How many different ways are there to prime diesel engines? Gino Pinar
There are basically three different methods. The first is for vehicles with a hand primer built into either the fuel filter or fuel line, which can be used to bleed the system through. The second method for vehicles equipped with a low-pressure electric supply pump is to repeatedly turn the ignition on and off. When the ignition is turned on, the system will initially activate the fuel pump to prime the system. Unless the engine is running or cranking, this initial burst will cease after a short time. Turning the ignition on and off repeatedly will utilise this initial burst of fuel to bleed the system.
The third method is used when there is no electric pump fitted and no builtin primer incorporated in the system. Here, a syphon is used to draw the fuel through the filter after replacement. Very often the syphon can be placed on the return pipe from the high-pressure fuel pump, to draw the fuel through the complete system including the engine fuel supply pipes.