suspension CHRYSLER VOYAGER 1996 Repair Manual
[x] Cancel search | Manufacturer: CHRYSLER, Model Year: 1996, Model line: VOYAGER, Model: CHRYSLER VOYAGER 1996Pages: 1938, PDF Size: 55.84 MB
Page 106 of 1938

BRAKE DRUM MACHINING
Measure the runout and diameter of the rear brake
using only accurate measuring equipment. There
should be no variation in the drum diameter greater
than 0.090 mm (0.004 inch). Drum runout should not
exceed 0.15 mm (0.006 inch) out of round. If the
drum runout or diameter variation exceed these val-
ues the drum should be refaced. For best results in
eliminating the irregularities that cause brake rough-
ness and surge, the amount of material removed dur-
ing a single cut should be limited to 0.13 mm (0.005
inch). When the entire braking surface has been
cleaned. A final cut of 0.0254 mm (0.001 inch) will
assure a good drum surface providing the equipment
used is capable of the precision required for resurfac-
ing brake drums. Deeper cuts are permissible for the
sole purpose of removing deep score marks.Do not
reface more than 1.52 mm (0.060 inch) over the
standard drum diameter.
All drums will show markings of maximum allow-
able diameter (Fig. 36). For example, a drum will
have a marking of MAX. DIA. 251.55 mm (9.90 inch).
This marking includes 0.76 mm (0.030 inch) for
allowable drum wear beyond the recommended 1.52
mm (0.060 inch) of drum refacing
BRAKE TUBE REPAIR PROCEDURE
CAUTION: When repairing brake chassis lines or
flex hoses, the correct fasteners must be used to
attach the routing clips or hoses to the front sus-
pension cradle. The fasteners used to attach com-
ponents to the front suspension cradle have an
anti-corrosion coating due to the suspension cradle
being made of aluminum. Only Mopar replacement
fasteners with the required anti-corrosion coating
are to be used if a replacement fastener is required
when installing a brake chassis line or flex hose.
Only double wall 4.75mm (3/16 in.) steel tubing
with Al-rich/ZW-AC alloy coating and the correct tube
nuts are to be used for replacement of a hydraulic
brake tube.
NOTE: On vehicles equipped with traction control,
the primary and secondary hydraulic tubes between
the master cylinder and the hydraulic control unit
are 6 mm (15/64 in.). These tubes are also coated
with the Al-rich/ZW-AC alloy and must be replaced
with tubes having the same anti-corrosion coating.
Be sure the correct tube nuts are used for the
replacement of these hydraulic brake tubes.
Care should be taken when repairing brake tubing,
to be sure the proper bending and flaring tools and
procedures are used, to avoid kinking. Do not route
the tubes against sharp edges, moving components or
into hot areas. All tubes should be properly attached
with recommended retaining clips.
If the primary or secondary brake line from the
master cylinder to the ABS Hydraulic Control Unit,
or the flexible brake lines between the hydraulic con-
trol unit and the proportioning valve require replace-
mentonlythe original factory brake lines containing
a flexible section can be used. This is required due to
the movement of the front suspension cradle while
the vehicle is in motion.
Using Tubing Cutter, Special Tool C-3478-A or
equivalent, cut off damaged seat or tubing (Fig. 37).
Ream out any burrs or rough edges showing on
inside of tubing (Fig. 38). This will make the ends of
tubing square (Fig. 38) and ensure better seating of
ROTOR REFINISHING LIMITS
Braking RotorRotor Thick-
nessMinimum Rotor
ThicknessRotor Thick-
ness VariationRotor Run
Out*Rotor Micro
Finish
Front Rotor 23.87-24.13 mm
.939 -.949 in.22.4 mm
.881 in..013 mm
.0005 in..08 mm
.003 in.15-80 RMS
Rear Rotor 12.75-12.25 mm
.502 -.482 in.11.25 mm
.443 in..013 mm
.0005 in..08 mm
.003 in.15-80 RMS
* TIR Total Indicator Reading (Measured On Vehicle)
Fig. 36 Rear Brake Drum Maximum Diameter
Identification
5 - 24 BRAKESNS
SERVICE PROCEDURES (Continued)
Page 137 of 1938

CAUTION: The master cylinder is used to create
the seal for holding vacuum in the vacuum booster.
