURIZED. SERIOUS BURNS FROM THE COOLANT
CAN OCCUR.
DO NOT WASTE reusable coolant. If solution is
clean, drain coolant into a clean container for reuse.
WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094) (FIG. 27). SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS. AL-
WAYS WEAR SAFETY GLASSES WHEN SERVICING
CONSTANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps (Fig. 28). If re-
placement is necessary, use only an original equip-
ment clamp with matching number or letter.
REMOVAL
(1) Disconnect negative battery cable at battery.
(2) Observe the previousWARNINGS.
(3) Remove pressure cap.
Fig. 29 Radiator Remove/InstallÐXJ ModelsÐ2.5L 4-Cylinder Engine
Fig. 30 Condenser Mounting BoltsÐXJ ModelsÐ
2.5L 4-Cylinder EngineÐTypical
7 - 28 COOLING SYSTEM SERVICE PROCEDURESJ

(13) Remove four radiator upper crossmember
bolts (Fig. 32) and remove upper crossmember.
(14) If equipped with air conditioning, separate ra-
diator from condenser by removing condenser-to-radi-
ator mounting brackets (Fig. 33).
(15) Lift radiator straight up and out of engine
compartment taking care not to damage fins.
INSTALLATION
The radiator is supplied with two alignment dowels
(Figs. 32 or 34). They are located on the bottom tank
and fit into rubber grommets in the radiator lower
crossmember.
(1) Lower radiator into engine compartment. Posi-
tion alignment dowels into rubber grommets in radi-
ator lower crossmember (Figs. 32 or 34).
(2) If equipped with air conditioning, attach con-
denser to radiator with mounting brackets (Fig. 33).
(3) Install radiator upper crossmember and four
mounting bolts.
(4) Install radiator upper crossmember-to-isolator
nuts. Tighten nuts to 10 Nzm (86 in. lbs.) torque. If
isolator-to-radiator nuts had been removed, tighten
them to 5 Nzm (47 in. lbs.) torque.
(5) Install hood latch striker. Note previously
marked position.
(6) Connect radiator upper and lower hoses.
(7) If equipped, connect automatic transmission
fluid cooler lines. Refer to Group 21, Transmissions
for procedures. If equipped with remote cooler, attach
cooler line to bracket at bottom of radiator.
(8) Install electric cooling fan (if equipped). Insert
alignment tabs at bottom of fan shroud into slots inbracket at bottom of radiator. Tighten mounting bolts
to3Nzm (31 in. lbs.) torque.
(9) Connect electric cooling fan electrical connector.
(10) Install mechanical cooling fan shroud. Insert
alignment tabs at bottom of shroud into slots in
bracket at bottom of radiator. Tighten mounting bolts
to3Nzm (31 in. lbs.) torque.
(11) Close radiator draincock.
(12) Install grille.
(13) Connect negative battery cable.
(14) Fill cooling system with correct coolant. Refer
to the Coolant section of this group.
(15) Install pressure cap.
(16) Check and adjust automatic transmission
fluid level (if equipped).
YJ MODELS
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR
DRAINCOCK WITH THE SYSTEM HOT AND PRES-
SURIZED. SERIOUS BURNS FROM THE COOLANT
CAN OCCUR.
DO NOT WASTE reusable coolant. If solution is
clean, drain coolant into a clean container for reuse.
WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094) (FIG. 27). SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS. AL-
Fig. 33 Condenser-to-Radiator Mounting BracketsÐ
XJ with 4.0L 6- Cylinder Engine
Fig. 34 Radiator InstallationÐXJ Models with 4.0L
6-Cylinder Engine
7 - 30 COOLING SYSTEM SERVICE PROCEDURESJ

