lock CHRYSLER VOYAGER 2005 Manual PDF

ABS TRACTION CONTROL HYDRAULIC CIRCUIT,
SOLENOID VALVE, AND SHUTTLE VALVE
FUNCTION (ABS WITH TRACTION CONTROL)
The hydraulic diagram (Fig. 11) shows the vehicle
in the ABS braking mode. The diagram shows a drive
wheel is spinning and brake pressure is required to
reduce its speed.
²The normally open ASR valve is energized to iso-
late the brake fluid being pumped from the master
cylinder and to isolate the driven wheel.
²The normally open ASR valve bypasses the
pump output back to the master cylinder at a fixed
pressure setting.
²The normally open and normally closed valves
modulate (build/decay) the brake pressure as
required to the spinning wheel.
HCU (HYDRAULIC CONTROL
UNIT)
DESCRIPTION
The hydraulic control unit (HCU) is mounted to
the CAB as part of the ICU (Fig. 22). The HCU con-
trols the flow of brake fluid to the brakes using a
series of valves and accumulators. A pump/motor is
mounted on the HCU to supply build pressure to the
brakes during an ABS stop.
The HCU on a vehicle equipped with ABS and
traction control has a valve block housing that is
approximately 1 inch longer on the low pressure fluid
accumulators side than a HCU on a vehicle that is
equipped with only ABS.
Fig. 11 Traction Control Hydraulic Circuit
1 - OUTLET VALVE
2 - PUMP PISTON
3 - PUMP MOTOR (ON)
4 - LOW PRESSURE ACCUMULATOR PRESSURE
5 - LOW PRESSURE ACCUMULATOR
6 - NORMALLY CLOSED VALVE (MODULATING)
7 - TO RIGHT FRONT WHEEL (SPINNING)
8 - NORMALLY OPEN VALVE (MODULATING)
9 - NORMALLY OPEN ASR VALVE ON (REGULATING)10 - FROM MASTER CYLINDER
11 - HYDRAULIC SHUTTLE VALVE
12 - CONTROLLED WHEEL PRESSURE
13 - SUCTION VALVE
14 - PUMP INTERSTAGE PRESSURE
15 - NOISE DAMPER CHAMBER
16 - MASTER CYLINDER PRESSURE
17 - PUMP PRESSURE
5 - 100 BRAKES - ABSRS
HYDRAULIC/MECHANICAL (Continued)

For more information, (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/ICU (INTEGRATED CON-
TROL UNIT) - DESCRIPTION)
OPERATION
For information on the operation of the HCU as a
whole, refer to Hydraulic Circuits And Valve Opera-
tion which can be found elsewhere in this section.
For information on the operation of the components
within the HCU, refer to the following three topics.
VALVES AND SOLENOIDS
The valve block contains four inlet valves and four
outlet valves. The inlet valves are spring-loaded in
the open position and the outlet valves are spring-
loaded in the closed position during normal braking.
The fluid is allowed to flow from the master cylinder
to the wheel brakes.
During an ABS stop, these valves cycle to maintain
the proper slip ratio for each wheel. The inlet valve
closes preventing further pressure increase and the
outlet valve opens to provide a path from the wheel
brake to the HCU accumulators and pump/motor.
This releases (decays) pressure from the wheel brake,
thus releasing the wheel from excessive slippage.
Once the wheel is no longer slipping, the outlet valve
is closed and the inlet valve is opened to reapply
(build) pressure.
On vehicles with traction control, there is an extra
set of valves and solenoids. The ASR valves, mounted
in the HCU valve block, are normally in the open
position and close only when the traction control is
applied.
These isolator valves are used to isolate the rear
(non-driving) wheels of the vehicle from the hydraulic
pressure that the HCU pump/motor is sending to the
front (driving) wheels when traction control is being
applied. The rear brakes need to be isolated from the
master cylinder when traction control is being
applied so the rear wheels do not drag. For more
information, refer to Traction Control System in this
section.
