Loading Your Vehicle
It is the responsibility of the Final Stage
manufacturer to install a Certification label on
your vehicle. This label shows how much weight
your vehicle can properly carry. It may also
show the size of the vehicle’s original tires, and
the inflation pressures needed to obtain the
gross weight capacity of your vehicle. This is
called the Gross Vehicle Weight Rating (GVWR).
The tire information could also be shown on a
separate Tire Information label.
The GVWR includes the weight of the vehicle,
all occupants, fuel, and cargo.
The Certification label also tells you the maximum
weight for the front and rear axles, called the
Gross Axle Weight Rating (GAWR). To find out
the actual loads on your front and rear axles,
go to a weigh station and weigh your vehicle.
Your dealer can help you with this. Be sure
to spread out your load equally on both sides
of the center line.Never exceed the GVWR for your vehicle, or the
GAWR for either the front or rear axle.
And, if you do have a heavy load, spread it out.
{CAUTION:
Do not load your vehicle any heavier than
the Gross Vehicle Weight Rating (GVWR),
or either the maximum front or rear Gross
Axle Weight Rating (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.
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Service........................................................ 248
California Proposition 65 Warning.............. 248
Doing Your Own Service Work.................. 249
Engine Fan Breakage................................ 250
Fuel............................................................. 251
Gasoline Octane........................................ 251
Gasoline Specifications.............................. 251
Additives................................................... 252
Diesel Engine Fuel.................................... 253
What Fuel to Use...................................... 253
Very Cold Weather Operation.................... 256
Water in Fuel............................................ 256
Running Out of Fuel.................................. 262
Fuel Filter Replacement............................. 263
Fuels in Foreign Countries........................ 264
Filling the Tank......................................... 264
Filling a Portable Fuel Container............... 266Checking Things Under the Hood.............. 266
Hood Latches............................................ 267
Engine Oil (Caterpillar
®Diesel Engine)...... 268
Engine Oil (Gasoline Engine).................... 268
Engine Oil (DURAMAX
®/Isuzu Diesel
Engine).................................................. 272
Engine Oil Life System
(Gasoline Engine).................................. 276
Engine Oil Life System
(DURAMAX
®Diesel)............................... 278
Engine Oil Life System
(Caterpillar
®Diesel Engine).................... 279
Engine Air Cleaner/Filter............................ 280
Automatic Transmission Fluid.................... 282
Manual Transmission Fluid........................ 283
Engine Coolant (Gas and
DURAMAX
®/Isuzu Engines).................... 284
Engine Coolant (Caterpillar®Diesel
Engines)................................................ 287
Coolant Surge Tank Pressure Cap............ 288
Section 5 Service and Appearance Care
245
If the light comes on, use this chart to determine
what action to take.
Water In Fuel Light
Problem Recommended Action
Light comes on
intermittently.Drain water from the
fuel filter.
Light stays on at
temperatures above
freezing.Drain the fuel filter
immediately. If no water
can be drained and the
light stays on, see your
dealer for assistance.
Light stays on at
temperatures below
freezing.Drain the fuel filter
immediately. If no water
can be drained, water
may be frozen in the
water drain system, or in
the fuel lines. Move the
vehicle to a warm location
to thaw out, and then
drain the filter system.
Light stays on
immediately after
refueling, and a large
amount of water was
possibly pumped into the
fuel tank.Fuel tank purging is
required. See your dealer
for assistance.
Notice:If you drive when this warning
indicator is on, you can damage your fuel
injection system and your engine. If the
indicator comes on right after you refuel, it
means water was pumped into your fuel tank.
Turn off your engine immediately. Then,
have the water drained at once.
To drain water, do the following:
1. Stop and park the vehicle in a safe place. Turn
off the engine and apply the parking brake.
2. Remove the fuel cap.
3. Place a fuel-resistant container under the fuel
filter. The filter drain valve is located on the
bottom of the fuel filter.
If your vehicle has the 6.6L engine, the fuel
filter is located in the engine compartment on
the driver’s side of the vehicle. If your
vehicle has either the 7.2L or 7.8L engine, the
fuel filters are located in the engine
compartment on the driver’s side of the
vehicle, and on the driver’s side frame rail in
front of the fuel tank.
