(6) Check pedal travel. If pedal travel is excessive
or has not been improved, enough fluid has not
passed through the system to expel all the trapped
air. Be sure to monitor the fluid level in the pressure
bleeder, so it stays at a proper level so air will not
enter the brake system through the master cylinder.
(7) Perform a final adjustment of the rear brake
shoes (when applicable), then test drive vehicle to be
sure brakes are operating correctly and that pedal is
solid.
SPECIFICATIONS
BRAKE FASTENER TORQUE
DESCRIPTION N´mFt.
Lbs.In.
Lbs.
ABS ICU Mounting Bolts To
Bracket11 Ð 9 7
ABS ICU Mounting
Bracket-To-Cradle Bolts28 21 250
ABS CAB-To-HCU Mounting
Screws2Ð17
ABS Wheel Speed Sensor
Mounting Bolt12 Ð 105
Brake Tube Nuts 17 Ð 145
Brake Hose Intermediate
Bracket Bolt12 Ð 105
Brake Hose-To-Caliper
Mounting Bolt47 35 Ð
DESCRIPTION N´mFt.
Lbs.In.
Lbs.
Disc Brake Caliper Guide
Pin Bolts35 26 Ð
Disc Brake Caliper Bleeder
Screw15 Ð 125
Drum Brake Wheel Cylinder
Mounting Bolts8Ð75
Drum Brake Wheel Cylinder
Mounting Bleeder screw10 Ð 80
Drum Brake Support Plate
Mounting Bolts130 95 Ð
Junction Block (Non-ABS
Brakes) Mounting Bolts28 21 250
Master Cylinder Mounting
Nuts25 19 225
Power Brake Booster
Mounting Nuts28 21 250
Proportioning Valve
Mounting Bolts54 40 Ð
Proportioning Valve Axle
Bracket Mounting Bolt20 Ð 175
Parking Brake Lever (Pedal)
Mounting Bolts And Nut28 21 250
Wheel Mounting (Lug) Nuts 135 100 Ð
SPECIAL TOOLS
BASE BRAKE SYSTEM
Fig. 3 TOOL 6921 INSTALLED ON MASTER
CYLINDER
1 - SPECIAL TOOL 6921
2 - FLUID RESERVOIR
Tubes, Master Cylinder Bleeding 6920
5 - 8 BRAKES - BASERS
BRAKES - BASE (Continued)
out of master cylinder when brake tube is remove
from wheel cylinder.
(2) Raise vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE).
(3) Remove wheel and tire assembly.
(4) Disconnect brake tube from rear of wheel cylin-
der. Cap open ends
(5) Remove brake drum.
(6) Remove brake shoes from brake support plate.
(Refer to 5 - BRAKES/HYDRAULIC/MECHANICAL/
BRAKE PADS/SHOES - REMOVAL).
(7) Remove the 2 bolts attaching the wheel cylin-
der to the brake support plate.
(8) Remove the wheel cylinder from the brake sup-
port plate.
(9) Disconnect the park brake cable from the park
brake actuation lever.
(10) Using a suitable tool such as a 14 mm box
wrench (Fig. 73) or an aircraft type hose clamp, com-
press the flared legs on park brake cable retainer.
Then pull the park brake cable out of brake support
plate.
(11) Remove the rear hub and bearing. (Refer to 2
- SUSPENSION/REAR/HUB / BEARING -
REMOVAL)
(12) Remove the rear brake support plate from the
rear axle.
INSTALLATION
(1) Install the 4 hub and bearing to axle mounting
bolts into the mounting holes in the flange of the
rear axle.(2) Install the rear brake support plate on the 4
mounting bolts installed in the flange of the rear axle
(Fig. 74).
(3) Install the rear hub and bearing (and connect
wheel speed sensor where applicable) stopping short
of installing the brake drum. (Refer to 2 - SUSPEN-
SION/REAR/HUB / BEARING - INSTALLATION)
(4) Install the rear park brake cable into its
mounting hole in the rear brake support plate.
