1998 DODGE RAM 1500 8L Lamps

²Pedal Adjustment Inhibitors: Pedal adjust-
ment is inhibited when the vehicle is in reverse or
when cruise control is activated.
REMOVAL
(1) Disconnect the negative battery cable.
(2) Remove the kneeblocker (Refer to 23 - BODY/
INSTRUMENT PANEL/STEERING COLUMN
OPENING COVER - REMOVAL).
(3) Remove the brake light switch and discard
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
EXTERIOR/BRAKE LAMP SWITCH - REMOVAL).
(4) Disconnect the adjustable pedal cables from the
brake and accelerator pedalsAlso clutch pedal if
equipped with a manual transmission.
(5) Disconnect the electrical connector.
(6) Unclip the cable fasteners to the support.
(7) Remove the one mounting bolt for the adjust-
able pedal motor (Fig. 4).
(8) Remove the adjustable pedal motor with the
cables.
NOTE: Adjustable pedal cables are not serviceable.
If they need service the adjustable pedal motor with
the cables must be installed.
INSTALLATION
NOTE: Adjustable pedal cables are not serviceable.
If they need service the adjustable pedal motor with
the cables must be installed.
(1) Install the adjustable pedal motor with the
cables.
(2) Install the one mounting bolt for the adjustable
pedal motor (Fig. 4).
(3) Clip the cable fasteners to the support.
(4) Reconnect the electrical connector.
(5) Reconnect the adjustable pedal cables to the
brake and accelerator pedalsAlso clutch pedal if
equipped with a manual transmission.
(6) Install the new brake light switch (Refer to 8 -
ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
BRAKE LAMP SWITCH - REMOVAL).
(7) Install the kneeblocker (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - INSTALLATION).
(8) Reconnect the negative battery cable.
(9) Check for proper operation of the pedals.
Fig. 3 ADJUSTABLE PEDAL MOTOR
1 - ADJUSTABLE PEDAL MOTOR
2 - CABLES
3 - ELECTRICAL CONNECTOR
Fig. 4 ADJUSTABLE PEDAL MOTOR
1 - ADJUSTABLE PEDAL MOTOR
2 - MOUNTING BOLT
DRBRAKES - BASE 5 - 7
ADJUSTABLE PEDAL MOTOR (Continued)

PEDAL
DESCRIPTION
NOTE: The brake pedal is serviced as a complete
assembly including accelerator pedal and the
bracket.
A suspended-type brake pedal is used. The pedal is
attached to the pedal support bracket with a pivot
shaft pin and bushings. If the bushings become dry a
spray lubricant can be used to eliminate noises. The
booster push rod is attached to the pedal with a clip.
The pedal, bushings, pivot pin and support bracket
are not serviceable components (Fig. 50).
OPERATION
The brake pedal is attached to the booster push
rod. When the pedal is depressed, the primary
booster push rod is depressed which moves the
booster secondary rod. The booster secondary rod
depress the master cylinder piston.
REMOVAL
NOTE: The brake pedal is serviced as a complete
assembly including accelerator pedal and the
bracket.
(1) Disconnect the negative battery cable.
(2) Remove the steering column opening cover(Re-
fer to 23 - BODY/INSTRUMENT PANEL/STEERING
COLUMN OPENING COVER - REMOVAL).(3) Remove the brake lamp switch and discard(Re-
fer to 8 - ELECTRICAL/LAMPS/LIGHTING - EXTE-
RIOR/BRAKE LAMP SWITCH - REMOVAL).
(4)On vehicles equipped with adjustable ped-
als.Disconnect the adjuster cable to the pedal (Fig.
51).
(5) Remove the steering column (Refer to 19 -
STEERING/COLUMN - REMOVAL).
(6) Remove the brake booster (Fig. 52)(Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/POWER
BRAKE BOOSTER - REMOVAL).
(7) Disconnect the electrical connectors.
(8) Remove the module mounting bolts.
