brake fluid JEEP XJ 1995 Service And Owner's Guide
[x] Cancel search | Manufacturer: JEEP, Model Year: 1995, Model line: XJ, Model: JEEP XJ 1995Pages: 2158, PDF Size: 81.9 MB
Page 181 of 2158

(16) Install combination valve as follows:
(a) Work combination valve and brakelines into
position.
(b) Slide combination valve bracket onto booster
stud closest to driver side fender (Fig. 25). Then in-
stall bracket attaching nut but do not fully tighten
nut at this time.
(c) Connect flex lines to HCU. Start lines by
hand to avoid cross threading.
(17) Swing rear brakeline around and connect it to
master cylinder. Then install and connect front
brakeline to combination valve and master cylinder.
Start brakelines by hand to avoid cross threading.
(18) Tighten combination valve bracket attaching
nut to 25 Nzm (220 in. lbs.) torque.
(19) Install clip on lines from master cylinder to
combination valve.
(20) Connect wire to pressure differential switch
on combination valve.
(21) Connect flex lines to HCU (Fig. 10). Start line
fittings by hand to avoid cross threading. Then
tighten fittings snug but not to required torque at
this time.(22) Bleed brakes. Refer to procedure in Brake
Fluid-Brake Bleeding-Brakelines And Hoses section.
(23) Tighten brakeline fittings to 15-18 Nzm (130-
160 in. lbs.) at HCU and master cylinder, and 18-24
Nzm (160-210 in. lbs.) at combination valve.
(24) Install air cleaner assembly.
(25) Connect vacuum lines to manifold fittings.
(26) Check brake pedal action before moving vehi-
cle. Bleed brakes again if pedal is not firm (feels soft/
spongy).POWER BRAKE BOOSTER REMOVAL (XJ WITHOUT
ABS)
(1) Disconnect vent and vacuum hose from engine
air cleaner cover.
(2) Remove engine air cleaner cover, filter, housing
and hoses (Fig. 4).
(3) Disconnect brakelines at master cylinder.
(4) Disconnect wire at combination valve differen-
tial pressure switch.
(5) If combination valve does not have an integral
bracket, disconnect brakelines at combination valve
and remove valve.
(6) If combination valve has integral bracket, re-
move nut attaching valve bracket to booster studs
and remove valve.
(7) Remove nuts attaching master cylinder to
booster studs and remove cylinder.
(8) Disconnect vacuum hose from booster check
valve.
(9) In passenger compartment, remove instrument
panel lower trim cover.
(10) Remove retaining clip that secures booster
push rod to brake pedal (Fig. 5).
Fig. 23 HCU And Bracket Mounting (RHD Models)
Fig. 24 Starting Brakelines In HCU
Fig. 25 Combination Valve Installation
JPOWER BRAKE BOOSTERÐBRAKE PEDALÐBRAKELIGHT SWITCH 5 - 29
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(11) Remove nuts attaching booster to passenger
compartment side of dash panel.
(12) In engine compartment, slide booster studs
out of dash panel, tilt booster upward, and remove
booster from engine compartment.
(13) Remove dash seal from booster.
(14) If booster is only being removed for access to
other components, cover booster front opening with
clean shop towel.
POWER BRAKE BOOSTER INSTALLATION (XJ
WITHOUT ABS)
(1) If original booster is being installed, test check
valve with vacuum tool before booster installation.
Replace check valve if it will not hold vacuum.
(2) Install dash seal on booster.
(3) Align and position booster on dash panel (Fig.
17).
(4) In passenger compartment, install nuts that at-
tach booster to dash panel. Tighten nuts just enough
to hold booster in place.
(5) Slide booster push rod onto brake pedal. Then
secure push rod to pedal pin with retaining clip.
(6) Tighten booster attaching nuts to 41 Nzm (30 ft.
lbs.) on XJ and 34 Nzm (25 ft. lbs.) on YJ.
(7) Install instrument panel lower trim cover.
(8) If original master cylinder is being installed,
check condition of seal at rear of master cylinder
(Fig. 18). Clean and reposition seal if dislodged. Re-
place seal if cut, or torn.
