ABS DODGE NEON 1999 Service Owner's Manual

(19)On vehicles equipped with rear disc
brakes,remove brake shoe assemblies (Fig. 150)
from rear disc brake adapter. Then remove parking
brake actuating lever (Fig. 151) from the park brake
cable.
(20) On vehicles equipped with rear drum brakes,
remove park brake cable (Fig. 152) from rear brake
support plate. Park brake cable is removed from
brake support plate using a 1/2 in. wrench as shown
in (Fig. 152) to compress locking tabs on park brake
cable retainer.
(21) On vehicles equipped with rear disc brakes,
remove park brake cable (Fig. 153) from rear disc
brake adapter. Park brake cable is removed from disc
brake adapter using a screwdriver as shown in (Fig.
153) to compress locking tabs on park brake cable
retainer.
(22) Remove park brake cable routing bracket (Fig.
154) from vehicle frame rail.(23) Remove park brake cable and sealing grom-
met (Fig. 155) from floor pan of vehicle.
Fig. 148 Park Brake Cable Attachment To Actuating
Lever
Fig. 149 Brake Adjustment Lever Actuating Spring
Fig. 150 Parking Brake Shoe Assemblies
Fig. 151 Parking Brake Actuator Lever
Fig. 152 Park Brake Cable Removal From Brake
Support Plate
PLBRAKES 5 - 53
REMOVAL AND INSTALLATION (Continued)

INSTALL
(1) Install park brake cable into floor pan of vehi-
cle making sure sealing grommet is installed in floor
pan as far as possible to insure proper seal.
(2) Install park brake cable into brake support
plate or rear disc brake adapter. Be sure locking tabs
on cable retainer are expanded to ensure park brake
cable is securely held in support plate or adapter.
(3) Install park brake cable routing bracket (Fig.
154) on frame rail. Install and securely tighten rout-
ing bracket attaching bolt.
(4)On vehicles equipped with rear drum
brakes,install park brake cable on park brake cable
actuating lever (Fig. 148). Then install actuating
spring between brake shoe assembly and brake
adjustment lever (Fig. 149).
(5)On vehicles equipped with rear disc
brakes,install park brake shoes actuator lever (Fig.
151) on park brake cable. Then install park brake
shoe assemblies on disc brake adapter (Fig. 150).
(6) Install the hub/bearing assembly on the rear
spindle. Then installA NEWrear hub/bearing
assembly retaining nut. Torque hub/bearing assembly
retaining nut to 217 N´m (160 ft. lbs.).
(7) Install hub/bearing assembly dust cap, using a
soft faced hammer.
(8) On drum brake equipped vehicles, install rear
brake drum on hub/bearing assembly. On vehicles
equipped with rear disc brakes, install rotor on hub/
bearing assembly.
(9) On disc brake equipped vehicles install disc
brake caliper on disc brake adapter. Install the 2 cal-
iper guide pin bolts (Fig. 156) and torque to 22 N´m
(192 in. lbs.). Refer To Rear Disc Brake Service in
this group of the service manual for the required cal-
iper installation procedure.
(10) Install rear wheel and tire assembly on vehi-
cle. Tighten all wheel stud nuts in criss cross pattern
Fig. 153 Park Brake Cable Removal From Disc
Brake Adapter
Fig. 154 Park Brake Cable Routing Bracket
Fig. 155 Park Brake Cable Seal At Floor PanFig. 156 Rear Caliper Guide Pin Bolts
5 - 54 BRAKESPL

to one-half specified torque. Then repeat pattern,
fully tightening stud nuts to 135 N´m (100 ft. lbs.).
(11) Lower vehicle.
(12) Grasp park brake cable to floor pan seal
grommet (Fig. 157) by hand, and pull it into floor
pan to ensure seal grommet is fully seated into floor
pan.
(13) Route park brake cable under carpeting and
up to park brake cable retaining bracket on floor
pan. Then install park brake cable into retaining
bracket (Fig. 158). Be sure tabs (Fig. 158) on park
brake cable retainer, have expanded out to hold park
brake cable in retaining bracket.
