
{CAUTION:
Your brake system may not be working
properly if the SERVICE BRAKE BOOSTER
message is displayed.
If the brake system warning light is also on,
you should have the vehicle towed for service.
See ªBrake System Warning Lightº in the
Index.
If the brake system warning light isn't on, you
still have brakes, but the supplemental brake
assist system may not operate properly. In the
event of a vacuum loss, you may not have
vacuum power assist for braking. The brake
pedal will be harder to push and it will take
longer to stop. If you continue to drive with
this message displayed it can lead to a crash.
Have the brake system serviced as soon as
possible.
SERVICE 4 WHEEL STEER
If a problem occurs with the 4 wheel steer system, this
message will appear on the DIC. If this message
appears, stop as soon as possible, and turn off the
vehicle. Restart the vehicle and check for the message
on the DIC display. If the message is still displayed,
or appears again when you being driving, the four wheel
steer system needs service.
SERVICE 4WD
If a problem occurs with the four wheel drive system,
this message will appear on the DIC. If this message
appears, stop as soon as possible and turn off the
vehicle. Restart the vehicle and check for the message
on the DIC display. If the message is still displayed,
or appears again when you begin driving, the four wheel
drive system needs service.
SERVICE RIDE CONTROL
If a problem occurs with the suspension system, this
message will appear on the DIC. If this message
appears, stop and turn off the vehicle. Restart the
vehicle and check for the message on the DIC display.
If the message is still displayed, or appears again
when you begin driving, the air suspension system
needs service.
3-69

Driving in Water
Heavy rain can mean ¯ash ¯ooding, and ¯ood waters
demand extreme caution.
Find out how deep the water is before you drive through
it. If it's deep enough to cover your wheel hubs, axles
or exhaust pipe, don't try it Ð you probably won't
get through. Also, water that deep can damage your
axle and other vehicle parts.
If the water isn't too deep, drive slowly through it. At
faster speeds, water splashes on your ignition system
and your vehicle can stall. Stalling can also occur if you
get your tailpipe under water. And, as long as your
tailpipe is under water, you'll never be able to start your
engine. When you go through water, remember that when
your brakes get wet, it may take you longer to stop.
{CAUTION:
Driving through rushing water can be
dangerous. Deep water can sweep your vehicle
downstream and you and your passengers
could drown. If it is only shallow water, it can
CAUTION: (Continued)
CAUTION: (Continued)
still wash away the ground from under your
tires, and you could lose traction and roll the
vehicle over. Do not drive through rushing
water.
See
Driving in Rain and on Wet Roads on page 4-39for
more information on driving through water.
After Off-Road Driving
Remove any brush or debris that has collected on the
underbody, chassis or under the hood. These
accumulations can be a ®re hazard.
After operation in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the body structure,
steering, suspension, wheels, tires and exhaust
system for damage. Also, check the fuel lines and
cooling system for any leakage.
Your vehicle will require more frequent service due to
off-road use. Refer to the Maintenance Schedule
for additional information.
4-37

{CAUTION:
Do not load your vehicle any heavier than the
GVWR, or either the maximum front or rear
GAWR. If you do, parts on your vehicle can
break, and it can change the way your vehicle
handles. These could cause you to lose
control and crash. Also, overloading can
shorten the life of your vehicle.
Notice:Your warranty does not cover parts or
components that fail because of overloading.
This will help you decide how much cargo and installed
equipment your truck can carry.
Using heavier suspension components to get added
durability might not change your weight ratings. Ask your
dealer to help you load your vehicle the right way.
If you put things inside your vehicle ± like suitcases,
tools, packages, or anything else ± they go as fast
as the vehicle goes. If you have to stop or turn quickly,
or if there is a crash, they'll keep going.
{CAUTION:
Things you put inside your vehicle can strike
and injure people in a sudden stop or turn, or
in a crash.
·Put things in the trunk of your vehicle. In a
trunk, put them as far forward as you can.
Try to spread the weight evenly.
·Never stack heavier things, like suitcases,
inside the vehicle so that some of them
are above the tops of the seats.
·Don't leave an unsecured child restraint in
your vehicle.
·When you carry something inside the
vehicle, secure it whenever you can.
There's also important loading information for off-road
driving in this manual. See ªLoading Your Vehicle
for Off-Road Drivingº under
Off-Road Driving with Your
Four-Wheel-Drive Vehicle on page 4-22.
4-59

