traction control CHRYSLER VOYAGER 1996 User Guide

ANTILOCK BRAKE SYSTEM ± TEVES MARK-20
INDEX
page page
DESCRIPTION AND OPERATION
ABS BRAKE SYSTEM COMPONENTS........ 87
ABS BRAKES COMPONENT
ABBREVIATION LIST.................... 85
ABS BRAKES OPERATION AND VEHICLE
PERFORMANCE....................... 86
ABS FUSES............................ 89
ABS MASTER CYLINDER AND POWER
BRAKE BOOSTER..................... 87
ABS RELAYS........................... 89
ABS WARNING LAMP (YELLOW)............ 91
ANTILOCK BRAKES OPERATION
DESCRIPTION........................ 85
ASR VALVE (ABS WITH TRACTION
CONTROL ONLY)...................... 88
CONTROLLER ANTILOCK BRAKES (CAB)..... 90
HCU BRAKE FLUID ACCUMULATORS AND
NOISE DAMPING CHAMBER............. 88
HCU PUMP/MOTOR..................... 89
HYDRAULIC CIRCUITS AND VALVE
OPERATION.......................... 92
INLET VALVES AND SOLENOIDS............ 88
INTEGRATED CONTROL UNIT (ICU)......... 87
OUTLET VALVES AND SOLENOIDS.......... 88
PROPORTIONING VALVES................ 89
WHEEL SPEED SENSORS................. 89
DIAGNOSIS AND TESTING
ABS BRAKE DIAGNOSTIC TOOL
CONNECTOR......................... 96
ABS DIAGNOSTIC TROUBLE CODES........ 97
ABS DIAGNOSTICS MANUAL.............. 96ABS GENERAL DIAGNOSTICS
INFORMATION........................ 95
ABS SERVICE PRECAUTIONS.............. 99
ABS SYSTEM SELF DIAGNOSTICS.......... 96
ABS WIRING DIAGRAM INFORMATION....... 95
BRAKE FLUID CONTAMINATION............ 98
DRB DIAGNOSTIC SCAN TOOL USAGE...... 96
INTERMITTENT DIAGNOSTIC TROUBLE
CODES.............................. 97
PROPORTIONING VALVE................. 98
TEST DRIVING ABS COMPLAINT VEHICLE.... 98
TONEWHEEL INSPECTION................ 98
SERVICE PROCEDURES
BLEEDING TEVES MARK 20 HYDRAULIC
SYSTEM............................. 99
BRAKE FLUID LEVEL INSPECTION.......... 99
REMOVAL AND INSTALLATION
ABS GENERAL SERVICE PRECAUTIONS.... 100
CONTROLLER ANTILOCK BRAKES (CAB).... 103
HYDRAULIC CONTROL UNIT.............. 100
TONE WHEEL (REAR AWD)............... 111
TONE WHEEL (REAR FWD)............... 110
WHEEL SPEED SENSOR (FRONT)......... 105
WHEEL SPEED SENSOR (REAR AWD)...... 108
WHEEL SPEED SENSOR (REAR FWD)...... 106
SPECIFICATIONS
BRAKE FASTENER TORQUE
SPECIFICATIONS..................... 112
SPEED SENSOR TONE WHEEL RUNOUT.... 112
WHEEL SPEED SENSOR TO TONE
WHEEL CLEARANCE.................. 112
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 virtu-
ally any type of road surface. Antilock Braking is desirable
because a vehicle which is stopped without locking the
wheels will retain directional stability and some steering
capability. This allows the driver to retain greater control
of the vehicle during braking.
This section of the service manual covers the description
and on car service for the ITT Teves Mark 20 ABS Brake
System and the ITT Teves Mark 20 ABS Brake System
with Traction Control. 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 BRAKES 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 and the Teves
Mark 20 ABS Brake System with Traction Control.
They are listed below for your reference.
²CAB±Controller Antilock Brake
²ICU±Integrated Control Unit
²HCU±Hydraulic Control Unit
²TCS±Traction Control
²ABS±Antilock Brake System
²PSI±Pounds Per Square Inch (pressure)
²WSS±Wheel Speed Sensor
²FWD±Front Wheel Drive
²AWD±All Wheel Drive
²DTC±Diagnostic Trouble Code
NSBRAKES 5 - 85

