GMC TopKick 2007 Owner's Manual page 257

Priming the 7.8L Isuzu 6H Diesel Engine
If your vehicle is equipped with the
7.8L Isuzu 6H 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.
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, 4.9
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.
(43 in. lbs).
Y
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