The vacuum seal on the master cylinder MUST be
replaced with a NEW seal whenever the master cyl-
inder is removed from the vacuum booster.
CAUTION: When removing the vacuum seal from
the master cylinder do not use a sharp tool.
(7) Using a soft tool such as a trim stick, remove
the vacuum seal from the master cylinder mounting
flange.
(8) Install aNEWvacuum seal on mounting flange
of the master cylinder (Fig. 128).
(9) Position master cylinder on studs of vacuum
booster, aligning push rod on vacuum booster with
master cylinder piston.
(10) Install the 2 nuts mounting the master cylin-
der to the vacuum booster (Fig. 124). Tighten both
mounting nuts to a torque of 25 N´m (225 in. lbs.).
(11) Install the wiper module drain hose (Fig. 124)
on the wiper module. Install the tie strap attaching
the wiper module drain hose to brake tube at the
master cylinder.Tie strap should be loosely tight-
ened so as not to collapse the wiper module
drain hose.
(12) Install the wiring harness connector on the
brake fluid level sensor in the master cylinder fluid
reservoir (Fig. 123).
(13) Install the throttle body and throttle cable
bracket on the intake manifold. Install the 2 bolts
(Fig. 122) attaching the throttle body to the intake
manifold and tighten to a torque of 25 N´m (225 in.
lbs.) Install clip (Fig. 122) attaching the wiring har-
ness to the throttle cable bracket.
(14) Install the wiring harness connectors on the
throttle position sensor and the AIS motor on throttle
body (Fig. 121).(15) Install the wiring harness connector (Fig. 120)
on the EGR valve transducer.
(16) Install the battery tray. Install the 2 bolts and
the nut (Fig. 119) attaching the battery tray to the
vehicle. Tighten the 2 bolts and the nut to a torque of
14 N´m (125 in lbs.).
(17) If vehicle is equipped with speed control,
install the speed control servo and bracket on the
battery tray. Install and securely tighten bolt attach-
ing bracket to battery tray.
(18) If vehicle is equipped with speed control,
install the wiring harness connector on the speed
control servo. Then connect the vacuum lines onto
the speed control servo and vacuum reservoir on bat-
tery tray.
(19) Install the air inlet resonator and hoses as an
assembly on the throttle body and air cleaner hous-
ing (Fig. 118). Securely tighten hose clamp at air
cleaner housing and throttle body.
(20) Install the battery and the battery thermal
guard.
(21) Install the battery cables on the battery.
(22) Check the operation of the stop lamp switch
and adjust if necessary.
JUNCTION BLOCK
REMOVE
(1) Using a brake pedal depressor, move and lock
the brake pedal to a position past its first 1 inch of
travel. This will prevent brake fluid from draining
out of the master cylinder when the brake tubes are
removed from the junction block.
(2) Raise vehicle on jackstands or centered on a
hoist. See Hoisting in the Lubrication And Mainte-
nance Group of this service manual.
CAUTION: Before removing the brake tubes from
the junction block, the junction block and the brake
tubes must be thoroughly cleaned. This is required
to prevent contamination from entering the brake
hudraulic system.
(3) Remove the 6 chassis brake tubes (Fig. 129)
from the junction block.
(4) Remove the bolt (Fig. 130) attaching the junc-
tion block mounting braket to the front suspension
cradle.
INSTALL
(1) Install the junction block and mounting bracket
(Fig. 130) on the front suspension cradle. Install the
attaching bolt and tighten to a torque of 28 N´m (250
in. lbs.).
(2) Install the 6 chassis brake tubes (Fig. 131) into
the inlet and outlet ports of the junction block.
Fig. 128 Vacuum Seal Installed On Master Cylinder
NSBRAKES 5 - 55
REMOVAL AND INSTALLATION (Continued)
Page 140 of 1938

INSTALL
(1) Install the hooked end of the actuator on the
proportioning valve lever (Fig. 136).Be sure isola-
tor bushing on lever of proportioning valve
(Fig. 136) is fully seated in hook of actuator.