(5) Install the park brake cable on the park brake
actuation lever.
(6) Apply sealant such as Mopar Gasket-In-A-Tube
or equivalent around the wheel cylinder opening in
the brake support plate.
(7) Install wheel cylinder onto brake support.
Install and tighten the wheel cylinder to brake sup-
port plate attaching bolts to 8 N´m (75 in. lbs.)
torque.
(8) Install brake tube into wheel cylinder. Tighten
tube nut to a torque of 17 N´m (145 in. lbs.) torque.
(9) Install the rear brake shoes on the brake sup-
port plate. (Refer to 5 - BRAKES/HYDRAULIC/ME-
CHANICAL/BRAKE PADS/SHOES -
INSTALLATION).
(10) Install brake drum.
(11) Install wheel and tire.
(12) Tighten wheel stud nuts to 135 N´m (100 ft.
lbs.).
(13) Adjust drum brake shoes. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/BRAKE
PADS/SHOES - ADJUSTMENTS)
(14) Remove brake pedal depressor tool.
(15) Bleed the brake system as necessary. (Refer to
5 - BRAKES - BASE - STANDARD PROCEDURE).
(16) Lower the vehicle.
Fig. 73 Removing Park Brake Cable From Brake
Support Plate
1 - PARK BRAKE CABLE
2 - CABLE RETAINER
3 - 14 mm BOX WRENCH
4 - BRAKE SUPPORT PLATE
Fig. 74 Brake Support Plate Mounted On Bearing
Attaching Bolts
1 - REAR BRAKE SUPPORT PLATE
2 - HUB/BEARING MOUNTING BOLTS
RSBRAKES - BASE5-49
SUPPORT PLATE - DRUM BRAKE (Continued)
(11) Support caliper to prevent the weight of the
caliper from damaging the flexible brake hose (Fig.
86).
(12) Remove the rotor from the hub/bearing.
(13) Remove the horseshoe clip (Fig. 87) from the
retainer on the end of the park brake cable.
(14) Remove the end of the park brake cable from
the actuator lever on the adapter (Fig. 87).(15) Remove the end of the park brake cable from
the adapter. Park brake cable is removed from
adapter using a 1/2 wrench slipped over the park
brake cable retainer as show in (Fig. 88) to compress
the locking tabs on the park brake cable retainer.
(16) Remove the attaching bolt from the wheel
speed sensor (Fig. 89). Then remove wheel speed sen-
sor from hub/bearing and adapter.
Fig. 85 Removing/Installing Caliper
1 - LIFT THIS END OF CALIPER AWAY FROM ADAPTER FIRST
2 - DISC BRAKE CALIPER
3 - ADAPTER ABUTMENT
4 - OUTBOARD BRAKE SHOE HOLD DOWN CLIP
5 - OUTBOARD BRAKE SHOE
6 - ROTOR
7 - ADAPTER
Fig. 86 Correctly Supported Caliper
1 - WIRE
2 - CALIPER
3 - ADAPTER
4 - ROTOR
5 - INNER FENDER
Fig. 87 Park Brake Cable Attachment To Actuator
1 - ADAPTER
2 - PARK BRAKE CABLE
3 - ACTUATOR
4 - AXLE
5 - DRIVESHAFT
6 - PARK BRAKE CABLE RETAINER
7 - HORSESHOE CLIP
Fig. 88 Park Brake Cable Removal From Adapter
1 - DRIVESHAFT
2 - 1/2º WRENCH
3 - PARK BRAKE CABLE
4 - PARK BRAKE CABLE RETAINER
5 - ADAPTER
RSBRAKES - BASE5-55
SHOES (Continued)
(17) Remove the hub/bearing to axle mounting
bolts (Fig. 90).
(18) Remove the hub/bearing from the axle and the
stub shaft of the outer C/V joint (Fig. 91).(19) Remove the adapter from the rear axle.
(20) Mount the adapter in a vise using the anchor
boss for the park brake cable (Fig. 92).
(21) Remove the lower return spring (Fig. 93) from
the leading and trailing park brake shoes.
