1999 DODGE NEON Service Repair Manual

is damaged, or a fluid leak is visible, disassemble cal-
iper assembly and install a new seal and boot, and
piston if scored. Refer to Front Disc Brake Caliper in
the Disassembly And Assembly Section in this group
of the service manual.
Check the guide pin dust boots to determine if they
are in good condition. Replace if they are damaged,
dry, or found to be brittle. Refer to Front Disc Brake
Caliper in the Disassembly And Assembly Section in
this group of the service manual.
REAR DISC BRAKES
BRAKE PAD LINING WEAR
If a visual inspection does not adequately deter-
mine the condition of the lining, a physical check will
be necessary. To check the amount of lining wear,
remove the wheel and tire assemblies, and the cali-
pers.
Remove the rear disc brake shoes. Refer to Rear
Disc Brake Shoe Removal in the Removal And Instal-
lation section in this group of the service manual for
the required procedure.
The combined brake shoe and lining material
thickness should be measured at the thinnest part of
the assembly.
When a set of brake shoes are worn to a total
thickness of approximately 7.0 mm (9/32 inch) they
should be replaced.
Replacebothbrake shoe assemblies (inboard and
outboard). It is necessary thatbothrear wheel sets
be replaced whenever brake shoe assemblies on
either side are replaced.
If the brake shoe assemblies do not require
replacement, reinstall, the assemblies making sureeach brake shoe is returned to the original position.
Refer to Rear Disc Brake Shoe Installation in the
Removal And Installation section in this group of the
service manual for the required procedure.
CALIPER INSPECTION
Check for brake fluid leaks in and around boot
area and inboard lining, and for any ruptures, brit-
tleness or damage to the piston dust boot. If the boot
is damaged, or a fluid leak is visible, disassemble cal-
iper assembly and install a new seal and boot, and
piston if scored. Refer to Rear Disc Brake Caliper in
the Disassembly And Assembly Section in this group
of the service manual.
Check the guide pin dust boots to determine if they
are in good condition. Replace if they are damaged,
dry, or found to be brittle. Refer to Rear Disc Brake
Caliper in the Disassembly And Assembly Section in
this group of the service manual.
REAR DRUM BRAKES
Rear brake shoe lining should show contact across
entire width of the lining and also from the heel to
the toe of the lining, otherwise replace.
Brake shoes with lack of contact at the toe or heel
of the brake shoe linng may be improperly ground.
Clean and inspect the brake support plate and
adjusting screws. Apply a thin coat of Mopar Multi-
Purpose Lubricant or equivalent to the threads of the
self adjuster (Fig. 184). Replace adjusting screw if
corroded.
Fig. 183 Rear Wheel Cylinder (Exploded View)
5 - 64 BRAKESPL
CLEANING AND INSPECTION (Continued)

