engine JEEP XJ 1995 Service And Manual PDF

(4) Position clutch disc on flywheel. Be sure side of
disc marked flywheel side is positioned against fly-
wheel (Fig. 2). If disc is not marked, be sure flat side
of disc hub is toward flywheel.
(5) Inspect condition of pressure plate surface of
clutch cover (Fig. 2). Replace cover if this surface is
worn, heat checked, cracked, or scored.
(6) Insert clutch alignment tool in clutch disc (Fig.
3).
(7) Insert alignment tool in pilot bearing and posi-
tion disc on flywheel. Be sure disc hub is positioned
correctly. Side of hub marked Flywheel Side should
face flywheel (Fig. 2). If disc is not marked, place flat
side of disc against flywheel.
(8) Position clutch cover over disc and on flywheel
(Fig. 3).
(9) Install clutch cover bolts finger tight.(10) Tighten cover bolts evenly and in rotation a
few threads at a time.Cover bolts must be tight-
ened evenly and to specified torque to avoid
distorting cover. Tightening torques are 31 Nzm
(23 ft. lbs.) on 2.5L engines and 54 Nzm (40 ft.
lbs.) on 4.0L engines.
(11) Apply light coat of Mopar high temperature
bearing grease to pilot bearing hub and splines of
transmission input shaft.Do not overlubricate
shaft splines. This will result in grease contam-
ination of disc.
(12) Install transmission (Figs. 4 and 5). Refer to
procedures in Group 21.
RELEASE BEARING REPLACEMENT
(1) Remove transmission as described in Group 21.
Fig. 2 Clutch Disc And Pressure Plate InspectionFig. 3 Typical Method Of Aligning Clutch Disc
Fig. 4 Manual Transmission Mounting (4.0L)
JCLUTCH SERVICE 6 - 11

(8) Install transmission. Refer to Group 21 for pro-
cedure.
CLUTCH HOUSING REPLACEMENT
The clutch housing is removable and can be re-
placed when the transmission is out of the vehicle.
The bolts attaching the housing to the transmission
case are located inside the housing (Fig. 8). Recom-
mended tightening torque for the clutch housing-to-
transmission bolts is 38 Nzm (28 ft. lbs.).
Be sure the transmission and housing mating
surfaces are clean before installing an original,
or replacement clutch housing. Dirt/foreign ma-
terial trapped between the housing and trans-
mission will cause misalignment. If
misalignment is severe enough, the result will
be clutch drag, incomplete release and hard
shifting.
CLUTCH HYDRAULIC LINKAGE REMOVAL
The clutch master cylinder, slave cylinder
and connecting line are serviced as an assem-
bly only. The linkage components cannot be
overhauled or serviced separately. The cylin-
ders and connecting line are sealed units. Also
note that removal/installation procedures forright and left hand drive models are basically
the same. Only master cylinder location is dif-
ferent.
(1) Raise vehicle.
(2) Remove fasteners attaching slave cylinder to
clutch housing.
(3) Remove slave cylinder from clutch housing (Fig.
9).
(4) Disengage clutch fluid line from body clips.
(5) Lower vehicle.
(6) Verify that cap on clutch master cylinder reser-
voir is tight. This is necessary to avoid undue spill-
age during removal.
(7) Remove clutch master cylinder attaching nuts.
Note that one nut is accessible from engine compart-
ment and one nut is accessible from under instru-
ment panel (Figs. 10 and 11).
(8) Remove clip securing clutch master cylinder
push rod to pedal and slide push rod off pedal pin.
(9) Disconnect clutch pedal position switch wires.
(10) If pedal pin is equipped with bushing, inspect
condition of bushing and replace it if worn or dam-
aged.
(11) Remove clutch hydraulic linkage through en-
gine compartment.
Fig. 8 Clutch Housing AttachmentFig. 7 Pilot Bearing Installation
JCLUTCH SERVICE 6 - 13

