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If your vehicle has dual fuel tanks, the reading on the
gage is the total fuel left in both tanks.
Here are four concerns of some operators. None of
these shows a problem with your fuel gage:
•The gage moves a little when you turn a corner or
speed up.
•The gage does not go back to empty when you turn
off the ignition.
•At the gas station, the pump shuts off before the
gage reads full.
•It takes a little more or less fuel to fill up than the
gage indicated.
If you have a Caterpillar
®diesel engine, also see your
Caterpillar®Operation & Maintenance Manual.
Water in Fuel Warning Light
If your vehicle is equipped
with a diesel engine, you
may have this light.
This light will come on to warn you that there is water in
the fuel system. For more information on how this
light works, seeWater in Fuel on page 5-10.
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Sometimes, water can be pumped into your fuel tank
along with your diesel fuel. This can happen if a service
station doesn’t regularly inspect and clean its fuel
tanks, or if it gets contaminated fuel from its suppliers.
If this happens, a
water-in-fuel light will come
on. If it does, the water
must be drained. Your
dealer can show you how
to do this.
If it comes on, use the following chart.
Water In Fuel Light Chart
Problem Recommended Action
Light comes on
intermittently.Drain water from fuel
filter.
Light stays on at
temperatures above
freezing.Drain fuel filter
immediately. If no water
can be drained and light
stays on, see your dealer
for assistance.
Water In Fuel Light Chart (cont’d)
Problem Recommended Action
Light stays on at
temperatures below
freezing.Drain fuel filter
immediately. If no water
can be drained — water
may be frozen in water
drain system. Water may
be frozen in the fuel lines.
Move the vehicle to a
warm location to thaw
out, and then drain filter
system.
Light stays on
immediately after
refueling, large amount of
water possibly pumped
into fuel tank.Fuel tank purging
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.
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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. The fuel filter is located in the engine
compartment on the passenger’s side of the vehicle,
or on the driver’s side frame rail near the engine.
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 5-20orEngine Oil (Gasoline Engine) on
page 5-20orEngine Oil (DURAMAX™ Diesel) on
page 5-25for more information.
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.
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Page 219 of 366

Fuel Priming
In order for the DURAMAX™ diesel engine 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.
Q:How does air get into the fuel lines?
A:One of the following may have happened:
•The vehicle ran out of fuel, or
•The fuel filter was removed for servicing or
replacement, or
•The fuel lines were removed or disconnected for
servicing, or
•The fuel filter water drain valve was opened while
the engine was running.If one or more of the above occur, it is very likely that
air has entered your fuel system and that you will need
to prime the fuel system before operating the vehicle.
Air in the fuel lines will not harm the engine or the
vehicle.
However, the engine may not be able to start until the
fuel system is primed and the air is removed.
Q:How do I prime the vehicle?
A:Your vehicle is equipped with the priming pump
which is part of the engine mounted fuel filter. The
vent valve and the fuel filter primer pump are
located on top of the fuel filter housing. The
priming pump is hand operated and is designed to
bring fuel to the engine to eliminate any air that
may be in the fuel lines.
To prime the engine, do the following:
1. Make sure there is fuel in the tank.
2. Make sure the fuel filter had been installed and
properly tightened.
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Page 244 of 366
Cooling System
When you decide it’s safe to lift the hood, here’s what
you’ll 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,
don’t do anything else until it cools down. The vehicle
should be parked on a level surface.The coolant level should
be at COLD FILL or
higher. If it isn’t, 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.
{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.
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