Fig. 89 Speed Sensor Attaching Bolt
1 - ADAPTER
2 - TONE WHEEL
3 - WHEEL SPEED SENSOR
4 - AXLE
5 - BOLT
6 - DRIVESHAFT
Fig. 90 Hub/Bearing Mounting Bolts
1 - DRIVESHAFT
2 - MOUNTING BOLTS
3 - AXLE
4 - MOUNTING BOLTS
5 - ADAPTER
Fig. 91 Hub/Bearing Removal And Installation
1 - PARK BRAKE BRAKE SHOE
2 - OUTER C/V JOINT
3 - HUB/BEARING
4 - PARK BRAKE BRAKE SHOE
5 - STUB SHAFT
Fig. 92 Adapter Mounted In Vise
1 - ADAPTER
2 - PARK BRAKE CABLE BOSS
3 - VISE
4 - PARK BRAKE BRAKE SHOES
5 - 56 BRAKES - BASERS
SHOES (Continued)
(12) Install the wheel speed sensor on the hub/
bearing and adapter. Install the wheel speed sensor
attaching bolt (Fig. 89). Tighten the wheel speed sen-
sor attaching bolt to a torque of 12 N´m (105 in. lbs).
(13) Install the park brake cable into its mounting
hole in the adapter.Be sure all the locking tabs
on the park brake cable retainer are expanded
out to ensure the cable will not pull out of the
adapter.
(14) Install the end of the park brake cable on the
park brake actuator lever (Fig. 87).
NOTE: The horseshoe clip must be installed and
installed properly when the park brake cable is
installed in the adapter. The purpose of the horse-
shoe clip is to prevent park brake cable retainer
from moving in the adapter. If horseshoe clip is not
installed the park brake cable retainer will rattle in
the adapter.
(15) Install aNEWhorseshoe clip on the park
brake cable retainer (Fig. 87). The horseshoe clip is
installed between the retainer for the park brake
cable and the adapter. Horseshoe clip must be
installed with the curved end of the clip pointing
straight up and the edge of the curved end facing
toward the rear of the vehicle (Fig. 87).
(16) Remove the locking pliers (Fig. 83) from the
front park brake cable.
(17) Adjust the park brake drum-in-hat brake
shoes. (Refer to 5 - BRAKES/PARKING BRAKE/
SHOES - ADJUSTMENTS).
(18) Install the rotor on the hub/bearing.
(19) Carefully lower caliper and brake shoes over
rotor and onto the adapter using the reverse proce-
dure for removal (Fig. 85).
CAUTION: When installing guide pin bolts extreme
caution should be taken not to crossthread the cal-
iper guide pin bolts.
(20) Install the caliper guide pin bolts (Fig. 84).
Tighten the guide pin bolts to a torque of 22 N´m
(192 in. lbs.).
(21) Clean all foreign material off the threads of
the outer C/V joint stub shaft. Install the washer and
hub nut (Fig. 82) on the stub shaft of the outer C/V
joint.
(22) Set the parking brake.
(23) Tighten the hub nut to a torque of 244 N´m
(180 ft. lbs.).
(24) Install the spring washer (Fig. 81) on the stub
shaft of the outer C/V joint.
(25) Install the nut retainer and cotter pin (Fig.
80) on the stub shaft of the outer C/V joint.
(26) Install the wheel and tire assembly. Tighten
the wheel mounting stud nuts in proper sequenceuntil all nuts are torqued to half specification. Then
repeat the tightening sequence to the full specified
torque of 135 N´m (100 ft. lbs.).
(27) Lower vehicle.
(28) Fully apply and release the park brake pedal
one time. This will seat and correctly adjust the park
brake cables.
CAUTION: Before moving vehicle, pump the brake
pedal several times to insure the vehicle has a firm
brake pedal to adequately stop vehicle.
(29) Road test the vehicle and make several stops
to wear off any foreign material on the brakes and to
seat the brake shoe linings.
