coolant CHRYSLER CARAVAN 2003 Owner's Manual

(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 a
vehicle 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
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.
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 - 90 BRAKES - ABSRS
ICU (INTEGRATED CONTROL UNIT) (Continued)
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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 tightened
and torqued. These tubes must not contact eachother 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.
(21) Bleed the Base and ABS brake hydraulic sys-
tems (Refer to 5 - BRAKES - STANDARD PROCE-
DURE).
Fig. 24 (TYPICAL) Remove/Install CAB
1 - CAB
2 - HCU VALVES
3 - HCU VALVE BLOCK
5 - 94 BRAKES - ABSRS
ICU (INTEGRATED CONTROL UNIT) (Continued)
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COOLING
TABLE OF CONTENTS
page page
COOLING
DESCRIPTION
DESCRIPTION - COOLING SYSTEM........1
DESCRIPTION - HOSE CLAMPS...........1
OPERATION
OPERATION - COOLING SYSTEM.........2
OPERATION - HOSE CLAMPS............2
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - COOLING
SYSTEM LEAK TEST....................2
DIAGNOSIS AND TESTING - COOLING
SYSTEM FLOW CHECK.................3
DIAGNOSIS AND TESTING - COOLING
SYSTEM AERATION....................3
DIAGNOSIS AND TESTING - COOLING
SYSTEM DEAERATION..................4
STANDARD PROCEDURE
STANDARD PROCEDURE - COOLING
SYSTEM DRAINING....................4STANDARD PROCEDURE - COOLING
SYSTEM FILLING......................5
STANDARD PROCEDURE - ADDING
ADDITIONAL COOLANT.................5
STANDARD PROCEDURE - COOLANT
LEVEL CHECK........................5
SPECIFICATIONS
ACCESSORY DRIVE BELT TENSION.......5
TORQUE.............................5
SPECIAL TOOLS
COOLING SYSTEM.....................6
ACCESSORY DRIVE.......................7
ENGINE...............................13
TRANSMISSION.........................37
COOLING
DESCRIPTION
DESCRIPTION - COOLING SYSTEM
The cooling system components consist of a radia-
tor, electric fan motors, shroud, pressure cap, thermo-
stat, transmission oil cooler, water pump, hoses,
clamps, coolant, and a coolant reserve system to com-
plete the circuit.
DESCRIPTION - HOSE CLAMPS
The cooling system uses spring type hose clamps.
If a spring type clamp replacement is necessary,
replace with the original Mopartequipment spring
type clamp.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps. If replacement
is necessary, use only a original equipment clamp
with matching number or letter (Fig. 1).
Fig. 1 Spring Clamp Size Location
1 - SPRING CLAMP SIZE LOCATION
RSCOOLING7-1
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OPERATION
OPERATION - COOLING SYSTEM
The engine cooling systems primary purpose is to
maintain engine temperature in a range that will
provide satisfactory engine performance and emission
levels under all expected driving conditions. It also
provides hot water (coolant) for heater performance
and cooling for automatic transmission oil. It does
this by transferring heat from engine metal to cool-
ant, moving this heated coolant to the radiator, and
then transferring this heat to the ambient air.
²When engine is cold: thermostat is closed, cool-
ing system has no flow through the radiator. The
coolant bypass flows through the engine only.
²When engine is warm: thermostat is open, cool-
ing system has bypass flow and coolant flow through
radiator.
Coolant flow circuits for the 2.4L and 3.3/3.8L
engines are shown in (Fig. 2).
OPERATION - HOSE CLAMPS
The spring type hose clamp applies constant ten-
sion on a hose connection. To remove a spring type
hose clamp, use Special Tool 6094 or equivalent, con-
stant tension clamp pliers (Fig. 3) to compress the
hose clamp.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - COOLING SYSTEM
LEAK TEST
WARNING: THE WARNING WORDS ªDO NOT OPEN
HOTº ON THE RADIATOR PRESSURE CAP IS A
SAFETY PRECAUTION. WHEN HOT, PRESSURE
BUILDS UP IN COOLING SYSTEM. TO PREVENT
SCALDING OR INJURY, THE RADIATOR CAP
SHOULD NOT BE REMOVED WHILE THE SYSTEM
IS HOT OR UNDER PRESSURE.
Fig. 2 Cooling System Flow
1 - HEATER - REAR (3.3/3.8L OPTIONAL EQUIPMENT) 6 - WATER PUMP
2 - HEATER - FRONT 7 - RADIATOR
3 - ENGINE 8 - COOLANT RECOVERY/RESERVE CONTAINER
4 - THERMOSTAT 9 - COOLANT FLOW - PRESSURE CAP VACUUM
5 - ENGINE OIL COOLER (3.3/3.8L OPTIONAL EQUIPMENT) 10 - COOLANT FLOW - PRESSURE CAP RELIEF
7 - 2 COOLINGRS
COOLING (Continued)
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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 systemtester. 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.