(9) Clean cylinder mounting surface of brake
booster. Use shop towel wetted with brake cleaner for
this purpose. Dirt, grease, or similar materials will
prevent proper cylinder seating and could result in
vacuum leak.
(10) Align and install master cylinder on booster
studs. Tighten cylinder attaching nuts to 13-25 Nzm
(115-220 in. lbs.) torque.
(11) Connect vacuum hose to booster check valve.
(12) Connect and secure brakelines to combination
valve and master cylinder. Start all brakeline fittings
by hand to avoid cross threading.
(13) If combination valve has integral bracket, po-
sition bracket on booster studs. Then install and
tighten bracket attaching nuts to 13-25 Nzm (115-220
in. lbs.) torque.
(14) Connect wire to combination valve switch.
(15) Top off master cylinder fluid level.
(16) Bleed brakes. Refer to procedures in section
on brake bleeding.
(17) Install engine air cleaner and hoses.
(18) Verify proper brake operation before moving
vehicle.
POWER BRAKE BOOSTER REMOVAL (YJ)
(1) Disconnect brakelines at master cylinder. Then
loosen lines at combination valve and move lines
away from cylinder.
(2) Remove nuts master cylinder to booster studs.
(3) If combination valve has integral bracket, slide
bracket off studs and move valve aside.
(4) Remove master cylinder. Slide cylinder off
studs and remove it from engine compartment.
(5) Working under instrument panel, remove re-
tainer clip that secures booster push rod to brake
pedal.
(6) Disconnect vacuum hose at booster check valve.
(7) On non-ABS models, remove nuts attaching
brake booster spacer to dash panel and remove
booster (Fig. 26).
(8) On ABS models, remove nuts attaching booster
to spacer and remove booster (Fig. 27).
POWER BRAKE BOOSTER INSTALLATION (YJ)
(1) Install seal on booster spacer, if equipped.
(2) Position booster on dash panel, or on spacer.
(3) Secure booster push rod to brake pedal with re-
taining clip.
(4) Install and tighten booster attaching nuts to
27-47 Nzm (20-35 ft. lbs.) torque. Nut torque applies
to both styles of booster.
Fig. 26 Booster Mounting (4-Cyl. Models)
Fig. 27 Booster Mounting (With ABS)
5 - 30 POWER BRAKE BOOSTERÐBRAKE PEDALÐBRAKELIGHT SWITCHJ
Page 185 of 2158

ABS OPERATION AND SERVICE
INDEX
page page
ABS Component Serviceability............... 37
ABS Diagnostic Connector.................. 35
ABS Operation in Antilock Braking Mode........ 36
ABS Operation in Normal Braking Mode........ 35
ABS System Power-Up and Initialization........ 35
Acceleration Switch........................ 35
Acceleration Switch Installation............... 39
Acceleration Switch Operation................ 37
Acceleration Switch Removal................ 39
Combination Valve........................ 34
ECU Installation (XJ Models)................. 40
ECU Operation........................... 37
ECU Removal (XJ Models).................. 40
ECU Removal/Installation (YJ Models).......... 41
Electronic Control Unit (ECU)................ 34
Front Wheel Sensor Installation............... 38
Front Wheel Sensor Removal................ 38HCU Installation (XJ)....................... 43
HCU Installation (YJ)....................... 44
HCU Operation........................... 36
HCU Removal (XJ)........................ 41
HCU Removal (YJ)........................ 44
Hydraulic Control Unit (HCU)................. 33
Ignition Switch........................... 35
Master Cylinder/Power Brake Booster.......... 34
Rear Wheel Sensor Installation and Adjustment . . . 38
Rear Wheel Sensor Removal................ 38
Speed Sensor Air Gap..................... 37
System Description........................ 33
System Relays........................... 35
System Warning Light...................... 35
Wheel Speed Sensor Operation.............. 37
Wheel Speed Sensors..................... 34
SYSTEM DESCRIPTION
The Jeep antilock brake system (ABS) is an elec-
tronically operated, all wheel brake control system.
The system is designed to prevent wheel lockup
and maintain steering control during periods of high
wheel slip when braking. Preventing lockup is accom-
plished by modulating fluid pressure to the wheel
brake units.
The hydraulic system is a three channel design.
