section 5 DODGE RAM 1500 1998 2.G Workshop Manual

²National Lubricating Grease Institute (NLGI)
API SERVICE GRADE CERTIFIED
Use an engine oil that is API Certified. MOPARt
provides engine oils, that meet or exceed this
requirement.
SAE VISCOSITY
An SAE viscosity grade is used to specify the vis-
cosity of engine oil. Use only engine oils with multi-
ple viscosities such as 5W-30 or 10W-30. These are
specified with a dual SAE viscosity grade which indi-
cates the cold-to-hot temperature viscosity range.
Select an engine oil that is best suited to your par-
ticular temperature range and variation (Fig. 1).
ENERGY CONSERVING OIL
An Energy Conserving type oil is recommended for
gasoline engines. The designation of ENERGY CON-
SERVING is located on the label of an engine oil con-
tainer.
CONTAINER IDENTIFICATION
Standard engine oil identification notations have
been adopted to aid in the proper selection of engine
oil. The identifying notations are located on the front
label of engine oil plastic bottles and the top of
engine oil cans (Fig. 2).
This symbol means that the oil has been certified
by the American Petroleum Institute (API). Diamler-
Chrysler only recommend API Certified engine oils.
Use Mopartengine oil or equivalent.
GEAR LUBRICANTS
SAE ratings also apply to multigrade gear lubri-
cants. In addition, API classification defines the
lubricants usage. Such as API GL-5 and SAE 75W-
90.
LUBRICANTS AND GREASES
Lubricating grease is rated for quality and usage
by the NLGI. All approved products have the NLGIsymbol (Fig. 3) on the label. At the bottom of the
NLGI symbol is the usage and quality identification
letters. Wheel bearing lubricant is identified by the
letter ªGº. Chassis lubricant is identified by the letter
ªLº. The letter following the usage letter indicates
the quality of the lubricant. The following symbols
indicate the highest quality.
SPECIALIZED LUBRICANTS AND OILS
Some maintenance or repair procedures may
require the use of specialized lubricants or oils. Con-
sult the appropriate sections in this manual for the
correct application of these lubricants.
DESCRIPTION - ENGINE OIL - DIESEL
ENGINES
Use only Diesel Engine Oil meeting standardMIL-
2104Cor API ClassificationCD or higherorCCML
D4, D5.
SAE VISCOSITY GRADE
CAUTION: Low viscosity oils must have the proper
API quality or the CCMC G5 designation. (Fig. 4)
To assure of properly formulated engine oils, it is
recommended that SAE Grade 10W-40 engine oils
that meet Chrysler material standard MS-6395, be
used in accordance to ACEA B3, B4 specification.
European Grade 10W-40 oils are also acceptable.
Fig. 1 TEMPERATURE/ENGINE OIL VISCOSITY
Fig. 2 API SYMBOL
Fig. 3 NLGI SYMBOL
1 - WHEEL BEARINGS
2 - CHASSIS LUBRICATION
3 - CHASSIS AND WHEEL BEARINGS
0 - 2 LUBRICATION & MAINTENANCEDR
FLUID TYPES (Continued)

DESCRIPTION SPECIFICATION
REAR AXLE   .03 L (1 oz)
9 1/4 2.32 L (4.9 pts.)***
10 1/2 AA 2.25 L (4.75 pts.)
11 1/2 AA 3.62 L (7.65 pts)
*** With Trac-Lok add 118 ml (4 oz.) of Limited Slip
Additive.
** Includes 0.9L (1.0 qts.) for coolant reservoir.
*Nominal refill capacities are shown. A variation may
be observed from vehicle to vehicle due to
manufacturing tolerance and refill procedure.
MAINTENANCE SCHEDULES
DESCRIPTION
DESCRIPTION
Maintenance Schedule Information not included in
this section, is located in the appropriate Owner's
Manual.
There are two maintenance schedules that show
therequiredservice for your vehicle.
First is ScheduleªBº. It is for vehicles that are
operated under the conditions that are listed below
and at the beginning of the schedule.
²Day or night temperatures are below 0É C (32É
F).
²Stop and go driving.
²Extensive engine idling.
²Driving in dusty conditions.
²Short trips of less than 16 km (10 miles).
²More than 50% of your driving is at sustained
high speeds during hot weather, above 32É C (90É F).
²Trailer towing.
²Taxi, police, or delivery service (commercial ser-
vice).
²Off-road or desert operation.