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.
Fig. 3 Hose Clamp Tool
1 - HOSE CLAMP TOOL 6094
2 - HOSE CLAMP
Fig. 4 Pressure Testing
RSCOOLING7-3
COOLING (Continued)
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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 gather-
ing under the pressure cap. On the next heat up it will
be pushed past the pressure cap into the coolant recov-
ery 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 THESYSTEM 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, open the
draincock. The draincock is located on the lower left
side of radiator (Fig. 5).
(2) After the coolant recovery/reserve container is
empty, then remove coolant pressure cap (Fig. 6).
(3) Remove the cylinder block drain plug(s).
Fig. 6 Cooling System Service Locations
1 - COOLANT RECOVERY CONTAINER 3 - ENGINE OIL LEVEL DIPSTICK
2 - ENGINE OIL FILL CAP 4 - RADIATOR PRESSURE CAP
Fig. 5 Draincock Location
1 - LEFT SIDE FRAME RAIL
2 - DRAINCOCK
7 - 4 COOLINGRS
COOLING (Continued)
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STANDARD PROCEDURE - COOLING SYSTEM
FILLING
Remove radiator pressure cap (Fig. 6) 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. 6) 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. 6). 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. 6). The
coolant level should be between the MIN and MAX
marks.
SPECIFICATIONS
ACCESSORY DRIVE BELT TENSION
ACCESSORY DRIVE BELT TENSION
2.4L ENGINE
Air Conditioning
Compressor/GeneratorDynamic Tensioner
Power
SteeringNew Belt534 - 756 N
(120 - 170 lbs.)
Used Belt*356 - 534 N
(80 - 120 lbs)
*Belt is considered used after 15 minutes of run-in
time
3.3/3.8L ENGINES
Air Conditioning Compressor
Dynamic Tensioner
Generator/Water Pump/
Power Steering
TORQUE
DESCRIPTION N´mFt.
Lbs.In.
Lbs.
Accessory Drive Belt Tensioner
Assembly (3.3/3.8L)ÐBolt28 Ð 250
Engine Coolant Temperature
Sensor
(2.4 & 3.3/3.8L) 7 Ð 60
Generator & A/C Compressor
Drive Belt Tensioner Assembly
(2.4L)ÐBolt54 40 Ð
Coolant Outlet Connector/
Thermostat Housing
(2.4 & 3.3/3.8L)ÐBolts 28 Ð 250
Water Pump
(2.4 & 3.3/3.8L)ÐBolts 12 Ð 105
Water Pump Inlet Tube
(2.4L)ÐBolts12 Ð 105
Water Pump Inlet Tube
(3.3/3.8L)ÐBolts28 Ð 250
Water Pump Pulley (3.3/3.8L)Ð
Bolts28 Ð 250
Radiator to A/C CondenserÐ
Screws5Ð45
Radiator FanÐScrews 5 Ð 45
Radiator Mounting (Upper
Bracket)ÐNuts12 Ð 105
RSCOOLING7-5
COOLING (Continued)
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SPECIAL TOOLS
COOLING SYSTEM
Hose Clamp Pliers 6094
Hose Clamp Pliers 8495A
Cooling System Tester 7700
Coolant Refractometer 8286
DRB IIITwith PEP Module ± OT-CH6010A
Belt Tension Gauge Adapter 8371
Belt Tension Gauge 7198A
7 - 6 COOLINGRS
COOLING (Continued)
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ENGINE
TABLE OF CONTENTS
page page
ENGINE
DIAGNOSIS AND TESTING - ENGINE
COOLING SYSTEM....................14
CLEANING............................18
INSPECTION..........................18
COOLANT
DESCRIPTION - ENGINE COOLANT.........19
DIAGNOSIS AND TESTING - COOLANT
CONCENTRATION TESTING.............19
STANDARD PROCEDURE - COOLANT
SERVICE............................19
COOLANT RECOVERY CONTAINER
DESCRIPTION.........................19
OPERATION...........................19
DIAGNOSIS AND TESTING - COOLANT
RECOVERY SYSTEM..................20
REMOVAL.............................20
INSTALLATION.........................20
ENGINE BLOCK HEATER
DESCRIPTION.........................20
OPERATION...........................20
DIAGNOSIS AND TESTING - ENGINE BLOCK
HEATER TESTING.....................20
REMOVAL.............................20
INSTALLATION.........................20
ENGINE COOLANT TEMPERATURE SENSOR -
2.4L
DESCRIPTION.........................21
REMOVAL.............................21
INSTALLATION.........................21
ENGINE COOLANT TEMPERATURE SENSOR -
3.3/3.8L
DESCRIPTION.........................21
REMOVAL.............................21
INSTALLATION.........................22
ENGINE COOLANT THERMOSTAT
DESCRIPTION.........................22
OPERATION...........................22
DIAGNOSIS AND TESTING - ENGINE
COOLANT THERMOSTAT...............23
ENGINE COOLANT THERMOSTAT - 2.4L
REMOVAL.............................23
INSTALLATION.........................23
ENGINE COOLANT THERMOSTAT - 3.3/3.8L
REMOVAL.............................23
INSTALLATION.........................24
