1995 JEEP XJ drain bolt

The amount of piston retraction is determined by
brakelining wear. Generally, the amount is just
enough to maintain contact between the piston and
inboard brakeshoe. Brakelining running clearance at
the rotor, will be held between zero and a maximum
of 0.12 mm (0.005 in.).
DISC BRAKESHOE REMOVAL
(1) Raise vehicle and remove front wheels.
(2) Drain small amount of fluid from master cylin-
der front brake reservoir with suction gun.
(3) Bottom caliper piston in bore with C-clamp. Po-
sition clamp screw on outboard brakeshoe and clamp
frame on rear of caliper. Typical C-clamp attachment
is shown in Figure 3.Do not allow clamp screw to
bear directly on outboard shoe retainer spring.
Use wood or metal spacer between shoe and
clamp screw if necessary.
(4) Remove caliper mounting bolts (Fig. 4).If
brakeshoes are being removed to correct a pull
or drag condition, verify length of caliper bolts
as they may be incorrect length. Refer to bolt
information in brakeshoe installation proce-
dure.
(5) Tilt top of caliper outward. Use pry tool if nec-
essary (Fig. 5).
(6) Lift caliper off steering knuckle (Fig. 6).(7)If original brakeshoes will be used, keep
them in sets (left and right); they are not inter-
changeable.
Fig. 2 Lining Wear Compensation By Piston Seal
Fig. 3 Bottoming Caliper Piston With C-Clamp
Fig. 4 Removing/Installing Caliper Mounting Bolts
Fig. 5 Tilting Caliper Outward
Fig. 6 Caliper Removal
5 - 46 DISC BRAKESJ

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

(11) Remove idler pulley mounting bolt and remove
idler pulley. This must be done to gain clearance for
the water pump mounted heater hose fitting when
water pump is being removed. Note position of pulley
spacers after removal.
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. 8). 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. 9). If re-
placement is necessary, use only an original equip-
ment clamp with matching number or letter.
(12) Remove lower radiator hose from water pump.
Remove heater hose from water pump fitting.
(13) Remove four nuts or bolts (refer to the previ-
ous step #3).
(14) Remove the fan blade assembly and pulley (if
fan is installed at pump), or remove the pulley from
the 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.
(15) Remove the four pump mounting bolts (Fig.
10) and remove pump from vehicle. Discard old gas-
ket. Note that one of the four bolts is longer than the
other bolts.(16) If pump is to be replaced, the heater hose fit-
ting must be removed. Note position of fitting before
removal.
Fig. 8 Hose Clamp ToolÐTypical
Fig. 9 Clamp Number/Letter Location
Fig. 10 Water Pump Remove/InstallÐTypical
7 - 16 COOLING SYSTEM SERVICE PROCEDURESJ