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 Teves Mark 20 ABS
without optional traction control uses the same
type of a master cylinder and power brake
booster (Fig. 1) as a vehicle not equipped with
antilock brakes.
A vehicle equipped with Teves Mark 20 ABS
with Traction control uses a unique center port
master cylinder. If the master cylinder is
replaced on a vehicle equipped with traction
control be sure the right type of master cylin-
der is installed.A vehicle equipped with four wheel disc
brakes (AWD applications) also have a unique
master cylinder. The master cylinder used on
these vehicles have a piston bore diameter
which is larger then the master cylinder used
on the other brake applications.
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 contol 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.
Teves Mark 20 ABS uses two different HCU's and
CAB's depending on the type of ABS system the vehi-
cle is equipped with. There is a unique HCU and
CAB for a vehicle equipped with just ABS and a
unique HCU and CAB for a vehicle equipped with
ABS and traction control.
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.
Fig. 1 Master Cylinder And Vacuum Booster
NSBRAKES 5 - 87
DESCRIPTION AND OPERATION (Continued)

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)

fluid accumulators temporarily store brake fluid that
is decayed from the wheel brakes during an ABS
cycle. This stored brake fluid is then used by the
pump in the HCU to provide build pressure for the
brake hydraulic system.
Additionally on vehicles that are equipped with
only ABS (non-traction control vehicles) there is a
mini brake fluid accumulator on the secondary
hydraulic circuit which protects the master cylinder's
seals during an ABS stop. There is also a noise
damping chamber on the primary hydraulic circuit.
On ABS equipped vehicles with traction control, in
addition to the brake fluid accumulators there are
also two noise damping chambers in the HCU.
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.
ABS FUSES
The fuse for the ABS pump motor and the ABS system
are located in the power distribution center (PDC) (Fig. 5).
The PDC is located on the drivers side of the engine com-
partment forward of the strut tower. The fuse for the ABS
warning lamp in the instrument panel message center is
located in the junction block.
On vehicles equipped with traction control, the
fuse for the traction control switch is also located in
the junction block.The junction block is located on the left hand front
cowl panel on the vehicle.
ABS RELAYS
On the Teves Mark 20 Antilock Brake System both
the pump motor relay and the system relay are
located in the CAB. If either of the relays is diag-
nosed as not functioning properly the CAB will need
to be replaced. Refer to Controller Antilock Brakes in
the Removal And Installation Section in this group of
the service manual for the procedure.
PROPORTIONING VALVES
One assembly containing two proportioning valves
are used in the system, one for each rear brake
hydraulic circuit. The proportioning valve is located
on the frame rail next to the fuel tank, forward of the
right rear shock absorber (Fig. 6). Be sure replace-
ment proportioning valve assemblies have the same
split point and slope as the proportioning valve being
replaced.
WHEEL SPEED SENSORS
One Wheel Speed Sensor WSS is located at each
front and rear wheel of the vehicle (Fig. 7), (Fig. 8)
and (Fig. 9). The wheel speed sensor sends a small
AC signal to the CAB. This signal is generated by
magnetic induction created when a toothed sensor
ring (tone wheel) (Fig. 7), (Fig. 8) and (Fig. 9) passes
the stationary magnetic wheel speed sensor. The
CAB converts the AC signal generated at each wheel
into a digital signal. If a wheel locking tendency is
detected by the CAB, it will then modulate hydraulic
pressure via the HCU to prevent the wheel(s) from
locking.
Fig. 4 Teves Mark 20 HCU Pump/Motor
Fig. 5 Fuse Locations In Power Distribution Center
NSBRAKES 5 - 89
DESCRIPTION AND OPERATION (Continued)

