A brief description of each of these systems and their
The Series 53 Detroit Diesel engines incorporate four
components, and the necessary maintenance and
basic systems which direct the flow of fuel, air,
lubricating oil, and engine coolant.
adjustment procedures are given in this manual.
The fuel system (Figs. 1 and 2) consists of the fuel
A check valve may be installed between the fuel
injectors, fuel pipes, fuel manifolds (integral with the
strainer and the source of supply as optional
cylinder head), fuel pump, fuel strainer, fuel filter and
equipment to prevent fuel drain back when the engine
the necessary connecting fuel lines.
is not running.
On In-line engines, a restricted fitting is located in the
cylinder head fuel return manifold outlet to maintain
pressure within the fuel system. On V-type engines,
this restricted fitting is located in the left-bank
The fuel injector combines in a single unit all of the
parts necessary to provide complete and independent
fuel injection at each cylinder. The injector creates the
high pressure necessary for fuel injection, meters the
Fuel is drawn from the supply tank through the fuel
proper amount of fuel, atomizes the fuel and times the
strainer and enters the fuel pump at the inlet side.
Upon leaving the pump under pressure, the fuel is
forced through the fuel filter and into the fuel inlet
manifold where it passes through fuel pipes into the
Since the injector is one of the most important and
inlet side of each fuel injector. The fuel is filtered
carefully constructed parts of the engine, it is
through elements in the injectors and atomized
recommended that the engine operator replace the
through small spray tip orifices into the combustion
injector as an assembly if it is not operating properly.
chamber. Surplus fuel, returning from the injectors,
Authorized Detroit Diesel Allison Service Outlets are
passes through the fuel return manifold and
properly equipped to service injectors.
connecting fuel lines back to the fuel tank.
The continuous flow of fuel through the injectors helps
to cool the injectors and remove air from the fuel
Fig. 1 - Schematic Diagram of Typical Fuel
Fig. 2 - Schematic Diagram of Typical Fuel
System - In-Line Engine
System - V-type Engine