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CAUTION!
•Under no circumstances should oil change inter-
vals exceed 15,000 miles (24 000 km) pickup or
12,500 miles (20 000 km) chassis cab if operation
occurs with greater than 5% biodiesel blends. Oil
change intervals should not exceed 6 months in
either case. Failure to comply with these Oil
Change requirements for vehicles operating on
biodiesel blends up to B20 may result in premature
engine wear. Such wear is not covered by the New
Vehicle Limited Warranty.
• B20 Biodiesel capable: The engine may suffer se-
vere damage if operated with concentrations of
Biodiesel higher than 20%.
ADDING FUEL — 2500/3500 DIESEL MODELS
1. Open the fuel filler door.
1 — Diesel Exhaust Fluid Fill Location
2 — Diesel Fuel Fill Location
Diesel Fuel And Diesel Exhaust Fluid Fill Location
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NOTE:There is no fuel filler cap. A flapper door inside
the filler pipe seals the system.
2. Insert the fuel nozzle fully into the filler pipe – the nozzle opens and holds the flapper door while refuel-
ing.
3. Fill the vehicle with fuel – when the fuel nozzle “clicks” or shuts off the fuel tank is full.
4. Remove the fuel nozzle and close the fuel door.
Emergency Fuel Can Refueling
Most fuel cans will not open the flapper door.
A funnel is provided to open the flapper door to allow
emergency refueling with a fuel can. 1. Retrieve fuel funnel from the jack kit located under the
front passenger seat.
Diesel Fuel And DEF Fluid Filler Door
5
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CAUTION!
To avoid fuel spillage and overfilling, do not “top
off” the fuel tank after filling.
WARNING!
•Never have any smoking materials lit in or near the
vehicle when the fuel door is open or the tank is
being filled.
• Never add fuel when the engine is running. This is
in violation of most state and federal fire regula-
tions and may cause the “Malfunction Indicator
Light” to turn on.
• A fire may result if fuel is pumped into a portable
container that is inside of a vehicle. You could be
burned. Always place fuel containers on the
ground while filling.
ADDING FUEL — CHASSIS CAB MODELS
CAUTION!
To avoid fuel spillage and overfilling, do not “top
off” the fuel tank after filling.
NOTE:
• When the fuel nozzle “clicks” or shuts off, the fuel tank
is full.
• Tighten the fuel filler cap until you hear a “clicking”
sound. This is an indication that the fuel filler cap is
properly tightened.
• Make sure that the fuel filler cap is tightened each time
the vehicle is refueled.
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WARNING!
A fire may result if fuel is pumped into a portable
container that is on a truck bed. You could be burned.
Always place fuel containers on the ground while
filling.
Fuel Filler Cap
If the fuel filler cap is lost or damaged, be sure the
replacement cap is for use with this vehicle.
CAUTION!
Damage to the fuel system or emission control sys-
tem could result from using an improper fuel tank
filler tube cap. A poorly fitting cap could let impuri-
ties into the fuel system.
WARNING!
•Never have any smoking materials lit in or near the
vehicle when the fuel filler cap is removed or the
tank filled.
• Never add fuel to the vehicle when the engine is
running.
Avoid Using Contaminated Fuel
Fuel that is contaminated by water or dirt can cause
severe damage to the engine fuel system. Proper main-
tenance of the engine fuel filter and fuel tank is essential.
Refer to “Maintenance Procedures” in “Maintaining Your
Vehicle” for further information.
Bulk Fuel Storage — Diesel Fuel
If you store quantities of fuel, good maintenance of the
stored fuel is also essential. Fuel contaminated with
water will promote the growth of “microbes.” These
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Adding Diesel Exhaust Fluid
The DEF gauge (located on the instrument cluster) will
display the level of DEF remaining in the tank. Refer to
“Instrument Cluster” and “Instrument Cluster Descrip-
tions” in “Understanding Your Instrument Panel” for
further information.
NOTE:Driving conditions (altitude, vehicle speed, load,
etc.) will effect the amount of DEF that is used in your
vehicle.
Another factor is that outside temperature can affect DEF
consumption. In cold conditions, 12° F (-11° C) and
below, the DEF gauge needle can stay on a fixed position
and may not move for extended periods of time. This is
a normal function of the system.
DEF Fill Procedure
NOTE: Refer to “Fluids, Lubricants, and Genuine Parts”
in “Maintaining Your Vehicle” for the correct fluid type. 1. Remove cap from DEF tank (located on drivers side of
the vehicle or in fuel door).
DEF Filler Cap Chassis Cab Models
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1 — Diesel Exhaust Fluid Fill Location
2 — Diesel Fuel Fill Location
2. Insert DEF fill adapter/nozzle into DEF tank fillerneck.
CAUTION!
•To avoid DEF spillage, and possible damage to the
DEF tank from overfilling, do not “top off” the DEF
tank after filling.
(Continued)
DEF Filler Cap And Fuel Fill 1500/2500/3500 ModelsFilling The DEF Tank
5
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CAUTION!
Do not engage the starter motor for more than 15 sec-
onds at a time. Allow two minutes between the
cranking intervals.
NOTE: The engine may run rough until the air is forced
from all the fuel lines.
WARNING!
Do 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.
CAUTION!
Due to lack of lubricants in alcohol or gasoline, the
use of these fuels can cause damage to the fuel
system.
NOTE:
• A maximum blend of 5% biodiesel, meeting ASTM
specification D-975 may be used with your Cummins
diesel engine. (Chassis Cab models not configured
with B20 capability.)
• A maximum blend of 20% biodiesel, meeting ASTM
specification D-7467 may be used with your Cummins
diesel engine. (Pickup models and Chassis Cab models
configured with B20 capability.)
7
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•Do 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 engine coolant (antifreeze)
performance, poor gas mileage, and increased emis-
sions.
Charge Air Cooler — Inter-Cooler
The charge air cooler is positioned below 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°F
(10° to 38°C). This cooling process enables more efficient
burning of fuel resulting in fewer emissions. To guarantee optimum performance of the system, keep
the surfaces of the charge air cooler, condenser and
radiator clean and free of debris. Periodically check the
hoses leading to and from the charge air cooler for cracks
or loose clamps resulting in loss of pressure and reduced
engine performance.
Brake System
Brake Master Cylinder — Brake Fluid Level Check
The fluid level of the master cylinder should be checked
when performing under the hood service, or immedi-
ately if the “Brake System Warning Light” indicates
system failure.
The brake master cylinder has a translucent plastic
reservoir. On the outboard side of the reservoir, there is a
“MAX” mark and a “MIN” mark. The fluid level must be
kept within these two marks. Do not add fluid above the
full mark because leakage may occur at the cap.
296 MAINTAINING YOUR VEHICLE