(14) Install rear park brake cables into equalizer
(Fig. 140) on park brake lever cable.
(15) Reposition rear carpeting.
(16) Install both rear door sill plate scuff moldings,
by snapping them onto rear door sills.(17) Install lower rear seat cushion. Be sure lower
seat cushion is fully installed in retainers on floor
pan of vehicle.
(18) Firmly grasp park brake lever locking pin
(3/16 in. drill bit) (Fig. 159) and quickly remove it
from the park brake lever mechanism. This will
allow the park brake lever mechanism to correctly
adjust the park brake cables.
(19) Cycle park brake lever ounce to position park
brake cables. Then return the park brake lever its
released position. Check the rear wheels of the vehi-
cle, they should rotate freely without dragging.
(20) Apply park brake to full engagement.
(21) Install center console assembly.
(22) Install the center console assembly attaching
screws.
PARK BRAKE SHOES WITH REAR DISC BRAKES
REMOVE
(1) Remove rear disc brake caliper assembly from
adapter and rotor (See Disc Brake Shoe Removal).
(2) Remove rear rotor from rear hub.
(3) Remove dust cap from rear hub.
(4) Remove rear hub and bearing assembly retain-
ing nut and washer.
(5) Remove rear hub and bearing assembly from
rear spindle.
(6) Remove rear brake shoe assembly hold down
clip (Fig. 160).
(7) Turn brake shoe adjuster wheel until adjuster
is at shortest length.
(8) Remove adjuster assembly from the parking
brake shoe assemblies (Fig. 161).
(9) Remove lower shoe to shoe spring (Fig. 162).
(10) Pull rear brake shoe assembly away from
anchor. Then remove rear brake shoe and upper
spring (Fig. 163).
Fig. 157 Seal Grommet Installation In Floor Pan
Fig. 158 Park Brake Cable Installed In Retaining
Bracket
Fig. 159 Removing Lockout Pin From Park Brake
Lever
PLBRAKES 5 - 55
REMOVAL AND INSTALLATION (Continued)

(5) Install new master cylinder housing to brake
fluid reservoir sealing grommets (Fig. 166) in master
cylinder housing.
(6) Lubricate reservoir mounting area with fresh
clean brake fluid. Place reservoir in position over
grommets. Seat reservoir into grommets using a
rocking motion while firmly pressing down on fluid
reservoir.
(7) Be sure reservoir is positioned properly.
(8) Make sure bottom of reservoir touches top of
grommet.
BRAKE FLUID LEVEL SWITCH
The master cylinder or brake fluid reservoir does
not have to be removed from vehicle for replacement
of the brake fluid level sensor.
(1) Remove wiring harness connector from brake
fluid reservoir level sensor (Fig. 167).
(2) Compress retaining tabs (Fig. 168) on end of
brake fluid level switch.(3) While compressing retaining tabs, grasp oppo-
site end of brake fluid level switch and pull it out of
master cylinder brake fluid reservoir (Fig. 169).
(4) Correctly align the replacement level switch
with its mounting hole in the brake fluid reservoir.
Push switch into fluid reservoir until retaining tabs
are fully expanded on opposite side of fluid reservoir
(Fig. 168).
(5) Install the wiring harness connector onto the
brake fluid level switch.
FRONT AND REAR DISC BRAKE CALIPER
CLEANING AND INSPECTION
Check for brake fluid leaks in and around dust
boot area and inboard brake pad, and for any rup-
tures, brittleness or damage to the piston dust boot.
If the dust boot is damaged, or a fluid leak is visible,
disassemble caliper assembly and install a new pis-
ton seal and dust boot, and piston if scored. Refer to
Fig. 166 Removing Fluid Reservoir From Master
Cylinder
Fig. 167 Master Cylinder Fluid Level Sensor
Fig. 168 Brake Fluid Level Switch Retaining Tabs
Fig. 169 Removing/Installing Fluid Reservoir Level
Switch
5 - 58 BRAKESPL
DISASSEMBLY AND ASSEMBLY (Continued)

(3) Remove the rubber plug from the adjusting
hole in the brake shoe backing plate on both sides of
the vehicle.
