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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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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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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.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 idle for a few minutes.
11. Check the filter for leaks.
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