NOTE: When installing height sensing proportion-
ing valve on mounting bracket be sure proportion-
ing valve shield (Fig. 135) is installed between the
proportioning valve and the mounting bracket.
(2) Install height sensing proportioning valve on
mounting bracket. Install the proportioning valve
attaching bolts (Fig. 135). Tighten the attaching bolts
to a torque of 23 N´m (200 in. lbs.).
(3) Install the 4 chassis brake lines (Fig. 134) into
the inlet and outlet ports of the proportioning valve.
Tighten all 4 line nuts to a torque of 16 N´m (142 in.
lbs.).
(4) Adjust the proportioning valve actuator. See
Height Sensing Proportioning Valve in the Adjust-
ment Section in this group of the service manual for
the adjustment procedure.
(5) Bleed the brake system thoroughly to ensure
that all air has been expelled from the hydraulic sys-
tem. See Bleeding Brake System in the Service
Adjustments section in this group of the service man-
ual for the proper bleeding procedure.
(6) Lower the vehicle to the ground.
(7) Road test the vehicle to verify proper operation
of the vehicles brake system.
HYDRAULIC BRAKE TUBES AND HOSES
CAUTION: When installing brake chassis lines or
flex hoses on the vehicle, the correct fasteners
must be used to attach the routing clips or hoses to
the front suspension cradle. The fasteners used toattach components to the front suspension cradle
have an antiÐcorrosion coating due to the suspen-
sion cradle being made of aluminum. Only Mopar
replacement fasteners with the required anti-corro-
sion coating are to be used if a replacement fas-
tener is required when installing a brake chassis
line or flex hose.
Only double wall 4.75mm (3/16 in.) steel tubing
with Al-rich/ZW-AC alloy coating and the correct tube
nuts are to be used for replacement of a hydraulic
brake tube.
NOTE: On vehicles equipped with traction control,
the primary and secondary hydraulic tubes between
the master cylinder and the hydraulic control unit
are 6 mm (15/64 in.). These tubes are also coated
with the Al-rich/ZW-AC alloy and must be replaced
with tubes having the same anti-corrosion coating.
Be sure that the correct tube nuts are used for the
replacement of these hydraulic brake tubes.
Care should be taken when replacing brake tubing,
to be sure the proper bending and flaring tools and
procedures are used, to avoid kinking. Do not route
the tubes against sharp edges, moving components or
into hot areas. All tubes should be properly attached
with recommended retaining clips.
If the primary or secondary brake tube from the
master cylinder to the ABS Hydraulic Control Unit
(HCU) or the brake tubes from the HCU to the pro-
portioing valve require replacement,onlythe origi-
nal factory brake line containing the flexible section
can be used as the replacement part. This is required
due to cradle movement while the vehicle is in
motion.
PARK BRAKE PEDAL MECHANISM
REMOVE
(1) Disconnect negative (ground) cable from the
battery and isolate cable from battery terminal.
(2) Remove sill scuff plate from left door sill.
(3) Remove the left side kick panel.
(4) Remove the steering column cover from the
lower instrument panel.
(5) Remove the reinforcement from the lower
instrument panel.
(6) Lock out front park brake cable using the fol-
lowing procedure. Grasp the exposed section of the
front park brake cable and pull rearward on it. While
holding the park brake in this position, install a pair
of locking pliers on the front park brake cable just
rearward of the second body outrigger bracket (Fig.
137).
(7) Remove the front park brake cable from the
park brake cable equalizer.
Fig. 136 Actuator Attachment To Proportioning
Valve
5 - 58 BRAKESNS
REMOVAL AND INSTALLATION (Continued)
Page 163 of 1938

group of the service manual for the installation pro-
cedure.
(13) Install wheel and tire.
(14) Tighten the wheel mounting nuts in the
proper sequence until all nuts are torqued to half the
specified torque. Then repeat the tightening sequence
to the full specified torque of 129 N´m (95 ft. lbs.).
(15) Lower vehicle.
