2008 DODGE RAM 2500 DIESEL cooling

The automatic transmission fluid and filter should be
changed if you REGULARLY tow a trailer for more than
45 minutes of continuous operation. See Maintenance
Schedule in section 8 of this manual for transmission
fluid change intervals.
NOTE:Check the automatic transmission fluid level
before towing.
Towing Tips Ð Tow/Haul (If Equipped)
To reduce potential for automatic transmission overheat-
ing, turn the ªTOW HAULº feature ON when driving in
hilly areas or downshift the transmission (using the
Auto-6 [ERS] switch).
Towing Tips Ð Electronic Speed Control (If
Equipped)
þ
Don't use in hilly terrain or with heavy loads.
þWhen using the speed control, if you experience speed
drops greater than 10 mph (16 km/h), disengage until
you can get back to cruising speed.
þUse speed control in flat terrain and with light loads to
maximize fuel efficiency.
Towing Tips Ð Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
þCity Driving
When stopped for short periods of time, put transmission
in neutral and increase engine idle speed.
þHighway Driving
Reduce speed.
þAir Conditioning
Turn off temporarily.
STARTING AND OPERATING 369
5

þrefer to Cooling System Operating information in the
Maintenance section of this manual for more informa-
tion.
Trailer Towing Mirrors Ð If Equipped
These mirrors are designed with an adjustable mirror
head to provide a greater vision range when towing
extra-wide loads. To change position inboard or out-
board, the mirror head should be rotated (flipped Out or
In). A small blindspot mirror is integrated onto the main
mirror surface.
NOTE: Fold the7x10inch trailer towing mirrors
rearward prior to entering an automated car wash.
Blindspot Mirror
370 STARTING AND OPERATING

NFront Suspension Ball Joints..............431
NSteering Linkage Ð Inspection............432
NFront Prop Shaft Lubrication.............432
NFront Axle Universal Drive Joints And Ball
Joints..............................432
NBody Lubrication.....................433
NWindshield Wiper Blades................433
NWindshield Washers...................434
NExhaust System......................435
NCooling System.......................436
NFan ...............................442
NCharge Air Cooler (Inter-Cooler)..........442
NHoses And Vacuum/Vapor Harnesses.......443NBrake System........................443
NClutch Linkage.......................445
NClutch Hydraulic System................445
NRear Axle And 4X4 Front Driving Axle Fluid
Level..............................446
NTransfer Case Ð If Equipped.............446
NManual Transmission Ð If Equipped.......447
NAutomatic Transmission................447
NFront Wheel Bearings..................450
NNoise Control System Required Maintenance
& Warranty.........................451
NAppearance Care And Protection From
Corrosion...........................455
mFuses (Integrated Power Module)...........459
406 MAINTAINING YOUR VEHICLE

WARNING!
To maintain your vehicle safely and avoid personal injury, follow these
guidelines:
²Never spray or pour diesel fuel, flammable liquid or starting fluids
(ether) into the air cleaner assembly, air intake piping or turbocharger
inlet in an attempt to start the vehicle, unintended engine acceleration
may occur.
²Do not use alcohol or gasoline as a fuel blending agent. They can be
unstable under certain conditions and be hazardous or explosive
when mixed with diesel fuel.
²If an engine has been operating and the coolant is hot, allow the
engine to cool before you slowly loosen the filler cap and relieve the
pressure from the cooling system.
²To avoid burns, remember that the engine components will stay hot
after the engine is shut off.
²Do not use gasoline or other flammable materials to clean parts.
Always use approved cleaning solvents.
²Relieve all pressure in the fuel, oil and cooling systems before any
lines, fittings or related items are removed or disconnected. Be alert
for possible pressure when disconnecting any device from a system
that utilizes pressure. Do not check for pressure leaks with your hand.
High pressure oil or fuel can cause personal injury.
²Important: All maintenance other than that listed in this manual, as
well as some procedures listed here, MUST be performed by your
authorized dealer. Your authorized dealer has been trained and has
the necessary parts to maintain your engine.
WARNING!
Do not open the high pressure fuel system with the
engine running. Engine operation causes high fuel
pressure. High pressure fuel spray can cause serious
injury or death.
MAINTENANCE PROCEDURES
The pages that follow contain therequiredmaintenance
services determined by the engineers who designed your
vehicle.
Besides the maintenance items for which there are fixed
maintenance intervals, there are other items that should
operate satisfactorily without periodic maintenance.
However, if a malfunction of these items does occur, it
could adversely affect the engine or vehicle performance.
These items should be inspected if a malfunction is
observed or suspected.
412 MAINTAINING YOUR VEHICLE

