steering DODGE NEON 1999 Service Service Manual

Place gauge (Form A) on edge over end of brake
tubing. Push tubing through jaws until end of tubing
contacts the recessed notch in gauge matching the
tubing size. Squeeze handles of flaring tool and lock
tubing in place. Place 3/16 inch plug of gauge (A)
down in end of tubing. Swing compression disc over
gauge and center tapered flaring screw in recess of
disc. Screw in until plug gauge has seated on jaws of
flaring tool. This action has started to invert the
extended end of the tubing. Remove gauge and con-
tinue to screw down until tool is firmly seated in tub-
ing. Remove tubing from flaring tool and inspect
seat. Refer to tube routing diagrams for proper brake
tube routing and clip locations. Replace any damaged
tube routing clips.
REMOVAL AND INSTALLATION
WHEEL AND TIRE ASSEMBLY
To install the wheel and tire assembly, first posi-
tion it properly on the mounting surface using the
hub pilot as a guide. Then progressively tighten the
lug nuts in the proper sequence (Fig. 55) to half of
the required torque. Finally tighten the lug nuts in
the proper sequence (Fig. 55) to 129 N´m (95 ft. lbs.).
Never use oil or grease on studs or nuts.
FRONT DISC BRAKE CALIPER
REMOVE
During service procedures, grease or any other for-
eign material must be kept off caliper assembly, sur-
faces of braking rotor and external surfaces of hub.
Handling of the braking rotor and caliper should
be done in such a way as to avoid deformation of the
rotor and scratching or nicking of the brake linings.
During removal and installation of a wheel and
tire assembly, use care not to strike the caliper.
(1) Raise vehicle on jackstands or centered on a
hoist. See Hoisting in the Lubrication and Mainte-
nance section of this service manual for the required
lifting procedure for this vehicle.
(2) Remove the front wheel and tire assemblies
from this vehicle.
(3) Remove the 2 brake caliper to steering knuckle
guide pin bolts (Fig. 56).
(4) Remove caliper from steering knuckle, by first
rotating free end of caliper away from steering
Fig. 53 Double Inverted Brake Line Tubing Flare
Fig. 54 Double Wall Inverted Flare Connection
Fig. 55 Wheel Nut Tightening Sequence
Fig. 56 Caliper Guide Pin Bolts
5 - 26 BRAKESPL
SERVICE PROCEDURES (Continued)

knuckle. Then slide opposite end of caliper out from
under machined abutment on steering knuckle (Fig.
57).
(5) Support the disc brake caliper firmly using a
wire hanger (Fig. 58). This is required to prevent the
weight of the caliper from damaging the flexible
brake hose.
INSTALL
NOTE: Step 1 below is only required when install-
ing a caliper after new brake shoes have been
installed.
(1) Completely retract the caliper piston back into
the bore of the caliper.
(2) Lubricate both steering knuckle abutments
with a liberal amount of MopartMultipurpose Lubri-
cant, or equivalent.
(3) If removed, install the front rotor on the hub,
making sure it is squarely seated on face of hub.CAUTION: Use care when installing the caliper
assembly onto the steering knuckle so the seals on
the caliper guide pin bushings do not get damaged
by the steering knuckle bosses.
(4) Carefully position the brake caliper and brake
shoes on the steering knuckle by first hooking the
end of the caliper under the edge of the steering
knuckle as shown in (Fig. 59). Then rotate caliper
into position on the steering knuckle.
(5) Install the caliper guide pin bolts and tighten
to 18 to 20 N´m (192 in. lbs.) (Fig. 56).Extreme
caution should be taken not to cross thread the
caliper guide pin bolts.
(6) Install the wheel and tire assembly.
(7) Tighten the wheel mounting stud nuts in
proper sequence until all nuts are torqued to half
specification. Then repeat the tightening sequence to
the full specified torque of 135 N´m (100 ft. lbs.).
(8) Remove jackstands or lower hoist.Before
moving vehicle, pump the brake pedal several
times to insure the vehicle has a firm brake
pedal.
(9) Road test the vehicle and make several stops to
wear off any foreign material on the brakes and to
seat the brake pads.
Fig. 57 Removing Caliper Assembly From Steering
Knuckle
Fig. 58 Storing Disc Brake Caliper
Fig. 59 Installing Caliper Assembly On Steering
Knuckle
PLBRAKES 5 - 27
REMOVAL AND INSTALLATION (Continued)