The front wheel brakes are controlled individually
and the rear wheel brakes in tandem (Fig. 1). The
ABS electrical system is separate from other electri-
cal circuits in the vehicle. A specially programmed
electronic control unit (ECU) operates the system
components.
ABS system major components include:
²hydraulic control unit (HCU)
²electronic control unit (ECU)
²wheel speed sensors and axle shaft tone rings
²acceleration switch
²main relay and pump motor relay
²ABS warning light
²pump motor sensor
HYDRAULIC CONTROL UNIT (HCU)
The hydraulic control unit (HCU) consists of a
valve body, pump body, accumulators, pump motor,
and wire harnesses (Fig. 2).
The pump, motor, and accumulators are combined
into an assembly attached to the valve body. The ac-
cumulators store the extra fluid released to the sys-
tem for ABS mode operation. The pump provides the
fluid volume needed and is operated by a DC type
motor. The motor is controlled by the ECU.The valve body contains the solenoid valves. The
valves modulate brake pressure during antilock brak-
ing and are controlled by the ECU.
The HCU provides three channel pressure control
to the front and rear brakes. One channel controls
the rear wheel brakes in tandem. The two remaining
channels control the front wheel brakes individually.
During antilock braking, the solenoid valves are
opened and closed as needed. The valves are not static.
They are cycled rapidly and continuously to modulate
pressure and control wheel slip and deceleration.
Fig. 1 Jeep ABS System
JABS OPERATION AND SERVICE 5 - 33
Page 186 of 2158

MASTER CYLINDER/POWER BRAKE BOOSTER
A 25 mm bore master cylinder and 205 mm (8.07
in.) dual diaphragm power brake booster are used for
all ABS applications (Fig. 2).
The master cylinder has a removable plastic reser-
voir which is the only serviceable component. The
cylinder body and pistons are not repairable and are
serviced as an assembly. The check valve and grom-
met are the only serviceable parts on the booster.
The booster itself is only serviced as an assembly.
COMBINATION VALVE
A combination valve is used with the ABS system
(Fig. 2). The valve contains a front/rear brake pres-
sure differential switch and rear brake proportioning
valve. The combination valve is connected between
the master cylinder and HCU.
The pressure differential switch is connected to the
red brake warning light. The switch is actuated by
movement of the switch valve. The switch monitors
fluid pressure in the separate front/rear brake hy-
draulic circuits.
A decrease or loss of fluid pressure in either hy-
draulic circuit will cause the switch valve to shuttle
forward or rearward in response to the pressure dif-
ferential. Movement of the switch valve will push the
switch plunger upward. This closes the switch inter-
nal contacts completing the electrical circuit to the
red warning light. The switch valve remains in an
actuated position until the fault is repaired.
The rear proportioning valve is used to balance front-
rear brake action.
ELECTRONIC CONTROL UNIT (ECU)
A separate electronic control unit (ECU) operates
the ABS system (Fig. 3). The ECU is separate from
other vehicle electrical circuits. ECU voltage source
is through the ignition switch in the Run position.The ECU is located under the instrument panel in
the passenger compartment. On YJ models, it is just
above the heater plenum in line with the glove box.
In left hand drive XJ models, it at the right side of
the steering column. In right hand drive models, it is
near the cowl panel
The ECU contains dual microprocessors. A logic
block in each microprocessor receives identical sensor
signals. These signals are processed and compared si-
multaneously.
The ECU contains a self check program that illu-
minates the ABS warning light when a system fault
is detected. Faults are stored in a diagnostic program
memory and are accessible with the DRB scan tool.
ABS faults remain in memory until cleared, or un-
til after the vehicle is started approximately 50
times. Stored faults arenoterased if the battery is
disconnected.
WHEEL SPEED SENSORS
A speed sensor is used at each wheel. The sensors
convert wheel speed into an electrical signal. This
signal is transmitted to the antilock ECU.
A gear type tone ring serves as the trigger mecha-
nism for each sensor. The tone rings are mounted at
the outboard ends of the front and rear axle shafts.
Different sensors are used at the front and rear
wheels (Fig. 4). The front/rear sensors have the same
electrical values but are not interchangeable.
