This fuel feed pump draws diesel from the tank and delivers it to the injection pump at the required pressure for the host tractor. It mounts on the engine block and is driven by the camshaft or an intermediate gear; the pump's internal diaphragm or plunger mechanism creates the suction and discharge strokes that maintain a steady fuel supply. A failing feed pump causes hard starting, loss of power under load, or erratic engine speed as fuel starvation occurs. The original manufacturer machines the mounting flange and drive interface to the same tolerances as the original assembly, so no shimming or adapter plates are needed for installation. When replacing, inspect the fuel lines for debris and replace any gaskets or seals disturbed during the swap.