²If equipped for and operating with E-85
(ethanol) fuel.
NOTE: If ANY of these apply to the vehicle then
change the engine oil every 3,000 miles (5 000 km)
or 3 months, whichever comes first and follow
schedule ªBº of the(Maintenance Schedules(sec-
tion of this manual.
NOTE: Most vehicles are operated under the condi-
tions listed for Schedule(B(.
Second is ScheduleªAº. It is for vehicles that are
not operated under any of the conditions listed under
Schedule9B9.Use the schedule that best describes the driving
conditions. Where time and mileage are listed, follow
the interval that occurs first.
CAUTION: Failure to perform the required mainte-
nance items may result in damage to the vehicle.
At Each Stop for Fuel
²Check the engine oil level about 5 minutes after
a fully warmed engine is shut off. Checking the oil
level while the vehicle is on level ground will
improve the accuracy of the oil level reading. Add oil
only when the level is at or below the ADD or MIN
mark.
²Check the windshield washer solvent and add if
required.
Once a Month
²Check tire pressure and look for unusual wear
or damage.
²Inspect the battery and clean and tighten the
terminals as required.
²Check the fluid levels of coolant reservoir, brake
master cylinder, power steering and transmission
and add as needed.
²Check all lights and all other electrical items for
correct operation.
At Each Oil Change
²Change the engine oil filter.
²Inspect the exhaust system.
²Inspect the brake hoses.
²Inspect the CV joints (if equipped) and front sus-
pension components.
²Check the automatic transmission fluid level.
²Check the manual transmission fluid level.
²Check the coolant level, hoses, and clamps.
²Rotate the tires at each oil change interval
shown on Schedule ªAº 10 000 km (6,000 miles) or
every other interval shown on Schedule ªBº 10 000
km (6,000 miles).
Tire Rotation
²Rotate the tires at 6,000 miles (10 000 km).
Schedule ªBº
Follow schedule ªBº if you usually operate your
vehicle under one or more of the following conditions.
²Day or night temperatures are below 0É C (32É
F).
²Stop and go driving.
²Extensive engine idling.
²Driving in dusty conditions.
²Short trips of less than 16 km (10 miles).
²More than 50% of your driving is at sustained
high speeds during hot weather, above 32É C (90É F).
0 - 6 LUBRICATION & MAINTENANCEDR
FLUID CAPACITIES (Continued)

²Trailer towing.
²Snowplowing.
²Heavy Loading.
²Taxi, police, or delivery service (commercial ser-
vice).
²Off-road or desert operation.
²If equipped for and operating with E-85
(ethanol) fuel.NOTE: If ANY of these apply to the vehicle then
change the engine oil every 3,000 miles (5 000 km)
or 3 months, whichever comes first and follow
schedule ªBº of the(Maintenance Schedules(sec-
tion of this manual.
If none of these apply to the vehicle, then change
the engine oil at every interval shown on schedule
(A(of the(Maintenance Schedules(section of this
manual.
Miles 3,000 6,000 9,000 12,000 15,000
(Kilometers) (5 000) (10 000) (14 000) (19 000) (24 000)
Change engine oil and engine oil filter.XXXX X
Lubricate outer tie rod ends 2500/3500
(4X4) models only.XX
Change rear axle fluid.X
Change front axle fluid (4X4).X
Inspect brake linings.X
Inspect engine air cleaner filter, replace
if necessary.X
Miles 18,000 21,000 24,000 27,000 30,000
(Kilometers) (29 000) (34 000) (38 000) (43 000) (48 000)
Change engine oil and engine oil filter.XXXX X
Lubricate outer tie rod ends 2500/3500
(4X4) models only.XX X
Change rear axle fluid.X
Change front axle fluid (4X4).X
Check transfer case fluid level (4X4). X
Inspect brake linings. X
Inspect engine air cleaner filter, replace
if necessary.X
Replace spark plugs.X
Inspect PCV valve, replace as necessary.X*
Drain and refill automatic tranmission fluid
and change main sump filter (45RFE/
545RFE only).X
DRLUBRICATION & MAINTENANCE 0 - 7
MAINTENANCE SCHEDULES (Continued)

²Drum brake shoes binding on worn/damaged
support plates.
²Mis-assembled components.
²Long booster output rod.
If brake drag occurs at all wheels, the problem
may be related to a blocked master cylinder return
port, or faulty power booster (binds-does not release).
