Chevrolet GMC 2002 Owner's Manual Supplement page 40

Fuel Filter Replacement (3500HD Models)
Your vehicle's engine should be off until the end of
the following procedure.
The fuel filter is located at the rear of the engine.
To access the filter, remove the engine cover.
See "Engine Compartment Overview" in the
Index for more information on location.
1. Apply the parking brake.
2. Take off the fuel cap. This releases vacuum or
pressure in the tank.
3. Unscrew and remove the ring nut from the top of the
filter head.
4. Lift the element out of the filter head using the pull
tab attached to the top of the filter. If there is any
dirt on the element sealing surface of the filter head,
clean it off.
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