Page 257 of 2438
INSTALL
CAUTION: Be sure that the dual function pressure
switch is thoroughly cleaned using Mopar Brake
Parts Cleaner or an equivalent before installing it
into the hydraulic assembly. Wet the O-ring seals
on the switch with fresh clean brake fluid before in-
stalling it into the hydraulic assembly.
Fig. 8 Body Routing of Rear Speed Sensor Wiring
Fig. 9 Dual Function Pressure Switch And Pressure Transducer Wiring
Fig. 10 Dual Function Pressure Switch Remove/ Install
Ä ANTI-LOCK 10 BRAKE SYSTEM 5 - 107
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CAUTION: Do not insert dual function pressure
switch into hydraulic assembly using the socket
and ratchet. Cross threading of the switch may oc-
cur. (1) Install the dual function pressure switch into
the hydraulic assembly by hand until the O-ring
seals are seated. (2) Using Socket, Special Tool 6607, (Fig. 10)
torque the dual function pressure switch into the hy-
draulic assembly to 12 N Im (9 ft. lbs.).
(3) Connect the wiring harness connectors (Fig. 9)
onto the dual function pressure switch and the boost
pressure transducer. Be sure the locking tabs on the
connectors are fully engaged on the switches. (4) Lower the vehicle.
(5) Turn the ignition switch to the on position and
let the system pressurize. Check for any leaks at the
dual function pressure switch. (6) Fully de-pressurize the hydraulic assembly a
second time. This will purge any air out that may
have entered hydraulic assembly when the switch
was removed. Turn the ignition switch to the on po-
sition and let the system pressurize again. (7) Road test vehicle to insure that the brake sys-
tem is performing correctly.
PRIMARY PRESSURE TRANSDUCER
REMOVE
WARNING: FAILURE TO FULLY DE-PRESSURIZE
THE HYDRAULIC BLADDER ACCUMULATOR PRIOR
TO REMOVING PRIMARY PRESSURE TRANS-
DUCER. WILL RESULT IN PERSONAL INJURY
AND/OR DAMAGE TO PAINTED SURFACES OF THE
VEHICLE.
To remove primary pressure transducer (Fig. 11),
from hydraulic assembly, removal of hydraulic as-
sembly from vehicle is notrequired.
(1) Fully de-pressurize the hydraulic accumulator
by pumping brake pedal a minimum of 40 times. Use
procedure described in De-Pressurizing Hydraulic Ac-
cumulator listed earlier in this section. (2) Remove as much brake fluid as possible from
the brake fluid reservoir, using a syringe or equiva-
lent method. (3) Using oil filter band wrench, Special Tool
C-4065 or equivalent, (Fig. 12) loosen bladder accu-
mulator. Then remove bladder accumulator and
brake fluid spray shield from hydraulic assembly. (4) Remove high pressure banjo fitting (Fig. 13)
from hydraulic assembly. (5) Using needle nose pliers, remove the 3 fluid
reservoir retaining pins from the hydraulic assembly
(Fig. 14). Compress barb on opposite side of retaining
pin, to prevent pin from breaking. CAUTION: Be extremely careful during the following
procedure to avoid damaging or puncturing brake
fluid reservoir during its removal.
(6) Remove brake fluid reservoir from hydraulic
assembly by carefullyprying between reservoir and
hydraulic assembly using a blunt pry bar (Fig. 15).
Use a rocking motion to help disengage reservoir
from grommets while prying. (7) Remove brake fluid level sensor from reservoir
and remove fluid reservoir from vehicle. (8) Remove hydraulic assembly wiring harness
connector from the primary pressure transducer (Fig.
16).
Fig. 11 Primary Pressure Transducer Location On Hydraulic Assembly
Fig. 12 Removing Bladder Accumulator
5 - 108 ANTI-LOCK 10 BRAKE SYSTEM Ä
Page 259 of 2438

(9) Using Socket, Special Tool 6684 loosen and re-
move primary pressure transducer from hydraulic as-
sembly (Fig. 17)
INSTALL
(1) Install primary pressure transducer into hy-
draulic assembly by hand, until O-ring is fully seated
into hydraulic assembly. Then torque primary pres-
sure transducer, into hydraulic assembly, using
Socket, Special Tool 6684, to 12 N Im (106 in. lbs.).