Fig. 2 ABS Master Cylinder-Booster-Combination
Valve-HCU
Fig. 3 Antilock ECU
5 - 34 ABS OPERATION AND SERVICEJ
Page 188 of 2158

During normal braking, the master cylinder, power
booster and wheel brake units all function as they
would in a vehicle without ABS. The HCU compo-
nents are not activated.
ABS OPERATION IN ANTILOCK BRAKING MODE
The purpose of the antilock system is to prevent
wheel lockup during periods of high wheel slip. Pre-
venting lockup helps maintain vehicle braking action
and steering control.
The antilock ECU activates the system whenever
sensor signals indicate periods of high wheel slip.
High wheel slip can be described as the point where
wheel rotation begins approaching zero (or lockup)
during braking. Periods of high wheel slip may occur
when brake stops involve high pedal pressure and
rate of deceleration.
The antilock system prevents lockup during high
slip conditions by modulating fluid apply pressure to
the wheel brake units.
Brake fluid apply pressure is modulated according
to wheel speed, degree of slip and rate of decelera-
tion. A sensor at each wheel converts wheel speed
into electrical signals. These signals are transmitted
to the ECU for processing and determination of
wheel slip and deceleration rate.
The ABS system has three fluid pressure control
channels. The front brakes are controlled separately
and the rear brakes in tandem (Fig. 1). A speed sen-
sor input signal indicating a high slip condition acti-
vates the ECU antilock program.
Two solenoid valves are used in each antilock con-
trol channel. The valves are all located within the
HCU valve body and work in pairs to either increase,
hold, or decrease apply pressure as needed in the in-
dividual control channels.
The solenoid valves are not static during antilock
braking. They are cycled continuously to modulate
pressure. Solenoid cycle time in antilock mode can be
measured in milliseconds.
HCU OPERATION
Normal Braking
During normal braking, the HCU solenoid valves
and pump are not activated. The master cylinder and
power booster operate the same as a vehicle without
an ABS brake system.
Antilock Pressure Modulation
Solenoid valve pressure modulation occurs in three
stages which are: pressure increase, pressure hold,
and pressure decrease. The valves are all contained
in the valve body portion of the HCU.
Pressure Decrease
The outlet valve is opened and the inlet valve is
closed during the pressure decrease cycle (Fig. 6).A pressure decrease cycle is initiated when speed
sensor signals indicate high wheel slip at one or
more wheels. At this point, the ECU opens the outlet
valve, which also opens the return circuit to the ac-
cumulators. Fluid pressure is allowed to bleed off (de-
crease) as needed to prevent wheel lock.
Once the period of high wheel slip has ended, the
ECU closes the outlet valve and begins a pressure in-
crease or hold cycle as needed.
Pressure Hold
Both solenoid valves are closed in the pressure hold
cycle (Fig. 7). Fluid apply pressure in the control
channel is maintained at a constant rate. The ECU
maintains the hold cycle until sensor inputs indicate
a pressure change is necessary.
Pressure Increase
The inlet valve is open and the outlet valve is
closed during the pressure increase cycle (Fig. 8). The
pressure increase cycle is used to counteract unequal
wheel speeds. This cycle controls re-application of
fluid apply pressure due to changing road surfaces or
wheel speed.
Fig. 6 Pressure Decrease Cycle
5 - 36 ABS OPERATION AND SERVICEJ
Page 189 of 2158

WHEEL SPEED SENSOR OPERATION
Wheel speed input signals are generated by a sen-
sor and tone ring at each wheel. The sensors, which
are connected directly to the ECU, are mounted on
brackets attached to the front steering knuckles and
rear brake support plates.
The sensor triggering devices are the tone rings
which are similar in appearance to gears. The tone
rings are located on the outboard end of each front/rear axle shaft. The speed sensors generate a signal
whenever a tone ring tooth rotates past the sensor
pickup face.
The wheel speed sensors provide the input signal
to the ECU. If input signals indicate ABS mode brak-
ing, the ECU causes the HCU solenoids to decrease,
hold, or increase fluid apply pressure as needed.