BRAKE FLUID ACCUMULATORS
There are two fluid accumulators in the HCU±one
for the primary hydraulic circuit and one for the sec-
ondary hydraulic circuit. Each hydraulic circuit uses
a 5 cc accumulator.
The fluid accumulators temporarily store brake
fluid that is removed from the wheel brakes during
an ABS cycle. This stored fluid is used by the pump/
motor to provide build pressure for the brake hydrau-
lic system. When the antilock stop is complete, the
accumulators are drained by the pump/motor.
On ABS-only vehicles, there is a mini-accumulator
on the secondary hydraulic circuit that protects the
master cylinder seals during an ABS stop, and there
is a noise dampening chamber on the primary circuit.
On ABS with traction control vehicles, there are
two noise dampening chambers in the HCU.
PUMP/MOTOR
There are two pump assemblies in the HCUÐone
for the primary hydraulic circuit and one for the sec-
ondary hydraulic circuit. Both pumps are driven by a
common electric motor. This DC-type motor is inte-
gral to the HCU and is controlled by the CAB.
The pump/motor provides the extra amount of
brake fluid needed during antilock braking. Brake
fluid is released to the accumulators when the outlet
valve is opened during an antilock stop. The pump
mechanism consists of two opposing pistons operated
by an eccentric camshaft. In operation, one piston
draws fluid from the accumulators, and the opposing
piston pumps fluid to the master cylinder circuits.
When the antilock stop is complete, the pump/motor
drains the accumulators.
The CAB may turn on the pump/motor when an
antilock stop is detected. The pump/motor continues
to run during the antilock stop and is turned off after
the stop is complete. Under some conditions, the
pump/motor runs to drain the accumulators during
the next drive-off.
The pump/motor is not a serviceable item; if it
requires replacement, the HCU must be replaced.
RSBRAKES - ABS5 - 101
HCU (HYDRAULIC CONTROL UNIT) (Continued)

ICU (INTEGRATED CONTROL
UNIT)
DESCRIPTION
The hydraulic control unit (HCU) and the control-
ler antilock brake (CAB) used with this antilock
brake system are combined (integrated) into one
unit, which is called the integrated control unit (ICU)
(Fig. 12). The ICU is located below the master cylin-
der in the engine compartment (Fig. 13).
Two different ICU's (HCU and CAB) are used on
this vehicle depending on whether or not the vehicle
is equipped with traction control. The HCU on avehicle equipped with traction control has a valve
block that is approximately one inch longer than a
HCU on a vehicle that is equipped with ABS only.
The ABS-only ICU consists of the following compo-
nents: the CAB, eight (build/decay) solenoid valves
(four inlet valves and four outlet valves), valve block,
fluid accumulators, a pump, and an electric motor.
The ABS-with traction control ICU consists of the
following components: the CAB, eight (build/decay)
solenoid valves (four inlet valves and four outlet
valves), two traction control (ASR) valves, two
hydraulic shuttle valves, valve block, fluid accumula-
tors, a pump, and an electric motor.
The replaceable components of the ICU are the
HCU and the CAB. No attempt should be made to
service any individual components of the HCU or
CAB. For information on the CAB, (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/CONTROLLER ANTILOCK BRAKE -
DESCRIPTION).
OPERATION
For information of the ICU, refer to these individ-
ual components of the ICU:
²CONTROLLER ANTILOCK BRAKE (CAB)
(Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/CONTROLLER ANTILOCK
BRAKE - OPERATION)
²HYDRAULIC CONTROL UNIT (HCU) (Refer to
5 - BRAKES - ABS/HYDRAULIC/MECHANICAL/
HCU (HYDRAULIC CONTROL UNIT) - OPERA-
TION)
For information on the ICU's hydraulic circuits,
refer to HYDRAULIC CIRCUITS AND VALVE
OPERATION. (Refer to 5 - BRAKES - ABS/HY-
DRAULIC/MECHANICAL - OPERATION)
REMOVAL
REMOVAL - LHD
(1) Disconnect the negative (ground) cable from
the battery and isolate cable.