(16) Apply and release the park brake pedal one
time. This will seat and correctly adjust the park
brake cables.
CAUTION: Before moving vehicle, pump brake
pedal several times to ensure the vehicle has a firm
enough pedal to stop the vehicle.
(17) Road test the vehicle to ensure proper func-
tion of the vehicle's brake system.
PARK BRAKE CABLE ADJUSTMENT
The park brake cables on this vehicle have an
automatic self adjuster built into the park brake
pedal mechanism. When the foot operated park brake
pedal is in its released (upward most) position, a
clock spring automatically adjusts the park brake
cables. The park brake cables are adjusted (ten-
sioned) just enough to remove all the slack from the
cables. The automatic adjuster system will not over
adjust the cables causing rear brake drag.
Due to the automatic adjust feature of the park
brake pedal, adjustment of the parking brake cables
on these vehicles relies on proper drum brake and
park brake shoe adjustment. See Rear Brake Adjust-
ment and Park Brake Shoe Adjustment in the Ser-
vice Adjustments Section in this group of the service
manual.
When the park brake pedal is applied the self
adjuster is by-passed and the pedal operates nor-
mally to engage the park brakes.
When a service procedure needs to be performed on
the park brake pedal or the park brake cables, the
automatic self adjuster can be manually locked out
by the service technician.
PROPORTIONING VALVE (HEIGHT SENSING)
Proportioning valve actuator adjustment will be
required if there is a complaint of premature rear
wheel lockup and the front and rear brake shoe lin-
ings checked OK during inspection, the height sens-
ing proportioning valve required replacement, or
there is a complaint of excessive pedal effort and the
vacuum booster and brake pedal checked OK. Make
sure the proportioning valve and the mounting
bracket are firmly attached to the vehicle. Then, pro-
ceed with the following procedure to perform the
adjustment of the actuator.(1) Raise vehicle. Vehicle is to be raised and sup-
ported on jackstands or with a frame contact type
hoist so the rear suspension of the vehicle is hanging
free. See hoisting in the Lubrication And Mainte-
nance section of this service manual.
(2) Remove rear wheels/tires.
(3) Using an appropriate jack, support the rear
axle prior to the removal of the track bar and shock
absorber bolts from the rear axle.
(4) Unbolt the track bar from the rear axle.
(5) Unbolt both shock absorbers from the rear
axle.
(6) Loosen (do not remove) both of the leaf spring
to front spring hanger pivot bolts.
NOTE: When lowering the rear axle be sure that the
leaf springs do not come in contact with the hoist
limiting the downward movement of the axle. If this
occurs an improper adjustment of the actuator may
result.
(7) Lower the rear axle so it is at its farthest point
of downward movement.
(8) Loosen the adjustment nut (Fig. 203) on the
actuator.
(9) Be sure the hooked end of the actuator is cor-
rectly (fully) seated in the clip on the proportioning
valve lever and that the clip is correctly positioned
on the lever of the proportioning valve.
(10) Pull the housing of the proportioning valve
actuator toward the spring hanger (Fig. 203) until
the lever on the proportioning valve bottoms on the
body of the proportioning valve.Hold the propor-
tioning valve actuator in this position while
tightening the adjustment nut (Fig. 203) to a
torque of 5 N´m (45 in. lbs.). Proportioning
valve adjustment is now complete.
(11) Install shock absorbers and track bar on rear
axle.Do not tighten the mounting bolts for any
of the loosened suspension components at this
time.
(12) Install the wheel/tires.
Fig. 203 Proportioning Valve Actuator Adjustment
NSBRAKES 5 - 81
ADJUSTMENTS (Continued)
Page 164 of 1938

(13) Lower the vehicle to the ground.Be sure
that the suspension is supporting the full
weight of the vehicle.
(14) Tighten the spring to front hanger pivot bolts
to a torque of 156 N´m (115 ft. lbs.).
(15) Tighten the shock absorber mounting bolts to
a torque of 101 N´m (75 ft. lbs.).
(16) Tighten the track bar mounting bolt to a
torque of 95 N´m (70 ft. lbs.).
(17) Road test vehicle to ensure that the prema-
ture rear wheel lockup condition has been corrected.