BRAKE FADE
Brake fade is usually a product of overheating
caused by brake drag. However, brake overheating
and resulting fade can also be caused by riding the
brake pedal, making repeated high deceleration stops
in a short time span, or constant braking on steep
mountain roads. Refer to the Brake Drag information
in this section for causes.
BRAKE PULL
Front brake pull condition could result from:
²Contaminated lining in one caliper
²Seized caliper piston
²Binding caliper
²Loose caliper
²Rusty caliper slide surfaces
²Improper brake pads
²Damaged rotor
A worn, damaged wheel bearing or suspension
component are further causes of pull. A damaged
front tire (bruised, ply separation) can also cause
pull.
A common and frequently misdiagnosed pull condi-
tion is where direction of pull changes after a few
stops. The cause is a combination of brake drag fol-
lowed by fade at one of the brake units.
As the dragging brake overheats, efficiency is so
reduced that fade occurs. Since the opposite brake
unit is still functioning normally, its braking effect is
magnified. This causes pull to switch direction in
favor of the normally functioning brake unit.
An additional point when diagnosing a change in
pull condition concerns brake cool down. Remember
that pull will return to the original direction, if the
dragging brake unit is allowed to cool down (and is
not seriously damaged).
REAR BRAKE GRAB OR PULL
Rear grab or pull is usually caused by improperly
adjusted or seized parking brake cables, contami-
nated lining, bent or binding shoes and support
plates, or improperly assembled components. This is
particularly true when only one rear wheel is
involved. However, when both rear wheels are
affected, the master cylinder or proportioning valve
could be at fault.BRAKES DO NOT HOLD AFTER DRIVING THROUGH DEEP
WATER PUDDLES
This condition is generally caused by water soaked
lining. If the lining is only wet, it can be dried by
driving with the brakes very lightly applied for a
mile or two. However, if the lining is both soaked and
dirt contaminated, cleaning and/or replacement will
be necessary.
BRAKE LINING CONTAMINATION
Brake lining contamination is mostly a product of
leaking calipers or worn seals, driving through deep
water puddles, or lining that has become covered
with grease and grit during repair. Contaminated lin-
ing should be replaced to avoid further brake prob-
lems.
WHEEL AND TIRE PROBLEMS
Some conditions attributed to brake components
may actually be caused by a wheel or tire problem.
A damaged wheel can cause shudder, vibration and
pull. A worn or damaged tire can also cause pull.
Severely worn tires with very little tread left can
produce a grab-like condition as the tire loses and
recovers traction. Flat-spotted tires can cause vibra-
tion and generate shudder during brake operation. A
tire with internal damage such as a severe bruise,
cut, or ply separation can cause pull and vibration.
BRAKE NOISES
Some brake noise is common with rear drum
brakes and on some disc brakes during the first few
stops after a vehicle has been parked overnight or
stored. This is primarily due to the formation of trace
corrosion (light rust) on metal surfaces. This light
corrosion is typically cleared from the metal surfaces
after a few brake applications causing the noise to
subside.
BRAKE SQUEAK/SQUEAL
Brake squeak or squeal may be due to linings that
are wet or contaminated with brake fluid, grease, or
oil. Glazed linings and rotors with hard spots can
also contribute to squeak. Dirt and foreign material
embedded in the brake lining will also cause squeak/
squeal.
A very loud squeak or squeal is frequently a sign of
severely worn brake lining. If the lining has worn
through to the brake pads in spots, metal-to-metal
contact occurs. If the condition is allowed to continue,
rotors can become so scored that replacement is nec-
essary.
BRAKE CHATTER
Brake chatter is usually caused by loose or worn
components, or glazed/burnt lining. Rotors with hard
spots can also contribute to chatter. Additional causes
5 - 4 BRAKES - BASEDR
BRAKES - BASE (Continued)

The cylinder reservoir can be replaced when neces-
sary. However, the aluminum body section of the
master cylinder is not a repairable component.
NOTE: If diagnosis indicates that an internal mal-
function has occurred, the aluminum body section
must be replaced as an assembly.
OPERATION
The master cylinder bore contains a primary and
secondary piston. The primary piston supplies
hydraulic pressure to the front brakes. The secondary
piston supplies hydraulic pressure to the rear brakes.
DIAGNOSIS AND TESTING - MASTER
CYLINDER/POWER BOOSTER
(1) Start engine and check booster vacuum hose
connections. A hissing noise indicates vacuum leak.
