The fuel system (Figure 2) consists of hoses, steel injector piping, fuel tank, fuel filter/water separator, fuel
transfer pump, injection pump and injectors. Fuel is drawn from the fuel tank by the fuel transfer pump. Fuel
passes through a fuel filter/water separator where water and small impurities are removed before arriving at the
fuel transfer pump. The fuel is then pushed through the secondary fuel filter that removes even smaller particles
from the fuel. The fuel then enters the injector manifold and goes into the injectors which are controlled by the
ECM and actuated by a hydraulic injection pump that is part of the high pressure oil system. Through the
injectors fuel enters the diesel engine combustion chamber, where it is mixed with air and ignited. The fuel that is
not used is cooled and returned to the fuel tank via an excess fuel return line.