
WARNING!
Do not use the “TOW/HAUL” feature when driving
in icy or slippery conditions. The increased engine
braking could cause the rear wheels to slide, and the
vehicle to swing around with the possible loss of
vehicle control, which could cause an accident possi-
bly resulting in personal injury or death.
Torque Converter Clutch
A feature designed to improve fuel economy has been
included in the automatic transmission on your vehicle.
A clutch within the torque converter engages automati-
cally at calibrated speeds. This may result in a slightly
different feeling or response during normal operation in
the upper gears. When the vehicle speed drops or during
some accelerations, the clutch automatically disengages.NOTE:
•
The torque converter clutch will not engage (and 68RFE-
equipped trucks will not shift to sixth gear), until the
transmission fluid and engine coolant are warm [usually
after 1 to 3 miles (2 to 5 km) of driving]. Because the
engine speed is higher when the torque converter clutch
is not engaged, it may seem as if the transmission is not
shifting properly when cold. This is normal. Using the
Electronic Range Select (ERS) shift control, when the
transmission is sufficiently warm, will demonstrate that
the transmission is able to shift into and out of Overdrive.
•If the vehicle has not been driven for several days, the
first few seconds of operation after shifting the transmis-
sion into gear may seem sluggish. This is due to the fluid
partially draining from the torque converter into the
transmission. This condition is normal and will not
cause damage to the transmission. The torque converter
will refill within five seconds after starting the engine.
4
STARTING AND OPERATING 243

Truck models with manual transmission are equipped
with a clutch interlocking ignition system. The clutch
pedal must be fully pressed to start the vehicle.
Fully press the clutch pedal before shifting gears. As you
release the clutch pedal, lightly press the accelerator
pedal.
This transmission has a “creeper” first gear which should
be used to start from a standing position when carrying a
payload or towing a trailer. Damage to the clutch can result
from starting in second or third gear with a loaded vehicle.
An unloaded vehicle may be launched in second gear. Use
each gear in numerical order – do not skip a gear.
NOTE:When loaded, pulling a trailer or on a grade, the
truck should always start in first gear and not skip gears.
Recommended Vehicle Shift Speeds
To utilize your manual transmission efficiently for both
fuel economy and performance, it should be upshifted as
listed in recommended shift speed chart. Shift at the
vehicle speeds listed for acceleration. When heavily
loaded or pulling a trailer these recommended up-shift
speeds may not apply.
Maximum Recommended Up-Shift Speeds
Gear Selection 1 to 2 2 to 33 to 44 to 5 5 to 6
Maximum Speed 7 mph
(11 km/h) 15 mph
(24 km/h) 25 mph
(40 km/h) 40 mph
(64 km/h) 45 mph
(72 km/h)
4
STARTING AND OPERATING 245

WARNING!
Do not use alcohol or gasoline as a fuel blending
agent. They can be unstable under certain conditions
and hazardous or explosive when mixed with diesel
fuel.
Diesel fuel is seldom completely free of water. To prevent
fuel system trouble, drain the accumulated water from
the fuel/water separator using the fuel/water separator
drain provided on both fuel filters. If you buy good
quality fuel and follow the cold weather advice above,
fuel conditioners should not be required in your vehicle.
If available in your area, a high cetane “premium” diesel
fuel may offer improved cold-starting and warm-up
performance.
CAUTION!
If the “Water in Fuel Indicator Light” remains on, DO
NOT START engine before you drain the water from
the fuel filter(s) to avoid engine damage. Refer to
“Maintenance Procedures/Draining Fuel/Water Sepa-
rator Filter” in “Maintaining Your Vehicle” for fur-
ther information.
Fuel Specifications
The Cummins® diesel engine has been developed to take
advantage of the high energy content and generally
lower cost No. 2 Ultra Low Sulfur diesel fuel or No. 2
Ultra Low Sulfur climatized diesel fuels. Experience has
shown that it also operates on No. 1 Ultra Low Sulfur
diesel fuels or other fuels within specification.
4
STARTING AND OPERATING 253

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.
260 STARTING AND OPERATING