Engine Oil Filter
Refer to Fluids, Lubricants and Genuine Parts for the
correct part number. The engine oil filter should be
changed ateveryengine oil change.
Engine Oil And Filter Ð Change
Operate the engine until the coolant temperature reaches
140ÉF (60ÉC). Shut the engine OFF. Remove the oil drain
plug.
Use a container that can hold at least 12 quarts (11.3
Liters) to hold the used oil.
Always check the condition of the used oil. This can give
you an indication of some engine problems that might
exist.
²Thin, black oil indicates fuel dilution.
²Milky discoloration indicates coolant dilution.Clean the area around the oil filter base. Remove the filter
from the underside of the vehicle using a cap style oil
filter wrench.
Clean the gasket surface of the filter mount. The filter
gasket can stick on the filter mount. Make sure it is
removed.
Change the engine oil filter with every engine oil change.
Only a high quality Mopartfilter should be used to
assure most efficient service.
CAUTION!
The filtering medium of other aftermarket filters
may disintegrate. Debris from failed filters may plug
the piston oil cooling nozzles, resulting in scuffed
pistons and engine failure.
416 MAINTAINING YOUR VEHICLE

Cooling System
WARNING!
You or others can be badly burned by hot coolant or
steam from your radiator. If you see or hear steam
coming from under the hood, don't open the hood
until the radiator has had time to cool. Never try to
open a cooling system pressure cap when the radiator
is hot.
Engine Coolant Checks
Check the engine coolant (antifreeze) protection every 12
months (before the onset of freezing weather, where
applicable). If coolant is dirty or rusty in appearance, the
system should be drained, flushed and refilled with fresh
coolant. Check the front of the A/C condenser for anyaccumulation of bugs, leaves, etc. If dirty, clean by gently
spraying water from a garden hose vertically down the
face of the condenser.
Check the coolant recovery bottle tubing for brittle rub-
ber, cracking, tears, cuts and tightness of the connection
at the bottle and radiator. Inspect the entire system for
leaks.
Extremely cold ambient temperatures may require the
addition of a ªwinter frontº for effective operation of the
cab heating/cooling system. Make certain that a percent-
age of the radiator is exposed for adequate air flow
through the charge air cooler and automatic transmission
oil cooler. The percentage of opening must be increased
with the increasing ambient air temperature and/or
engine load. If the cooling fan can be heard cycling
frequently, increase the size of the opening in the winter
front.
436 MAINTAINING YOUR VEHICLE

Coolant bottle level check
The coolant reserve system provides a quick visual
method of determining that the coolant level is adequate.
With the engine idling and warmed to the normal
operating temperature, the level of the coolant on the
coolant bottle should be between the fluid level marks.
Check the coolant level whenever the hood is raised.
The radiator normally remains completely full, so there is
no longer a need to remove the coolant pressure cap
except for checking coolant freeze point or replacement
with new antifreeze coolant.WARNING!
Never add coolant to the radiator when the engine is
overheated. Do not loosen or remove pressure cap to
cool overheated engine! The coolant is under pres-
sure and severe scalding could result.
Cooling System Ð Drain, Flush and Refill
At the intervals shown on the Maintenance Schedules,
the system should be drained, flushed and refilled. See
you authorized dealer for service.
MAINTAINING YOUR VEHICLE 437
7

CAUTION!
The manufacturer highly recommends that all cool-
ing system service, maintenance, and repairs be per-
formed by your local authorized dealer.
If the solution is dirty or contains a considerable amount
of sediment, clean and flush with a reliable cooling
system cleaner. Follow with a thorough rinsing to remove
all deposits and chemicals. Properly dispose of old
antifreeze solution.
Selection Of Coolant
Use only the manufacturer's recommended coolant; for
correct coolant type, refer to ªEngine Coolantº under
ªFluids, Lubricants and Genuine Partsº in this section.
CAUTION!
²Mixing of coolants other than specified HOAT
engine coolants may result in engine damage and
may decrease corrosion protection. If a non-HOAT
coolant is introduced into the cooling system in an
emergency, it should be replaced with the speci-
fied coolant as soon as possible.
²Do not use plain water alone or alcohol-base
engine coolant (antifreeze) products. Do not use
additional rust inhibitors or antirust products, as
they may not be compatible with the radiator
engine coolant and may plug the radiator.
²This vehicle has not been designed for use with
Propylene Glycol based coolants. Use of Propy-
lene Glycol based coolants is not recommended.
438 MAINTAINING YOUR VEHICLE