CLUTCH HYDRAULIC LINKAGE INSTALLATION
(1) Be sure reservoir cover on clutch master cylin-
der is tight to avoid spills.
(2) Position clutch linkage components in vehicle.
Work connecting line and slave cylinder downward
past engine and adjacent to clutch housing.
(3) Position clutch master cylinder on dash panel
(Fig. 12).
(4) Attach clutch master cylinder push rod to pin
on clutch pedal. Secure rod with new clip if neces-
sary.
(5) Install and tighten clutch master cylinder at-
taching nuts to 23-34 Nzm (200-300 in. lbs.) torque.
(6) Raise vehicle.
(7) Insert slave cylinder push rod through clutch
housing opening and into release lever. Be sure cap
on end of rod is securely engaged in lever. Check this
before installing cylinder attaching nuts.
(8) Install and tighten slave cylinder attaching
nuts to 23-34 Nzm (200-300 in. lbs.) torque.
(9) Secure clutch fluid line in body clips.
(10) Lower vehicle.
(11) Connect clutch pedal position switch wires.
CLUTCH FLUID LEVEL
The clutch fluid reservoir, master cylinder, slave
cylinder and fluid lines are prefilled with fluid at the
factory during assembly operations.
The hydraulic system should not require additional
fluid under normal circumstances. In fact,the reser-
voir fluid level will actually increase as normal
clutch wear occurs. For this reason, it is impor-
tant to avoid overfilling, or removing fluid from
the reservoir.
Fig. 9 Slave Cylinder Attachment
Fig. 10 Clutch Master Cylinder And Push Rod
Attachment (Left Hand Drive Models)
Fig. 11 Clutch Master Cylinder Location (Right Hand
Drive Models)
Fig. 12 Clutch Master Cylinder Mounting (Typical)
6 - 14 CLUTCH SERVICEJ

COOLING SYSTEM
CONTENTS
page page
DIAGNOSIS............................. 4
ENGINE ACCESSORY DRIVE BELTS......... 38
ENGINE BLOCK HEATER.................. 44GENERAL INFORMATION.................. 1
SERVICE PROCEDURES.................. 13
SPECIFICATIONS........................ 45
GENERAL INFORMATION
Throughout this group, references are made to par-
ticular vehicle models by alphabetical designation
(XJ or YJ) or by the particular vehicle nameplate. A
chart showing a breakdown of alphabetical designa-
tions is included in the Introduction section at the
beginning of this manual.
COOLING SYSTEM
The cooling system regulates engine operating tem-
perature. It allows the engine to reach normal oper-
ating temperature as quickly as possible, maintains
normal operating temperature and prevents over-
heating.
The cooling system also provides a means of heat-
ing the passenger compartment and cooling the auto-
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump to circulate coolant throughout the system.
An optional factory installed heavy duty cooling
package is available on most models. The package
consists of a radiator that has an increased number
of cooling fins. XJ models equipped with a 4.0L 6-cyl-inder engine and heavy duty cooling and/or air con-
ditioning also have an auxiliary electric cooling fan.
COOLING SYSTEM COMPONENTS
The cooling system consists of:
²A radiator
²Cooling fan (mechanical and/or electrical)
²Thermal viscous fan drive
²Fan shroud
²Radiator pressure cap
²Thermostat
²Coolant reserve/overflow system
²Transmission oil cooler (if equipped with an auto-
matic transmission)
²Coolant
²Water pump
²Hoses and hose clamps
SYSTEM COOLANT ROUTING
For cooling system flow routings, refer to Figs. 1, 2,
3or4.
JCOOLING SYSTEM 7 - 1

Fig. 1 Coolant FlowÐXJ Models with 2.5L 4-Cylinder EngineÐTypical
Fig. 2 Coolant FlowÐYJ Models with 2.5L 4-Cylinder EngineÐTypical
7 - 2 COOLING SYSTEMJ

Fig. 3 Coolant FlowÐXJ Models with 4.0L 6-
Cylinder EngineÐTypicalFig. 4 Coolant FlowÐYJ Models with 4.0L 6-
Cylinder EngineÐTypical
JCOOLING SYSTEM 7 - 3

DIAGNOSIS
INDEX
page page
DRB Scan Tool............................ 5
On-Board Diagnostics (OBD).................. 4Preliminary Checks......................... 5
ON-BOARD DIAGNOSTICS (OBD)
FOR CERTAIN COOLING SYSTEM
COMPONENTS
The powertrain control module (PCM) has been
programmed to monitor the certain following cooling
system components:
²If the engine has remained cool for too long a pe-
riod, such as with a stuck open thermostat, a Diag-
nostic Trouble Code (DTC) number 17 can be
observed at the malfunction indicator lamp. This
lamp is displayed on the instrument panel as the
CHECK ENGINE lamp (Figs. 5 or 6).
²If an open or shorted condition has developed in
the relay circuit controlling the electric radiator fan,
a Diagnostic Trouble Code (DTC) number 35 can be
observed at the CHECK ENGINE lamp (XJ models
only).
If the problem is sensed in a monitored circuit of-
ten enough to indicate an actual problem, a DTC is
stored. The DTC will be stored in the PCM memory
for eventual display to the service technician. If theproblem is repaired or ceases to exist, the PCM can-
cels the DTC after 51 engine starts.
Certain criteria must be met for a DTC to be en-
tered into PCM memory. The criteria may be a spe-
cific range of engine rpm, engine temperature and/or
input voltage to the PCM.
A DTC indicates that the PCM has recognized an
abnormal signal in a circuit or the system. A DTC
may indicate the result of a failure, but never iden-
tify the failed component directly.
It is possible that a DTC for a monitored circuit
may not be entered into memory even though a mal-
function has occurred. Refer to On-Board Diagnostics
(OBD) in Group 14, Fuel Systems for additional DTC
information.
ACCESSING DIAGNOSTIC TROUBLE CODES
A stored Diagnostic Trouble Code (DTC) can be dis-
played by cycling the ignition key On-Off-On-Off-On
within three seconds and observing the malfunction
indicator lamp. This lamp is displayed on the instru-
ment panel as the CHECK ENGINE lamp (Figs. 5 or
6).
They can also be displayed through the use of the
Diagnostic Readout Box (DRB) scan tool. The DRB
connects to the data link connector in the engine
compartment (Figs. 7 or 8). For operation of the
DRB, refer to the appropriate Powertrain Diagnostic
Procedures service manual.
Fig. 5 Check Engine LampÐXJ ModelsÐTypical
Fig. 6 Check Engine LampÐYJ ModelsÐTypical
7 - 4 COOLING SYSTEM DIAGNOSISJ

