2003 DODGE RAM light

brake pressure in proportion to the front brake pres-
sure. If impending rear wheel lock-up is sensed, the
CAB signals the RWAL valve to modulate hydraulic
brake pressure to the rear wheels to prevent lock-up.
NORMAL BRAKING Since the RWAL valve also
performs the EVBP or proportioning function, vehicle
deceleration under normal braking may be sufficient
to trigger the EVBP function of the RWAL system
without full RWAL activity as would normally occur
during an impending rear wheel lock-up. As previ-
ously mentioned, the isolation valve is selectively
closed and opened to increase rear brake pressure in
proportion to the front brake pressure under EVBP
control. Slight brake pedal pulsations may be noticed
as the isolation valve is opened.
REMOVAL
(1) Install a prop rod on the brake pedal to keep
pressure on the brake system.
(2) Disconnect the battery cables from the battery.
(3) Remove the battery.
(4) Disconnect the electrical harness connector
(Fig. 6).
(5) Remove the brake lines from the rwal valve
(Fig. 6).
(6) Remove rwal valve mounting nuts and remove
the rwal valve (Fig. 6).
INSTALLATION
(1) Install rwal valve and Tighten the nuts to 15
N´m (11 ft. lbs.) (Fig. 6).(2) Install the brake lines to the rwal valve and
tighten to 19 N´m (170 in. lbs.) (Fig. 6).
(3) Install the electrical harness connector to the
rwal valve and secure the connector.
(4) Install the battery.
(5) Install the battery cables to the battery.
(6) Remove the prop rod on the brake pedal.
(7) Bleed ABS brake system (Refer to 5 - BRAKES
- STANDARD PROCEDURE).
Fig. 6 RWAL VALVE
1 - RWAL VALVE
2 - MOUNTING NUTS
DRBRAKES - ABS 5 - 45
RWAL VALVE (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
Clutch will not disengage properly. 1. Low hydraulic linkage fluid level. 1. Add hydraulic linkage fluid.
2. Clutch cover loose. 2. Follow proper bolt tightening
procedure.
3. Clutch disc bent or distorted. 3. Replace clutch disc.
4. Clutch cover diaphragm spring
bent or warped.4. Replace clutch cover.
5. Clutch disc installed backwards. 5. Remove and install clutch disc
correctly.
6. Release fork bent or fork pivot
loose or damaged.6. Replace fork or pivot as
necessary.
7. Clutch master or slave cylinder
failure.7. Replace hydraulic linkage
assembly.
Clutch pedal squeak. 1. Pivot pin loose. 1. Tighten pivot pin if possible.
Replace clutch pedal if necessary.
2. Master cylinder bushing not
lubricated.2. Lubricate master cylinder
bushing.
3. Pedal bushings worn out or
cracked.3. Replace and lubricate bushings.
4. Rough surface on front bearing
retainer.4. Replace front bearing retainer.
Clutch master or slave cylinder
plunger dragging andùr binding1. Master or slave cylinder
components worn or corroded.1. Replace clutch hydraulic linkage
assembly.
Release bearing is noisy. 1. Release bearing defective or
damaged.1. Replace release bearing.
Contact surface of release bearing
damaged.1. Clutch cover incorrect or release
fingers bent or distorted.1. Replace clutch cover and release
bearing.
2. Release bearing defective or
damaged.2. Replace the release bearing.
3. Release bearing misaligned. 3. Check and correct runout of
clutch components. Check front
bearing sleeve for damage/
alignment. Repair as necessary.
Partial engagement of clutch disc.
One side of disc is worn and the
other side is glazed and lightly
worn.1. Clutch pressure plate position
incorrect.1. Replace clutch disc and cover.
2. Clutch cover, spring, or release
fingers bent or distorted.2. Replace clutch disc and cover.
3. Clutch disc damaged or
distorted.2. Replace clutch disc.