ADJUSTMENT - PARKING BRAKE SHOES
CAUTION: Before adjusting the park brake shoes be
sure that the park brake pedal is in the fully
released position. If park brake pedal is not in the
fully released position, the park brake shoes can
not be accurately adjusted.
(1) Raise vehicle.
(2) Remove tire and wheel.
(3) Remove disc brake caliper from caliper adapter
(Fig. 100). (Refer to 5 - BRAKES/HYDRAULIC/ME-
CHANICAL/DISC BRAKE CALIPERS - REMOVAL).
(4) Remove rotor from hub/bearing.
Fig. 100 Disc Brake Caliper
1 - DISC BRAKE CALIPER
2 - ADAPTER
3 - AXLE
4 - GUIDE PIN BOLTS
5 - DRIVESHAFT (AWD MODELS ONLY)
RSBRAKES - BASE5-59
SHOES (Continued)
BRAKES - ABS
TABLE OF CONTENTS
page page
BRAKES - ABS
DESCRIPTION...........................67
OPERATION.............................67
CAUTION...............................69
STANDARD PROCEDURE..................70
ANTILOCK BRAKE SYSTEM BLEEDING.....70
SPECIFICATIONS........................71
FRONT WHEEL SPEED SENSOR
REMOVAL..............................71
INSTALLATION...........................71
REAR WHEEL SPEED SENSOR - AWD
REMOVAL..............................72
INSTALLATION...........................72
REAR WHEEL SPEED SENSOR - FWD
REMOVAL..............................73INSTALLATION...........................74
TONE WHEEL
INSPECTION............................74
TRACTION CONTROL SWITCH
DIAGNOSIS AND TESTING.................74
TRACTION CONTROL SWITCH............74
ICU (INTEGRATED CONTROL UNIT)
DESCRIPTION...........................75
OPERATION.............................75
REMOVAL..............................76
DISASSEMBLY...........................77
ASSEMBLY.............................77
INSTALLATION...........................77
BRAKES - ABS
DESCRIPTION - ANTILOCK BRAKE SYSTEM
This section covers the physical and operational
descriptions and the on-car service procedures for the
Mark 20e Antilock Brake System and the Mark 20e
Antilock Brake System with traction control.
The purpose of the antilock brake system (ABS) is
to prevent wheel lockup under braking conditions on
virtually any type of road surface. Antilock braking is
desirable because a vehicle that is stopped without
locking the wheels retains directional stability and
some steering capability. This allows the driver to
retain greater control of the vehicle during braking.
DESCRIPTION - ELECTRONIC BRAKE
DISTRIBUTION
Vehicles equipped with ABS use electronic brake
distribution (EBD) to balance front-to-rear braking.
The EBD is used in place of a rear proportioning
valve. The EBD system uses the ABS system to con-
trol the slip of the rear wheels in partial braking
range. The braking force of the rear wheels is con-
trolled electronically by using the inlet and outlet
valves located in the integrated control unit (ICU).
DESCRIPTION - TRACTION CONTROL SYSTEM
Traction control reduces wheel slip and maintains
traction at the driving wheels at speeds below 56
km/h (35 mph) when road surfaces are slippery. The
traction control system reduces wheel slip by braking
the wheel that is losing traction.
HYDRAULIC SHUTTLE VALVES
Two pressure relief hydraulic shuttle valves are
included on vehicles with traction control. These
valves are located inside the HCU and cannot be ser-
viced separately from the HCU.
TRACTION CONTROL LAMP
The traction control function lamp is located in the
transmission range indicator display of the instru-
ment cluster, displaying TRAC, TRAC OFF or nei-
ther depending on system mode.
The TRAC OFF lamp is controlled by a Traction
Control Off switch that is a momentary contact type
switch. The Traction Control Off switch is located on
the steering column upper shroud.
OPERATION - ANTILOCK BRAKE SYSTEM
There are a few performance characteristics of the
Mark 20e Antilock Brake System that may at first
seem abnormal, but in fact are normal. These char-
acteristics are described below.