(9) Disconnect the accelerator pedal cable.
(10) Remove the pedal assembly mounting nuts/
fasteners (Fig. 52).
INSTALLATION
(1) Install the pedal assembly to the vehicle (Fig.
52).
(2) Install the mounting bolts (Fig. 52) and tighten
to 28 N´m (21 ft. lbs.).
(3) Reconnect the accelerator cable to the pedal.
(4) Install the module mounting bolts and tighten
to 38 N´m (28 ft. lbs.).
(5) Reconnect the electrical connectors.
(6) Install the brake booster (Refer to 5 - BRAKES/
HYDRAULIC/MECHANICAL/POWER BRAKE
BOOSTER - INSTALLATION).
(7) Install the steering column (Refer to 19 -
STEERING/COLUMN - INSTALLATION).
(8) Install a new brake lamp switch. (Refer to 8 -
ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
BRAKE LAMP SWITCH - REMOVAL).
Fig. 50 BRAKE PEDAL
1 - CLIP
2 - BUSHINGS
3 - PIVOT SHAFT PIN
4 - PEDAL ASSEMBLY
ADJUSTABLE PEDAL SHOWN
NON ADJUSTABLE PEDAL IS SIMILIAR
5-PAD
Fig. 51 PEDAL/CABLE
1 - CABLE
2 - BRAKE PEDAL ASSEMBLY
5 - 28 BRAKES - BASEDR

COOLING
TABLE OF CONTENTS
page page
COOLING
DESCRIPTION
DESCRIPTION - COOLING SYSTEM FLOW
3.7L/4.7L/5.7L ENGINE..................1
DESCRIPTION - COOLING SYSTEM FLOW -
5.9L DIESEL..........................3
DESCRIPTION - HOSE CLAMPS...........3
OPERATION
OPERATION - COOLING SYSTEM.........5
OPERATION - HOSE CLAMPS............5
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTINGÐON-BOARD
DIAGNOSTICS (OBD)...................5
DIAGNOSIS AND TESTING - COOLING
SYSTEM - TESTING FOR LEAKS..........5
DIAGNOSIS AND TESTING - COOLING
SYSTEM DIESEL ENGINE................7
DIAGNOSIS AND TESTING - PRELIMINARY
CHECKS............................10
STANDARD PROCEDURE
STANDARD PROCEDURE - COOLANT
LEVEL CHECK........................17STANDARD PROCEDURE - COOLING
SYSTEM CLEANING/REVERSE FLUSHING . . 17
STANDARD PROCEDURE - DRAINING
COOLING SYSTEM - ALL GAS ENGINES . . . 17
STANDARD PROCEDURE - REFILLING
COOLING SYSTEM - ALL GAS ENGINES . . . 18
STANDARD PROCEDURE - DRAINING
COOLING SYSTEM 5.9L DIESEL ENGINE . . . 18
STANDARD PROCEDURE - REFILLING
COOLING SYSTEM 5.9L DIESEL ENGINE . . . 19
STANDARD PROCEDURE - ADDING
ADDITIONAL COOLANT.................19
SPECIFICATIONS
TORQUE............................19
SPECIFICATIONS -....................20
SPECIAL TOOLS
COOLING...........................20
ACCESSORY DRIVE......................21
ENGINE...............................30
TRANSMISSION.........................67
COOLING
DESCRIPTION
DESCRIPTION - COOLING SYSTEM FLOW
3.7L/4.7L/5.7L ENGINE
The cooling system regulates engine operating tem-
perature. It allows the engine to reach normal oper-
ating temperature as quickly as possible. It also
maintains normal operating temperature and pre-
vents overheating.The cooling system provides a means of heating
the passenger compartment and cooling the auto-
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump to circulate coolant through the system. The
coolant recovery/reserve system utilizes an ambient
overflow bottle (Fig. 2).