The primary functions of the (CAB) are:
(1) Detect wheel locking or wheel slipping tenden-
cies by monitoring the speed of all four wheels of the
vehicle.
(2) Illuminate the TRAC lamp in the message cen-
ter on the instrument panel when a traction control
event is occurring.
(3) Control fluid modulation to the wheel brakes
while the system is in an ABS mode or the traction
control system is activated.
(4) Monitor the system for proper operation.
(5) Provide communication to the DRB Scan Tool
while in diagnostic mode.
(6) Store diagnostic information.
(7)The CAB continuously communicates with
the body controller by sending out a message to
the body controller on the CCD Bus. This mes-
sage is used for illumination of the yellow
antilock warning lamp. This is used if the ABS
controller communication is lost in the hard
wire between the body controller and the yel-
low antilock warning lamp. If the body control-
ler does not receive this message from the CAB,
the body controller will illuminate the antilock
yellow warning lamp.
The CAB continuously monitors the speed of each
wheel through the signals generated by the wheel
speed sensors to determine if any wheel is beginning
to lock. When a wheel locking tendency is detected,
the CAB commands the CAB command coils to actu-
ate. The CAB command coils then open and close the
valves in the HCU which modulate brake fluid pres-
sure in some or all of the hydraulic circuits. The CAB
continues to control pressure in individual hydraulic
circuits until a locking tendency is no longer present.
The ABS system is constantly monitored by the
CAB for proper operation. If the CAB detects a fault,
it will turn on the Amber ABS Warning Lamp anddisable the ABS braking system. The normal base
braking system will remain operational.
The CAB contains a self-diagnostic program which
will turn on the Amber ABS Warning Lamp when a
ABS system fault is detected. Faults are then stored
in a diagnostic program memory. There are multiple
fault messages which may be stored in the CAB and
displayed through the DRB Scan Tool. These fault
messages will remain in the CAB memory even after
the ignition has been turned off. The fault messages
can be read and or cleared from the CAB memory by
a technician using the DRB Scan Tool. The fault
occurrence and the fault code will also be automati-
cally cleared from the CAB memory after the identi-
cal fault has not been seen during the next 3500
miles of vehicle operation. Mileage though of the last
fault occurrence will not be automatically cleared.CONTROLLER ANTILOCK BRAKE INPUTS
²Four wheel speed sensors.
²Stop lamp switch.
²Ignition switch.
²System relay voltage.
²Ground.
²Traction Control Switch (If Equipped).
²Diagnostics Communications (CCD)
CONTROLLER ANTILOCK BRAKE OUTPUTS
²C2D Communication To Body Controller And
Instrument Cluster
²ABS warning lamp actuation.
²Traction Control Light (If Equipped).
²Diagnostic communication. (CCD)
ABS WARNING LAMP (YELLOW)
The ABS system uses a yellow colored ABS Warn-
ing Lamp. The ABS warning lamp is located on the
right side of the message center located at the top of
the instrument panel. The purpose of the warning
lamp is discussed in detail below.
The ABS warning lamp will turn on when the CAB
detects a condition which results in a shutdown of
ABS function or when the body controller does not
receive C2D messages from the CAB. When the igni-
tion key is turned to the on position, the ABS Warn-
ing Lamp is on until the CAB completes its self tests
and turns the lamp off (approximately 4 seconds
after the ignition switch is turned on). Under most
conditions, when the ABS warning lamp is on, only
the ABS function of the brake system is affected. The
standard brake system and the ability to stop the car
will not be affected when only the ABS warning lamp
is on.
The ABS warning lamp is controlled by the CAB
and the body controller through a diode located in
the wiring harness junction block. The junction block
is located under the instrument panel to the left of
Fig. 10 Controller Antilock Brake (CAB)
NSBRAKES 5 - 91
DESCRIPTION AND OPERATION (Continued)