Correct any vacuum leak before proceeding.
(2) Stop engine and shift transmission into Neu-
tral.
(3) Pump brake pedal until all vacuum reserve in
booster is depleted.
(4) Press and hold brake pedal under light foot
pressure. The pedal should hold firm, if the pedal
falls away master cylinder is faulty (internal leak-
age).
(5) Start engine and note pedal action. It should
fall away slightly under light foot pressure then hold
firm. If no pedal action is discernible, power booster,
vacuum supply, or vacuum check valve is faulty. Pro-
ceed to the POWER BOOSTER VACUUM TEST.
(6) If the POWER BOOSTER VACUUM TEST
passes, rebuild booster vacuum reserve as follows:
Release brake pedal. Increase engine speed to 1500
rpm, close the throttle and immediately turn off igni-
tion to stop engine.
(7) Wait a minimum of 90 seconds and try brake
action again. Booster should provide two or more vac-
uum assisted pedal applications. If vacuum assist is
not provided, booster is faulty.
POWER BOOSTER VACUUM TEST
(1) Connect vacuum gauge to booster check valve
with short length of hose and T-fitting (Fig. 44).
(2) Start and run engine at curb idle speed for one
minute.
(3) Observe the vacuum supply. If vacuum supply
is not adequate, repair vacuum supply.
(4) Clamp hose shut between vacuum source and
check valve.
(5) Stop engine and observe vacuum gauge.
(6) If vacuum drops more than one inch HG (33
millibars) within 15 seconds, booster diaphragm or
check valve is faulty.
POWER BOOSTER CHECK VALVE TEST
(1) Disconnect vacuum hose from check valve.
(2) Remove check valve and valve seal from
booster.
(3) Use a hand operated vacuum pump for test.
(4) Apply 15-20 inches vacuum at large end of
check valve (Fig. 45).
(5) Vacuum should hold steady. If gauge on pump
indicates vacuum loss, check valve is faulty and
should be replaced.
Fig. 44 Typical Booster Vacuum Test Connections
1 - TEE FITTING
2 - SHORT CONNECTING HOSE
3 - CHECK VALVE
4 - CHECK VALVE HOSE
5 - CLAMP TOOL
6 - INTAKE MANIFOLD
7 - VACUUM GAUGE
Fig. 45 Vacuum Check Valve And Seal
1 - BOOSTER CHECK VALVE
2 - APPLY TEST VACUUM HERE
3 - VALVE SEAL
DRBRAKES - BASE 5 - 25
MASTER CYLINDER (Continued)

INSTALLATION
(1) Install support plate on axle flange (Fig. 66).
Tighten attaching bolts to 115 N´m (85 ft. lbs.).
(2) Install parking brake cable in the brake lever.
(3) Install the park brake shoes (Refer to 5 -
BRAKES/PARKING BRAKE/SHOES - INSTALLA-
TION). (Fig. 66).
(4) Install axle shaft, (Refer to 3 - DIFFEREN-
TIAL & DRIVELINE/REAR AXLE - 9 1/4/AXLE
SHAFTS - INSTALLATION).
(5) Adjust brake shoes to drum with brake gauge
(Refer to 5 - BRAKES/PARKING BRAKE/SHOES -
ADJUSTMENTS).
(6) Install the rotor (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/ROTORS - INSTALLA-
TION).
(7) Install the caliper adapter (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPER ADAPTER - INSTALLATION).
(8) Install the caliper (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/DISC BRAKE CALIPERS
- INSTALLATION).
(9) Install the wheel and tire assembly (Refer to 22
- TIRES/WHEELS/WHEELS - STANDARD PROCE-
DURE).
PARKING BRAKE
DESCRIPTION
The parking brakes are operated by a system of
cables and levers attached to a primary and second-
ary shoe positioned within the drum section of the
rotor.
The drum-in-hat design utilizes an independent set
of shoes to park the vehicle (Fig. 67).
OPERATION
To apply the parking brake the pedal is depressed.
This creates tension in the cable which pulls forward
on the park brake lever. The lever pushes the park
brake shoes outward and into contact with the drum
section of the rotor. The contact of shoe to rotor parks
the vehicle.
A torsion locking mechanism is used to hold the
pedal in an applied position. Parking brake release is
accomplished by the hand release.