JUMP STARTING
WARNING!
•To prevent personal injury or damage to clothing,
do not allow battery fluid to contact eyes, skin or
fabrics. Do not lean over a battery when connecting
jumper cables or allow cable clamps to touch each
other. Keep open flames or sparks away from
battery vent holes. Always wear eye protection
when working with batteries.
• Do not use a booster battery or any other booster
source that has a greater than 12 Volt system, i.e., do
not use a 24 Volt power source.
NOTE: Replacement batteries should both be of equal
size to prevent damage to the vehicle’s charging system.
Your vehicle is equipped with two 12 Volt batteries. If it
becomes necessary to use a booster battery with jumper cables to start a vehicle’s engine because its batteries are
discharged, the following procedure should be used:
Set the parking brake and place an automatic transmis-
sion in PARK (or NEUTRAL for a manual transmission).
Turn off lights, heater and other electrical loads. Observe
charge indicator (if equipped) in both batteries. If the
indicator (if equipped) is light or yellow on either battery,
replace that battery.
CAUTION!
Use the jump start procedure only when the charge
indicator (if equipped) in both batteries is dark in the
center. Do not attempt jump starting when either
battery charge indicator (if equipped) is bright or
yellow. If the charge indicator (if equipped) has a
green dot in the center, failure to start is not due to a
discharged battery and cranking system should be
checked.
270 WHAT TO DO IN EMERGENCIES

Engine Air Cleaner Filter Installation
NOTE:Inspect and clean the housing if dirt or debris is
present before replacing the air filter element.
1. Install the air cleaner filter element into the housing assembly with the air cleaner filter inspection surface
facing downward.
2. Install the air cleaner cover onto the housing assembly locating tabs.
3. Install screws to secure the air cleaner cover to the housing assembly.
Draining Fuel/Water Separator Filter
There are two fuel filter assemblies. One is located on the
driver’s side of the engine. The best access to this water
drain valve is from under the hood. The second one is on
the under body, located in front of the rear axle above the
drive shaft on pick-up models. The Chassis Cab models second filter location is on the frame behind the front
axle. The best access to this water drain valve is from
under the vehicle.
CAUTION!
•
Do not drain the fuel/water separator filters when
the engine is running.
• Diesel fuel will damage blacktop paving surfaces.
Drain the filters into an appropriate container.
If water is detected in the water separator while the
engine is running, or while the ignition switch is in the
ON position, the “Water In Fuel Indicator Light” will
illuminate and an audible chime will be heard five times.
At this point you should stop the engine and drain the
water from both of the filters.
288 MAINTAINING YOUR VEHICLE

CAUTION!
If the “Water In Fuel Indicator Light” remains on, DO
NOT START the engine before you drain water from
the fuel filters to avoid engine damage.
If the “Water In Fuel Indicator Light” comes on and a
single chime is heard while you are driving, or with the
ignition switch in the ON position, there may be a
problem with your water separator wiring or sensor. See
your authorized dealer for service.
Upon proper draining of the water from both fuel filters,
the “Water In Fuel Indicator Light” will remain illumi-
nated for approximately 10 seconds. If the water was
drained while the engine was running, the “Water In Fuel
Indicator Light” may remain on for approximately three
minutes. NOTE:
Care should be taken in disposing of used fluids
from your vehicle. Used fluids, indiscriminately dis-
carded, can present a problem to the environment. Con-
tact an authorized dealer, service station, or government
agency for advice on recycling programs and for where
used fluids and filters can be properly disposed of in
your area.
Drain the fuel/water separator filters when the “Water In
Fuel Indicator Light” is ON. Within 10 minutes of vehicle
shutdown, turn the engine mounted filter drain valve
(located on the side of the filter assembly) counterclock-
wise 1/4 turn, and turn the under body mounted filter
drain valve (located on the bottom of the filter assembly)
counterclock wise 1 full turn. Then turn the ignition
switch to the ON position, and allow any accumulated
water to drain. Leave the drain valve open until all water
and contaminants have been removed. When clean fuel is
visible, close the drain valves by turning them fully
clockwise, and turn the ignition switch to OFF.
6
MAINTAINING YOUR VEHICLE 289

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.With disc brakes, the fluid level can be expected to fall as
the brake linings wear. However, an unexpected drop in
fluid level may be caused by a leak and a system check
should be conducted.
Refer to “Fluids, Lubricants, and Genuine Parts” in
“Maintaining Your Vehicle” for further information.
WARNING!
•
Use only manufacturer’s recommended brake
fluid. Refer to “Fluids, Lubricants, and Genuine
Parts” in “Maintaining Your Vehicle” for further
information. Using the wrong type of brake fluid
can severely damage your brake system and/or
impair its performance. The proper type of brake
fluid for your vehicle is also identified on the
original factory installed hydraulic master cylinder
reservoir.
(Continued)
304 MAINTAINING YOUR VEHICLE