4. Clutch misalignment. 4. Check alignment and runout of
flywheel, disc, pressure plate, andùr
clutch housing. Correct as
necessary.
DRCLUTCH 6 - 5
CLUTCH (Continued)

(10) Apply light coat of Mopar high temperature
bearing grease to splines of transmission input shaft
and to release bearing slide surface of the transmis-
sion front bearing retainer (Fig. 6).
CAUTION: Do not over lubricate shaft splines. This
can result in grease contamination of the disc.
(11) Wipe pilot bearing surface clean.
(12) Install release lever and bearing in clutch
housing. Verify spring clips that retain fork on pivot
ball and release bearing on fork are installed prop-
erly (Fig. 7).
NOTE: If release lever is installed correctly, the
lever part number will be toward the bottom of the
transmission and right side up. There is also a
stamped ªIº in the lever which goes to the pivot ball
side of the transmission.
(13) Install transmission and transfer case if
equipped.
Fig. 4 CLUTCH DISC AND PRESSURE PLATE
1 - FLYWHEEL
2 - PRESSURE PLATE AND DISC
3 - ALIGNMENT TOOL
Fig. 5 LUBRICATION POINTS
1 - CLUTCH HOUSING
2 - FORK PIVOT BALL
3 - RELEASE FORK
4 - RELEASE BEARING BORE
5 - LUBE POINTS
Fig. 6 INPUT SHAFT LUBRICATION POINTS
1 - INPUT SHAFT
2 - BEARING RETAINER
3 - SPLINE AND RELEASE BEARING SURFACE
DRCLUTCH 6 - 7
CLUTCH DISC (Continued)

(3) Install clutch disc, pressure plate and trans-
mission.
LINKAGE
REMOVAL
CAUTION: The hydraulic linkage has a quick dis-
connect at the slave cylinder. This fitting should
never be disconnected or tampered with. Once the
hydraulic line is connected to the slave cylinder, it
should never be disconnected.
(1) Raise and support vehicle.
(2) Remove nuts attaching slave cylinder to studs
on clutch housing (Fig. 20).
(3) Remove slave cylinder from clutch housing.
(4) Remove plastic clip securing the hydraulic line
to the dash panel from the lower dash panel flange.
(5) Remove plastic clip securing hydraulic line to
the dash panel from the upper dash panel stud.
(6) Lower vehicle.
(7) Disconnect clutch pedal interlock switch wires
(Fig. 21).
(8) Remove clutch master cylinder rod pin.
(9) Verify that cap on clutch master cylinder reser-
voir is tight. This will avoid spillage during removal.
(10) Remove clutch master cylinder nuts holding
the to the dash panel.(11) Remove clutch cylinders, reservoir and con-
necting lines from vehicle.
INSTALLATION
(1) Position cylinders and connecting line in vehi-
cle engine compartment. Position clutch hydraulic
line against the dash panel and behind all engine
hoses and wiring.
(2) Apply a light coating of grease to the inside
diameter of the master cylinder push rod eye.
(3) Install clutch master cylinder on dash panel
and tighten clutch master cylinder nuts to 28 N´m
(21 ft. lbs.).
(4) Install clutch master cylinder push rod pin.
(5) Connect clutch pedal position interlock switch
wires.
Fig. 19 PILOT BEARING
1 - PILOT BEARING
2 - ALIGNMENT TOOL
3 - LETTER SIDE MUST FACE TRANSMISSION
Fig. 20 SLAVE CYLINDER
1 - MOUNTING NUTS
2 - SLAVE CYLINDER
Fig. 21 CLUTCH MASTER CYLINDER
1 - MASTER CYLINDER
2 - INTERLOCK CONNECTOR
3 - ROD PIN
DRCLUTCH 6 - 13
PILOT BEARING (Continued)

system is pressurized and uses a centrifugal water
pump to circulate coolant throughout the system.