EXAMPLES:
²If the lamp (Figs. 5 or 6) flashes 1 time, pauses
and flashes 2 more times, a flashing Diagnostic Trou-
ble Code (DTC) number 12 is indicated. If this code is
observed, it is indicating that the battery has been
disconnected within the last 50 key-on cycles. It
could also indicate that battery voltage has been dis-
connected to the PCM. In either case, other DTC's
may have been erased.
²If the lamp flashes 1 time, pauses and flashes 7
more times, a flashing Diagnostic Trouble Code
(DTC) number 17 is indicated.
²If the lamp flashes 3 times, pauses and flashes 5
more times, a flashing Diagnostic Trouble Code
(DTC) number 35 is indicated.
After any stored DTC information has been ob-
served, the display will end with a flashing DTC
number 55. This will indicate the end of all stored in-
formation.
ERASING TROUBLE CODES
After the problem has been repaired, the DRB scan
tool must be used to erase a DTC. Refer to the ap-
propriate Powertrain Diagnostic Procedures service
manual for operation of the DRB scan tool.
DRB SCAN TOOL
For operation of the DRB scan tool, refer to the ap-
propriate Powertrain Diagnostic Procedures service
manual.
PRELIMINARY CHECKS
ENGINE COOLING SYSTEM OVERHEATING
Establish what driving conditions caused the com-
plaint. Abnormal loads on the cooling system such as
the following may be the cause.
1. PROLONGED IDLE, VERY HIGH AMBIENT
TEMPERATURE, SLIGHT TAIL WIND AT IDLE,
SLOW TRAFFIC, TRAFFIC JAMS, HIGH
SPEED, OR STEEP GRADES:
Driving techniques that avoid overheating are:
²Idle with A/C off when temperature gauge is at
end of normal range.
²Increasing engine speed for more air flow is recom-
mended.
2. TRAILER TOWING:
Consult Trailer Towing section of owners manual.
Do not exceed limits.
3. AIR CONDITIONING; ADD-ON OR AFTER
MARKET:
A maximum cooling package should have been or-
dered with vehicle if add-on or after market A/C is
installed. If not, maximum cooling system compo-
nents should be installed for model involved per
manufacturer's specifications.
4. RECENT SERVICE OR ACCIDENT REPAIR:
Determine if any recent service has been performed
on vehicle that may effect cooling system. This may
be:
²Engine adjustments (incorrect timing)
²Slipping engine accessory drive belt(s)
²Brakes (possibly dragging)
²Changed parts (incorrect water pump rotating in
wrong direction)
²Reconditioned radiator or cooling system refilling
(possibly under-filled or air trapped in system).
If investigation reveals none of the previous
items as a cause for an engine overheating com-
plaint, refer to following Cooling System Diag-
nosis charts.
These charts are to be used as a quick-reference
only. Refer to the group text for information.
Fig. 7 Data Link ConnectorÐXJ ModelsÐTypical
Fig. 8 Data Link ConnectorÐYJ ModelsÐTypical
JCOOLING SYSTEM DIAGNOSIS 7 - 5