The HCU solenoid valves are activated only when
wheel speed input signals indicate that a wheel is
approaching a high slip, or lockup condition. At this
point, the ECU will cycle the appropriate wheel con-
trol channel solenoid valves to prevent lockup.
The wheel sensors provide speed signals whenever
the vehicle wheels are rotating. The ECU examines
these signals for degree of deceleration and wheel
slip. If signals indicate normal braking, the solenoid
valves are not activated. However, when incoming
signals indicate the approach of wheel slip, or lockup,
the ECU cycles the solenoid valves as needed.
ACCELERATION SWITCH OPERATION
The ECU monitors the acceleration switch at all
times. The switch assembly contains three mercury
switches that monitor vehicle ride height and decel-
eration rates (G-force). Sudden, rapid changes in ve-
hicle and wheel deceleration rate, triggers the switch
sending a signal to the ECU. The switch assembly
provides three deceleration rates; two for forward
braking and one for rearward braking.
ECU OPERATION
The antilock ECU controls all phases of antilock
operation. It monitors and processes input signals
from the system sensors.
It is the ECU that activates the solenoid valves to
modulate apply pressure during antilock braking.
The ECU program is able to determine which wheel
control channel requires modulation and which fluid
pressure modulation cycle to use. The ECU cycles the
solenoid valves through the pressure decrease, hold
and increase phases.
ABS COMPONENT SERVICEABILITY
The ECU, acceleration sensor, wheel sensors, and
wire harnesses are serviced as assemblies only. The
axle shaft tone wheels are also not serviceable. If a
tone wheel becomes damaged, it will be necessary to
replace the axle shaft, or disc brake rotor and hub
assembly.
SPEED SENSOR AIR GAP
Front sensor air gap is fixed and not adjustable.
Only rear sensor air gap is adjustable.
Although front air gap is not adjustable, it can be
checked if diagnosis indicates this is necessary. Front
Fig. 7 Pressure Hold Cycle
Fig. 8 Pressure Increase Cycle
JABS OPERATION AND SERVICE 5 - 37
Page 197 of 2158

DISC BRAKES
INDEX
page page
Caliper Assembly......................... 50
Caliper Cleaning and Inspection.............. 50
Caliper Disassembly....................... 48
Caliper Installation........................ 51
Caliper Operation and Wear Compensation...... 45
Caliper Removal.......................... 48
Disc Brake Rotor Refinishing................. 53
Disc Brake Rotor Runout.................... 52Disc Brake Rotor Thickness................. 52
Disc Brake Rotor Thickness Variation.......... 52
Disc Brakeshoe Installation.................. 47
Disc Brakeshoe Removal................... 46
General Information....................... 45
Rotor Installation.......................... 51
Rotor Removal........................... 51
Wheel Nut Tightening...................... 54
GENERAL INFORMATION
Jeep XJ/YJ models are equipped with single piston,
floating-type disc brake calipers. Ventilated, cast ro-
tors are used for all applications.
The disc brake calipers are supported in mounting
arms that are an integral part of the steering
knuckle. The calipers slide on mounting bolts that
also attach the calipers to the steering knuckle.
CALIPER OPERATION AND WEAR COMPENSATION
Caliper Operation
The significant feature of single piston caliper op-
eration is that the calipers are free to slide laterally
on the mounting bolts. It is the freedom of lateral
movement that allows continuous compensation for
lining wear.
A simplified cross section of a single piston caliper
is shown in Figure 1. The illustration graphically
portrays the forces at work when the brakes are ap-
plied.
Upon brake application, fluid pressure exerted
against the caliper piston increases greatly. Of equal
importance, is the fact that fluid pressure is exerted
equally and in all directions. What this means, is
that pressure in the caliper bore, will be exactly the
same as pressure on the piston. In other words, pres-
sure against piston and caliper bore is equal.
Fluid pressure applied to the piston is transmitted
directly to the inboard brakeshoe. This forces the
shoe lining against the inner surface of the disc
brake rotor (Fig. 1).
At the same time, fluid pressure within the piston
bore, forces the caliper to slide inward on the mount-
ing bolts. This action brings the outboard brakeshoe
lining into contact with the outer surface of the disc
brake rotor (Fig. 1).