(2) Remove the battery shield.
(3) Remove the battery (Refer to 8 - ELECTRI-
CAL/BATTERY SYSTEM/BATTERY - REMOVAL).
(4) Disconnect the vacuum hose connector at the
tank built into the battery tray.
(5) Remove the screw securing the engine coolant
filler neck to the battery tray.
(6) Remove the battery tray (Refer to 8 - ELEC-
TRICAL/BATTERY SYSTEM/TRAY - REMOVAL).
(7) Using a brake pedal depressor, move and lock
the brake pedal to a position past the first inch of
pedal travel.This will prevent brake fluid from
Fig. 12 INTEGRATED CONTROL UNIT (ICU)
1 - PUMP/MOTOR
2 - HCU
3 - PUMP/MOTOR CONNECTOR
4 - CAB
Fig. 13 ICU LOCATION IN VEHICLE
1 - POWER BRAKE BOOSTER
2 - MASTER CYLINDER
3 - ICU
5 - 102 BRAKES - ABSRS

draining out of the master cylinder once the
brake tubes are removed from the HCU.
CAUTION: Do not apply a 12±volt power source to
any terminals of the 24-way CAB connector when
disconnected.
(8) Disconnect the wiring harness connector from
the speed control servo.
(9) Remove the speed control servo mounting nuts
and move the servo out of the way.
(10) Disconnect the 24±way connector from the
CAB. To disconnect the 24±way connector, grasp the
lock on the 24±way connector and pull it as far up as
possible. This will unlock the 24±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.
(11) Thoroughly clean all surfaces of the ICU and
brake tube nuts. Use only a solvent such as Mopart
Brake Parts Cleaner or equivalent to clean the ICU.
(12) Remove the brake tubes (4) from the outlet
ports on the HCU (Fig. 14).
(13) Remove the primary and secondary brake
tubes from the inlet ports on the HCU (Fig. 14).
(14) Center and prop the steering wheel.
(15) Remove the pinch bolt and disconnect the
steering shaft coupling.
(16) If equipped, remove the two clips securing
silencer to dash seal (Fig. 15). Remove silencer.
(17) Remove the three screws securing the dash
seal (Fig. 15). Remove seal.(18) Remove the 3 bolts attaching the ICU to its
mounting bracket (Fig. 16).
(19) Remove ICU from the vehicle through engine
compartment.
(20) If required, to separating the CAB from the
HCU, (Refer to 5 - BRAKES - ABS/HYDRAULIC/ME-
Fig. 14 Brake Tube Nuts At ICU
1 - PRIMARY BRAKE TUBE
2 - SECONDARY BRAKE TUBE
3 - CHASSIS BRAKE TUBES
Fig. 15 Lower Coupling And Dash Seal
1 - COUPLING
2 - DASH SEAL
3 - SILENCER
4 - MOUNTING SCREWS
5 - RETAINING CLIPS
6 - DASH
Fig. 16 ICU Mounting Bolts
1 - ICU MOUNTING BOLTS
2 - COUPLER
RSBRAKES - ABS5 - 103
ICU (INTEGRATED CONTROL UNIT) (Continued)

CHANICAL/ICU (INTEGRATED CONTROL UNIT) -
DISASSEMBLY).
REMOVAL - RHD
NOTE: Before proceeding, (Refer to 5 - BRAKES -
WARNING)(Refer to 5 - BRAKES - CAUTION)
(1) Disconnect the negative (ground) cable from
the battery and isolate cable.
(2) Using a brake pedal depressor, move and lock
the brake pedal to a position past the first inch of
pedal travel.This will prevent brake fluid from
draining out of the master cylinder when the
brake tubes are removed from the HCU.
(3) Raise vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE)
(4) Remove the routing clip attaching the ICU wir-
ing harness to the ICU mounting bracket (Fig. 17).
CAUTION: Do not apply a 12 volt power source to
any terminals of the HCU connector when discon-
nected.