mulators is returned to the master cylinder circuits.
The brake fluid will then be routed to either the mas-
ter cylinder or the wheel brake depending on the
position of the normally open valve. A volume of 1.2
cc's of brake fluid is taken in by the lip seal saver
(Fig. 13) to protect the lip seals on the piston of the
master cylinder.
TEVES MARK 20 ABS WITH TRACTION
CONTROL NORMAL BRAKING HYDRAULIC
CIRCUIT ± SOLENOID AND SHUTTLE VALVE
FUNCTION
This condition is the normal operation of the vehi-
cles base brake hydraulic system when the vehicle is
equipped with ABS and traction control. The hydrau-
lic system circuit diagram (Fig. 14) shows a situation
where no wheel spin or slip is occurring relative to
the speed of the vehicle. The driver is applying the
brake pedal to build pressure in the brake hydraulic
system to apply the brakes and stop the vehicle. The
hydraulic shuttle valve (Fig. 14) closes with every
brake pedal application so pressure is not created at
the inlet to the pump.
TEVES MARK 20 ABS WITH TRACTION
CONTROL ABS BRAKING HYDRAULIC
CIRCUIT ± SOLENOID AND SHUTTLE VALVE
FUNCTION
This hydraulic circuit diagram (Fig. 15) shows a
vehicle equipped with ABS and traction control in
the ABS braking mode. This hydraulic circuit (Fig.
15) shows a situation where one wheel is slipping
because the driver is attempting to stop the vehicle
at a faster rate than the surface the vehicle's tires
are on will allow. The hydraulic shuttle valve (Fig.
15) closes upon brake application so that the pump
can not suck brake fluid from the master cylinder.
The normally open and normally closed valves mod-
ulate the brake hydraulic pressure as required. The
pump/motor is switched on so that the brake fluid
from the low pressure accumulators is returned to
the master cylinder circuits. The brake fluid will
then be routed to either the master cylinder or the
wheel brake depending on the position of the nor-
mally open valve.
Fig. 12 ABS Mode Hydraulic Circuit
NSBRAKES 5 - 93
DESCRIPTION AND OPERATION (Continued)

Fig. 13 ABS Mode Secondary Hydraulic Circuit
Fig. 14 ABS With Traction Control Normal Braking Hydraulic Circuit
5 - 94 BRAKESNS
DESCRIPTION AND OPERATION (Continued)

TEVES MARK 20 ABS WITH TRACTION
CONTROL± TRACTION CONTROL HYDRAULIC
CIRCUIT ± SOLENOID AND SHUTTLE VALVE
FUNCTION
This hydraulic circuit diagram (Fig. 16) shows a
vehicle equipped with ABS and traction control in
the traction control mode. The hydraulic circuit (Fig.
16) shows a situation where a driven wheel is spin-
ning and brake pressure is required to reduce its
speed. The normally open ASR valve (Fig. 16) is ener-
gized to isolate the brake fluid being pumped from
the master cylinder and to isolate the driven wheel.
Also, the normally open ASR valve bypasses the
pump output back to the master cylinder at a fixed
pressure setting. The normally open and normally
closed valves (Fig. 16) modulate the brake pressure
as required to the spinning wheel.
DIAGNOSIS AND TESTING
ABS GENERAL DIAGNOSTICS INFORMATION
This section contains the information necessary to
diagnose the ITT Teves Mark 20 ABS Brake System.
Specifically, this section should be used to help diag-
nose conditions which result in any of the following:
(1) ABS Warning Lamp turned on.(2) Brakes Lock-up on hard application
Diagnosis of base brake conditions which are obvi-
ously mechanical in nature should be directed to
Group 5 Brakes in this service manual. This includes
brake noise, brake pulsation, lack of power assist,
parking brake, Red BRAKE Warning Lamp lighting,
or vehicle vibration during normal braking.
Many conditions that generate customer com-
plaints may be normal operating conditions, but are
judged to be a problem due to not being familiar with
the ABS system. These conditions can be recognized
without performing extensive diagnostic work, given
adequate understanding of the operating principles
and performance characteristics of the ABS. See the
ABS System Operation Section in this group of the
service manual to familiarize yourself with the oper-
ating principles of the ABS system.
ABS WIRING DIAGRAM INFORMATION
During the diagnosis of the antilock brake system
it may become necessary to reference the wiring dia-
grams covering the antilock brake system and its
components. For wiring diagrams refer to Antilock
Brakes in Group 8W of this service manual. This
group will provide you with the wiring diagrams and
the circuit description and operation information cov-
ering the antilock brake system.
Fig. 15 ABS With Traction Control ABS Braking Hydraulic Circuit
NSBRAKES 5 - 95
DESCRIPTION AND OPERATION (Continued)