A parking brake switch is mounted on the parking
brake lever and is actuated by movement of the
lever. The switch, which is in circuit with the red
warning light in the dash, will illuminate the warn-
ing light whenever the parking brake is applied.
Parking brake adjustment is controlled by a cable
tensioner mechanism. The cable tensioner, once
adjusted at the factory, should not need further
adjustment under normal circumstances. Adjustment
may be required if a new tensioner, or cables are
installed, or disconnected.
CABLES
REMOVAL
REMOVAL - FRONT PARKING BRAKE CABLE
(1) Raise and support vehicle.
(2) Lockout the parking brake cable (Fig. 69).
(3) Loosen adjusting nut to create slack in front
cable.
(4) Remove the front cable from the cable connec-
tor.
Fig. 66 SUPPORT PLATE WITH BRAKES MOUNTED
1 - SUPPORT PLATE
2 - MOUNTING NUTS
Fig. 67 SUPPORT PLATE WITH BRAKES MOUNTED
1 - SUPPORT PLATE
2 - MOUNTING NUTS
5 - 36 BRAKES - BASEDR
SUPPORT PLATE (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
INADEQUATE AIR CONDITIONER
PERFORMANCE (COOLING
SYSTEM SUSPECTED)1. Radiator and/or A/C condenser
air flow obstructed.1. Remove obstruction and/or clean.
2. Electronically controlled viscous
fan drive not working.2. Check viscous fan drive (Refer to
7 - COOLING/ENGINE/FAN DRIVE
VISCOUS CLUTCH - DIAGNOSIS
AND TESTING)
3. Air seals around radiator
damaged or missing.3. Inspect air seals, repair or
replace as necessary.
INADEQUATE HEATER
PERFORMANCE. GAUGE MAY OR
MAY NOT READ LOW.1. Heavy duty cooling system, and
cooler ambient temperatures.1. None. Normal condition.
2. Obstruction in heater hoses. 2. Remove hoses, remove
obstruction.
3. Electronically controlled viscous
fan stuck on.Check viscous fan drive. (Refer to 7
- COOLING/ENGINE/FAN DRIVE
VISCOUS CLUTCH - DIAGNOSIS
AND TESTING)
4. Water pump damaged. 4. Replace water pump.
HEAT ODOR 1. Damaged or missing drive line
heat shields.1. Repair or replace damaged or
missing heat shields.
2. Electronically controlled viscous
fan drive damaged.2. Check viscous fan drive. (Refer
to 7 - COOLING/ENGINE/FAN
DRIVE VISCOUS CLUTCH -
DIAGNOSIS AND TESTING)
DIAGNOSIS AND TESTING - PRELIMINARY
CHECKS
ENGINE COOLING SYSTEM OVERHEATING
Establish what driving conditions caused the com-
plaint. Abnormal loads on the cooling system such as
the following may be the cause:
²PROLONGED IDLE
²VERY HIGH AMBIENT TEMPERATURE
²SLIGHT TAIL WIND AT IDLE
²SLOW TRAFFIC
²TRAFFIC JAMS
²HIGH SPEED OR STEEP GRADES
Driving techniques that avoid overheating are:
²Idle with A/C off when temperature gauge is at
end of normal range.
²Increasing engine speed for more air flow is rec-
ommended.
TRAILER TOWING:
Consult Trailer Towing section of owners manual.
Do not exceed limits.RECENT SERVICE OR ACCIDENT REPAIR:
Determine if any recent service has been per-
formed on vehicle that may effect the cooling system.
This may be:
²Engine adjustments (incorrect timing)
²Slipping engine accessory drive belt(s)
²Brakes (possibly dragging)
²Changed parts. Incorrect water pump or pump
rotating in wrong direction due to belt not correctly
routed
²Reconditioned radiator or cooling system refill-
ing (possibly under filled or air trapped in system).
²Service to electrically controlled viscous fan
clutch
NOTE: If investigation reveals none of the previous
items as a cause for an engine overheating com-
plaint, refer to COOLING SYSTEM DIAGNOSIS
CHART BELOW.
These charts are to be used as a quick-reference
only. Refer to COOLING SYSTEM DIAGNOSIS
CHART
7 - 10 COOLINGDR
COOLING (Continued)

COOLING SYSTEM DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
TEMPERATURE GAUGE READS
LOW1. Has a Diagnostic Trouble Code
(DTC) been set indicating a stuck
open thermostat?1. (Refer to 25 - EMISSIONS
CONTROL - DESCRIPTION) for
On-Board Diagnostics and DTC
information. Replace thermostat if
necessary.