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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, seeEngine Oil
(Caterpillar
®Diesel Engine) on page 268or
Engine Oil (Gasoline Engine) on page 268or
Engine Oil (DURAMAX
®/Isuzu Diesel
Engine) on page 272.6. 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.
Fuel Priming
If your vehicle has a Caterpillar®diesel engine,
see the Caterpillar®Diesel Engine Operation and
Maintenance Manual provided with your vehicle.
If your vehicle has a DURAMAX
®/Isuzu diesel
engine, in order for the fuel system to work
properly, the fuel lines must be full of fuel and
contain no air. If air gets into the fuel lines, it will
be necessary to prime the fuel lines to eliminate air
before operating the vehicle.
258
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.
Filling the Tank
{CAUTION:
Fuel vapor is highly ammable. It burns
violently, and that can cause very bad
injuries. Do not smoke if you are near
fuel or refueling your vehicle. Keep
sparks, ames and smoking materials
away from fuel.
The fuel cap can be on either or both sides of
your vehicle depending on option content.
To take off the cap, turn it slowly counterclockwise.
Fuel caps for all
gasoline applications,
and all diesel between
frame rail fuel tank
applicationsFuel caps for all side
mounted diesel
applications
264
{CAUTION:
If you get fuel on yourself and then
something ignites it, you could be badly
burned. Fuel can spray out on you if you
open the fuel cap too quickly. This spray
can happen if your tank is nearly full, and is
more likely in hot weather. Open the fuel
cap slowly and wait for any “hiss” noise to
stop. Then unscrew the cap all the way.
When you put the cap back on, turn it clockwise
until it is tight.
Notice:If you need a new fuel cap, be sure to
get the right type. Your dealer can get one
for you. If you get the wrong type, it may not
t properly. This may cause your malfunction
indicator lamp to light and may damage
your fuel tank and emissions system. See
Malfunction Indicator Lamp on page 174.If you have dual tanks, fill the driver’s side tank, or
forward tank, first. The fuel gage will give better
readings this way. Your gage will show the
total fuel left in both tanks.
If your vehicle is a C4/C5 model and you have
dual tanks, the engine must be off when refueling
or the fuel transfer system may become
inoperable.
If you have a single tank with dual fillers, where
there is a filler on each side of the vehicle, do not
attempt to fill the tank through both fillers at the
same time. Also, do not fill the tank with both caps
removed, as this may result in over-filling the
tank and fuel spillage.
265
Checking Engine Oil
It is a good idea to check the engine oil every time
you get fuel. In order to get an accurate reading,
the oil must be warm and the vehicle must be
on level ground.
The engine oil
dipstick is located in the
engine compartment
on the driver’s side
of the vehicle.
1. Turn off the engine and give the oil several
minutes to drain back into the oil pan. If you
do not do this, the oil dipstick might not
show the actual level.
2. Pull out the dipstick and clean it with a paper
towel or cloth, then push it back in all the
way. Remove it again, keeping the tip down,
and check the level.
When to Add Engine Oil
If the oil is below the cross-hatched area at the tip
of the dipstick, you will need to add at least one
quart/liter of oil. But you must use the right
kind. This section explains what kind of oil to use.
For engine oil crankcase capacity, seeCapacities
and Speci cations on page 347.
Notice:Do not add too much oil. If the engine
has so much oil that the oil level gets above the
cross-hatched area that shows the proper
operating range, the engine could be damaged.
269
4. With the coolant surge tank pressure cap off,
start the engine and let it run until you can
feel the upper radiator hose getting hot. Watch
out for the engine cooling fan.
By this time, the coolant level inside the
coolant surge tank may be lower. If the level is
lower, add more of the proper mixture to the
coolant surge tank until the level reaches
slightly above the FULL COLD mark.
5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
Engine Fan Noise
Your vehicle has a clutched engine cooling fan.
When the clutch is engaged, the fan spins faster to
provide more air to cool the engine. In most
everyday driving conditions, the clutch is not fully
engaged. This improves fuel economy and
reduces fan noise. Under heavy vehicle loading,
trailer towing and/or high outside temperatures, the
fan speed increases when the clutch engages.
So you may hear an increase in fan noise. This is
normal and should not be mistaken as the
transmission slipping or making extra shifts. It is
merely the cooling system functioning properly.
The fan will slow down when additional cooling is
not required and the clutch disengages.
You may also hear this fan noise when you start
the engine. It will go away as the fan clutch
disengages.
294