(10) Check and adjust automatic transmission
fluid level (if equipped).
COOLING SYSTEM HOSES
Rubber hoses route coolant to and from the radia-
tor, intake manifold and heater core. All XJ models
equipped with air conditioning have a coolant control
valve. This is located in-line with the heater core in-
let and outlet hoses. It controls coolant flow to the
heater core when the air conditioning system is in
operation.
Radiator lower hoses are spring-reinforced to pre-
vent collapse from water pump suction at moderate
and high engine speeds.
WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094) (FIG. 36). SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS. AL-
WAYS WEAR SAFETY GLASSES WHEN SERVICING
CONSTANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps (Fig. 37). If re-
placement is necessary, use only an original equip-
ment clamp with matching number or letter.
Inspect the hoses at regular intervals. Replace
hoses that are cracked, feel brittle when squeezed, or
swell excessively when the system is pressurized.
For all vehicles: In areas where specific routing
clamps are not provided, be sure that hoses are posi-
tioned with sufficient clearance. Check clearance
from exhaust manifolds and pipe, fan blades, drive
belts and sway bars. Improperly positioned hoses can
be damaged, resulting in coolant loss and engine
overheating.Ordinary worm gear type hose clamps (when
equipped) can be removed with a straight screw-
driver or a hex socket.To prevent damage to
hoses or clamps, the hose clamps should be
tightened to 4 Nzm (34 in. lbs.) torque. Do not
over tighten hose clamps.
When performing a hose inspection, inspect the ra-
diator lower hose for proper position and condition of
the internal spring.
COOLING SYSTEM FANS
Also refer to either the Viscous Fan Drive and/or
the Auxiliary Electric Cooling FanÐXJ Models With
4.0L Engine sections for additional information.
All models are equipped with a mechanical temper-
ature controlled fan. This thermal viscous fan drive
(Fig. 38) is a torque-and-temperature-sensitive clutch
unit. It automatically increases or decreases fan
speed to provide proper engine cooling. XJ models
equipped with a 4.0L 6-cylinder engine may also
have an auxiliary electrical cooling fan. This is with
models that have air conditioning and/or heavy duty
cooling.
REMOVAL
Some engines have the mechanical fan/viscous fan
drive assembly mounted directly to the water pump
hub (Fig. 38). It may also be mounted to a hub/bear-
ing attached to an aluminum bracket on the right
front side of engine (Fig. 39).
(1) Loosen but do not remove at this time, the four
fan hub mounting nuts (Figs. 38 or 39).
Fig. 36 Hose Clamp ToolÐTypical
Fig. 37 Clamp Number/Letter Location
7 - 32 COOLING SYSTEM SERVICE PROCEDURESJ

(2) Remove accessory serpentine drive belt. Refer
to Belt Service in the Engine Accessory Drive Belt
section of this group.
(3) Some models with certain engines may require
the removal of the fan shroud to remove the viscous
fan drive. The fan shroud and fan blade/viscous fan
drive should be removed from the vehicle as one as-
sembly.
(4) Remove four fan hub mounting nuts (Figs. 38
or 39) and remove fan/viscous fan drive assembly
from vehicle.After removing fan blade/viscous fan drive assem-
bly,do notplace thermal viscous fan drive in hori-
zontal position. If stored horizontally, silicone fluid in
viscous fan drive could drain into its bearing assem-
bly and contaminate lubricant.
FAN BLADE INSPECTION
The fan blades cannot be repaired. If fan is dam-
aged, it must be replaced. Inspect fan as follows:
(1) Remove fan blade and viscous fan drive as an
assembly from the engine. Refer to preceding Re-
moval procedure.
(2) Remove fan blade assembly from viscous fan
drive unit (four bolts).
(3) Lay fan on a flat surface with leading edge fac-
ing down. With tip of blade touching flat surface, re-
place fan if clearance between opposite blade and
surface is greater than 2.0 mm (.090 inch). Rocking
motion of opposite blades should not exceed 2.0 mm
(.090 inch). Test all blades in this manner.
WARNING: DO NOT ATTEMPT TO BEND OR
STRAIGHTEN FAN BLADES IF NOT WITHIN SPECI-
FICATIONS.
(4) Inspect fan assembly for cracks, bends, loose
rivets or broken welds. Replace fan if any damage is
found.
CAUTION: If fan blade assembly is replaced be-
cause of mechanical damage, water pump and vis-
cous fan drive should also be inspected. These
components could have been damaged due to ex-
cessive vibration.
INSTALLATION
(1) Assemble fan blade to viscous fan drive.
Tighten mounting bolts to 27 Nzm (20 ft. lbs.) torque.
(2) Position mounting flange of fan blade/viscous
fan drive assembly onto hub. Install four nuts and
tighten to 24 Nzm (18 ft. lbs.) torque. Tighten the
first two nuts 180 degrees apart. Then tighten last
two nuts.
CAUTION: When installing a serpentine accessory
drive belt, the belt MUST be routed correctly. If not,
the engine may overheat due to the water pump ro-
tating in the wrong direction. Refer to appropriate
Engine Accessory Drive Belt Schematic in this
group for correct belt routing.
(3) Install accessory drive belts. Tension belts to
specifications. Refer to the Specifications section at
the end of this group.
Fig. 38 Water Pump Mounted Cooling Fan
Fig. 39 Bracket Mounted Cooling Fan
JCOOLING SYSTEM SERVICE PROCEDURES 7 - 33