Air bubbles can become trapped in the fuel line of a gasoline or diesel engine if you run out of fuel when running the engine, or perform maintenance such as changing a fuel filter. These air bubbles can become trapped in the fuel line, impeding or completely blocking the flow of the fuel to the engine, making the engine run rough or keeping it from running at all. If this is an issue for your John Deere tractor, you can fix it by bleeding the fuel system.
Fill the fuel tank with diesel fuel.
Open the fuel shut-off valve on the fuel tank. The arrow on the valve points up when it is open.
Open the shut-off valve on the fuel filter. The lever will point down to O, which indicates that it is in the open position.
Prime the fuel pump manually by moving the fuel pump primer lever up and down. Continue doing this until the sight bowl on the side of the fuel filter is completely filled with fuel, and you can hear the fuel flowing back to the tank through the return hose.
Start the engine and allow it to run until it idles smoothly.