2008 DODGE RAM 3500 DIESEL air condition

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

of the plow. Front end tow-in should be checked and
reset if necessary at the beginning and end of the
snowplow season. This will help prevent uneven tire
wear.
The blade should be lowered whenever the vehicle is
parked.
Maintain and operate your vehicle and snowplow equip-
ment following the recommendations provided by the
specific snowplow manufacturer.
Over the Road Operation With Snowplow
Attached
The blade restricts air flow to the radiator and causes the
engine to operate at higher than normal temperatures.
Therefore, when transporting the plow, angle the blade
completely and position it as low as road or surface
conditions permit. Do not exceed 40 mph (64 km/h). The
operator should always maintain a safe stopping distance
and allow adequate passing clearance.
Methods For Removing Snow
Operating Tips
Under ideal snow plowing conditions, 20 mph (32 km/h)
should be maximum operating speed. The operator
should be familiar with the area and surface to be
cleaned. Reduce speed and use extreme caution when
plowing unfamiliar areas or under poor visibility.
STARTING AND OPERATING 373
5

MAINTAINING YOUR VEHICLE
CONTENTS
mEngine Compartment Ð 6.7L Diesel Engine....408
mOnboard Diagnostic System (OBD II).........409
mReplacement Parts......................409
mEngine Data Plate......................410
mAuthorized Dealer Service................410
mService Information.....................410
mMaintenance Procedures..................412
NEngine Oil..........................413
NDrive Belt...........................418NEngine Air Cleaner Filter (6.7L Diesel
Engines)............................419
NDraining Fuel/Water Separator Filter (6.7L
Diesel Engine).......................422
NIntervention Regeneration Strategy ± EVIC
Message Process Flow (Catalyst Full Message)
(6.7L Diesel Engines Only)...............425
NMaintenance Free Batteries...............428
NAir Conditioner Maintenance.............430
NPower Steering Ð Fluid Check............431
7

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 Air Cleaner Filter (6.7L Diesel Engines)
CAUTION!
All air entering the engine intake must be filtered.
The abrasive particles in unfiltered air will cause
rapid wear to engine components.
The condition of the air cleaner filter is monitored by the
Engine Control Module. The Electronic Vehicle Informa-
tion Center (EVIC) will display SERVICE AIR FILTER
when service is required.
Do not remove the top of the air filter housing to
inspect the filter element on your diesel engine under
normal operating conditions.
The EVIC message SERVICE AIR FILTER could be dis-
played periodically. This is because engine air flow
requirements change based on driving conditions. As thefilter becomes more restrictive and air flow requirements
increase the EVIC message SERVICE AIR FILTER will be
displayed. The message may not be displayed in subse-
quent drive cycles if the same conditions are not met. The
air filter element should be replaced within 250 miles
from the first time this message is displayed to ensure
proper engine operation during all driving conditions.
The air filter housing on your vehicle may also come
equipped with a Filter MinderŸ. This is an air flow
restriction gauge that will indicate when the filter ele-
ment needs to be replaced.
CAUTION!
Driving with a restricted air filter can cause engine
damage.
MAINTAINING YOUR VEHICLE 419
7

Battery Blanket Usage
A battery loses 60% of its cranking power as the battery
temperature decreases to 0ÉF (-18ÉC). For the same de-
crease in temperature, the engine requires twice as much
power to crank at the same RPM. The use of 120 VAC
powered battery blankets will greatly increase starting
capability at low temperatures. Suitable battery blankets
are available from your authorized Mopartdealer.
Air Conditioner Maintenance
For best possible performance, your air conditioner
should be checked and serviced by an authorized dealer
at the start of each warm season. This service should
include cleaning of the condenser fins and a performance
test. Drive belt tension should also be checked at this
time.
WARNING!
²Use only refrigerants and compressor lubricants
approved by the manufacturer for your air condi-
tioning system. Some unapproved refrigerants are
flammable and can explode, injuring you. Other
unapproved refrigerants or lubricants can cause
the system to fail, requiring costly repairs. Refer to
Section 3 of the Warranty Information book for
further warranty information.
²The air conditioning system contains refrigerant
under high pressure. To avoid risk of personal
injury or damage to the system, adding refrigerant
or any repair requiring lines to be disconnected
should be done by an experienced repairman.
430 MAINTAINING YOUR VEHICLE

NOTE:Use only manufacturer approved A/C System
Sealers, Stop Leak Products, Seal Conditioners, Compres-
sor Oil, or Refrigerants.
Refrigerant Recovery and Recycling
R-134a Air Conditioning Refrigerant is a hydrofluorocar-
bon (HFC) that is endorsed by the Environmental Pro-
tection Agency and is an ozone-saving product. How-
ever, the manufacturer recommends that air conditioning
service be performed by dealers or other service facilities
using recovery and recycling equipment.
Power Steering Ð Fluid Check
Checking the power steering fluid level at a defined
service interval is not required. The fluid should only be
checked if a leak is suspected, abnormal noises are
apparent, and/or the system is not functioning as antici-
pated. Coordinate inspection efforts through a certified
DaimlerChrysler Dealership.
WARNING!
Fluid level should be checked on a level surface and
with the engine off to prevent injury from moving
parts and to ensure accurate fluid level reading. Do
not overfill. Use only manufacturer recommended
power steering fluid.
If necessary, add fluid to restore to the proper indicated
level. With a clean cloth, wipe any spilled fluid from all
surfaces. Refer to Fluids, Lubricants, and Genuine Parts
for correct fluid type.
Front Suspension Ball Joints
The ball joints originally supplied with the vehicle are
permanently lubricated at the factory and do not require
service. The ball joints and seals should be inspected
whenever the vehicle is serviced for other reasons.
MAINTAINING YOUR VEHICLE 431
7

²Make sure that the radiator and coolant recovery
bottle overflow hoses are not kinked or obstructed.
²Keep the front of the radiator clean. If your vehicle is
equipped with air conditioning, keep the front of the
condenser clean also.
²Do not change the thermostat for summer or winter
operation. If replacement is ever necessary, install
ONLY the correct type thermostat. Other designs may
result in unsatisfactory coolant performance, poor gas
mileage, and increased emissions.
Fan
Inspection
Check the fan for cracks and bent or broken blades. If any
of these conditions exist, you must replace the fan. Make
sure it is securely mounted.NOTE:This service procedure must be performed by a
trained service technician. Make arrangements with your
authorized dealer for this inspection.
Charge Air Cooler (Inter-Cooler)
The charge air cooler is positioned between the radiator
and the air conditioner condenser. Air enters the engine
through the air cleaner and passes through the turbo-
charger where it is pressurized. This pressurized air
rapidly reaches high temperature. The air is then directed
through a hose to the charge air cooler and through
another hose to the intake manifold of the engine. The air
entering the engine has been cooled by about 50 to 100
degrees Fahrenheit. This cooling process enables more
efficient burning of fuel resulting in fewer emissions.
442 MAINTAINING YOUR VEHICLE