2. Is the temperature sending unit
connected?2. Check the temperature sensor
connector. (Refer to 8 -
ELECTRICAL/INSTRUMENT
CLUSTER - SCHEMATIC -
ELECTRICAL) Repair connector if
necessary.
3. Is the temperature gauge
operating OK?3. Check gauge operation. (Refer to
8 - ELECTRICAL/INSTRUMENT
CLUSTER/ENGINE
TEMPERATURE GAUGE -
DESCRIPTION). Repair as
necessary.
4. Coolant level low in cold ambient
temperatures accompanied with
poor heater performance.4. Check coolant level in the coolant
reserve/overflow tank or degas
bottle and the radiator. Inspect
system for leaks. Repair leaks as
necessary. Refer to the Coolant
section of the manual text for
WARNINGS and CAUTIONS
associated with removing the
radiator cap.
5. Improper operation of internal
heater doors or heater controls.5. Inspect heater and repair as
necessary. (Refer to 24 - HEATING
& AIR CONDITIONING -
DIAGNOSIS AND TESTING) for
procedures.
TEMPERATURE GAUGE READS
HIGH OR THE COOLANT
WARNING LAMP ILLUMINATES.
COOLANT MAY OR MAY NOT BE
LOST OR LEAKING FROM THE
COOLING SYSTEM1. Trailer is being towed, a steep
hill is being climbed, vehicle is
operated in slow moving traffic, or
engine is being idled with very high
ambient (outside) temperatures and
the air conditioning is on. Higher
altitudes could aggravate these
conditions.1. This may be a temporary
condition and repair is not
necessary. Turn off the air
conditioning and attempt to drive the
vehicle without any of the previous
conditions. Observe the temperature
gauge. The gauge should return to
the normal range. If the gauge does
not return to the normal range,
determine the cause for overheating
and repair. Refer to Possible
Causes (2-18).
2. Is the temperature gauge reading
correctly?2. Check gauge. (Refer to 8 -
ELECTRICAL/INSTRUMENT
CLUSTER - SCHEMATIC -
ELECTRICAL). Repair as
necessary.
DRCOOLING 7 - 11
COOLING (Continued)

STANDARD PROCEDURE
STANDARD PROCEDURE - COOLANT LEVEL
CHECK
NOTE: Do not remove radiator cap for routine cool-
ant level inspections. The coolant level can be
checked at coolant recovery bottle or the coolant
degas bottle.
WARNING: DO NOT REMOVE OR LOOSEN THE
RADIATOR CAP WITH THE COOLING SYSTEM HOT
AND UNDER PRESSURE. SERIOUS BURNS FROM
COOLANT OR HIGH PRESSURE STEAM CAN
OCCUR.
The coolant reserve/overflow system provides a
quick method for determining the coolant level with-
out removing the radiator pressure cap. With the
engine at normal operating temperature and idling,
observe the level of the coolant on the external level
indicator on the side of the coolant reserve / overflow
bottle. The coolant level should be between the MIN
and MAX marks. If the coolant is below the MIN
mark, add a 50/50 mixture of antifreeze and water to
the bottle until the level reaches the MIN mark.Do
Not Overfill the bottle by adding fluid above
the MAX line.This may cause coolant to spill onto
the ground during subsequent vehicle operation.
STANDARD PROCEDURE - COOLING SYSTEM
CLEANING/REVERSE FLUSHING
CLEANING
Drain the cooling system and refill with water. Run
the engine with the radiator cap installed until the
upper radiator hose is hot. Stop the engine and drain
the water from system. If the water is dirty, fill the
system with water, run the engine and drain the sys-
tem. Repeat this procedure until the water drains
clean.
REVERSE FLUSHING
Reverse flushing of the cooling system is the forc-
ing of water through the cooling system. This is done
using air pressure in the opposite direction of normal
coolant flow. It is usually only necessary with very
dirty systems with evidence of partial plugging.
REVERSE FLUSHING RADIATOR
Disconnect the radiator hoses from the radiator
inlet and outlet. Attach a section of the radiator hose
to the radiator bottom outlet fitting and insert the
flushing gun. Connect a water supply hose and air
supply hose to the flushing gun.CAUTION: Internal radiator pressure must not
exceed 138 kPa (20 psi) as damage to radiator may
result.