An optional factory installed maximum duty cool-
ing package is available on most models. This pack-
age will provide additional cooling capacity for
vehicles used under extreme conditions such as
trailer towing in high ambient temperatures (Fig. 1).
DRCOOLING 7 - 1

DESCRIPTION - COOLING SYSTEM FLOW -
5.9L DIESEL
The diesel engine cooling system consists of :
²Cross-flow radiator
²Belt driven water pump
²Cooling fan (attached to the electronic viscous
fan drive)
²Belt driven Electronic viscous fan drive
²Two piece fan shroud
²Radiator pressure cap
²Vertically mounted thermostat
²Coolant reserve/recovery system
²Transmission oil cooler
²Coolant
Coolant flow circuits for the 5.9L diesel engine are
shown in (Fig. 3).
DESCRIPTION - HOSE CLAMPS
The cooling system utilizes spring type hose
clamps. If a spring type clamp replacement is neces-
sary, 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 and ensure the
clamp has the same size width (Fig. 4).
Fig. 2 5.7L Engine Coolant System Flow
1 - LH CYLINDER HEAD
2 - TO RADIATOR3 - FROM RADIATOR
4 - TO RH CYLINDER HEAD
DRCOOLING 7 - 3
COOLING (Continued)

OPERATION
OPERATION - COOLING SYSTEM
The cooling system regulates engine operating tem-
perature. It allows the engine to reach normal oper-
ating temperature as quickly as possible. It also
maintains normal operating temperature and pre-
vents overheating.
The cooling system also provides a means of heat-
ing the passenger compartment and cooling the auto-
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump to circulate coolant throughout the system.
All engines utilize an ambient overflow bottle for
coolant recovery/reserve.
An optional factory installed maximum duty cool-
ing package is available on most models. This pack-
age will provide additional cooling capacity for
vehicles used under extreme conditions such as
trailer towing in high ambient temperatures.
OPERATION - HOSE CLAMPS
The spring type hose clamp applies constant ten-
sion on a hose connection. To remove a spring type
hose clamp, only use constant tension clamp pliers
designed to compress the hose clamp.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTINGÐON-BOARD
DIAGNOSTICS (OBD)
COOLING SYSTEM RELATED DIAGNOSTICS
The Engine Control Module (ECM) has been pro-
grammed to monitor certain cooling system compo-
nents:
²If the engine has remained cool for too long a
period, such as with a stuck open thermostat, a Diag-
nostic Trouble Code (DTC) can be set.
²If an open or shorted condition has developed in
the electronically controlled viscous fan clutch circuit,
a Diagnostic Trouble Code (DTC) can be set.
²If fan speed is not detected a DTC will be set.
²Coolant temperature sensor circuit problems can
set a DTC.
If the problem is sensed in a monitored circuit
often enough to indicated an actual problem, a DTC
is stored. The DTC will be stored in the ECM mem-
ory for eventual display to the service technician.
(Refer to 25 - EMISSIONS CONTROL - DESCRIP-
TION).
ACCESSING DIAGNOSTIC TROUBLE CODES
To read DTC's and to obtain cooling system data,
(Refer to 25 - EMISSIONS CONTROL - DESCRIP-
TION).
ERASING TROUBLE CODES
After the problem has been repaired, use the
DRBIIItscan tool to erase a DTC. Refer to the
appropriate Powertrain Diagnostic Procedures ser-
vice information for operation of the DRBIIItscan
tool.
DIAGNOSIS AND TESTING - COOLING SYSTEM
- TESTING FOR LEAKS
ULTRAVIOLET LIGHT METHOD
A leak detection additive is available through the
parts department that can be added to cooling sys-
tem. The additive is highly visible under ultraviolet
light (black light). Pour one ounce of additive into
cooling system. Place heater control unit in HEAT
position. Start and operate the engine until the radi-
ator upper hose is warm to the touch. Aim the com-
mercially available black light tool at the components
to be checked. If leaks are present, the black light
will cause the additive to glow a bright green color.