(2) Connect vehicle wiring harness connector, onto
primary pressure transducer (Fig. 16). Be sure latch
on vehicle wiring harness connector is fully engaged
with locking tab on primary pressure transducer. (3) Using fingers, remove the 3 reservoir sealing
grommets from hydraulic assembly or reservoir and discard.
Sealing grommets must not be reused,
when brake fluid reservoir is installed back on
hydraulic assembly. (4) Thoroughly lubricate new reservoir sealing
grommets, using fresh clean brake fluid, and install on
fluid reservoir outlet ports. (5) Install brake fluid level switch into brake fluid
reservoir. (6) Press brake fluid reservoir into hydraulic assem-
bly by hand , using a rocking motion to help seat fluid
reservoir into hydraulic assembly. Be sure that sealing
grommets are fully seated into the hydraulic assembly.
Do not attempt to pound fluid reservoir into
hydraulic assembly using a hammer.
Fig. 13 High Pressure Banjo Fitting
Fig. 14 Reservoir Retaining Pin Removal
Fig. 15 Reservoir Removal From Hydraulic Assem- bly
Fig. 16 Wiring Harness Connection To Primary Pres-sure Transducer
Ä ANTI-LOCK 10 BRAKE SYSTEM 5 - 109
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(7) Using needle nose pliers, install the 3 brake fluid
reservoir to hydraulic assembly retaining pins (Fig.
14). Be sure retaining pins are fully installed with
barbs extending out past reservoir on opposite
side. (8) Install high pressure hose banjo fitting onto
hydraulic assembly and install banjo fitting attaching
bolt. Torque banjo fitting to hydraulic assembly banjo
bolt to 13 N Im (10 ft. lbs.).
(9) Install brake fluid spray shield onto hydraulic
assembly. Install bladder accumulator into hydraulic
assembly by hand (using care not to cross thread
accumulator) until O-ring seal is fully seated into
hydraulic assembly. (10) Using Oil Filter Band Wrench, Special Tool
C-4065 or equivalent, (Fig. 12) torque bladder accumu-
lator to 48 N Im (35 ft. lbs.).
(11) Fill hydraulic assembly fluid reservoir to the top
of the screen on the filter rainer. Use only fresh clean
brake fluid conforming to DOT 3 requirements, such as
Mopar tor equivalent.
(12) Bleed the brake hydraulic system using proce-
dure shown in Bleeding Brake System in this section of
the service manual.
DIFFERENTIAL PRESSURE SWITCH
REMOVE
WARNING: FAILURE TO FULLY DE-PRESSURIZE THE
HYDRAULIC BLADDER ACCUMULATOR PRIOR TO
REMOVING DIFFERENTIAL PRESSURE SWITCH.
WILL RESULT IN PERSONAL INJURY AND/OR DAM-
AGE TO PAINTED SURFACES OF THE VEHICLE.
To remove the differential pressure switch (Fig. 18),
from the hydraulic assembly, removal of the hydraulic
assembly from the vehicle is notrequired. (1) De-pressurize hydraulic bladder accumulator on
hydraulic assembly by pumping the brake pedal a
minimum of 40 times. Refer to the procedure as de-
scribed in De-Pressurizing Hydraulic Accumulator
listed earlier in this section. (2) Disconnect the hydraulic assembly wiring har-
ness connector from the primary pressure transducer
(Fig. 19).
(3) Disconnect differential pressure switch wiring
harness connector from hydraulic assembly wiring
harness (Fig. 19). Do not attempt to remove wiring
harness from differential pressure switch. (4) Raise vehicle on a frame contact type hoist. See
Hoisting in the Lubrication And Maintenance section
of this manual, for the required lifting procedure to be
used for this vehicle. (5) Using a long extension and Socket, Special Tool
6684 loosen and remove differential pressure switch
from bottom of hydraulic assembly (Fig. 20)
Fig. 18 Differential Pressure Switch Location
Fig. 19 Primary Pressure Transducer And Differen- tial Pressure Switch Wiring Harness Connectors
Fig. 17 Primary Pressure Transducer Removal And Replacement
5 - 110 ANTI-LOCK 10 BRAKE SYSTEM Ä
Page 261 of 2438

INSTALL (1) Install differential pressure switch into hydrau-
lic assembly by hand, until fully threaded into hy-
draulic assembly. Then torque differential pressure
switch, into hydraulic assembly, using Socket, Spe-
cial Tool 6684, to 1.5 N Im (13 in. lbs.).