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. An
open 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.
VEHICLE BRAKE SYSTEM COMPONENT SPECIFICATIONS
Brake System Component Specifications
5 - 82 BRAKESNS
ADJUSTMENTS (Continued)
Page 165 of 1938

BRAKE ACTUATION SYSTEM
ACTUATION:
Vacuum Operated Power Brakes.........Standard
Hydraulic System...........Dual-Diagonally Split
Antilock Brake Sytem (Teves Mark-20)...........
MASTER CYLINDER ASSEMBLY:
Supplier..............................Bosch
Type For Non-ABSAnd
ABS Brakes. . . .Conventional Compensating Port
Type For ABS Brakes
With Traction Control . . .Dual Center Port Design
Body Material...............Anodized Aluminum
Reservoir Material................Polypropelene
MASTER CYLINDER BORE /
STROKE AND SPLIT:
ABS W/Disc/Drum Brakes......23.8 mm x 36 mm
(.937 in. x 1.47 in.)
AWD W/Disc/Disc Brakes........25.4 mm x 39 mm
(1.00 in. x 1.50 in.)
Displacement Split.....................50/50
MASTER CYLINDER FLUID OUTLET PORTS:
Non-ABS And ABS . . .Primary 7/16±24 Secondary 7/
16±24
ABS With Traction Control.......Primary M12 x 1
Secondary M12 x 1
Outlet Fitting Type Non-ABS
AndABS...........Double Wall Inverted Flare
Outlet Fitting Type ABS With
Traction Control...................ISO Flare
ABS HYDRAULIC CONTROL UNIT:
Hydraulic Tube Fitting Type............ISO Flare
BOOSTER:
Make/Type.................Bosch Vacuum Assist
Mounting Studs.....................M8x1.25
Type .........................270 ZLT RSMV
Boost At 20 inches Of
Manifold Vacuum...........3800 N´m (850 lbs.)
PROPORTIONING VALVE:
Material...........................Aluminum
Function....................Hydraulic Pressure
Proportioning To Rear Brakes
BRAKE PEDAL
Pedal Ratio.............................3.36
BRAKE FASTENER TORQUE SPECIFICATIONS
DESCRIPTION TORQUE
BRAKE TUBES:
Tube Nuts To Fittings And
Components..............17N´m(145 in. lbs.)
BRAKE HOSE:
To Caliper Banjo Bolt..........48N´m(35ft.lbs.)
Intermediate Bracket.........12N´m(105 in. lbs.)
MASTER CYLINDER:
To Vacuum Booster
Mounting Nut............25N´m(225 in. lbs.)
FIXED PROPORTIONING VALVE:
To Frame Rail Attaching
Bolts....................14N´m(125 in. lbs.)
HEIGHT SENSING PROPORTIONING VALVE:
To Mounting Bracket
Attaching Bolts...........23N´m(200 in. lbs.)
Actuator Assembly
Adjustment Nut.............5N´m(45in.lbs.)
Mounting Bracket To Frame
Rail Bolts................17N´m(150 in. lbs.)
JUNCTION BLOCK (NON-ABS BRAKES)
To Suspension Cradle
Mounting Bolt............28N´m(250 in. lbs.)
VACUUM BOOSTER:
To Dash Panel Mounting
Nuts....................28N´m(250 in. lbs.)
REAR WHEEL CYLINDER:
To Support Plate Mounting
Bolts.....................8N´m(75in.lbs.)
Bleeder Screw...............10N´m(80in.lbs.)
BRAKE SUPPORT PLATE:
To Rear Axle Mounting Bolts . . .130 N´m (95 ft. lbs.)
DISC BRAKE CALIPER:
Guide Pin Bolts..............41N´m(30ft.lbs.)
Bleeder Screw..............15N´m(125 in. lbs.)
ABS HYDRAULIC CONTROL UNIT:
Mounting Bracket To
Suspension Cradle Bolts.....28N´m(250 in. lbs.)
To Mounting Bracket Isolator
Attaching Bolts............11N´m(97in.lbs.)
