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