SERVICE PROCEDURES
INDEX
page page
Auxiliary Electric Cooling FanÐXJ Models with 4.0L
6-Cylinder Engine....................... 35
Coolant................................. 20
Coolant Reserve/Overflow System............. 24
Cooling System Cleaning/Reverse Flushing...... 22
Cooling System Fans...................... 32
Cooling System Hoses..................... 32
Draining Cooling System.................... 21
Radiator Pressure Cap..................... 25
Radiators............................... 26Refilling Cooling System.................... 21
Testing Cooling System for Leaks............. 22
Thermostat.............................. 17
Transmission Oil Coolers.................... 36
Viscous Fan Drive......................... 34
Water Pump Tests......................... 13
Water PumpsÐGeneral Information............ 13
Water PumpsÐRemoval/Installation........... 14
WATER PUMPSÐGENERAL INFORMATION
A centrifugal water pump circulates coolant
through the water jackets, passages, intake manifold,
radiator core, cooling system hoses and heater core.
The pump is driven from the engine crankshaft by a
drive belt on all engines.
The water pump impeller is pressed onto the rear
of a shaft that rotates in bearings pressed into the
housing. The housing has a small hole to allow seep-
age to escape. The water pump seals are lubricated
by the antifreeze in the coolant mixture. No addi-
tional lubrication is necessary.
CAUTION: All engines are equipped with a reverse
(counter-clockwise) rotating water pump and vis-
cous fan drive assembly. REVERSE is stamped or
imprinted on the cover of the viscous fan drive and
inner side of the fan. The letter R is stamped into
the back of the water pump impeller (Fig. 1).
Engines from previous model years, depending
upon application, may have been equipped with a for-
ward (clockwise) rotating water pump. Installation of
the wrong water pump will cause engine overheating.
A quick test to determine if the pump is working is
to check if the heater warms properly. A defective wa-
ter pump will not be able to circulate heated coolant
through the long heater hose to the heater core.
WATER PUMP TESTS
LOOSE IMPELLER
DO NOT WASTE reusable coolant. If solution is
clean, drain 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 THE COOL-
ANT CAN OCCUR.(1) Drain the cooling system.
(2) Loosen the fan belt(s).
(3) Disconnect the lower radiator hose from the
water pump.
(4) Bend a stiff clothes hanger or welding rod as
shown in (Fig. 2).
(5) Position the rod in the water pump inlet and
attempt to hold the impeller while turning the fan
blades. If equipped with a viscous fan drive, turn the
water pump shaft with a breaker bar and socket at-
tached to a mounting flange nut. If the impeller is
loose and can be held with the rod while the fan
blades are turning, the pump is defective. If the im-
peller turns, the pump is OK.
Connect the hose and install the coolant, or proceed
with repairs.
Fig. 1 Reverse Rotating Water PumpÐTypical
JCOOLING SYSTEM SERVICE PROCEDURES 7 - 13

INSPECTING FOR INLET RESTRICTIONS
Inadequate heater performance may be caused by a
metal casting restriction in the water pump heater
hose inlet.
DO NOT WASTE reusable coolant. If solution is
clean, drain 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 THE COOL-
ANT CAN OCCUR.
(1) Drain sufficient coolant from the radiator to de-
crease the level below the water pump heater hose
inlet.
(2) Remove the heater hose.
(3) Inspect the inlet for metal casting flash or
other restrictions.
Remove the pump from engine before remov-
ing restriction to prevent contamination of the
coolant with debris. Refer to Water Pump Re-
moval.
WATER PUMPSÐREMOVAL/INSTALLATION
REMOVALÐALL MODELS
CAUTION: If the water pump is replaced because of
mechanical damage, the fan blades and viscous fan
drive should also be inspected. These components
could have been damaged due to excessive vibra-
tion.The water pump on all models can be removed
without discharging the air conditioning system (if
equipped).
CAUTION: All engines have a reverse (counter-
clockwise) rotating water pump. The letter R is
stamped into the back of the water pump impeller
(Fig. 1) to identify. Engines from previous model
years, depending upon application, may be
equipped with a forward (clockwise) rotating water
pump. Installation of the wrong water pump will
cause engine over heating.
The water pump impeller is pressed on the rear of
the pump shaft and bearing assembly. The water
pump is serviced only as a complete assembly.
WARNING: DO NOT REMOVE THE BLOCK DRAIN
PLUG(S) OR LOOSEN RADIATOR DRAINCOCK
WITH THE SYSTEM HOT AND UNDER PRESSURE.
SERIOUS BURNS FROM COOLANT CAN OCCUR.
DO NOT WASTE reusable coolant. If the solution
is clean, drain coolant into a clean container for re-
use.
(1) Disconnect negative battery cable at battery.
(2) Drain the cooling system. Refer to Draining
Cooling System in this group.
(3)XJ models with 4.0L 6-cylinder engine
equipped with A/C or heavy duty cooling sys-
tem:
Loosen (but do not remove at this time) the four
water pump pulley-to-water pump hub mounting
bolts (Fig. 3).
XJ models with 4.0L 6-cylinder engine with-
out A/C or heavy duty cooling system; or any
2.5L 4-cylinder engines; or any YJ models:
Loosen (but do not remove at this time) the four
fan hub-to-water pump pulley mounting nuts (Fig. 4).
Fig. 2 Impeller TestÐTypical
Fig. 3 Water Pump Pulley Bolts
7 - 14 COOLING SYSTEM SERVICE PROCEDURESJ