(4)Driver (left) side park brake shoe adjust-
ment procedure.Insert a medium size screwdriver
through adjustment hole in backing plate. Position
the srewdriver against the starwheel on the park
brake shoe adjuster mechanism. Using the screw-
driver rotate the starwheeldownwarduntil a slight
drag is felt when turning the rear tire and wheel.
Then, using the screwdriver rotate the starwheel
upwardjust until the rear tire and wheel can be
rotated with no park brake shoe drag. From the
point where there is no more park brake drag rotate
the starwheelupwarda maximum of two additional
clicks. The park brake shoe to drum clearance is
know properly adjusted.
(5)Passenger (right) side park brake shoe
adjustment procedure.Insert a medium size
screwdriver through adjustment hole in backing
plate. Position the srewdriver against the starwheel
on the park brake shoe adjuster mechanism. Using
the screwdriver rotate the starwheelupwarduntil a
slight drag is felt when turning the rear tire and
wheel. Then, using the screwdriver rotate the star-
wheeldownwardjust until the rear tire and wheel
can be rotated with no park brake shoe drag. From
the point where there is no more park brake drag
rotate the starwheeldownwarda maximum of two
additional clicks. The park brake shoe to drum clear-
ance is know properly adjusted.
(6) Install the rubber plug in the adjusting hole on
the brake shoe backing plate on both sides of the
vehicle.
(7) Lower vehicle far enough to allow access the
park brake lever. The rear tires must not be on the
ground.
(8) Fully apply and release the park brakes two
times after adjusting the park brake shoes. Then
rotate both rear wheels to ensure that the park
brake shoes do not drag on the brake drum following
the application and release of the park brakes.
SPECIFICATIONS
BRAKE FLUID
The brake fluid used in this vehicle must conform
to DOT 3 specifications and SAE J1703 standards.
No other type of brake fluid is recommended or
approved for usage in the vehicle brake system. Use
only Mopar brake fluid or an equivalent from a
tightly sealed container.
CAUTION: Never use reclaimed brake fluid or fluid
from an container which has been left open. Anopen container will absorb moisture from the air
and contaminate the fluid.
CAUTION: Never use any type of a petroleum-
based fluid in the brake hydraulic system. Use of
such type fluids will result in seal damage of the
vehicle brake hydraulic system causing a failure of
the vehicle brake system. Petroleum based fluids
would be items such as engine oil, transmission
fluid, power steering fluid ect.
BRAKE ACTUATION SYSTEM
ACTUATION:
Vacuum Operated Power Brakes.........Standard
Hydraulic System...........Dual-Diagonally Split
MASTER CYLINDER ASSEMBLY:
Type ...........................Dual Tandem
Body Material...............Anodized Aluminum
Reservoir Material................Polypropelene
MASTER CYLINDER BORE / STROKE
AND SPLIT:
NonABS ....21mmx32.6 mm (.875 in. x 1.28 in.)
ABS........21mmx32.7 mm (.874 in. x 1.29 in.)
Displacement Split.....................50/50
MASTER CYLINDER FLUID OUTLET PORTS:
ABS ..........Primary 3/8±24 Secondary 7/16±24
Non ABS . . .Primary Inboard And Outboard 7/16±24
Non ABS . . .Secondary Inboard And Outboard 3/8±23
Outlet Fitting Type.......SAE 45 É Inverted Flare
ABS HYDRAULIC CONTROL UNIT:
Hydraulic Tube Fitting Type.SAE 45 É Inverted Flare
BOOSTER:
Make/Type.........Bendix Vacuum W/&W/O ABS
Mounting Studs.....................M8x1.25
Type ..........................230 mm Single
Boost At 20 inches Of Manifold Vacuum. . . .4690 All
PROPORTIONING VALVE:
Material...........................Aluminum
Function........Hydraulic Pressure Proportioning
BRAKE PEDAL
Pedal Ratio.............................3.28
BRAKE FASTENER TORQUE SPECIFICATIONS
DESCRIPTION TORQUE
BRAKE TUBES:
Tube Nuts To Fittings And
Components Except HCU. . . . 17 N´m (145 in. lbs.)
