PIN 3034958 - 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.
Illustration 1 g00123061
(1) Plug. (2) Fuel priming pump. (3) Fuel filter.
Priming the fuel system fills the fuel filters. Priming the fuel system also removes air from the fuel system. This procedure is used primarily when the engine runs out of fuel.Note: DO NOT remove plug (1) in the fuel filter base in order to release air from the fuel system during periodic service of the fuel filter. Periodic removal of the plug (1) will result in increased wear of the threads in the fuel filter base. This can lead to fuel leakage. However, plug (1) can be used to remove air from the fuel system if the engine runs out of fuel.
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.
Open fuel priming pump (2) and operate the fuel priming pump until a strong pressure is felt on the fuel priming pump and until the check valve "clicks". This procedure will require considerable strokes. Lock the fuel priming pump.
Crank the engine after pressurizing the system.
Do not crank the engine continuously for more than 30 seconds. Allow the starting motor to cool for two minutes before cranking the engine again.
If the engine does not start, open fuel priming pump (2) and repeat Steps 1 and 2 in order to start the engine.