Antilock Brake System - Chrysler Stratus RHD 1999 Electronic Service Manual

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DESCRIPTION AND OPERATION
ANTILOCK BRAKE SYSTEM COMPONENTS . . . 74
ANTILOCK BRAKE SYSTEM OPERATION . . . . . 73
HYDRAULIC CIRCUITS AND VALVE
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 78
DIAGNOSIS AND TESTING
ABS ELECTRONIC DIAGNOSIS . . . . . . . . . . . . . 80
ABS GENERAL DIAGNOSTICS
INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . 80
ABS VEHICLE TEST DRIVE . . . . . . . . . . . . . . . . 80
ABS WIRING DIAGRAM INFORMATION . . . . . . . 80
BRAKE FLUID CONTAMINATION . . . . . . . . . . . . 84
PROPORTIONING VALVE . . . . . . . . . . . . . . . . . 82
SERVICE WARNINGS AND CAUTIONS . . . . . . . 80
TONE WHEEL . . . . . . . . . . . . . . . . . . . . . . . . . . 82
SERVICE PROCEDURES
ANTILOCK BRAKE SYSTEM BLEEDING . . . . . . 85
BRAKE FLUID LEVEL CHECKING . . . . . . . . . . . 84
DESCRIPTION AND OPERATION
ANTILOCK BRAKE SYSTEM OPERATION
This section covers the physical and operational
descriptions and the on-car service procedures for the
ITT Teves Mark 20 Antilock Brake System.
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.
There are a few performance characteristics of the
ITT Teves Mark 20 Antilock Brake System that may
at first seem abnormal, but in fact are normal. These
characteristics 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-
tem enters the ABS mode. During ABS braking,

ANTILOCK BRAKE SYSTEM

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INDEX
REMOVAL AND INSTALLATION
INTEGRATED CONTROL
UNIT (HCU and CAB) . . . . . . . . . . . . . . . . . . . 86
PROPORTIONING VALVE . . . . . . . . . . . . . . . . . 90
SERVICE WARNINGS AND CAUTIONS . . . . . . . 85
WHEEL SPEED SENSOR (FRONT) . . . . . . . . . . 91
WHEEL SPEED SENSOR (REAR) . . . . . . . . . . . 92
DISASSEMBLY AND ASSEMBLY
INTEGRATED CONTROL
UNIT (HCU AND CAB) . . . . . . . . . . . . . . . . . . . 94
SPECIFICATIONS
BRAKE FASTENER TORQUE
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . 95
TONE WHEEL RUNOUT . . . . . . . . . . . . . . . . . . . 95
WHEEL SPEED SENSOR RESISTANCE . . . . . . . 95
WHEEL SPEED SENSOR-TO-TONE WHEEL
CLEARANCE . . . . . . . . . . . . . . . . . . . . . . . . . . 95
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 four 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.
BRAKES 5 - 73
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