From Master Cylinder To
HCU At HCU Ports........21N´m(185 in. lbs.)
BRAKE HOSE:
To Caliper Banjo Bolt..........48N´m(35ft.lbs.)
Intermediate Bracket.........12N´m(105 in. lbs.)
PLBRAKES 5 - 67
ADJUSTMENTS (Continued)

DESCRIPTION TORQUE
MASTER CYLINDER:
To Vacuum Booster Mounting Nut.28 N´m (250 in. lbs.)
BRAKE BOOSTER:
To Dash Panel Mounting Nuts . .28 N´m (250 in. lbs.)
REAR WHEEL CYLINDER:
To Support Plate Mounting Bolts.13 N´m (115 in. lbs.)
Bleeder Screw...............10N´m(80in.lbs.)
BRAKE SUPPORT PLATE:
To Axle Mounting Bolts.........75N´m(55ft.lbs.)
REAR DISC BRAKE ADAPTER:
To Axle Mounting Bolts.........75N´m(55ft.lbs.)
DISC BRAKE CALIPER:
Guide Pin Bolts.............22N´m(192 in. lbs.)
Bleeder Screw..............15N´m(125 in. lbs.)
ABS HYDRAULIC CONTROL UNIT:
To Mounting Bracket Bolts.....28N´m(250 in. lbs.)
Bracket To Frame Rail Mounting Bolt (Top) . .18 N´m
(160 in. lbs.)
Bracket To Frame Rail Mounting Bolts (Side).22 N´m
(200 in. lbs.)
PARKING BRAKE:
Lever Mounting Nuts.........28N´m(250 in. lbs.)
REAR HUB AND BEARING:
To Knuckle Retaining Nut.....217 N´m (160 ft. lbs.)
WHEEL:
Stud Lug Nut........109±150 N´m (80±110 ft. lbs.)
SPECIAL TOOLS
BASE BRAKE SYSTEM
Adapters, Brake Pressure Test 6805
Gauge Set C-4007-A
Handle, Universal C-4171
Installer, Dust Boot C-4689
Dial Indicator C-3339
Tubes, Master Cylinder Bleeding 6802
5 - 68 BRAKESPL
SPECIFICATIONS (Continued)

ANTILOCK BRAKE SYSTEM±TEVES MARK 20
INDEX
page page
DESCRIPTION AND OPERATION
ABS BRAKE SYSTEM COMPONENTS........ 71
ABS BRAKES OPERATION AND VEHICLE
PERFORMANCE....................... 69
ABS COMPONENT ABBREVIATION LIST...... 69
ABS FLUID ACCUMULATORS.............. 72
ABS FUSES............................ 73
ABS MASTER CYLINDER AND POWER BRAKE
BOOSTER............................ 71
ABS RELAYS........................... 73
ABS WARNING LAMP (YELLOW)............ 75
ANTILOCK BRAKES OPERATION
DESCRIPTION........................ 69
CONTROLLER ANTILOCK BRAKES (CAB)..... 74
HCU PUMP/MOTOR..................... 72
HYDRAULIC CIRCUITS AND VALVE
OPERATION.......................... 75
INLET VALVES AND SOLENOIDS............ 72
INTEGRATED CONTROL UNIT (ICU)......... 71
OUTLET VALVES AND SOLENOIDS.......... 72
PROPORTIONING VALVE................. 73
WHEEL SPEED SENSORS................. 73
DIAGNOSIS AND TESTING
ABS DIAGNOSTIC TROUBLE CODES........ 78
ABS DIAGNOSTICS MANUAL.............. 76
ABS GENERAL DIAGNOSTICS INFORMATION . 75
ABS SERVICE PRECAUTIONS.............. 76
ABS SYSTEM SELF DIAGNOSTICS.......... 77ABS WIRING DIAGRAM INFORMATION....... 76
BRAKE FLUID CONTAMINATION............ 80
DRB DIAGNOSTIC CONNECTOR............ 77
DRB DIAGNOSTIC SCAN TOOL USAGE...... 77
INTERMITTENT DIAGNOSTIC TROUBLE
CODES.............................. 78
PROPORTIONING VALVE................. 79
TEST DRIVING ABS COMPLAINT VEHICLE.... 80
TONEWHEEL INSPECTION................ 79
SERVICE PROCEDURES
BLEEDING TEVES MARK 20 HYDRAULIC
SYSTEM............................. 81
BRAKE FLUID LEVEL INSPECTION.......... 80
REMOVAL AND INSTALLATION
ABS GENERAL SERVICE PRECAUTIONS..... 81