NORMAL BRAKING
Under normal braking conditions, the ABS func-
tions the same as a standard base brake system with
a diagonally split master cylinder and conventional
vacuum assist.
ABS BRAKING
ABS operation is available at all vehicle speeds
above 3±5 mph. If a wheel locking tendency is
detected during a brake application, the brake sys-
RSBRAKES - ABS5-67
tem enters the ABS mode. During ABS braking,
hydraulic pressure in the four wheel circuits is mod-
ulated to prevent any wheel from locking. Each
wheel circuit is designed with a set of electric sole-
noids to allow modulation, although for vehicle sta-
bility, both rear wheel solenoids receive the same
electrical signal. Wheel lockup may be perceived at
the very end of an ABS stop and is considered nor-
mal.
During an ABS stop, the brakes hydraulic system
is still diagonally split. However, the brake system
pressure is further split into three control channels.
During antilock operation of the vehicle's brake sys-
tem, the front wheels are controlled independently
and are on two separate control channels, and the
rear wheels of the vehicle are controlled together.
The system can build and release pressure at each
wheel, depending on signals generated by the wheel
speed sensors (WSS) at each wheel and received at
the controller antilock brake (CAB).
NOISE AND BRAKE PEDAL FEEL
During ABS braking, some brake pedal movement
may be felt. In addition, ABS braking will create
ticking, popping, or groaning noises heard by the
driver. This is normal and is due to pressurized fluid
being transferred between the master cylinder and
the brakes. If ABS operation occurs during hard
braking, some pulsation may be felt in the vehicle
body due to fore and aft movement of the suspension
as brake pressures are modulated.
At the end of an ABS stop, ABS is turned off when
the vehicle is slowed to a speed of 3±4 mph. There
may be a slight brake pedal drop anytime that the
ABS is deactivated, such as at the end of the stop
when the vehicle speed is less than 3 mph or during
an ABS stop where ABS is no longer required. These
conditions exist when a vehicle is being stopped on a
road surface with patches of ice, loose gravel, or sand
on it. Also, stopping a vehicle on a bumpy road sur-
face activates ABS because of the wheel hop caused
by the bumps.
TIRE NOISE AND MARKS
Although the ABS system prevents complete wheel
lockup, some wheel slip is desired in order to achieve
optimum braking performance. Wheel slip is defined
as follows: 0 percent slip means the wheel is rolling
freely and 100 percent slip means the wheel is fully
locked. During brake pressure modulation, wheel slip
is allowed to reach up to 25±30 percent. This means
that the wheel rolling velocity is 25±30 percent less
than that of a free rolling wheel at a given vehicle
speed. This slip may result in some tire chirping,
depending on the road surface. This sound should not
be interpreted as total wheel lockup.Complete wheel lockup normally leaves black tire
marks on dry pavement. The ABS will not leave dark
black tire marks since the wheel never reaches a
fully locked condition. However, tire marks may be
noticeable as light patched marks.
START-UP CYCLE
When the ignition is turned on, a popping sound
and a slight brake pedal movement may be noticed.
The ABS warning lamp will also be on for up to 5
seconds after the ignition is turned on. When the
vehicle is first driven off, a humming may be heard
or felt by the driver at approximately 20±40 kph
(12±25 mph). All of these conditions are a normal
function of ABS as the system is performing a diag-
nosis check.
PREMATURE ABS CYCLING
Symptoms of premature ABS cycling include: click-
ing sounds from the solenoid valves; pump/motor
running; and pulsations in the brake pedal. Prema-
ture ABS cycling can occur at any braking rate of the
vehicle and on any type of road surface. Neither the
red BRAKE warning lamp, nor the amber ABS warn-
ing lamp, illuminate and no fault codes are stored in
the CAB.
Premature ABS cycling is a condition that needs to
be correctly assessed when diagnosing problems with
the antilock brake system. It may be necessary to use
a DRB scan tool to detect and verify premature ABS
cycling.