In summary, fluid pressure acting simultaneously
on both piston and caliper, produces a strong clamp-
ing action. When sufficient force is applied, friction
will stop the rotors from turning and bring the vehi-
cle to a stop.Brakeshoe Wear Compensation
Application and release of the brake pedal gener-
ates only a very slight movement of the caliper and
piston. Upon release of the pedal, the caliper and pis-
ton return to a rest position. The brakeshoes do not
retract an appreciable distance from the rotor. In
fact, clearance is usually at, or close to zero. The rea-
sons for this are to keep road debris from getting be-
tween the rotor and lining and in wiping the rotor
surface clear each revolution.
The caliper piston seal controls the amount of pis-
ton extension needed to compensate for normal lining
wear.
During brake application, the seal is deflected out-
ward by fluid pressure and piston movement (Fig. 2).
When the brakes (and fluid pressure) are released,
the seal relaxes and retracts the piston.
Fig. 1 Disc Brake Caliper Operation
JDISC BRAKES 5 - 45
Page 198 of 2158

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
Page 200 of 2158

install caliper over rotor and seat upper ends of
brakeshoes on top mounting ledge (Fig. 11).
CAUTION: Before securing the caliper, be sure the
caliper brake hose is not twisted, kinked or touch-
ing any chassis components. Also be sure the hose
is clear of all suspension and steering components.
Loosen and reposition the hose if necessary.
(8) Install and tighten caliper mounting bolts to
10-20 Nzm (7-15 ft. lbs.) torque.
CAUTION: If new caliper bolts are being installed,
or if the original reason for repair was a drag/pull
condition, check caliper bolt length before proceed-
ing. If the bolts have a shank length greater than
67.6 mm (2.66 in.), they will contact the inboard
brakeshoe causing a partial apply condition. Refer
to Figure 14 for required caliper bolt length.
(9) Install wheels. Tighten lug nuts to 102 Nzm (75
ft. lbs.) torque.
(10) Pump brake pedal until caliper pistons and
brakeshoes are seated.(11) Top off brake fluid level if necessary. Use Mo-
par brake fluid or equivalent meeting SAE J1703 and
DOT 3 standards only.
CALIPER REMOVAL
(1) Raise vehicle and remove front wheels.
(2) Remove fitting bolt and disconnect front brake
hose at caliper. Discard fitting bolt gaskets. They
should not be reused.
(3) Remove caliper mounting bolts (Fig. 4).
(4) Rotate caliper rearward by hand or with pry
tool (Fig. 5). Then rotate caliper and brakeshoes off
mounting ledges.
(5) Remove caliper from vehicle.
CALIPER DISASSEMBLY
(1) Remove brakeshoes from caliper.
Fig. 11 Installing Inboard Brakeshoe
Fig. 12 Installing Outboard Brakeshoe
Fig. 13 Caliper Installation
Fig. 14 Caliper Mounting Bolt Dimensions
5 - 48 DISC BRAKESJ
Page 201 of 2158

(2) Pad interior of caliper with minimum, 2.54 cm
(1 in.) thickness of shop towels or rags (Fig. 15). Tow-
els are needed to protect caliper piston during re-
moval.
(3) Remove caliper piston withshort burstsof low
pressure compressed air. Direct air through fluid in-
let port and ease piston out of bore (Fig. 16).
CAUTION: Do not blow the piston out of the bore
with sustained air pressure. This could result in a
cracked piston. Use only enough air pressure to
ease the piston out. In addition, NEVER attempt to
catch the piston as it leaves the bore. This will re-
sult in personal injury.(4) Remove caliper piston dust boot (Fig. 17). Col-
lapse boot with suitable tool and remove and discard
boot.
(5) Remove and discard caliper piston seal with
wood or plastic tool (Fig. 18). Do not use metal tools
as they will scratch piston bore.
(6) Remove caliper mounting bolt bushings and
boots (Fig. 19).
Fig. 15 Padding Caliper Interior To Protect Piston
During Removal
Fig. 16 Removing Caliper Piston
Fig. 17 Removing Caliper Piston Dust Boot
Fig. 18 Removing Caliper Piston Seal
Fig. 19 Caliper Bushing And Boot
JDISC BRAKES 5 - 49