(5) Remove the 24-way connector (Fig. 17) from
the CAB. The 24-way connector is removed from the
CAB using the following procedure. Grasp the lock
on the 24-way connector (Fig. 17) and pull it as far
out as possible (Fig. 18). This will raise and unlock
the 24-way connector from the socket on the CAB.
CAUTION: Before removing the brake tubes from
the HCU, the HCU must be thoroughly cleaned. Thismust 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. 19).
Fig. 17 CAB 24-Way Connector
1 - CAB WIRING HARNESS
2 - 24±WAY CONNECTOR
3 - FLOOR PAN
4 - HCU
5 - CAB
6 - HCU MOUNTING BRACKET
7 - CONNECTOR LOCK
Fig. 18 Unlocked 24-Way CAB Connector
1 - HCU
2 - CAB
3 - 24±WAY CONNECTOR
4 - CONNECTOR LOCK (UNLOCKED)
Fig. 19 Brake Tube Connections To HCU
1 - LEFT REAR WHEEL BRAKE TUBE
2 - SECONDARY BRAKE TUBE FROM MASTER CYLINDER
3 - LEFT FRONT WHEEL BRAKE TUBE
4 - CAB
5 - RIGHT REAR WHEEL BRAKE TUBE
6 - HCU MOUNTING BRACKET
7 - BRAKE TUBE TO HCU CONNECTION LOCATION LEGEND
8 - RIGHT FRONT WHEEL BRAKE TUBE
9 - PRIMARY BRAKE TUBE FROM MASTER CYLINDER
5 - 104 BRAKES - ABSRS
ICU (INTEGRATED CONTROL UNIT) (Continued)

(8) Remove the 3 bolts (Fig. 20) attaching the ICU
mounting bracket to the front suspension crossmem-
ber.
(9) Remove ICU and the mounting bracket as a
unit from the vehicle.
(10) Remove the 3 bolts (Fig. 21) mounting the
ICU to the mounting bracket. Separate the ICU from
the mounting bracket.
(11) For the procedure on separating and attaching
the CAB to the HCU, refer to DISASSEMBLY.DISASSEMBLY - ICU
(1) Remove the ICU from the vehicle. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/ICU (INTE-
GRATED CONTROL UNIT) - REMOVAL)
(2) Disconnect the pump/motor wiring harness
from the CAB (Fig. 22).
(3) Remove the 4 bolts (Fig. 23) attaching the CAB
to the HCU.
Fig. 20 ICU To Suspension Cradle Mounting Bolts
1 - HCU MOUNTING BRACKET BOLTS
2 - HCU MOUNTING BRACKET BOLT
3 - CAB
4 - HCU MOUNTING BRACKET
5 - HCU
Fig. 21 ICU Mounting Bolts
1 - HCU
2 - HCU MOUNTING BOLTS
3 - HCU MOUNTING BRACKET
Fig. 22 INTEGRATED CONTROL UNIT (ICU)
1 - PUMP/MOTOR
2 - HCU
3 - PUMP/MOTOR CONNECTOR
4 - CAB
Fig. 23 (TYPICAL) CAB Attaching Bolts
1 - MOUNTING BOLTS
2 - CAB
3 - HCU VALVE BLOCK
RSBRAKES - ABS5 - 105
ICU (INTEGRATED CONTROL UNIT) (Continued)

(4) Remove the CAB from the HCU (Fig. 24).
ASSEMBLY - ICU
(1) Install the CAB (Fig. 24) on the HCU.
(2) Install the 4 bolts mounting the CAB (Fig. 23)
to the HCU. Tighten the CAB mounting bolts to a
torque of 2 N´m (17 in. lbs.).
(3) Plug the pump/motor wiring harness into the
CAB.
(4) Install the ICU in the vehicle and bleed the
base and ABS hydraulic systems. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/ICU (INTE-
GRATED CONTROL UNIT) - INSTALLATION)
INSTALLATION
INSTALLATION - LHD
(1) Place the ICU in its bracket below the master
cylinder. Start the upper mounting bolt to hold it in
place.