CAB To HCU Mounting Screws . . .2 N´m (17 in. lbs.)
WHEEL SPEED SENSOR:
To Axle Or Steering Knuckle
Mounting Bolt............12N´m(105 in. lbs.)
PARKING BRAKE:
Pedal Assembly Mounting
Bolts....................28N´m(250 in. lbs.)
REAR HUB AND BEARING:
To Axle Mounting Bolts........129 N´m (95 ft. lbs.)
WHEEL:
Stud Lug Nut........115±156 N´m (84-115 ft. lbs.)
NSBRAKES 5 - 83
SPECIFICATIONS (Continued)
Page 168 of 1938

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.
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, extremesteering 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 - 86 BRAKESNS
DESCRIPTION AND OPERATION (Continued)
Page 170 of 1938

The ICU is located on the driver's side of the vehi-
cle, and is mounted to the front suspension cradle
(Fig. 3). TheABS onlyICU contains the following
components for controlling the brake system hydrau-
lic pressure during ABS braking: The CAB, eight
valve solenoids, (four inlet valves and four outlet
valves) fluid accumulators a pump, and an electric
motor. TheABS with traction controlICU con-
tains the following components for controlling the
brake system hydraulic pressure during ABS braking
and traction control operation: The CAB, four sole-
noid controlled inlet valves, four solenoid controlled
outlet valves, two hydraulic shuttle valves, two ASR
valves, fluid accumulators a pump and an electric
motor. Also attached to the hydraulic control unit are
the master cylinder primary and secondary brake
tubes and the brake tubes going to each wheel of the
vehicle. (Fig. 3).
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 solenoids, 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 solenoids, one for each wheel.
In the released position they are closed to allow for
normal braking. In the actuated (open) position, they
provide a fluid path from the wheel brakes of the
vehicle to the hydraulic control unit HCU accumula-
tors and pump motor. The outlet solenoids are spring
loaded in the released (closed) position during normal
braking.
ASR VALVE (ABS WITH TRACTION CONTROL
ONLY)
On vehicles equipped with ABS having traction
control, there are two special ASR valves located in
the HCU portion of the ICU. The ASR valves are a
normally open type valve and are solenoid actuated.
The special ASR valves are used to isolate the rear
(non-driven) wheels of the vehicle from the hydraulic
pressure that the HCU pump motor is sending to the
front (driven) wheels, when the traction control sys-
tem is in operation. The rear brakes need to be iso-
lated from the master cylinder when traction control
is in operation so that the HCU can build the
required hydraulic pressure to the front brakes.
HCU BRAKE FLUID ACCUMULATORS AND NOISE
DAMPING CHAMBER
There are two brake fluid accumulators in the
HCU. There is one brake fluid accumlator for the pri-
mary and secondary hydraulic circuits. The brake
Fig. 2 Teves Mark 20 ICUFig. 3 ICU Mounting Location
5 - 88 BRAKESNS
DESCRIPTION AND OPERATION (Continued)
Page 183 of 1938

hoist. See Hoisting in the Lubrication And Mainte-
nance section of this service manual.
(4) Remove the routing clip attaching the HCU
wiring harness to the HCU mounting bracket (Fig.
19).
CAUTION: Do not apply a 12 volt power source to
any terminals of the 25 way HCU connector when
disconnected.
(5) Remove the 25 way connector (Fig. 19) from
the CAB. The 25 way connector is removed from the
CAB using the following procedure. Grasp the lock
on the 25 way connector (Fig. 19) and pull it as far
out as possible (Fig. 20). This will raise and unlock
the 25 way connector from the socket on the CAB.
CAUTION: Before removing the brake tubes from
the HCU, the HCU must be thoroughly cleaned. This
must be done to prevent dirt particles from falling
into the ports of HCU or entering the brake tubes.(6) Thoroughly clean all surfaces of the HCU, and
all brake tube nuts located on the HCU. Use only a
solvent such as Mopar Brake Parts Cleaner or an
equivalent to clean the HCU.
(7) Remove the brake tubes (6) from the inlet and
outlet ports on the HCU. (Fig. 21).
