The fuel pump has an internal check valve built into the pump to keep the fuel pressure in the fuel lines up to the fuel injectors. You will have to replace the fuel pump assembly to repair this problem. The check valve is not a separate item. It will not cause any damage to the vehicle or the engine if you do not repair it right away. Just cycle the ignition key on and of a couple of times and fuel will flow to the engine, then you should be able to start the truck.