temperature, coolant is allowed to flow to the radia-
tor. This provides quick engine warmup and overall
temperature control.
An arrow plus the wordUPis stamped on the
front flange next to the air bleed. The wordsTO
RADare stamped on one arm of the thermostat.
They indicate the proper installed position.
The same thermostat is used for winter and sum-
mer seasons. An engine should not be operated with-
out a thermostat, except for servicing or testing.
Operating without a thermostat causes other prob-
lems. These are: longer engine warmup time, unreli-
able warmup performance, increased exhaust
emissions and crankcase condensation. This conden-
sation can result in sludge formation.
CAUTION: Do not operate an engine without a ther-
mostat, except for servicing or testing.
ON-BOARD DIAGNOSTICS
XJ and YJ models are equipped with On-Board Di-
agnostics for certain cooling system components. Re-
fer to On-Board Diagnostics (OBD) in the Diagnosis
section of this group for additional information. If the
powertrain control module (PCM) detects low engine
coolant temperature, it will record a Diagnostic Trou-
ble Code (DTC) in the PCM memory. The DTC num-
ber for low coolant temperature is 17. Do not change
a thermostat for lack of heat as indicated by the in-
strument panel gauge or heater performance unless a
DTC number 17 is present. Refer to the Diagnosis
section of this group for other probable causes. For
other DTC numbers, refer to On-Board Diagnostics
in the General Diagnosis section of Group 14, Fuel
Systems.
The DTC can also be accessed through the DRB
scan tool. Refer to the appropriate Powertrain Diag-
nostic Procedures manual for diagnostic information
and operation of the DRB scan tool.
REMOVAL
WARNING: DO NOT LOOSEN THE RADIATOR
DRAINCOCK WITH THE SYSTEM HOT AND PRES-
SURIZED. SERIOUS BURNS FROM THE COOLANT
CAN OCCUR.
DO NOT WASTE reusable coolant. If the solution
is clean, drain the coolant into a clean container for
reuse.
(1) Drain the coolant from the radiator until the
level is below the thermostat housing.
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. 15). 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. 16). If re-
placement is necessary, use only an original equip-
ment clamp with matching number or letter.
(2) Remove radiator upper hose and heater hose at
thermostat housing.
(3) Disconnect wiring connector at engine coolant
temperature sensor.
(4) Remove thermostat housing mounting bolts,
thermostat housing, gasket and thermostat (Fig. 17).
Discard old gasket.
(5) Clean the gasket mating surfaces.
Fig. 13 XJ Models with 4.0L 6-Cylinder EngineÐ
Without A/C
Fig. 14 XJ Models With 4.0L 6-Cylinder EngineÐ
With A/C
7 - 18 COOLING SYSTEM SERVICE PROCEDURESJ

INSTALLATION
(1) Install the replacement thermostat so that the
pellet, which is encircled by a coil spring, faces the
engine. All thermostats are marked on the outer
flange to indicate the proper installed position.
(a) Observe the recess groove in the engine cylin-
der head (Fig. 18).
(b) Position thermostat into this groove with ar-
row and air bleed hole on outer flange pointing up.
(2) Install replacement gasket and thermostat
housing.
CAUTION: Tightening the thermostat housing un-
evenly or with the thermostat out of its recess may
result in a cracked housing.(3) Tighten the housing bolts to 20 Nzm (15 ft. lbs.)
torque.
(4) Install hoses to thermostat housing.
(5) Install electrical connector to coolant tempera-
ture sensor.
(6) Be sure that the radiator draincock is tightly
closed. Fill the cooling system to the correct level
with the required coolant mixture. Refer to Refilling
Cooling System in this group.
(7) Start and warm the engine. Check for leaks.
Fig. 15 Hose Clamp ToolÐTypical
Fig. 16 Clamp Number/Letter Location
Fig. 17 Thermostat Removal/Installation
Fig. 18 Thermostat Recess
JCOOLING SYSTEM SERVICE PROCEDURES 7 - 19

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

(4) For access to radiator draincock, remove radia-
tor grille mounting screws and remove grill. Refer to
Group 23, Body for procedures.
(5) 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 radiator.
(6) If equipped, disconnect auxiliary electric cooling
fan electrical connector (Fig. 31).
(7) If equipped, remove two electric cooling fan
mounting bolts. Lift cooling fan straight up until
alignment tabs at the bottom are clear of slots in
bracket at bottom of radiator (Fig. 32).
(8) Remove the two mechanical (non-electrical) fan
shroud mounting bolts. Lift shroud straight up until
alignment tabs at the bottom are clear of slots in
bracket at bottom of radiator (Fig. 32). Place shroud
over mechanical fan.
(9) If equipped, disconnect and plug automatic
transmission fluid cooler lines. Refer to Group 21,
Transmissions for procedures. If equipped with re-
mote transmission cooler, remove line to cooler from
bracket at bottom of radiator.
(10) Disconnect radiator upper and lower hoses
clamps (Figs. 27 and 28). Disconnect radiator upper
and lower hoses.
(11) Mark the position of the hood latch striker on
the radiator crossmember and remove hood latch
striker.(12) Remove two radiator upper crossmember-to-
isolator nuts (Fig. 32).
Fig. 31 Auxiliary Electric Cooling Fan Wiring
ConnectorÐTypical
Fig. 32 Auxiliary Electric Cooling Fan and Fan ShroudÐTypical
JCOOLING SYSTEM SERVICE PROCEDURES 7 - 29