Allow the radiator to fill with water. When the
radiator is filled, apply air in short blasts. Allow the
radiator to refill between blasts. Continue this
reverse flushing until clean water flows out through
the rear of the radiator cooling tube passages.
REVERSE FLUSHING ENGINE
Drain the cooling system. Remove the thermostat
housing and thermostat. Install the thermostat hous-
ing. Disconnect the radiator upper hose from the
radiator and attach the flushing gun to the hose. Dis-
connect the radiator lower hose from the water pump
and attach a lead-away hose to the water pump inlet
fitting.
CAUTION: On vehicles equipped with a heater water
control valve, be sure the heater control valve is
closed (heat off). This will prevent coolant flow with
scale and other deposits from entering the heater
core.
Connect the water supply hose and air supply hose
to flushing gun. Allow the engine to fill with water.
When the engine is filled, apply air in short blasts,
allowing the system to fill between air blasts. Con-
tinue until clean water flows through the lead away
hose.
Remove the lead away hose, flushing gun, water
supply hose and air supply hose. Remove the thermo-
stat housing and install the thermostat. Install the
thermostat housing with a replacement gasket. Refer
to Thermostat Replacement. Connect the radiator
hoses. Refill the cooling system with the correct anti-
freeze/water mixture. Refer to Refilling the Cooling
System.
CHEMICAL CLEANING
In some instances, use a radiator cleaner (Mopart
Radiator Kleen or equivalent) before flushing. This
will soften scale and other deposits and aid flushing
operation.
CAUTION: Follow manufacturers instructions when
using these products.
STANDARD PROCEDURE - DRAINING COOLING
SYSTEM - ALL GAS ENGINES
WARNING: DO NOT REMOVE CYLINDER BLOCK
DRAIN PLUGS OR LOOSEN RADIATOR DRAIN-
COCK WITH SYSTEM HOT AND UNDER PRESSURE.
SERIOUS BURNS FROM COOLANT CAN OCCUR.
DRCOOLING 7 - 17
COOLING (Continued)

REMOVAL
3.7L V-6
The Engine Coolant Temperature (ECT) sensor on
the 3.7L engine is installed into a water jacket at
front of intake manifold near rear of generator (Fig.
10).
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. COOLING SYSTEM
MUST BE PARTIALLY DRAINED BEFORE REMOV-
ING THE COOLANT TEMPERATURE SENSOR.
(1) Partially drain the cooling system.
(2) Disconnect the electrical connector from the
sensor.
(3) Remove the sensor from the intake manifold.
4.7L V-8
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. COOLING SYSTEM
MUST BE PARTIALLY DRAINED BEFORE REMOV-
ING THE ENGINE COOLANT TEMPERATURE (ECT)
SENSOR.
The Engine Coolant Temperature (ECT) sensor on
the 4.7L V-8 engine is located near the front of the
intake manifold (Fig. 11).(1) Partially drain the cooling system. Refer to 7,
COOLING.
(2) Disconnect the electrical connector from the
ECT sensor.
(3) Remove the sensor from the intake manifold.
5.7L V-8
The Engine Coolant Temperature (ECT) sensor on
the 5.7L engine is located under the air conditioning
compressor (Fig. 12). It is installed into a water
jacket at the front of the cylinder block (Fig. 13).
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. COOLING SYSTEM
MUST BE PARTIALLY DRAINED BEFORE REMOV-
ING THE COOLANT TEMPERATURE SENSOR.
(1) Partially drain the cooling system.
(2) Remove fan belt. Refer to Accessory Drive in
Cooling section.
(3) Carefully unbolt air conditioning compressor
from front of engine. Do not disconnect any A/C hoses
from compressor. Temporarily support compressor to
gain access to ECT sensor. Refer to Heating and Air
Conditioning section for information.
(4) Disconnect electrical connector from sensor
(Fig. 13).
(5) Remove sensor from cylinder block.
Fig. 10 MAP SENSOR / ECT SENSOR - 3.7L V-6
1 - MOUNTING SCREWS
2 - MAP SENSOR
3 - ECT SENSOR
4 - FRONT OF INTAKE MANIFOLD
Fig. 11 ECT SENSOR - 4.7L V-8
1 - ECT SENSOR
2 - MOUNTING BOLTS (2)
3 - MAP SENSOR
4 - INTAKE MANIFOLD
DRENGINE 7 - 39
ENGINE COOLANT TEMPERATURE SENSOR (Continued)