5.9L, 5.9L Diesel, and 8.0L engines utilize an
ambient overflow bottle for coolant recovery/reserve.
The 3.7L and 4.7L engines utilize a pressurized
degas bottle for coolant deaeration and reserve. This
degas bottle has coolant flowing through it continu-
ously, supplied by a vent in the hot side radiator
tank and returning to the heater return hose.
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.
OPERATIONÐHOSE 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 TESTINGÐCOOLING 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).
PRESSURE TESTER METHOD
The engine should be at normal operating temper-
ature. Recheck the system cold if the cause of coolant
loss is not located during the warm engine examina-
tion.
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING.
Carefully remove the radiator pressure cap from
the filler neck and check the coolant level. Push
down on the cap to disengage it from the stop tabs.
Wipe the inside of the filler neck and examine the
Fig. 4 Spring Clamp Size Location
1 - SPRING CLAMP SIZE LOCATION
DRCOOLING 7 - 5
COOLING (Continued)

lower inside sealing seat for nicks, cracks, paint, dirt
and solder residue. Inspect the radiator-to- reserve/
overflow tank hose for internal obstructions. Insert a
wire through the hose to be sure it is not obstructed.
Inspect the cams on the outside of the filler neck.
If the cams are damaged, seating of the pressure cap
valve and tester seal will be affected.
Attach pressure tester (7700 or an equivalent) to
radiator filler neck.
Operate the tester pump to apply 103.4 kPa (15
psi) pressure to the system. If the hoses enlarge
excessively or bulges while testing, replace as neces-
sary. Observe the gauge pointer and determine the
condition of the cooling system according to following
criteria:
Holds Steady:If the pointer remains steady for
two minutes, serious coolant leaks are not present in
system. However, there could be an internal leak
that does not appear with normal system test pres-
sure. If it is certain that coolant is being lost and
leaks cannot be detected, inspect for interior leakage
or perform Internal Leakage Test. Refer to INTER-
NAL LEAKAGE INSPECTION.
Drops Slowly:Indicates a small leak or seepage
is occurring. Examine all of the connections for seep-
age or slight leakage with a flashlight. Inspect the
radiator, hoses, gasket edges and heater. Seal the
small leak holes with a Sealer Lubricant (or equiva-
lent). Repair the leak holes and inspect the system
again with pressure applied.Drops Quickly:Indicates that serious leakage is
occurring. Examine the system for external leakage.
If leaks are not visible, inspect for internal leakage.
Large radiator leak holes should be repaired by a
reputable radiator repair shop.
INTERNAL LEAKAGE INSPECTION
Remove the engine oil pan drain plug and drain a
small amount of engine oil. If coolant is present in
the pan, it will drain first because it is heavier than
oil. An alternative method is to operate engine for a
short period to churn the oil. After this is done,
remove the engine dipstick and inspect for water
globules. Also inspect the transmission dipstick for
water globules and transmission fluid cooler for leak-
age.
WARNING: WITH RADIATOR PRESSURE TESTER
TOOL INSTALLED ON RADIATOR, DO NOT ALLOW
PRESSURE TO EXCEED 145 kPa (21 PSI). PRES-
SURE WILL BUILD UP QUICKLY IF A COMBUSTION
LEAK IS PRESENT. TO RELEASE PRESSURE,
ROCK TESTER FROM SIDE TO SIDE. WHEN
REMOVING TESTER, DO NOT TURN TESTER MORE
THAN 1/2 TURN IF SYSTEM IS UNDER PRESSURE.
Operate the engine without the pressure cap on
the radiator until the thermostat opens. Attach a
Pressure Tester to the filler neck. If pressure builds
up quickly it indicates a combustion leak exists. This
is usually the result of a cylinder head gasket leak or
crack in engine. Repair as necessary.
If there is not an immediate pressure increase,
pump the Pressure Tester. Do this until indicated
pressure is within system range of 110 kPa (16 psi).
