GEAR 7G3454 - Caterpillar

Fuel leaked or spilled onto hot surfaces or electrical components can cause a fire. To help prevent possible injury, turn the start switch off when changing fuel filters or water separator elements. Clean up fuel spills immediately.
The fuel system should be primed after a unit injector is changed or when the fuel system is totally dry.Note: The fuel system does not typically need to be primed when the primary fuel filters or secondary fuel filters are changed or when an Electronic Control Module (ECM) is replaced. When the engine is started under these circumstances, the engine may momentarily run rough until the air is purged from the system.
Do not allow dirt to enter the fuel system. Thoroughly clean the area around a fuel system component that will be disconnected. Fit a suitable cover over any disconnected fuel system components.
Illustration 1 g01518793
Typical industrial engine
Illustration 2 g01518794
Typical petroleum engine
Illustration 3 g01275944
The secondary fuel filter gp is shown.
(1) Fuel priming pump
(2) Fuel filter base
(3) Secondary fuel filter
(4) Priming pump plunger Follow the procedure below in order to prime the engine with fuel.
Turn the priming pump plunger (4) counterclockwise in order to unlock the plunger. Manually pump the plunger in order to fill the fuel lines and the fuel filters with fuel.
As the air is purged from the fuel system, fuel pressure will increase. This will create resistance in the plunger. Continue to pump the plunger until a strong resistance is felt. The number of strokes will vary with the amount of air in the fuel lines.
After resistance is felt in the plunger, push in the plunger. Lock the plunger by turning the plunger clockwise.
Start the engine at low idle.
If the engine runs rough, continue to run the engine at low idle until the engine runs smoothly.