TUBE AS 5328165 - Caterpillar

Move the control valve to the AUX RUN position. The fuel pressure gauge for the auxiliary fuel filter should indicate full pressure. The fuel pressure gauge for the main fuel filter should indicate no pressure.
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.
Use a suitable container to catch any fuel that might spill. Clean up any spilled fuel immediately.
Remove the used main fuel filter. Use a cloth or use a container