Once you have refilled your tank with fresh diesel, the task of "bleeding" the system begins. But how exactly do you do it? The process starts at the fuel filter. Most diesel engines are equipped with a manual primer pump—often a small plunger or a flexible bulb located near the filter housing.

First, locate the bleed screw on top of the fuel filter housing. Loosen it slightly, then begin pumping the primer. You will likely see a mixture of bubbles and foam escaping. Continue pumping until a steady stream of pure, liquid diesel flows out without any air. Tighten the screw and move to the next point in the system, typically the fuel injection pump. In some older engines, you may even need to slightly loosen the high-pressure union nuts at the injectors themselves. As you crank the engine, fuel will spurt out; once it is free of air, tighten the nuts. This systematic removal of air restores the solid column of fuel required for the injectors to function, allowing the engine to roar back to life. Click here to know more.