FRONT DISC BRAKE SHOES
WARNING: ALTHOUGH FACTORY INSTALLED
BRAKELININGS ARE MADE FROM ASBESTOS
FREE MATERIALS, SOME AFTER MARKET BRAKE-
LINING MAY CONTAIN ASBESTOS. THIS SHOULD
BE TAKEN INTO ACCOUNT WHEN SERVICING A
VEHICLE'S BRAKE SYSTEM, WHEN AFTERMARKET
BRAKELININGS MAY HAVE BEEN INSTALLED ON
THE VEHICLE. ALWAYS WEAR A RESPIRATOR
WHEN CLEANING BRAKE COMPONENTS AS
ASBESTOS CAN CAUSE SERIOUS BODILY HARM
SUCH AS ASBESTOSIS AND OR CANCER. NEVER
CLEAN BRAKE COMPONENTS BY USING COM-
PRESSED AIR, USE ONLY A VACUUM CLEANER
SPECIFICALLY DESIGNED FOR THE REMOVAL OF
BRAKE DUST. IF A VACUUM CLEANER IS NOT
AVAILABLE, CLEAN BRAKE PARTS USING ONLY
WATER DAMPENED SHOP TOWELS. DO NOT CRE-
ATE BRAKELINING DUST BY SANDING BRAKE LIN-
INGS WHEN SERVICING A VEHICLE. DISPOSE OF
ALL DUST AND DIRT SUSPECTED OF CONTAINING
ASBESTOS FIBERS USING ONLY SEALED AIR-
TIGHT BAGS OR CONTAINERS. FOLLOW ALL REC-
OMMENDED SAFETY PRACTICES PRESCRIBED BY
THE OCCUPATIONAL SAFETY AND HEALTH ADMIN-
ISTRATION (OSHA) AND THE ENVIRONMENTAL
PROTECTION AGENCY (EPA), FOR HANDLING AND
DISPOSAL OF PRODUCTS CONTAINING ASBES-
TOS.
During service procedures, grease or any other for-
eign material must be kept off caliper assembly, sur-
faces of braking rotor and external surfaces of hub.
Handling of the brake rotor and caliper should be
done in such a way as to avoid deformation of the
rotor and scratching or nicking of the brake linings.
If inspection reveals that the square sectioned cal-
iper piston seal is worn or damaged, it should be
replaced immediately.
During removal and installation of a wheel and
tire, use care not to strike the caliper.
NOTE: Before vehicle is moved after any brake
service work, pump the brake pedal several times
to insure the vehicle has a firm brake pedal.
NOTE: Starting with the 1998 model year, different
lining material is used on the disc brake shoes
depending on the type of brake system the vehicle
is equipped with. Vehicles equipped with standard
front disc and rear drum brakes use a new lining
material on the front disc brake shoes. Vehicles that
are equipped with optional 4 wheel disc brakes use
a new lining material on both the front and rear disc
brake shoes. When new brake shoes are installed,be sure brake shoes for the correct model year and
type of brake system the vehicle is equipped with
are used.
REMOVE
(1) Raise vehicle on jackstands or centered on a
hoist. See Hoisting in the Lubrication and Mainte-
nance section of this manual.
(2) Remove the front wheel and tire assemblies
from vehicle.
(3) Remove the 2 guide pin bolts (Fig. 60) mount-
ing the caliper to the steering knuckle.
(4) Remove brake caliper from steering knuckle, by
first rotating free end of caliper away from steering
knuckle. Then slide opposite end of caliper out from
under machined abutment on steering knuckle (Fig.
61).
(5) Support caliper firmly to prevent weight of cal-
iper from damaging the flexible brake hose (Fig. 62).
Fig. 60 Caliper Guide Pin Bolts
Fig. 61 Removing Caliper From Steering Knuckle
5 - 28 BRAKESPL
REMOVAL AND INSTALLATION (Continued)

(6) Remove brake rotor from hub by pulling it
straight off the wheel mounting studs (Fig. 63).
(7) Remove outboard brake shoe by prying the
shoe retaining clip over raised area on caliper. Then
slide the brake shoe down and off the caliper (Fig.
64).
(8) Pull the inboard brake shoe away from the cal-
iper piston until the retaining clip is out of the cavity
in the piston. (Fig. 65).
CALIPER INSPECTION
Check caliper for piston seal leaks (brake fluid in
and around boot area and inboard lining) and for any
ruptures of the piston dust boot. If boot is damaged,
or fluid leak is visible, disassemble caliper and
install a new seal and boot, (and piston if scored).
Refer to Caliper Disassembly And Re-Assembly Pro-
cedures in Disc Brake Caliper Service in this section
of the service manual.
Check the caliper dust boot and caliper pin bush-
ings to determine if they are in good condition.Replace if they are damaged, dry, or found to be brit-
tle. Refer to Guide Pin Bushing Service in Disc
Brake Caliper Service in this section of the service
manual.
INSTALL
(1) Completely retract caliper piston back into pis-
ton bore of caliper. This is required for caliper instal-
lation with new brake shoe assemblies.
(2) Lubricate both steering knuckle abutments
with a liberal amount of MopartMultipurpose Lubri-
cant, or equivalent.
(3) Install the front rotor on the hub, making sure
it is squarely seated on face of hub (Fig. 63).
(4) Remove the protective paper from the noise
suppression gasket on both the inner and outer brake
shoes (if equipped).
NOTE: Note: The inboard and outboard brake
shoes are not common (Fig. 66).
Fig. 62 Storing Caliper
Fig. 63 Removing/Installing Brake Rotor
Fig. 64 Removing Outboard Brake Shoe
Fig. 65 Removing Inboard Brake Shoe
PLBRAKES 5 - 29
REMOVAL AND INSTALLATION (Continued)