(2) Inside the vehicle, install the remaining 2
mounting bolts attaching the ICU to the mounting
bracket (Fig. 16). Tighten all 3 mounting bolts to a
torque of 11 N´m (97 in. lbs.).
(3) Install the dash seal and three mounting
screws (Fig. 15).
(4) If equipped, install the silencer on top of the
dash seal (Fig. 15).
(5) Connect the steering shaft coupling and install
the pinch bolt (Fig. 15). Tighten the pinch bolt to 28
N´m (250 in. lbs.).
(6) Remove the steering wheel holder.
CAUTION: Because of the flexible section in the pri-
mary and secondary brake tubes, the brake tubes
must be held in proper orientation when tightenedand torqued. These tubes must not contact each
other or other vehicle components when installed.
Also, after the brake tubes are installed on the HCU,
ensure all spacer clips are reinstalled on the brake
tubes.
(7) Install the primary and secondary brake tubes
into their correct port locations on the HCU valve
block (Fig. 14). Tighten the tube nuts to a torque of
17 N´m (145 in. lbs.).
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.
NOTE: The chassis brake tube attachment locations
to the HCU, are marked on the bottom of the CAB.
(8) Install the (4) chassis brake tubes into their
correct port locations on the HCU valve block as
shown (Fig. 14). Tighten the tube nuts to a torque of
17 N´m (145 in. lbs.).
NOTE: Before installing the 24±way connector in
the CAB be sure the seal is properly installed in the
connector.
(9) Install the 24±way connector on the CAB by,
first, positioning the 24±way connector in the socket
of the CAB and carefully pushing it down as far as
possible. Once connector is fully seated by hand into
the CAB socket, push down on connector lock. This
will pull the connector into the socket of the CAB
and lock it in the installed position.
(10) Install any routing clips on the brake tubes.
(11) Remove the brake pedal holder.
(12) Install the speed control servo with its mount-
ing nuts.
(13) Connect the wiring harness to the speed con-
trol servo.
(14) Install the battery tray (Refer to 8 - ELEC-
TRICAL/BATTERY SYSTEM/TRAY - INSTALLA-
TION).
(15) Install the screw securing the coolant filler
neck to the battery tray.
(16) Reconnect the vacuum hose connector at the
tank built into the battery tray.
(17) Install the battery (Refer to 8 - ELECTRI-
CAL/BATTERY SYSTEM/BATTERY - INSTALLA-
TION).
(18) Install the battery shield.
(19) Remove the brake pedal holder.
(20) Connect negative cable back on negative post
of the battery.
Fig. 24 (TYPICAL) Remove/Install CAB
1 - CAB
2 - HCU VALVES
3 - HCU VALVE BLOCK
5 - 106 BRAKES - ABSRS
ICU (INTEGRATED CONTROL UNIT) (Continued)

(21) Bleed the Base and ABS brake hydraulic sys-
tems (Refer to 5 - BRAKES - STANDARD PROCE-
DURE).
(22) Road test vehicle to ensure proper operation
of the base and antilock brake systems.
INSTALLATION - RHD
(1) Install the ICU on the mounting bracket (Fig.
21). Install the 3 bolts (Fig. 21) attaching the ICU to
the mounting bracket. Tighten the 3 mounting bolts
to a torque of 11 N´m (97 in. lbs.).
CAUTION: The ICU 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 ICU bracket to the front suspen-
sion crossmember.
(2) Install the ICU and its mounting bracket as an
assembly on the front suspension crossmember.
Install the 3 bolts attaching the ICU bracket to the
crossmember (Fig. 20). Tighten the 3 mounting bolts
to a torque of 28 N´m (250 in. lbs.).
CAUTION: Because of the flexible section in the pri-
mary 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. 19) for the correct chassis
brake tube locations.
NOTE: The chassis brake tube attachment locations
to the HCU, are marked on the bottom of the ICU
mounting bracket.
(3) Install the 6 chassis brake tubes into their cor-
rect port locations on the HCU valve block as shown
in (Fig. 19). Tighten the tube nuts to a torque of 17
N´m (145 in. lbs.).