(2) Lower vehicle
(3) Connect differential pressure switch wiring
harness connector into hydraulic assembly wiring
harness (Fig. 19). (4) Connect the hydraulic assembly wiring harness
connector into the primary pressure transducer (Fig.
19). (5) Turn the ignition switch to the on position and
let the system pressurize. Check for any signs of
leakage at the differential pressure switch. (6) Fully de-pressurize the hydraulic assembly a
second time to purge any air out that may have en-
tered hydraulic assembly when the differential pres-
sure switch was removed. Turn the ignition switch to
the on position and let the system pressurize again. (7) Fill hydraulic assembly fluid reservoir to the
top of the screen on the filter rainer. Use only fresh
clean brake fluid conforming to DOT 3 requirements,
such as Mopar tor equivalent.
(8) Road test vehicle to insure that the brake sys-
tem is performing correctly.
BOOST PRESSURE TRANSDUCER
REMOVE
WARNING: FAILURE TO FULLY DE-PRESSURIZE
THE HYDRAULIC BLADDER ACCUMULATOR PRIOR
TO REMOVING BOOST PRESSURE TRANSDUCER.
MAY RESULT IN PERSONAL INJURY AND/OR DAM-
AGE TO PAINTED SURFACES OF THE VEHICLE. To remove the boost pressure transducer (Fig. 21),
from the hydraulic assembly, removal of the hydrau-
lic assembly from the vehicle is notrequired.
(1) De-pressurize hydraulic bladder accumulator on
hydraulic assembly by pumping the brake pedal a
minimum of 40 times. Refer to the procedure as de-
scribed in De-Pressurizing Hydraulic Accumulator
listed earlier in this section. (2) Raise vehicle on a frame contact type hoist. See
Hoisting in the Lubrication And Maintenance section
of this manual, for the required lifting procedure to
be used for this vehicle. (3) Disconnect hydraulic assembly wiring harness
connectors from the dual function pressure switch
and boost pressure transducer (Fig. 21). (4) Using a long extension and Socket, Special Tool
6607, remove dual function pressure switch from bot-
tom of hydraulic assembly (Fig. 22)
(5) Remove boost pressure transducer from hydrau-
lic assembly, from under vehicle using a long exten-
sion and Socket, Special Tool 6684 (Fig. 23).
Fig. 20 Differential Pressure Switch Removal And Replacement
Fig. 21 Boost Pressure Transducer Location
Fig. 22 Remove And Install Dual Function Pressure Switch
Ä ANTI-LOCK 10 BRAKE SYSTEM 5 - 111
Page 262 of 2438

INSTALL (1) Install boost pressure transducer (Fig. 23) into
hydraulic assembly by hand, until O-ring is fully
seated into hydraulic assembly. Then torque boost pressure transducer, into hydraulic assembly, using
Socket, Special Tool 6684, to 12 N Im (106 in. lbs.).
(2) Install Dual Function Pressure Switch (Fig. 22)
into hydraulic assembly by hand, until O-ring is
fully seated into hydraulic assembly. Then torque
dual function pressure switch, into hydraulic assem-
bly, using Socket, Special Tool 6607, to 12 N Im (106
in. lbs.). (3) Connect hydraulic assembly wiring harness
connectors, onto the dual function pressure switch
and boost pressure transducer (Fig. 21). (4) Turn the ignition switch to the on position and
let the system pressurize. Check for any signs of
leakage at the differential pressure switch. (5) Fully de-pressurize the hydraulic assembly a
second time to purge any air out that may have en-
tered hydraulic assembly when the differential pres-
sure switch was removed. Turn the ignition switch to
the on position and let the system pressurize again. (6) Fill hydraulic assembly fluid reservoir to the
top of the screen on the filter rainer. Use only fresh
clean brake fluid conforming to DOT 3 requirements,
such as Mopar tor equivalent.
(7) Road test vehicle to insure that the brake sys-
tem is performing correctly.