Check the following common causes when diagnos-
ing premature ABS cycling: damaged tone wheels;
incorrect tone wheels; damaged steering knuckle
wheel speed sensor mounting bosses; loose wheel
speed sensor mounting bolts; excessive tone wheel
runout; or an excessively large tone wheel-to-wheel
speed sensor air gap. Give special attention to these
components when diagnosing a vehicle exhibiting
premature ABS cycling.
After diagnosing the defective component, repair or
replace it as required. When the component repair or
replacement is completed, test drive the vehicle to
verify that premature ABS cycling has been cor-
rected.
OPERATION - ELECTRONIC BRAKE
DISTRIBUTION
Upon entry into EBD the inlet valve for the rear
brake circuit is switched on so that the fluid supply
from the master cylinder is shut off. In order to
decrease the rear brake pressure, the outlet valve for
the rear brake circuit is pulsed. This allows fluid to
enter the low pressure accumulator (LPA) in the
hydraulic control unit (HCU) resulting in a drop in
fluid pressure to the rear brakes. In order to increase
5 - 68 BRAKES - ABSRS
BRAKES - ABS (Continued)
SPECIFICATIONS
SPECIFICATIONS - ABS FASTENER TORQUE
(Refer to 5 - BRAKES - BASE - SPECIFICA-
TIONS)
TONE WHEEL RUNOUT
DESCRIPTION SPECIFICATION
Front Tone Wheel
Maximum Runout0.15 mm (0.006 in.)
Rear Tone Wheel
Maximum Runout0.15 mm (0.006 in.)
WHEEL SPEED SENSOR AIR GAP
DESCRIPTION SPECIFICATION
Front Sensor0.35 ± 1.20 mm
0.014 ± 0.047 in.
Rear Sensor0.40 ± 1.20 mm
0.016 ± 0.047 in.
FRONT WHEEL SPEED
SENSOR
REMOVAL - WHEEL SPEED SENSOR (FRONT)
(1) Raise vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE)
(2) Remove the tire and wheel assembly.
(3) Remove the sensor cable routing clamp screws.
CAUTION: When disconnecting the wheel speed
sensor from vehicle wiring harness, be careful not
to damage pins on connector
(4) Remove speed sensor cable grommets from
intermediate bracket on strut.
(5) Disconnect speed sensor cable from vehicle wir-
ing harness behind fender well shield.
(6) Remove the wheel speed sensor head mounting
bolt (Fig. 1).
(7) Remove sensor head from steering knuckle. If
sensor has seized due to corrosion,DO NOT USE
PLIERS ON SENSOR HEAD.Use a hammer and a
punch and tap edge of sensor ear, rocking the sensor
side-to-side until free.
(8) Remove front wheel speed sensor from vehicle.
INSTALLATION - WHEEL SPEED SENSOR
(FRONT)
CAUTION: Proper installation of wheel speed sen-
sor cables is critical to continued system operation.
Be sure that cables are installed in retainers. Fail-
ure to install cables in retainers as shown in this
section may result in contact with moving parts and
over extension of cables, resulting in an open cir-
cuit.
(1) Connect the front wheel speed sensor cable to
the vehicle wiring harness connector. Be sure speed
sensor cable connector is fully seated and locked into
vehicle wiring harness connector.
(2) Install the bolts attaching the routing clamps
to the body of the vehicle. Tighten the bolts to a
torque of 11 N´m (95 in. lbs.).
(3) Insert speed sensor cable grommets into inter-
mediate bracket on strut.
(4) Install the wheel speed sensor head mounting
bolt (Fig. 1). Tighten the bolt to a torque of 12 N´m
(105 in. lbs.)
(5) Install the wheel and tire assembly on vehicle.
(6) Lower vehicle.
(7) Road test vehicle to ensure proper operation of
the base and ABS brake systems.
Fig. 1 Front Wheel Speed Sensor Attaching Bolt
1 - MOUNTING BOLT
2 - WHEEL SPEED SENSOR
3 - DRIVESHAFT
4 - TONE WHEEL
5 - STEERING KNUCKLE
RSBRAKES - ABS5-71
BRAKES - ABS (Continued)