NOTE: Before installing the 24-way connector in the
CAB be sure the seal is properly installed in the
connector.(4) Install the 24-way connector (Fig. 17) on the
CAB using the following procedure. Position the
24-way connector in the socket of the CAB and care-
fully push it down as far as possible. When connector
is fully seated by hand into the CAB socket, push in
the connector lock (Fig. 18). This will pull the connec-
tor into the socket of the CAB and lock it in the
installed position.
NOTE: The CAB wiring harness must be clipped to
the ICU 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.
(5) Clip the cab wiring harness (Fig. 17) to the
ICU mounting bracket.
(6) Install the routing clips (Fig. 25) on the brake
tubes.
(7) Lower the vehicle.
(8) Connect negative cable back on negative post of
the battery.
(9) Bleed the base and ABS hydraulic systems.
(Refer to 5 - BRAKES - STANDARD PROCEDURE)
(10) Road test vehicle to ensure proper operation
of the base and antilock brake systems.
Fig. 25 Brake Tube Routing Clips
1 - ROUTING CLIP
2 - HCU
3 - BRAKE TUBES
4 - ROUTING CLIP
RSBRAKES - ABS5 - 107
ICU (INTEGRATED CONTROL UNIT) (Continued)

With engine not running, remove radiator pressure
cap and wipe the radiator filler neck sealing seat
clean. The radiator should be full.
Attach the Cooling System Tester 7700 or equiva-
lent to the radiator, as shown in (Fig. 4) and apply
104 kPa (15 psi) pressure. If the pressure drops more
than 13.8 kPa (2 psi) in 2 minutes, inspect all points
for external leaks.
All radiator and heater hoses should be shaken
while at 104 kPa (15 psi), since some leaks occur only
while driving due to engine movement.If there are no external leaks, after the gauge dial
shows a drop in pressure, detach the tester. Start
engine and run until the thermostat opens, allowing
the coolant to expand. Reattach the cooling system
tester. If the needle on the dial fluctuates it indicates
a combustion leak, usually a head gasket leak.
WARNING: WITH TOOL IN PLACE, PRESSURE WILL
BUILD UP FAST. EXCESSIVE PRESSURE BUILT UP,
BY CONTINUOUS ENGINE OPERATION, MUST BE
RELEASED TO A SAFE PRESSURE POINT. NEVER
PERMIT PRESSURE TO EXCEED 138 kPa (20 psi).
If the needle on the dial does not fluctuate, raise
the engine rpm a few times. If an abnormal amount
of coolant or steam emits from the tailpipe, it may
indicate a coolant leak caused by a faulty head gas-
ket, cracked engine block, or cracked cylinder head.
There may be internal leaks that can be deter-
mined by removing the oil dipstick. If water globules
appear intermixed with the oil it will indicate an
internal leak in the engine. If there is an internal
leak, the engine must be disassembled for repair.
DIAGNOSIS AND TESTING - COOLING SYSTEM
FLOW CHECK
To determine whether coolant is flowing through
the cooling system, use one of the following proce-
dures:
PREFERRED METHOD
WARNING: DO NOT REMOVE THE COOLING SYS-
TEM PRESSURE CAP OR ANY HOSE WITH THE
SYSTEM HOT AND UNDER PRESSURE BECAUSE
SERIOUS BURNS FROM COOLANT CAN OCCUR.
²Remove pressure cap when engine is cold.
Remove small amount of coolant. Idle engine until
thermostat opens. You should observe coolant flow
while looking down the filler neck. Once flow is
detected install the pressure cap. Replace removed
coolant into coolant recovery container.
ALTERNATIVE METHOD
²If engine is cold, idle engine until normal oper-
ating temperature is reached. Feel the upper radiator
hose. If it is hot, coolant is circulating.