Tow/haul is designed to be most effective when the
vehicle and trailer combined weight is at least 75% of
the vehicle's Gross Combined Weight Rating (GCWR).
See
Weight of the Trailerlater in the section. Tow/haul
is most useful under the following driving conditions:
·When pulling a heavy trailer or a large or heavy load
through rolling terrain.
·When pulling a heavy trailer or a large or heavy
load in stop and go traffic.
·When pulling a heavy trailer or a large or heavy
load in busy parking lots where improved low
speed control of the vehicle is desired.
Operating the vehicle in tow/haul when lightly loaded or
with no trailer at all will not cause damage. However,
there is no bene®t to the selection of tow/haul when the
vehicle is unloaded. Such a selection when unloaded
may result in unpleasant engine and transmission driving
characteristics and reduced fuel economy. Tow/haul
is recommended only when pulling a heavy trailer or a
large or heavy load.
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For
example, speed, altitude, road grades, outside
temperature and how much your vehicle is used to pull
a trailer are all important. And, it can also depend
on any special equipment that you have on your vehicle.
Use one of the following charts to determine how
much your vehicle can weigh, based upon your vehicle
model and options.
Maximum trailer weight is calculated assuming the
driver and one passenger are in the tow vehicle and it
has all the required trailering equipment. The weight
of additional optional equipment, passengers and cargo
in the tow vehicle must be subtracted from the
maximum trailer weight.
Above the 5,000 lbs. (2 268 kg) trailer rating, the
handling/trailering suspension is required on
C-1500 models and the handling/trailering or off-road
suspension is required on K-1500 models.
4-70

Tire Chains
{CAUTION:
If your vehicle has dual wheels or P265/75R16,
LT265/75R16 or P275/55R20 size tires, don't
use tire chains. They can damage your vehicle
because there's not enough clearance. Tire
chains used on a vehicle without the proper
amount of clearance can cause damage to the
brakes, suspension or other vehicle parts. The
area damaged by the tire chains could cause
you to lose control of your vehicle and you or
others may be injured in a crash.
Use another type of traction device only if its
manufacturer recommends it for use on your
vehicle and tire size combination and road
conditions. Follow that manufacturer's
instructions. To help avoid damage to your
vehicle, drive slowly, readjust or remove the
device if it's contacting your vehicle, and don't
spin your wheels.
If you do ®nd traction devices that will ®t,
install them on the rear tires.²
Notice:If your vehicle does not have dual wheels
and is equipped with a tire size other than
P265/75R16, LT65/75R16 or P275/55R20, use tire
chains only where legal and only when you must.
Use chains that are the proper size for your
tires. Install them on the tires of the rear axle. Don't
use chains on the tires of the front axle. Tighten
them as tightly as possible with the ends securely
fastened. Drive slowly and follow the chain
manufacturer's instructions. If you can hear the
chains contacting your vehicle, stop and retighten
them. If the contact continues, slow down until
it stops. Driving too fast or spinning the wheels with
chains on will damage your vehicle.
5-78