The black light can be used in conjunction with a
pressure tester to determine if any external leaks
exist (Fig. 5).
Fig. 4 Spring Clamp Size Location
1 - SPRING CLAMP SIZE LOCATION
DRCOOLING 7 - 5
COOLING (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
TEMPERATURE GAUGE READS
HIGH. COOLANT MAY OR MAY
NOT BE LEAKING FROM SYSTEM1. Vehicle overloaded, high ambient
(outside) temperatures with A/C
turned on, stop and go driving or
prolonged operation at idle speeds.1. Temporary condition, repair not
required. Notify customer of vehicle
operation instructions located in
Owners Manual.
NOTE: Information on dash cluster
is displayed based on broadcast
information from ECM. DTC will be
set for engine sensor circuit
concern.2. Temperature gauge not
functioning correctly.2. Check cluster (Refer to 8 -
ELECTRICAL/INSTRUMENT
CLUSTER - DIAGNOSIS AND
TESTING)
3. Air trapped in cooling system 3. Drain cooling system (Refer to 7 -
COOLING - STANDARD
PROCEDURE) and refill (Refer to 7
- COOLING - STANDARD
PROCEDURE)
4. Radiator cap faulty. 4. Replace radiator cap.
5. Plugged A/C or radiator cooling
fins.5. Clean all debris away from A/C
and radiator cooling fins.
6. Coolant mixture incorrect. 6. Drain cooling system (Refer to 7 -
COOLING - STANDARD
PROCEDURE) refill with correct
mixture (Refer to 7 - COOLING -
STANDARD PROCEDURE).
7. Thermostat stuck shut. 7. Inspect and test thermostat.
Replace thermostat if necessary.
8. Bug screen or winter front being
used.8. Remove bug screen or winter
front.
9. Electronically controlled viscous
fan drive not operating properly.9. Check viscous fan (Refer to 7 -
COOLING/ENGINE/FAN DRIVE
VISCOUS CLUTCH - DIAGNOSIS
AND TESTING)
10. Cylinder head gasket leaking. 10. Check for leaking head gaskets
(Refer to 7 - COOLING -
DIAGNOSIS AND TESTING).
11. Heater core leaking. 11. Replace heater core.
12. Cooling system hoses leaking. 12. Tighten clamps or Replace
hoses.
13. Brakes dragging. 13. Check brakes. (Refer to 5 -
BRAKES/HYDRAULIC/
MECHANICAL - DIAGNOSIS AND
TESTING)
14. Accessory drive belt. 14. Inspect. Replace as necessary.
15. Water Pump. 15. Inspect and replace as
necessary.
16. Engine sensor stuck in range. 16. Monitor sensor with DRBIII to
verify sensor reading changes
increase in temperature.
17. Temperature sensor failed out
of range.17. A DTC will be set.
7 - 8 COOLINGDR
COOLING (Continued)

DIAGNOSIS AND TESTINGÐTHERMOSTAT
ON-BOARD DIAGNOSTICS
Allgasoline powered modelsare equipped with
On-Board Diagnostics for certain cooling system com-
ponents. Refer to On-Board Diagnostics (OBD) in the
Diagnosis section of this group for additional infor-
mation. If the powertrain control module (PCM)
detects low engine coolant temperature, it will record
a Diagnostic Trouble Code (DTC) in the PCM mem-
ory. Do not change a thermostat for lack of heat as
indicated by the instrument panel gauge or by poor
heater performance unless a DTC is present. Refer to
the Diagnosis section of this group for other probable
causes.
The DTC can also be accessed through the
DRBIIItscan tool. Refer to the appropriate Power-
train Diagnostic Procedures information for diagnos-
tic information and operation of the DRBIIItscan
tool.
REMOVAL
WARNING: DO NOT LOOSEN THE RADIATOR
DRAINCOCK WITH THE COOLING SYSTEM HOT
AND PRESSURIZED. SERIOUS BURNS FROM THE
COOLANT CAN OCCUR.Do not waste reusable coolant. If the solution is
clean, drain the coolant into a clean container for
reuse.