ABS DIAGNOSTICS MANUAL
Detailed procedures for diagnosing specific ABS
conditions are covered in the diagnostics manual cov-
ering the ITT Teves Mark 20 ABS system. The fol-
lowing information is presented to give the
technician a general background on the diagnostic
capabilities of the ITT Teves Mark 20 ABS system.
Please refer to the above mentioned manual for any
further electronic diagnostics and service procedures
that are required.
DRB DIAGNOSTIC SCAN TOOL USAGE
The diagnostics of the ITT Teves Mark 20 ABS sys-
tem is performed using the DRB scan tool. Refer to
the diagnostics manual covering the ITT Teves Mark
20 ABS system for the required diagnostics and test-
ing procedures and the DRB operators manual for its
proper operational information.
ABS BRAKE DIAGNOSTIC TOOL CONNECTOR
On this vehicle, the diagnostic connector used for
the diagnosis of the ITT Teves Mark 20 ABS system
is located under the lower steering column cover, to
the left side of the steering column, just below the
hood release lever (Fig. 17). The ITT Teves Mark 20
ABS system uses the ISO 9141-K connector which is
shared by other vehicle diagnostic systems such asthe powertrain control module and air bag electronic
control module.ABS SYSTEM SELF DIAGNOSTICS
The ITT Teves Mark 20 ABS system is equipped
with a self diagnostic capability which may be used
to assist in the isolation of ABS faults. The features
of the self diagnostics system are described below.
Fig. 16 Traction Control Hydraulic Circuit
Fig. 17 Diagnostic Scan Tool Data Link Connector
5 - 96 BRAKESNS
DIAGNOSIS AND TESTING (Continued)

COOLANT RECOVERY SYSTEM (CRS)
This system works with the radiator pressure cap
to use thermal expansion and contraction of the cool-
ant to keep the coolant free of trapped air. Provides a
convenient and safe method for checking coolant
level and adjusting level at atmospheric pressure
without removing the radiator pressure cap. It also
provides some reserve coolant to cover deaeration
and evaporation or boiling losses. All vehicles are
equipped with this system and take various shapes
and forms. (Fig. 3) shows a typical system in the typ-
ical location.
See Coolant Level Service, and Deaeration, and
Pressure Cap sections for operation and service.
AUTOMATIC TRANSMISSION OIL COOLERÐ2.4L
Oil cooler is internal oil to coolant type, mounted
in the radiator left tank (Fig. 4). Rubber oil lines feed
the oil cooler and the automatic transmission. Use
only approved transmission oil cooler hose. Since
these are molded to fit space available, molded hoses
are recommended.
ENGINE THERMOSTAT
The engine cooling thermostats are a wax pellet
driven, reverse poppet choke type. They are designed
to provide the fastest warm up possible by prevent-
ing leakage through them and to guarantee a mini-
mum engine operating temperature of 88 to 93ÉC
(192 to 199ÉF). They also automatically reach wide
open so they do not restrict flow to the radiator as
temperature of the coolant rises in hot weather to
around 104ÉC (220ÉF). Above this temperature the
coolant temperature is controlled by the fan, the
radiator, and the ambient temperature, not the ther-
mostat.
WATER PUMPS
A quick test to tell whether the pump is working is
to see if the heater warms properly. A defective pump
can not circulate heated coolant through the long
heater hose.The water pump on all models can
be replaced without discharging the air condi-
tioning system.
COOLANT
The cooling system is designed around the coolant.
The coolant must accept heat from engine metal, in
the cylinder head area near the exhaust valves. Cool-
ant then carries this heat to the radiator, where the
tube/fin assemblies of these components can give it
up to the air.
The use of aluminum cylinder heads, intake mani-
folds, and water pumps requires special corrosion
protection. MopartAntifreeze or the equivalent is
recommended for best engine cooling without corro-
sion, when mixed only to a freeze point of -37ÉC
(-35ÉF) to -59ÉC (-50ÉF). If it loses color or becomes
contaminated, drain, flush, and replace with fresh
properly mixed solution.
CAUTION: Do not use well water, or suspect water
supply in cooling system. A 50/50 ethylene glycol
and distilled water mix is recommended.
RADIATOR
The radiators are cross-flow types (horizontal
tubes) with design features that provide greater
strength along with sufficient heat transfer capabili-
Fig. 3 Coolant Recovery System
Fig. 4 Automatic Transmission Oil Cooler
NSCOOLING SYSTEM 7 - 3
GENERAL INFORMATION (Continued)