ABS HYDRAULIC CONTROL UNIT........... 82
CONTROLLER ANTILOCK BRAKES (CAB)..... 86
FRONT WHEEL SPEED SENSOR........... 87
MASTER CYLINDER AND POWER BRAKE
BOOSTER............................ 86
PROPORTIONING VALVES................ 86
REAR WHEEL SPEED SENSOR............ 88
SPECIFICATIONS
BRAKE FASTENER TORQUE SPECIFICATIONS . 89
SPEED SENSOR TONE WHEEL RUNOUT..... 89
WHEEL SPEED SENSOR TO TONE WHEEL
CLEARANCE.......................... 89
DESCRIPTION AND OPERATION
ANTILOCK BRAKES OPERATION DESCRIPTION
The purpose of an Antilock Brake System (ABS) is
to prevent wheel lock-up under braking conditions on
virtually any type of road surface. Antilock Braking
is desirable because a vehicle which is stopped with-
out locking the wheels will retain directional stability
and some steering capability. This allows the driver
to retain greater control of the vehicle during brak-
ing.
This section of the service manual covers the
description and on car service for the ITT Teves
Mark 20 ABS 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 service manual for the specific service
procedure required.
ABS COMPONENT ABBREVIATION LIST
In this section of the service manual, several
abbreviations are used for the components of the
Teves Mark 20 ABS Brake System. They are listed
below for your reference.
²CAB±Controller Antilock Brake
²ICU±Integrated Control Unit
²HCU±Hydraulic Control Unit
²ABS±Antilock Brake System
²PSI±Pounds Per Square Inch (pressure)
²WSS±Wheel Speed Sensor
²FWD±Front Wheel Drive
²DTC±Diagnostic Trouble Code
ABS BRAKES OPERATION AND VEHICLE
PERFORMANCE
This ABS System represents the current state-of-
the-art in vehicle braking systems and offers the
driver increased safety and control during braking.
PLBRAKES 5 - 69

This is accomplished by a sophisticated system of
electrical and hydraulic components. As a result,
there are a few performance characteristics that may
at first seem different but should be considered nor-
mal. These characteristics are discussed below.
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.
ABS SYSTEM OPERATION
If a wheel locking tendency is detected during a
brake application, the brake system will enter the
ABS mode. During ABS braking, hydraulic pressure
in the four wheel circuits is modulated to prevent
any wheel from locking. Each wheel circuit is
designed with a set of electric solenoids to allow mod-
ulation, although for vehicle stability, both rear
wheel solenoids receive the same electrical signal.
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).
ABS operation is available at all vehicle speeds
above 3 to 5 mph. Wheel lockup may be perceived at
the very end of an ABS stop and is considered nor-
mal.
VEHICLE HANDLING PERFORMANCE DURING
ABS BRAKING
It is important to remember that an antilock brake
system does not shorten a vehicle's stopping distance
under all driving conditions, but does provide
improved control of the vehicle while stopping. Vehi-
cle stopping distance is still dependent on vehicle
speed, weight, tires, road surfaces and other factors.