If the thermostat is being replaced, be sure that
the replacement is the specified thermostat for the
vehicle model and engine type.
Factory installed thermostat housings on 5.9L
engine is installed on a gasket with an anti-stick
coating. This will aid in gasket removal and clean-up.
(1) Disconnect the negative battery cable.
(2) Drain the cooling system until the coolant level
is below the thermostat (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Air Conditioned vehicles: Remove the support
bracket (generator mounting bracket-to-intake mani-
fold) located near the rear of the generator (Fig. 17).
NOTE: On air conditioning equipped vehicles, the
generator must be partially removed.
(4) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL) (Fig. 18).
(5) Remove the generator mounting bolts. Do not
remove any of the wiring at the generator. If
equipped with 4WD, unplug the 4WD indicator lamp
wiring harness (located near rear of generator).
(6) Remove the generator. Position the generator
to gain access for the thermostat gasket removal.
WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP. ALWAYS WEAR SAFETY GLASSES WHEN
SERVICING CONSTANT TENSION CLAMPS.
Fig. 16 Thermostat - 5.7L/5.9L Gas Powered
Engines
1 - THERMOSTAT HOUSING
2 - GASKET
3 - INTAKE MANIFOLD
4 - THERMOSTAT
5 - MACHINED GROOVE
Fig. 17 Generator Support Bracket ± 5.9L Engine
1 - IDLER PULLEY BUSHING
2 - A/C AND/OR GENERATOR MOUNTING BRACKET
3 - IDLER PULLEY
4 - SCREW AND WASHER
7 - 42 ENGINEDR
ENGINE COOLANT THERMOSTAT- 5.7L (Continued)

CAUTION: A number or letter is stamped into the
tongue of the constant tension clamps (Fig. 19). If
replacement is necessary, use only an original
equipment clamp with a matching number, letter
and width.
(7) Remove the radiator upper hose clamp and
upper hose at the thermostat housing.
(8) Position the wiring harness (behind thermostat
housing) to gain access to the thermostat housing.(9) Remove the thermostat housing mounting
bolts, thermostat housing, gasket and thermostat
(Fig. 20). Discard old gasket.
INSTALLATION
(1) Clean the mating areas of the intake manifold
and thermostat housing.
(2) Install the thermostat (spring side down) into
the recessed machined groove on the intake manifold
(Fig. 20).
(3) Install the gasket on the intake manifold and
over the thermostat (Fig. 20).
(4) Position the thermostat housing to the intake
manifold.Note:The word FRONT stamped on hous-
ing (Fig. 21). For adequate clearance, thismustbe
placed towards the front of the vehicle. The housing
is slightly angled forward after the installation to the
intake manifold.
(5) Install the housing-to-intake manifold bolts.
Tighten the bolts to 23 N´m (200 in. lbs.).
(6) Install the radiator upper hose to the thermo-
stat housing.
CAUTION: When installing the serpentine accessory
drive belt, the belt must be routed correctly. If not,
the engine may overheat due to the water pump
rotating in wrong direction. Refer to (Fig. 22) for the
correct 5.9L engine belt routing. The correct belt
with correct length must be used.
Fig. 18 Automatic Belt Tensioner ± 5.9L Engines
1 - IDLER PULLEY
2 - TENSIONER
3 - FAN BLADE
Fig. 19 SPRING CLAMP SIZE LOCATION
1 - SPRING CLAMP SIZE LOCATION
Fig. 20 Thermostat ± 5.9L Engines
1 - THERMOSTAT HOUSING
2 - GASKET
3 - INTAKE MANIFOLD
4 - THERMOSTAT
5 - MACHINED GROOVE
DRENGINE 7 - 43
ENGINE COOLANT THERMOSTAT- 5.7L (Continued)