Fig. 23 Remove And Install Boost Pressure Transducer
5 - 112 ANTI-LOCK 10 BRAKE SYSTEM Ä
Page 263 of 2438

ANTI-LOCK BRAKE SYSTEMÐBENDIX ANTI-LOCK 6 AA,AG,AJ,AP BODY INDEX
page page
ABS Brake System Diagnosis .............. 123
ABS Brake System Diagnostic Features ...... 125
ABS Computer System Service Precautions . . . 124
ABS General Service Precautions ........... 124
Anti-Lock Brake System Components ........ 116
Anti-Lock Brake System Definitions .......... 113
Anti-Lock Brakes Operation and Performance . . 115
Anti-Lock System Relays and Warning Lamps . . 120
Controller Anti-Lock Brake (CAB) ............ 119
Diagnostic Connector ..................... 120
Electronic Components ................... 130 General Information
...................... 113
Hydraulic Circuits and Valve Operation ....... 121
Major Components ...................... 114
Mechanical Diagnostics and Service Procedures . 125
Normal Braking System Function ............ 114
On-Car ABS Brake System Service .......... 126
Specifications .......................... 135
System Self-Diagnostics .................. 115
Vehicle Performance ..................... 115
Warning Systems Operation ............... 116
GENERAL INFORMATION
The purpose of the Anti-Lock Brake System (ABS)
is to prevent wheel lock-up under heavy braking con-
ditions on virtually any type of road surface. Anti-
Lock Braking is desirable because a vehicle which is
stopped without locking the wheels will retain direc-
tional stability and some steering capability. This al-
lows the driver to retain greater control of the
vehicle during heavy braking. This section of the service manual covers the de-
scription, diagnostics, and on car service for the Ben-
dix Anti-Lock 6 Brake System. If other service is required on the non ABS related components of the
brake system. Refer to the appropriate section in this
group of the manual for the specific service procedure
required.
ANTI-LOCK BRAKE SYSTEM DEFINITIONS
In this section of the manual several abbreviations
are used for the components that are in the Anti-
Lock Braking System They are listed below for your
reference.
² CABÐController Anti-Lock Brake
² ABSÐAnti-Lock Brake System
Fig. 1 Four-Wheel Anti-Lock Brake System Components AA/AG/AJ Body
Ä ANTI-LOCK 6 BRAKE SYSTEM 5 - 113
Page 264 of 2438

² PSIÐPounds per Square Inch (pressure)
² WSSÐWheel Speed Sensor
NORMAL BRAKING SYSTEM FUNCTION
Under normal braking conditions, the ABS System
functions the same as a standard brake system with
a diagonally split master cylinder and conventional
vacuum assist. If a wheel locking tendency is detected during a
brake application, the system will enter Anti-Lock
mode. During Anti-Lock Braking, hydraulic pressure
in the four wheel circuits is modulated to prevent
any wheel from locking. Each wheel circuit is de-
signed with a set of electrical valves and hydraulic
line to provide modulation, although for vehicle sta-
bility, both rear wheel valves receive the same elec-
trical signal. The system can build or reduce
pressure at each wheel, depending on signals gener-
ated by the wheel speed sensors (WSS) at each wheel
and received at the Controller Anti-Lock Brake
(CAB).
MAJOR COMPONENTS
The following is a list of major system components.
Details of all components can be found later in this
section. See (Fig. 1) for the general location of the
components in the vehicle.
MASTER CYLINDER AND VACUUM BOOSTER
The Bendix Anti-Lock 6 Brake System uses the ve-
hicles standard Master Cylinder/Reservoir and Vac-
uum Booster (Fig. 2). The master cylinder primary
and secondary outputs go directly to the Modulator
Assembly.
MODULATOR AND PUMP MOTOR/ASSEMBLY
The Modulator Assembly (Fig. 3) contains the
wheel circuit valves used for brake pressure modula-
tion and the Pump/Motor. The Pump/Motor function, as part of the Modulator
Assembly. Is to pump low pressure brake fluid from
the brake fluid sump into the ABS Accumulator.
During a stop which requires the ABS system to be-
come operational.
WHEEL SPEED SENSORS
A Wheel Speed Sensor (Fig. 4) is located at each
wheel to transmit wheel speed information to the
Controller Anti-Lock Brake (CAB).
Fig. 2 Master Cylinder Brake Booster Assemble
Fig. 3 Modulator And Pump/Motor Assembly
Fig. 4 Wheel Speed Sensor
5 - 114 ANTI-LOCK 6 BRAKE SYSTEM Ä