Though ABS provides the driver with some steer-
ing control during hard braking, there are conditions
however, where the system does not provide any ben-
efit. In particular, hydroplaning is still possible when
the tires ride on a film of water. This results in the
vehicles tires leaving the road surface rendering the
vehicle virtually uncontrollable. In addition, extreme
steering maneuvers at high speed or high speed cor-
nering beyond the limits of tire adhesion to the road
surface may cause vehicle skidding, independent of
vehicle braking. For this reason, the ABS system is
termed Antilock instead of Anti-Skid.
NOISE AND BRAKE PEDAL FEEL
During ABS braking, some brake pedal movement
may be felt. In addition, ABS braking will create
ticking, popping and/or groaning noises heard by the
driver. This is normal 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 will be 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 then 3 mph or during
an ABS stop where ABS is no longer required. These
conditions will 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
surface will activate ABS because of the wheel hop
caused by the bumps.
TIRE NOISE AND MARKS
Although the ABS system prevents complete wheel
lock-up, 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 to30%. This
means that the wheel rolling velocity is 25 to 30%
less than that of a free rolling wheel at a given vehi-
cle speed. This slip may result in some tire chirping,
depending on the road surface. This sound should not
be interpreted as total wheel lock-up.
Complete wheel lock up normally leaves black tire
marks on dry pavement. The ABS System will not
leave dark black tire marks since the wheel never
reaches a fully locked condition. Tire marks may
however 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.
Additionally, when the vehicle is first driven off a
humming may be heard and/or felt by the driver at
approximately 20 to 40 kph (12 to 25 mph). The ABS
warning lamp will also be on for up to 5 seconds
after the ignition is turned on. All of these conditions
are a normal function of ABS as the system is per-
forming a diagnosis check.
5 - 70 BRAKESPL
DESCRIPTION AND OPERATION (Continued)

PREMATURE ABS CYCLING
NOTE: When working on a vehicle which has a
complaint of premature ABS cycling it may be nec-
essary to use a DRB Scan Tool to detect and verify
the condition.
There is one complaint called Premature ABS
Cycling in which neither the Red Brake Warning
Lamp nor the Amber Antilock Lamp were illumi-
nated and no fault codes were stored in the CAB.
Symptoms of Premature ABS Cycling, include click-
ing sounds from the solenoids valves, pump motor
running and pulsations in the brake pedal. This con-
dition can occur at any braking rate of the vehicle
and on any type of road surface. This creates an
additional condition which needs to be correctly
assessed when diagnosing problems with the antilock
brake system.
The following conditions are common causes that
need to be checked when diagnosing a condition of
Premature ABS Cycling. Damaged tone wheels,
incorrect tone wheels, damage to a wheel speed sen-
sor mounting boss on a steering knuckle, a loose
wheel speed sensor mounting bolt, and excessive tone
wheel runout. Also, an excessively large tone wheel
to wheel speed sensor air gap can lead to the condi-
tion of Premature ABS Cycling. Special attention is
to be given to these components when diagnosing a
vehicle exhibiting the condition of Premature ABS
Cycling. After diagnosing the defective component,
repair or replace as required.
When the component repair or replacement is com-
pleted, test drive the vehicle to verify the condition of
Premature ABS Cycling has been corrected.
ABS BRAKE SYSTEM COMPONENTS
The following is a detailed description of the Teves
Mark 20 ABS brake system components. For infor-
mation on servicing the base brake system compo-
nents, see the base Brake System section of this
Service Manual.
ABS MASTER CYLINDER AND POWER BRAKE
BOOSTER
A vehicle equipped with the Teves Mark 20 ABS
uses a different master cylinder and power brake
booster (Fig. 1) then a vehicle that is not equipped
with antilock brakes. A vehicle equipped with ABS
uses a center port master cylinder while a vehicle
which is not equipped with ABS uses a compensating
port master cylinder.
The primary and secondary outlet ports on the
master cylinder go directly to the hydraulic control
unit HCU.Reference the appropriate section of this service
manual for further information on the individual
components.
