Water In Fuel Light Chart
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. The fuel filter is located in the engine
compartment, 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.
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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 5-22orEngine Oil (DURAMAX®Diesel)
on page 5-22orEngine Oil (Gasoline Engine) on
page 5-26.
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
®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.
Air can get into the fuel lines if any of the following happen:
•The vehicle runs out of fuel.
•The fuel filter is removed for servicing or
replacement.
•The fuel lines are removed or disconnected for
servicing.
•The fuel filter water drain valve is opened while the
engine is running.
If one or more of the above occurred, 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.
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Priming the 6.6L DURAMAX®Diesel
Engine
If your vehicle is equipped with the 6.6L DURAMAX®
diesel engine, it has a 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 6.6L DURAMAX
®diesel 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.
3. Make sure the fuel lines are properly connected
and the fuel filter is cool enough to touch.4. Remove any dirt from the fuel filter head and vent
valve by wiping with a cloth.
5. Open the fuel filter vent
valve by turning the
screw counterclockwise
several full turns.
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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.
5-14
6. Use the palm of your hand to repeatedly press and
release the plunger (1) at the top of the fuel filter
priming pump. Continue until the plunger resistance
becomes firm. This may take from 20 to 100 times,
depending upon fuel tank location.
7. Turn the fuel filter breather valve screw (2)
counterclockwise several turns to open the
breather valve.
8. Use the palm of your hand to repeatedly press and
release the plunger (1) at the top of the fuel filter
priming pump until fuel begins to seep from
the breather valve.
9. Tighten the fuel filter breather screw (2) to the
specified torque, 4.9Y(43 in. lbs).
10. Use the palm of your hand to press and release the
plunger (1) at the top of the fuel filter priming pump
about 20 more times. This sends fuel to the engine.
11. Use a clean cloth to remove any fuel from the fuel
filter and surrounding area.
12. Start the engine and allow it to idle for a few minutes.
13. Check the fuel filter for leakage.Running Out of Fuel
If the diesel engine stalls and you think that you have
run out of fuel, do this to restart your engine:
{CAUTION:
Diesel fuel is ammable. It could start a re if
it gets on hot engine parts. You could be
burned. Do not let too much fuel ow from the
air bleed valve, and wipe up any spilled fuel
with a cloth.
1. If you are parked on a level surface, add at least
2 gallons (7.6 liters) of fuel. However, if you are
parked on a slope, you may need to add up
to 5 gallons (18.9 liters) of fuel.
2. Follow the fuel priming procedure earlier in this
section to prime the fuel filter.
3. Close the air bleed valve.
4. Turn the ignition key to START for 10 to 15 seconds
at a time until your engine starts. If the engine tries
to run, but does not run smoothly, increase the
rpm a little using the accelerator pedal. This will help
force air through the system.
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