
Other Service Items........................................5-70
Fuel Filter....................................................5-70
Primary Fuel Filter and Water Separator..........5-71
Secondary Fuel Filter and Water
Separator/Heater (Caterpillar
®Diesel)...........5-71
Automatic Ether Injection System
(Caterpillar
®Diesel)....................................5-72
Front Wheel Bearings with Oil-Filled Hubs........5-73
Air Conditioning System.................................5-74
Tires..............................................................5-74
Inflation - Tire Pressure.................................5-75
Wheel Loading.............................................5-75
Dual Tire Operation.......................................5-76
When It Is Time for New Tires.......................5-76
Wheel Alignment and Tire Balance..................5-77
Tightening the Wheel Nuts.............................5-77
Wheel Replacement......................................5-81
If a Tire Goes Flat........................................5-82
Appearance Care............................................5-83
Cleaning the Inside of Your Vehicle.................5-83
Fabric/Carpet...............................................5-85
Instrument Panel, Vinyl, and Other Plastic
Surfaces..................................................5-86
Care of Safety Belts......................................5-86
Weatherstrips...............................................5-86
Washing Your Vehicle...................................5-87Cleaning Exterior Lamps/Lenses.....................5-87
Finish Care..................................................5-87
Windshield and Wiper Blades.........................5-88
Aluminum or Chrome-Plated Wheels................5-89
Tires...........................................................5-89
Sheet Metal Damage.....................................5-89
Finish Damage.............................................5-89
Underbody Maintenance................................5-90
Chemical Paint Spotting.................................5-90
Vehicle Identi cation......................................5-91
Vehicle Identification Number (VIN).................5-91
Service Statement.........................................5-92
Service Parts Identification Label.....................5-92
Electrical System............................................5-92
Add-On Electrical Equipment..........................5-92
Headlamp Wiring..........................................5-93
Windshield Wiper Fuses................................5-93
Fusible Links................................................5-93
Power Windows and Other Power Options.......5-93
Fuses and Circuit Breakers............................5-93
Instrument Panel Fuse Block..........................5-94
Underhood Fuse Block..................................5-96
Capacities and Speci cations..........................5-99
Normal Maintenance Replacement Parts.........5-104
Section 5 Service and Appearance Care
5-2

Notice:Your vehicle was not designed for fuel that
contains methanol. Do not use fuel containing
methanol. It can corrode metal parts in your fuel
system and also damage the plastic and rubber
parts. That damage would not be covered under
your warranty.
Some gasolines that are not reformulated for low
emissions may contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. General Motors
recommends against the use of such gasolines. Fuels
containing MMT can reduce the life of spark plugs
and the performance of the emission control system may
be affected. The malfunction indicator lamp may turn
on. If this occurs, return to your authorized GM dealer for
service.Diesel Engine Fuel
For the Caterpillar®diesel, see the Caterpillar®
Operation & Maintenance Manual for information
concerning fuel usage.
Notice:Diesel fuel or fuel additives not
recommended in this manual could damage your
fuel system and engine. Your warranty would
not cover this damage. And:
Diesel fuel that has been mixed with engine oil
or automatic transmission uid could damage
your engine and emission controls.
Aftermarket diesel fuel additives are not tested
by General Motors. Some additives, particularly
those which contain alcohol or water
emulsi ers, may damage your fuel system. If
you believe that unique circumstances call for a
fuel additive to be used, consult your dealer
for advice.
If you ever run out of diesel fuel, it can be
difficult to restart your engine. To avoid
this, never let your tank get empty.
If gasoline is ever accidentally added to the fuel
tank, to avoid severe engine damage, do not run the
engine until the fuel tank can be drained.
If you run out of fuel,Running Out of Fuel on page 5-17
tells you how to restart your engine.
5-7