RADIATOR
REMOVAL.............................25INSTALLATION.........................25
RADIATOR DRAINCOCK
REMOVAL.............................26
INSTALLATION.........................26
RADIATOR PRESSURE CAP
DESCRIPTION.........................26
OPERATION...........................27
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - COOLING
SYSTEM PRESSURE CAP TESTING.......27
DIAGNOSIS AND TESTING - RADIATOR
CAP TO FILLER NECK SEAL.............27
CLEANING............................28
INSPECTION..........................28
RADIATOR FAN
DESCRIPTION.........................28
OPERATION...........................29
DIAGNOSIS AND TESTING - RADIATOR FAN
MOTOR .............................29
REMOVAL.............................30
INSTALLATION.........................30
RADIATOR FAN RELAY
DESCRIPTION.........................30
OPERATION...........................30
REMOVAL.............................30
INSTALLATION.........................30
WATER PUMP - 2.4L
DESCRIPTION.........................31
REMOVAL.............................31
CLEANING............................32
INSPECTION..........................32
INSTALLATION.........................32
WATER PUMP - 3.3/3.8L
DESCRIPTION.........................33
REMOVAL.............................33
CLEANING............................34
INSPECTION..........................34
INSTALLATION.........................34
WATER PUMP INLET TUBE - 2.4L
DESCRIPTION.........................35
REMOVAL.............................35
INSTALLATION.........................35
WATER PUMP INLET TUBE - 3.3/3.8L
REMOVAL.............................36
INSTALLATION.........................36
RSENGINE7-13
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ENGINE
DIAGNOSIS AND TESTING - ENGINE COOLING
SYSTEM
Establish what driving condition caused the cooling
system complaint. The problem may be caused by an
abnormal load on the system such as the following:
prolonged idle, very high ambient temperature, slight
tail wind at idle, slow traffic speed, traffic jam, high
speed, steep grade.
DRIVING TECHNIQUES
To avoid overheating the cooling system:
(1) Idle with A/C off when temperature gauge is at
end of normal range.
(2) Do not increase engine speed for more air flow
and coolant flow because the electric motor fan sys-
tems are not responsive to engine RPM. The added
cooling from higher coolant flow rate is more than
offset by increased heat rejection (engine heat added
to coolant).
TRAILER TOWING
Consult the owner's manual under Trailer Towing
and do not exceed specified limits.
VISUAL INSPECTION
If the cooling system problem is not caused by a
driving condition, perform a visual inspection to
determine if there was a recent service or accident
repair, including the following:
²Loose/damaged water pump drive belt
²Incorrect cooling system refilling (trapped air or
low level)
²Brakes possibly dragging
²Damaged hoses
²Loose/damaged hose clamps
²Damaged/incorrect engine thermostat
²Damaged cooling fan motor, fan blade and fan
shroud
²Damaged head gasket
²Damaged water pump
²Damaged radiator
²Damaged coolant recovery system
²Damaged heater core
²Open/shorted electrical circuits
If the visual inspection reveals none of the above
as cause for a cooling system complaint, refer to the
following diagnostic charts.
COOLING SYSTEM DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
PRESSURE CAP IS BLOWING
OFF STEAM AND/OR COOLANT.
TEMPERATURE GAUGE READING
MAY BE ABOVE NORMAL BUT
NOT HIGH. COOLANT LEVEL MAY
BE HIGH IN COOLANT RESERVE/
OVERFLOW TANK.1. Pressure relief valve in radiator
cap is defective, or was not
properly seated.1. Check condition of radiator cap
and cap seal. (Refer to 7 -
COOLING/ENGINE/RADIATOR
PRESSURE CAP - DIAGNOSIS
AND TESTING) Replace cap as
necessary.
2. Incorrect cap was installed. 2. Replace cap as necessary.
3. Incorrect coolant mixture. 3. Check concentration level of the
coolant. (Refer to 7 - COOLING/
ENGINE/COOLANT - DIAGNOSIS
AND TESTING) Adjust the ethylene
glycol-to-water ratio as required.
COOLANT LOSS TO THE
GROUND WITHOUT PRESSURE
CAP BLOWOFF. GAUGE IS
READING HIGH OR HOT.1. Coolant leaks in radiator, cooling
system hoses, water pump or
engine.1. Pressure test and repair as
necessary. (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING)
7 - 14 ENGINERS
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