TUBE ASSEM. 4K8512 - Caterpillar

Priming the fuel system fills the fuel filter. Priming the fuel system removes air bubbles from the fuel system. Prime the fuel system under the following conditions:
Fuel system that is run dry
Storage
Fuel filter maintenance
Disconnecting fuel lines and installing fuel lines
Repair of leaks in the fuel lines
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.
Use a suitable container to catch any fuel that might spill. Clean up any spilled fuel immediately.
Illustration 1 g00286060
Illustration 2 g00753296The fuel priming pump may be located on the left side of the engine behind the fuel filter on the fuel transfer pump. Some engines have a fuel priming pump that is mounted on top of the fuel filter base (1).
Illustration 3 g00753293
(2) Vent screw for the fuel 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 disconnected fuel system component.
The vent screw (2) for the fuel system is located on the fuel inlet connection. Turn the vent screw for two or three revolutions counterclockwise.
In order to operate the hand fuel priming pump, push down on the top of the lever and release the lever. Operate the fuel priming pump in order to fill the new filter element. Continue to pump until fuel that is free of air flows from the vent. Tighten the vent screw to 6 1 N m (4.4 0.74 lb ft). Note: It is not possible to operate the priming lever if the cam of the fuel transfer pump is at the cam's maximum lift position. If this occurs, the crankshaft must be rotated one revolution. If you are not able to prime the engine, consult your Caterpillar dealer.
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.
Start the engine. If the engine will not start, further priming is necessary. If the engine starts but the engine continues to misfire, further priming is necessary. If the engine starts but the engine continues to emit smoke, further priming is necessary.
If the engine starts but the engine runs rough, continue to run the engine at low idle. Continue to run the engine at low idle until the engine runs smoothly.