Fig. 3 Hose Clamp Tool
1 - HOSE CLAMP TOOL 6094
2 - HOSE CLAMP
Fig. 4 Pressure Testing
RSCOOLING7-3
COOLING (Continued)

DIAGNOSIS AND TESTING - COOLING SYSTEM
AERATION
Low coolant level in a cross flow radiator will
equalize in both tanks with engine off. With engine
at running and at operating temperature, the high
pressure inlet tank runs full and the low pressure
outlet tank drops, resulting in cooling system aera-
tion. Aeration will draw air into the water pump
resulting in the following:
²High reading shown on the temperature gauge.
²Loss of coolant flow through the heater core.
²Corrosion in the cooling system.
²Water pump seal may run dry, increasing the
risk of premature seal failure.
²Combustion gas leaks into the coolant can also
cause the above problems.
DIAGNOSIS AND TESTING - COOLING SYSTEM
DEAERATION
Air can only be removed from the system by gath-
ering under the pressure cap. On the next heat up it
will be pushed past the pressure cap into the coolant
recovery bottle by thermal expansion of the coolant.
It then escapes to the atmosphere in the coolant
recovery bottle and is replaced with coolant on cool
down.
To effectively deaerate the system, multiple ther-
mal cycles of the system may be required.
NOTE: Deaeration does not occur at engine idleÐ
higher engine speeds are required. Normal driving
will deaerate cooling system.
STANDARD PROCEDURE
STANDARD PROCEDURE - COOLING SYSTEM
DRAINING
WARNING: DO NOT REMOVE OR LOOSEN THE
COOLANT PRESSURE CAP, CYLINDER BLOCK
DRAIN PLUGS, OR THE DRAINCOCK WHEN THE
SYSTEM IS HOT AND UNDER PRESSURE
BECAUSE SERIOUS BURNS FROM THE COOLANT
CAN OCCUR.
(1)Without removing radiator pressure cap
and with system not under pressure, using a
screwdriver, open the draincock. The draincock is
located on the lower left side of radiator.
(2) After the coolant recovery/reserve container is
empty, then remove coolant pressure cap (Fig. 5).
(3) Remove the cylinder block drain plug(s).
STANDARD PROCEDURE - COOLING SYSTEM
FILLING
Remove radiator pressure cap (Fig. 5) and fill sys-
tem, using a 50/50 mix of MopartAntifreeze/Coolant,
5 Year/100,000 Mile Formula and distilled water.
Continue filling system until full.Be careful not
to spill coolant on drive belts or the generator.
For cooling system capacity, (Refer to LUBRICATION
& MAINTENANCE/FLUID CAPACITIES - SPECIFI-
CATIONS).
Fill coolant recovery/reserve container (Fig. 5) to at
least the MAX mark with 50/50 solution. It may be
necessary to add coolant to the recovery/reserve con-
tainer after three or four warm up/cool down cycles
to maintain coolant level between the MAX and MIN
mark. This will allow trapped air to be removed from
the system.
STANDARD PROCEDURE - ADDING
ADDITIONAL COOLANT
The radiator cap should not be removed.
When additional coolant is needed to maintain this
level, it should be added to the coolant recovery/re-
serve container (Fig. 5). Use only 50/50 mix of ethyl-
ene glycol type antifreeze and distilled water. For the
recommeded antifreeze/coolant type (Refer to LUBRI-
CATION & MAINTENANCE/FLUID TYPES -
DESCRIPTION).
CAUTION: Do not use well water, or suspect water
supply in cooling system. A 50/50 ethylene glycol
and distilled water mix is recommended. For the
recommeded antifreeze/coolant type (Refer to
LUBRICATION & MAINTENANCE/FLUID TYPES -
DESCRIPTION).
STANDARD PROCEDURE - COOLANT LEVEL
CHECK
NOTE: Do not remove radiator cap for routine cool-
ant level inspections.
The coolant reserve system provides a quick visual
method for determining the coolant level without
removing the radiator cap.With the engine cold
and not running,simply observe the level of the
coolant in the recovery/reserve container (Fig. 5). The
coolant level should be between the MIN and MAX
marks.
7 - 4 COOLINGRS
COOLING (Continued)