What Fuel to Use
In the United States, for best results use No. 2-D diesel
fuel year-round (above and below freezing conditions)
as oil companies blend No. 2-D fuel to address climate
differences. No. 1-D diesel fuel may be used in very
cold temperatures (when it stays below 0°F or−18°C);
however, it will produce a power and fuel economy
loss. Avoid the use of No. 1-D diesel fuel in warm or hot
climates. It may result in stalling, poor starting when
the engine is hot, and may damage the fuel injection
system.
At a minimum, the diesel fuel you use should meet the
latest version of ASTM specification D 975 (Grade
Low Sulfur) in the United States. In addition, the Engine
Manufacturers Association (EMA) has identified
properties of an improved diesel fuel for better engine
performance and durability. Diesel fuels corresponding
to the EMA Recommended Guideline on Premium
Diesel Fuel (FQP-1A) could provide better starting, less
noise, and better vehicle performance. If there are
questions about the fuel you are using, contact your fuel
supplier.
If your vehicle has the 6.6L engine, it is acceptable to
use diesel fuel containing up to 5% biodiesel (B5),
but the final blended fuel must meet the same
specification, ASTM D 975 (Grade Low Sulfur), as other
fuels used in your vehicle, and the biodiesel used for
making this fuel must meet the latest version ofASTM specification D 6751. Biodiesel is produced from
vegetable oils or animal fat that have been chemically
modified to reduce the possibility of damage to your fuel
system and engine. Higher concentration (i.e., greater
than B5) biodiesel-containing fuels or the use of
unmodified bio-oils blended into diesel fuel at any
concentration is not recommended and could damage
your fuel system and engine. Such damage would
not be covered by your warranty. If there are questions
about the biodiesel-containing fuels you are using,
contact your fuel supplier.
Diesel fuel may foam when you fill your tank. This can
cause the automatic pump nozzle to shut off, even
though your tank is not full. If this happens, just
wait for the foaming to stop and then continue to fill
your tank.
{CAUTION:
Heat coming from the engine may cause the
fuel to expand and force the fuel out of your
tank. If something ignites the fuel, a re could
start and people could be burned. To help
avoid this, ll your fuel tank only until the
automatic nozzle shuts off. Do not try to top
it off.
5-8

What Fuel to Use in Canada
Canadian fuels are blended for seasonal changes.
Diesel Type “A” fuel is blended for better cold weather
starting (below 0°F or−18°C); however, you may
notice some power and fuel economy loss. If Type “A”
fuel is used in warmer temperatures, stalling and
hard starting may occur. Diesel Type “B” fuel is blended
for temperatures above 0°F (−18°C). The emission
control system requires the use of diesel fuel with
low-sulfur (.05% by weight) content. Both low- and
higher-sulfur fuels will be available in Canada. Only
low-sulfur diesel fuels are available in the United States.
It is important that diesel-powered trucks are refueled
only with low-sulfur fuel. Use of fuels with higher-sulfur
content will affect the function of the emission
components and may cause reduced performance,
excessive smoke, and unpleasant odor.
At a minimum, the diesel fuel you use should meet the
latest version of specification CAN/CGSB-3.517
(Low Sulfur Diesel) in Canada. In addition, the Engine
Manufacturers Association (EMA) has identified
properties of an improved diesel fuel for better engine
performance and durability (FQP-1A). Diesel fuels
corresponding to the EMA description could provide
better starting, less noise, and better vehicle
performance. If there are questions about the fuel you
are using, contact your fuel supplier.If your vehicle has the 6.6L engine, it is acceptable to
use diesel fuel containing up to 5% biodiesel (B5),
but the final blended fuel must meet the same
specification, CAN/CGSB-3.517 (Low Sulfur Diesel) in
Canada, as other fuels used in your vehicle, and
the biodiesel used for making this fuel must meet the
latest version of ASTM specification D 6751. Biodiesel is
produced from vegetable oils or animal fat that have
been chemically modified to reduce the possibility
of damage to your fuel system and engine. Higher
concentration (i.e., greater than B5) biodiesel-containing
fuels or the use of unmodified bio-oils blended into
diesel fuel at any concentration is not recommended and
could damage your fuel system and engine. Such
damage would not be covered by your warranty. If there
are questions about the biodiesel-containing fuels you
are using, contact your fuel supplier.
5-9