Maintenance Schedule......................................6-2
Introduction...................................................6-2
Your Vehicle and the Environment....................6-2
Maintenance Requirements..............................6-2
How This Section is Organized.........................6-3
Part A: Scheduled Maintenance Services...........6-4
Using Your Maintenance Schedule....................6-4
Scheduled Maintenance...................................6-5
Part B: Owner Checks and Services................6-12
At the First 100, 1,000 and 6,000 Miles
(160, 1 600 and 10 000km)........................6-12
At Each Fuel Fill..........................................6-12
At Least Once a Month.................................6-12
At Least Twice a Year...................................6-13
At Least Once a Year...................................6-14Part C: Periodic MaintenanceInspections.........6-17
Steering and Suspension Inspection................6-17
Exhaust System Inspection............................6-17
Fuel System Inspection..................................6-17
Engine Cooling System Inspection...................6-17
Throttle System Inspection
(V6 Only).................................................6-18
Transfer Case and Front Axle (All-Wheel
Drive) Inspection.......................................6-18
Transfer Case and Front Axle (Four-Wheel
Drive) Inspection.......................................6-18
Brake System Inspection................................6-18
Part D: Recommended Fluids and Lubricants. . . .6-19
Part E: Maintenance Record...........................6-22
Section 6 Maintenance Schedule
6-1

It is also important to check your oil regularly and keep
it at the proper level.
If the system is ever reset accidentally, you must
change your oil at 3,000 miles (5 000 km) since your
last oil change. Remember to reset the oil life system
whenever the oil is changed. See
Engine Oil on
page 5-16for information on resetting the system.
An Emission Control Service.
Lubricate chassis components with each engine oil
and ®lter change. Vehicles used under severe
commercial operating conditions require lubrication
on a regular basis every 3,000 miles (5 000 km).
Lubricate the front suspension, ball joints, steering
linkage, transmission shift linkage and parking brake
cable guides. Ball joints should not be lubricated unless
their temperature is 10ÉF (-12ÉC) or higher or they
could be damaged.
See the mileage intervals following for additional
services that may be performed with an engine oil
change and chassis lubrication. After the services are
performed, record the date, odometer reading and
who performed the service on the maintenance record
pages in Part E of this schedule.
7,500 Miles (12 500 km)
qCheck rear/front axle ¯uid level and add ¯uid as
needed. Check constant velocity joints and axle seals
for leaking.
qRotate tires. See
Tire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +.)
qAllison TransmissionžOnly: Replace the external
control-main ®lter.
15,000 Miles (25 000 km)
qInspect engine air cleaner ®lter or change indicator (if
equipped). If necessary, replace the ®lter. If vehicle is
driven in dusty/dirty conditions, inspect ®lter or
change indicator (if equipped) at every engine oil
change. See
Engine Air Cleaner/Filter on page 5-21for more information.An Emission Control Service.
(See footnote ².)
qCheck rear/front axle ¯uid level and add ¯uid as
needed. Check constant velocity joints and axle seals
for leaking.
qRotate tires. See
Tire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +.)
6-6

Part C: Periodic
MaintenanceInspections
Listed in this part are inspections and services which
should be performed at least twice a year (for instance,
each spring and fall).
You should let your dealer's
service department do these jobs. Make sure any
necessary repairs are completed at once.
Proper procedures to perform these services may be
found in a service manual. SeeService Publications
Ordering Information on page 7-9.
Steering and Suspension Inspection
Inspect the front and rear suspension and steering
system for damaged, loose or missing parts, signs of
wear or lack of lubrication. Inspect the power steering
lines and hoses for proper hook-up, binding, leaks,
cracks, cha®ng, etc.
Exhaust System Inspection
Inspect the complete exhaust system. Inspect the body
near the exhaust system. Look for broken, damaged,
missing or out-of-position parts as well as open seams,
holes, loose connections or other conditions which
could cause a heat build-up in the ¯oor pan or could let
exhaust fumes into the vehicle. See
Engine Exhaust
on page 2-51.
Fuel System Inspection
Inspect the complete fuel system for damage or leaks.
Engine Cooling System Inspection
Inspect the hoses and have them replaced if they
are cracked, swollen or deteriorated. Inspect all pipes,
®ttings and clamps; replace as needed. Clean the
outside of the radiator and air conditioning condenser.
To help ensure proper operation, a pressure test of
the cooling system and pressure cap is recommended
at least once a year.
6-17