(8) Remove the 3 bolts (Fig. 22) attaching the
HCU mounting bracket to the front suspension cross-
member.
(9) Remove HCU and the mounting bracket as a
unit from the vehicle.
(10) Remove the 3 bolts (Fig. 23) mounting the
HCU to the mounting bracket. Separate the HCU
from the mounting bracket.
(11) Remove the CAB (Fig. 19) from the bottom of
the HCU for installation on the replacement HCU.
Refer to Controller Antilock Brakes (CAB) in the
Removal And Installation Section in this group of the
service manual for the required procedure.
Fig. 19 CAB 25 Way Connector
Fig. 20 Unlocked 25 Way CAB Connector
Fig. 21 Brake Tube Connections To HCU
Fig. 22 HCU To Suspension Cradle Mounting Bolts
NSBRAKES 5 - 101
REMOVAL AND INSTALLATION (Continued)
Page 184 of 1938

INSTALL
(1) Install the CAB (Fig. 19) on the bottom of the
HCU. Refer to Controller Antilock Brakes (CAB) in
the Removal And Installation Section in this group of
the service manual for the required procedure.
(2) Install the HCU on the mounting bracket (Fig.
23). Install the 3 bolts (Fig. 23) attaching the HCU to
the mounting bracket. Tighten the 3 mounting bolts
to a torque of 11 N´m (97 in. lbs.).
CAUTION: The HCU mounting bracket to front sus-
pension cradle mounting bolts have a unique corro-
sion protection coating and a special aluminum
washer. For this reason, only the original, or origi-
nal equipment Mopar replacement bolts can be
used to mount the HCU bracket to the front suspen-
sion crossmember.
(3) Install the HCU and its mounting bracket as
an assembly on the front suspension crossmember.
Install the 3 bolts attaching the HCU bracket to the
crossmember (Fig. 22). Tighten the 3 mounting bolts
to a torque of 28 N´m (250 in. lbs.).
CAUTION: Because of the flexible section in the
primary and secondary brake tubes, and the brake
tubes between the HCU and the proportioning
valve, the brake tubes must be held in proper ori-
entation when tightened and torqued. These tubes
must not contact each other or other vehicle com-
ponents when installed. Also, after the brake tubes
are installed on the HCU, ensure all spacer clips are
reinstalled on the brake tubes.
CAUTION: When installing the chassis brake tubes
on the HCU valve block, they must be located cor-
rectly in the valve block to ensure proper ABS oper-
ation. Refer to (Fig. 21) for the correct chassis
brake tube locations.NOTE: The chassis brake tube attachment loca-
tions to the HCU, are marked on the bottom of the
HCU mounting bracket.
(4) Install the 6 chassis brake tubes into their cor-
rect port locations on the HCU valve block as shown
in (Fig. 21). Tighten the tube nuts to a torque of 17
N´m (145 in. lbs.).
NOTE: Before installing the 25 way connector in
the CAB be sure the seal is properly installed in the
connector.
(5) Install the 25 way connector (Fig. 19) on the
CAB using the following procedure. Position the 25
way connector in the socket of the CAB and carefully
push it down as far as possible. When connector is
fully seated by hand into the CAB socket, push in the
connector lock (Fig. 20). This will pull the connector
into the socket of the CAB and lock it in the installed
position.
NOTE: The CAB wiring harness must be clipped to
the HCU mounting bracket. This will ensure the wir-
ing harness is properly routed and does not contact
the brake tubes or the body of the vehicle.
(6) Clip the cab wiring harness (Fig. 19) to the
HCU mounting bracket.
(7) Install the routing clips (Fig. 24) on the brake
tubes.
(8) Lower vehicle.
(9) Connect negative cable back on negative post of
the battery.
(10) Bleed the base brakes and the ABS brakes
hydraulic system. Refer to the Bleeding ABS System
in this section of the manual for the proper bleeding
procedure.
(11) Road test vehicle to ensure proper operation of
the base and ABS systems.
Fig. 23 HCU Mounting Bolts
Fig. 24 Brake Tube Routing Clips
5 - 102 BRAKESNS
REMOVAL AND INSTALLATION (Continued)