(5) Install the new inboard brake shoe into the cal-
iper piston by firmly pressing into piston bore with
thumbs (Fig. 67). Be sure inboard brake shoe is posi-
tioned squarely against the face of the caliper piston.
(6) Slide the new outboard brake shoe onto the cal-
iper (Fig. 68).
CAUTION: Use care when installing the caliper
onto the steering knuckle so the seals on the cali-
per guide pin bushings do not get damaged by the
steering knuckle bosses.
(7) Carefully position the brake caliper and brake
shoes over the rotor by hooking the end of the caliper
under the steering knuckle (Fig. 69). Then rotate cal-
iper into position on steering knuckle.
(8) Install the caliper guide pin bolts (Fig. 60) and
tighten to 18 to 20 N´m (192 in. lbs.).Extreme cau-
tion should be taken not to cross thread the
caliper guide pin bolts.
(9) Install the wheel and tire assembly.(10) Tighten the wheel mounting stud nuts in
proper sequence until all nuts are torqued to half
specification. Then repeat the tightening sequence to
the full specified torque of 135 N´m (100 ft. lbs.).
(11) Remove jackstands or lower hoist.Before
moving vehicle, pump the brake pedal several
times to insure the vehicle has a firm brake
pedal.
(12) Road test the vehicle and make several stops
to wear off any foreign material on the brakes and to
seat the brake pads.
REAR DISC BRAKE CALIPER
REMOVE
(1) Raise vehicle on jackstands or centered on a
hoist. See Hoisting in the Lubrication and Mainte-
nance section of this manual.
(2) Remove rear wheel and tire assemblies from
vehicle.
(3) Remove the 2 caliper assembly to adapter
guide pin bolts (Fig. 70).
Fig. 66 Front Brake Shoe Identification
Fig. 67 Installing Inboard Brake Shoe
Fig. 68 Installing Outboard Brake Shoe
Fig. 69 Installing Caliper On Steering Knuckle
5 - 30 BRAKESPL
REMOVAL AND INSTALLATION (Continued)

brake vacuum booster. Vacuum seal is removed by
carefullyinserting a small screw driver between the
push rod of the power brake vacuum booster and vac-
uum seal (Fig. 118) and prying seal out of power
brake vacuum booster.Do not attempt to pry seal
out of master cylinder by inserting a tool
between seal and power brake vacuum booster.
(8) Disconnect vacuum hoses from check valve on
power brake vacuum booster (Fig. 119).Do not
remove check valve from power brake vacuum
booster.
NOTE: If vehicle is equipped with antilock brakes,
the hydraulic control unit (HCU) needs to be
removed from the vehicle to allow removal of the
power brake vacuum booster. Refer to Antilock
Brake System Hydraulic Control Unit in the
Removal And Installation Section of the Antilock
Brake System Section of this service manual for the
required procedure.(9) Locate the power brake vacuum booster input
rod to brake pedal attachment under instrument
panel. Position a small screwdriver (Fig. 120) under
the center tang of the retaining clip.
CAUTION: Discard retaining clip when removed, it
is not to be reused. Replace only with a new retain-
ing clip when assembled.
(10) Rotate screwdriver (Fig. 120) enough to allow
retaining clip tang to pass over the end of the brake
pedal pin.
(11) Remove the 4 nuts attaching the power brake
vacuum booster to the dash panel (Fig. 121). The
nuts are accessible from under the instrument panel
in the area of the steering column and brake pedal
bracket.
(12) Slide power brake vacuum booster forward
until mounting studs clear dash panel, then tilt the
booster up and to the center of the vehicle to remove.
Fig. 118 Vacuum Seal Removal From Power Brake
Booster
Fig. 119 Power Brake Vacuum Booster Check Valve
Fig. 120 Input Rod Retaining Pin
Fig. 121 Power Brake Booster Mounting
PLBRAKES 5 - 45
REMOVAL AND INSTALLATION (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)

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)