Fluctuation of the gauge pointer indicates compres-
sion or combustion leakage into cooling system.
Because the vehicle is equipped with a catalytic
converter,do notshort out cylinders to isolate com-
pression leak.
If the needle on dial of the pressure tester does not
fluctuate, race engine a few times to check for an
abnormal amount of coolant or steam. This would be
emitting from exhaust pipe. Coolant or steam from
exhaust pipe may indicate a faulty cylinder head gas-
ket, cracked engine cylinder block or cylinder head.
A convenient check for exhaust gas leakage into
cooling system is provided by a commercially avail-
able Block Leak Check tool. Follow manufacturers
instructions when using this product.
COMBUSTION LEAKAGE TESTÐWITHOUT
PRESSURE TESTER
DO NOT WASTE reusable coolant. If the solution
is clean, drain the coolant into a clean container for
reuse.
Fig. 5 Leak Detection Using Black LightÐTypical
1 - TYPICAL BLACK LIGHT TOOL
7 - 6 COOLINGDR
COOLING (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 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 onCheck 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 thermal 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)

CONDITION POSSIBLE CAUSES CORRECTION
Temperature gauge reading is
inconsistent (flucttuates, cycles
or is erratic)1. During cold weather
operation, with the heater blower
in the high position, the gauge
reading may drop slightly.1. A normal condition. No correction
necessary.
2. Temperature gauge or engine
mounted gauge sensor defective
or shorted. Also, corroded or
loose wiring in this circuit.2. Check operation of gauge and repair if
necessary. (Refer to 8 - ELECTRICAL/
INSTRUMENT CLUSTER - DIAGNOSIS
AND TESTING).
3. Gauge reading rises when
vehicle is brought to a stop after
heavy use (engine still running)3. A normal condition. No correction is
necessary. Gauge should return to normal
range after vehicle is driven.
4. Gauge reading high after
re-starting a warmed up (hot)
engine.4. A normal condition. No correction is
necessary. The gauge should return to
normal range after a few minutes of
engine operation.
5. Coolant level low in radiator
(air will build up in the cooling
system causing the thermostat
to open late).5. Check and correct coolant leaks. (Refer
to 7 - COOLING - DIAGNOSIS AND
TESTING).
6. Cylinder head gasket leaking
allowing exhaust gas to enter
cooling system causing a
thermostat to open late.6. (a) Check for cylinder head gasket
leaks. (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING).
(b) Check for coolant in the engine oil.
Inspect for white steam emitting from the
exhaust system. Repair as necessary.
7. Water pump impeller loose on
shaft.7. Check water pump and replace as
necessary. (Refer to 7 - COOLING/
ENGINE/WATER PUMP - REMOVAL).
8. Loose accessory drive belt.
(water pump slipping)8. (Refer to 7 - COOLING/ACCESSORY
DRIVE/DRIVE BELTS - DIAGNOSIS AND
TESTING). Check and correct as
necessary.
9. Air leak on the suction side of
the water pump allows air to
build up in cooling system
causing thermostat to open late.9. Locate leak and repair as necessary.
PRESSURE CAP IS BLOWING
OFF STEAM AND/OR
COOLANT TO COOLANT TANK.
TEMPERATURE GAUGE
READING MAY BE ABOVE
NORMAL BUT NOT HIGH.
COOLANT LEVEL MAY BE
HIGH IN COOLANT RESERVE/
OVERFLOW TANK1. Pressure relief valve in
radiator cap is defective.1. Check condition of radiator cap and cap
seals. (Refer to 7 - COOLING/ENGINE/
RADIATOR PRESSURE CAP -
DIAGNOSIS AND TESTING). Replace cap
as necessary.
COOLANT LOSS TO THE
GROUND WITHOUT
PRESSURE CAP BLOWOFF.
GAUGE READING HIGH OR
HOT1. 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 COOLINGDR
COOLING (Continued)