Very Cold Weather Operation
Follow the instructions listed previously under the
heading “What Fuel to Use.”
Notice:Never use home heating oil or gasoline in
your diesel engine. They can cause engine
damage.
In cold weather, your fuel filter may become clogged
(waxed). To unclog it, move the vehicle to a warm
garage area and warm the filter to between 32°F and
50°F (0°C to 10°C). You will not need to replace it.
Additional information on the fuel filter follows.
Water in Fuel
{CAUTION:
Diesel fuel containing water is still ammable.
You could be burned. If you ever try to drain
water from your fuel, keep sparks, ames and
smoking materials away from the mixture.Notice:If there is water in your diesel fuel and the
weather is warm or humid, fungus and bacteria
can grow in the fuel. They can damage your
fuel system. A diesel fuel biocide can be used to
sterilize your fuel system. However, your fuel system
may still need to be cleaned. Your dealer can
advise you of the appropriate solution.
If your fuel tank needs to be purged to remove
water, see your dealer or a quali ed technician.
Improper purging can damage your fuel system.
Sometimes, water can be pumped into your fuel
tank along with your diesel fuel. This can happen if a
service station does not regularly inspect and clean
its fuel tanks, or if it gets contaminated fuel from
its suppliers.
If this happens, the
water-in-fuel light, if
equipped, will come on in
the instrument panel. If it
does, the water must be
drained. Your dealer can
show you how to do this.
If the light comes on, use this chart to determine what
action to take.
5-10

4. Open the drain valve
by turning two to
three turns. When fuel
empties from the
valve, all the water has
been drained. Close
the valve hand-tight.
5. Remove the fuel-resistant container and properly
dispose of the contaminated fuel. To find out how
to properly dispose of contaminated diesel fuel, see
Engine Oil (Caterpillar
®Diesel Engine) on
page 5-24orEngine Oil (DURAMAX®Diesel) on
page 5-24orEngine Oil (Gasoline Engine) on
page 5-28.6. Install the fuel cap.
7. Start the engine and let it run for a few minutes. If the
engine stalls, the fuel system may need to be primed.
While draining the water from the fuel filter, air may
enter the fuel system. If air has entered the fuel
system the fuel system will need to be primed.
If the water-in-fuel light comes on again after driving a
short distance or the engine runs rough or stalls, a large
amount of water has probably been pumped into the
fuel tank. The fuel tank should be purged.
5-12

6. Repeatedly push down
on the fuel filter primer
pump with the palm
of your hand. Let
the pump return
upward between
pushes.
7. Operate the priming pump until a small amount of
fuel seeps from the vent valve. When you see the
fuel, the filter is now full of fuel and the system
should be primed.
8. Close the vent valve.
9. Clean any fuel which accumulated on the fuel filter.
10. Start the engine and let it idle for a few minutes.
11. Check the filter for leaks.Priming the 7.8L DURAMAX®Diesel Engine
If your vehicle is equipped with the 7.8L DURAMAX®
diesel engine, use the following procedure to prime the
engine:
1. Make sure there is fuel in the fuel tank.
2. Make sure the specified fuel filter is properly
installed.
3. Make sure the fuel lines are securely connected.
4. Make sure the fuel filter is cool to the touch.
5. Use a clean cloth to remove dirt and oil from the
fuel filter head and breather valve.
5-15

3. Remove the filter element. If there is any dirt on the
filter sealing surface, clean it off. Remove and
reuse the water sensor float switch located on the
bottom of the fuel filter.
4. Install the new filter element.
5. Reinstall and tighten the filter container and
reconnect the water sensor wire to the filter.
6. Use the fuel filter priming procedure earlier in this
section to prime the fuel filter.
7. Tighten the air bleed valve by turning it clockwise
until hand-tight.
8. Start your engine and let it idle for five minutes.
Check your fuel filter and air bleed valve for
leaks.Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be hard
to find. Never use leaded gasoline or any other fuel
not recommended in the previous text on fuel. Costly
repairs caused by use of improper fuel would not
be covered by your warranty.
To check the fuel availability, ask an auto club, or
contact a major oil company that does business in the
country where you will be driving.
5-19