If old brake shoe return or hold down springs have
overheated or are damaged, replace. Overheating
indications are paint discoloration or distorted end
coils.
REAR DRUM BRAKE WHEEL CYLINDER
With brake drums removed, inspect the wheel cyl-
inder boots for evidence of a brake fluid leak. Visu-
ally check the boots for cuts, tears, or heat cracks. If
any of these conditions exist, the wheel cylinders
should be completely cleaned, inspected and new
parts installed.
If a wheel cylinder is leaking and the brake lining
material is saturated with brake fluid, the brake
shoes must be replaced.
CHASSIS TUBES AND HOSES
Flexible rubber hose is used at both front and rear
brakes. Inspection of brake hoses should be per-
formed whenever the brake system is serviced and
every 7,500 miles or 12 months, whichever comes
first (every engine oil change). Inspect hydraulic
brake hoses for severe surface cracking, scuffing,
worn spots or physical damage. If the fabric casing of
the rubber hose becomes exposed due to cracks or
abrasions in the rubber hose cover, the hose should
be replaced immediately. Eventual deterioration of
the hose can take place with possible burst failure.
Faulty installation can cause twisting, resulting in
wheel, tire, or chassis interference.
The steel brake tubing should be inspected periodi-
cally for evidence of corrosion, physical damage or con-
tact with moving or hot components of the vehicle.
REAR WHEEL HUB AND BEARING ASSEMBLY
The rear hub and bearing assembly is designed for
the life of the vehicle and should require no mainte-
nance. The following procedure may be used for eval-
uation of bearing condition.
With wheel and brake drum removed, rotate
flanged outer ring of hub. Excessive roughness, lat-
eral play or resistance to rotation may indicate dirt
intrusion or bearing failure. If the rear wheel bear-
ings exhibit these conditions during inspection, the
hub and bearing assembly should be replaced.Damaged bearing seals and resulting excessive
grease loss may also require bearing replacement.
Moderate grease loss from bearing is considered nor-
mal and should not require replacement of the hub
and bearing assembly.
ADJUSTMENTS
STOP LAMP SWITCH
(1) Remove stop lamp switch from its bracket by
rotating it approximately 30É in a counter-clockwise
direction.
(2) Disconnect wiring harness connector from stop
lamp switch.
(3) Hold stop lamp switch firmly in one hand.
Then using other hand, pull outward on the plunger
of the stop lamp switch until it has ratcheted out to
its fully extended position.
(4) Install the stop lamp switch into the bracket
using the following procedure. Depress the brake
pedal as far down as possible. Then while keeping
the brake pedal depressed, install the stop lamp
switch into the bracket by aligning index key on
switch with slot at top of square hole in mounting
bracket. When switch is fully installed in the square
hole of the bracket, rotate switch clockwise approxi-
mately 30É to lock the switch into the bracket.
CAUTION: Do not use excessive force when pulling
back on brake pedal to adjust the stop lamp switch.
If too much force is used, damage to the vacuum
booster, stop lamp switch or striker (Fig. 185) can
result.
(5) Connect the wiring harness connector to the
stop lamp switch.
(6) Gently pull back on brake pedal until the pedal
stops moving. This will cause the switch plunger
(Fig. 185) to ratchet backward to the correct position.
REAR DRUM BRAKE SHOE ADJUSTMENT
NOTE: Normally, self adjusting drum brakes will
not require manual brake shoe adjustment.
Although in the event of a brake reline it is advis-
able to make the initial adjustment manually to
speed up the adjusting time.
(1) Raise the vehicle so all wheels are free to turn.
See Hoisting Recommendations in the Lubrication
And Maintenance Section at the front of this service
manual.
(2) Remove rear brake adjusting hole rubber plug
(Fig. 186) from the rear brake shoe support plate.
Fig. 184 Adjuster Screw And Lever (Typical)
PLBRAKES 5 - 65
CLEANING AND INSPECTION (Continued)

(3)Be sure parking brake lever is fully
released.
(4) Insert Brake Adjuster, Special Tool C-3784,
(Fig. 187) or equivalent, through the adjusting hole
in support plate and against star wheel of adjusting
screw. Move handle of tool downward until a slight
drag is felt when the road wheel is rotated.
(5) Insert a thin screwdriver or piece of welding
rod into brake adjusting hole (Fig. 187). Push adjust-
ing lever out of engagement with star wheel.Care
should be taken so as not to bend adjusting
lever or distort lever spring.While holding
adjusting lever out of engagement with star wheel,
back off star wheel to ensure a free wheel with no
brake shoe drag.
(6) Repeat above adjustment at the other rear
wheel. Install adjusting hole rubber plugs (Fig. 186)
in rear brake supports.
(7) Apply and release the park brake lever one
timeafterwheel brake adjustment.
PARK BRAKE ADJUSTMENT
VEHICLE EQUIPPED REAR DRUM BRAKES
Due to the auto adjust feature of the park brake
lever, no manual adjustment of the operating cables
for the park brake system is required. On vehicles
equipped with rear drum brakes, proper operation of
the park brake relies on proper adjustment of the
rear drum brake shoes. See Rear Brake Adjustment
in the Service Adjustments Section in this group of
the service manual.
VEHICLE EQUIPPED REAR DISC BRAKES
Due to the auto adjust feature of the park brake
lever, no manual adjustment of the operating cables
for the park brake system is required. On vehicles
equipped with rear disc brakes, proper operation of
the park brake relies on the proper adjustment of the
drum-in-hat park brake shoes. Refer to the following
procedure to correctly adjust the drum-in-hat park
brake shoes.
NOTE: The park brake shoes used in the drum-in-
hat park brake system do not automatically adjust
to compensate for brake shoe lining wear. There-
fore, it is necessary to manually adjust the park
brake shoes. Manual adjustment of the park brake
shoes is required whenever any of the following
occurs. Excessive travel of the of the park brake
lever, new park brake shoes are installed, or any
service is performed that effects the location of the
park brake shoes like: replacing hold down clips,
return springs, adjuster mechanism etc.
(1) Fully release the park brake hand lever.
(2) Raise vehicle. See Hoisting Recommendations
in the Lubrication And Maintenance Section of this
service manual.
Fig. 185 Stop Light Switch Location In Vehicle
Fig. 186 Rear Brake Adjusting Hole Plug
Fig. 187 Brake Drum Adjustment With Tool C-3784
5 - 66 BRAKESPL
ADJUSTMENTS (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)