Page 206 of 384

Four-Wheel Drive............................................5-73
Front Axle......................................................5-74
Noise Control System.....................................5-75
Tampering with Noise Control System
Prohibited.................................................5-75
Bulb Replacement..........................................5-76
Windshield Wiper Blade Replacement..............5-76
Other Service Items........................................5-78
Fuel Filter....................................................5-78
Primary Fuel Filter and Water Separator..........5-79
Secondary Fuel Filter and Water Separator/
Heater (Caterpillar
®Diesel).........................5-80
Front Wheel Bearings with
Oil-Filled Hubs..........................................5-81
Tires..............................................................5-82
Inflation - Tire Pressure.................................5-82
Wheel Loading.............................................5-83
Dual Tire Operation.......................................5-84
When It Is Time for New Tires.......................5-84
Buying New Tires.........................................5-85
Wheel Alignment and Tire Balance..................5-86Tightening the Wheel Nuts.............................5-86
Wheel Replacement......................................5-90
If a Tire Goes Flat........................................5-92
Appearance Care............................................5-94
Interior Cleaning...........................................5-94
Fabric/Carpet...............................................5-95
Instrument Panel, Vinyl, and Other Plastic
Surfaces..................................................5-96
Care of Safety Belts......................................5-96
Weatherstrips...............................................5-96
Washing Your Vehicle...................................5-97
Cleaning Exterior Lamps/Lenses.....................5-97
Finish Care..................................................5-97
Windshield and Wiper Blades.........................5-98
Aluminum or Chrome-Plated Wheels
and Trim..................................................5-98
Tires...........................................................5-99
Sheet Metal Damage.....................................5-99
Finish Damage.............................................5-99
Underbody Maintenance...............................5-100
Chemical Paint Spotting...............................5-100
Vehicle Care/Appearance Materials................5-100
Section 5 Service and Appearance Care
5-2
Page 248 of 384

How to Add Fluid
To add transmission fluid, do the following:
1. Remove the filler plug.
2. Add fluid at the filler plug hole. Add only enough
fluid to bring the fluid level up to the bottom of
the fill opening. Refer to the Maintenance
Schedule to determine the proper fluid to use.
SeePart C: Recommended Fluids and Lubricants
on page 6-31.
3. Reinstall the filler plug. Be sure the plug is fully
seated.
Engine Coolant (Caterpillar®Diesel
Engines)
If your vehicle has a Caterpillar®diesel engine, see the
Caterpillar®Diesel Engine Operation & Maintenance
Manual provided with your vehicle to find out what to
add, as well as when and how to service your cooling
system.
Engine Coolant (Gas and
DURAMAX
®/Isuzu 7.8L L6 Engines)
The cooling system in your vehicle is filled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for five years or 150,000 miles
(240 000 km), whichever occurs first, if you add only
DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem with
engine overheating, seeEngine Overheating on
page 5-48.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
•Give freezing protection down to−34°F (−37°C).
•Give boiling protection up to 265°F (129°C).
•Protect against rust and corrosion.
•Help keep the proper engine temperature.
•Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
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Page 249 of 384

What to Use
Use a mixture of one-half clean, drinkable water and
one-half DEX-COOL®coolant which will not damage
aluminum parts. If you use this coolant mixture, you do
not need to add anything else.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.Notice:If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost would not be covered by your
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core, and
other parts.
If you have to add coolant more than four times a year,
have your dealer/retailer check your cooling system.
Notice:If you use extra inhibitors and/or additives
in your vehicle’s cooling system, you could
damage your vehicle. Use only the proper mixture
of the engine coolant listed in this manual for
the cooling system. SeePart C: Recommended
Fluids and Lubricants on page 6-31for more
information.
5-45
Page 253 of 384

If No Steam Is Coming From Your
Engine
An overheat warning, along with a low coolant light, can
indicate a serious problem. SeeLow Coolant Warning
Light on page 3-35for more information.
If you get an engine overheat warning with no low
coolant light, but see or hear no steam, the problem may
not be too serious. Sometimes the engine can get a
little too hot when you:
•Climb a long hill on a hot day.
•Stop after high-speed driving.
•Idle for long periods in traffic.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. In heavy traffic, let the engine idle in NEUTRAL
while stopped. If it is safe to do so, pull off the
road, shift to PARK (P) or NEUTRAL and let the
engine idle.
2. Turn on your heater to full hot at the highest fan
speed and open the windows as necessary.
3. If climbing a hill, downshift to raise engine and fan
speeds.If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning does not come back on, you can drive
normally.
If the warning continues and you have not stopped, pull
over, stop, and park your vehicle right away.
If there is still no sign of steam, you can push down the
accelerator until the engine speed is about twice as
fast as normal idle speed for at least three minutes while
you are parked. If you still have the warning, turn off the
engine and get everyone out of the vehicle until it
cools down.
You may decide not to lift the hood but to get service
help right away.
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Page 254 of 384
Cooling System
When you decide it is safe to lift the hood, here is what
you will see:
A. Engine Fan
B. Coolant Surge Tank
If your vehicle has a Caterpillar
®diesel engine, see the
Caterpillar®Diesel Engine Operation and Maintenance
Manual provided with your vehicle.
If the coolant inside the coolant surge tank is boiling, do
not do anything else until it cools down. The vehicle
should be parked on a level surface.The coolant level should
be at the FULL COLD
mark or higher. If it is not,
you may have a leak at
the pressure cap or in the
radiator hoses, heater
hoses, radiator, water
pump, or somewhere else
in the cooling system.
5-50
Page 255 of 384

{CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Do not touch them.
If you do, you can be burned.
Do not run the engine if there is a leak. If you
run the engine, it could lose all coolant. That
could cause an engine re, and you could be
burned. Get any leak xed before you drive the
vehicle.
If there seems to be no leak, start the engine again.
The engine cooling fan speed should increase when idle
speed is doubled by pushing the accelerator pedal
down. If it does not, your vehicle needs service. Turn off
the engine.Notice:Engine damage from running the engine
without coolant is not covered by the warranty.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
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Page 257 of 384
Notice:In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
1. You can remove the
coolant surge tank
pressure cap when the
cooling system,
including the coolant
surge tank pressure
cap and upper radiator
hose, is no longer hot.
Turn the pressure cap slowly counterclockwise
about one full turn. If you hear a hiss, wait for that to
stop. A hiss means there is still some pressure left.2. Then keep turning the pressure cap slowly, and
remove it.
3. Fill the coolant surge tank with the proper mixture,
to the FULL COLD mark.
5-53
Page 283 of 384
Primary Fuel Filter and Water
Separator
Your vehicle may have this
spin-on filter. It is located
on the driver’s side
frame rail.
It has a clear plastic drain bowl at the bottom. Check
the drain bowl occasionally for any water or particles.
To drain the water or to replace the element, follow the
water draining and element replacement procedure
underWater in Fuel on page 5-12.
Secondary Fuel Filter and Heater
Your vehicle may have this fuel filter and fuel heater.
It is mounted on the left side of the engine.
It has a metal drain bowl at the bottom. Occasionally,
check the bowl for any water or particles. To check or
drain the bowl, shut off the engine.
Then push up on the spring-loaded drain valve until
clear fuel is flowing from the valve. The particles or
water will drain out first.
5-79