INTEGRATED CONTROL UNIT (ICU)
The hydraulic control unit (HCU) (Fig. 2) used
with the Teves Mark 20 ABS is different from the
HCU used on previous Chrysler products with ABS.
The HCU used on this ABS system is part of the
integrated control unit (ICU). The HCU is part of
what is referred to as the ICU because the HCU and
the controller antilock brakes (CAB) are combined
(integrated) into one unit. This differs from previous
Chrysler products with ABS, where the HCU and the
CAB were separate components located in different
areas of the vehicle.
NOTE: The HCU and CAB used on a vehicle that is
equipped with only ABS and on a vehicle that is
equipped with ABS and traction control are differ-
ent. The HCU on a vehicle equipped with ABS and
traction control has a valve block housing (Fig. 2)
that is approximately 1 inch longer on the low pres-
sure fluid accumulators side than a HCU for a vehi-
cle that is equipped with only ABS.
The ICU is located on the driver's side of the vehi-
cle, and is mounted to the left front frame rail below
the master cylinder (Fig. 3). The ICU contains the
following components for controlling the brake sys-
tem hydraulic pressure during ABS braking: The
CAB, eight solenoid valves, (four inlet valves and
four outlet valves) fluid accumulators a pump, and
an electric motor. Also attached to the ICU are the
master cylinder primary and secondary brake tubes
and the brake tubes going to each wheel of the vehi-
cle.
Fig. 1 Master Cylinder And Vacuum Booster
PLBRAKES 5 - 71
DESCRIPTION AND OPERATION (Continued)

CAUTION: No components of the ICU are service-
able. If any component that makes up the ICU is
diagnosed as not functioning properly it MUST be
replaced. The replaceable components of the ICU,
are the HCU and the CAB (Fig. 2) and (Fig. 3). The
mounting bracket is also replaceable as a separate
component of the ICU. The remaining components
of the ICU are not serviceable items. No attempt
should ever be made to remove or service any indi-
vidual components of the HCU. This is due to the
concern of contamination entering the HCU while
performing a service procedure. Also no attempt
should ever be made to remove or service any indi-
vidual components of the CAB.
CAUTION: At no time when servicing the ICU
should a 12 volt power source be applied to any
electrical connector of the HCU or the CAB.
INLET VALVES AND SOLENOIDS
There are four inlet solenoid valves, one for each
wheel. In the released position they provide a fluid
path from the master cylinder to the wheel brakes of
the vehicle. When the ABS cycle has been completed
the inlet solenoids will return to their released (open)
position.
OUTLET VALVES AND SOLENOIDS
There are four outlet solenoid valves, one for each
wheel. In the released position they are closed to
allow for normal braking. In the actuated (open) posi-
tion, they provide a fluid path from the wheel brakes
of the vehicle to the ICU fluid accumulators and
pump motor. The outlet valves are spring loaded in
the released (closed) position during normal braking.
ABS FLUID ACCUMULATORS
There are two fluid accumulators in all hydraulic
control units, one each for the primary and secondary
hydraulic circuits. The fluid accumulators tempo-
rarily store brake fluid that is removed from the
wheel brakes during an ABS cycle. This fluid is then
used by the pump in the valve body to provide build
pressure for the brake hydraulic system.
HCU PUMP/MOTOR
The HCU (Fig. 4) contains 2 pump assemblies, one
for the primary and one for the secondary hydraulic
circuit of the brake system. Both pumps are driven
by a common electric motor (Fig. 4) which is part of
the HCU. The pumps draw brake fluid from the fluid
accumulators to supply build pressure to the brakes
during an ABS stop. The pump motor runs during
the drive-off cycle as a check and during an ABS stop
and is controlled by the CAB. The Pump/Motor
Assembly is not a serviceable item. If the pump/mo-
tor requires replacement the complete HCU (Fig. 4)
(minus the CAB) must be replaced.
Fig. 2 Teves Mark 20 ICU
Fig. 3 ICU Mounting LocationFig. 4 Teves Mark 20 HCU Pump/Motor
5 - 72 BRAKESPL
DESCRIPTION AND OPERATION (Continued)