TM 5-3810-300-24&P-3
2.3
FUEL STRAINER AND FUEL FILTER
The central stud is a permanent part of the shell and, when the
A fuel strainer (primary) and fuel filter (secondary), Fig. I are
unit is assembled, extends up through the cover where the nut
or bolt holds the assembly together.
The fuel strainer is located between the fuel tank and the fuel
A filter element sets over the central stud inside the shell and
pump. The replaceable density-type element is capable of
filtering out particles of 30 microns (a micron is approximately
is centered in the shell by the stud.
.00004" ). The fuel filter is installed between the fuel pump
and the fuel inlet manifold. The replaceable paper-type
The former and current cover assemblies are visibly different
element (Fig. 2) can remove particles as small as 10 microns.
by a cast letter "P" (primary) that has been added to the top of
the strainer cover and the letter "S" (secondary) that has been
added to the top of the filter cover.
CAUTION: A fuel tank of galvanized steel
should never be used for fuel storage, as the
Operation
fuel oil reacts chemically with the zinc
coating to form powdery flakes which quickly
clog the fuel filter and cause damage to the
Since the fuel strainer is between the fuel supply tank and the
fuel pump and the fuel injectors.
fuel pump, it functions under suction. The fuel filter. placed
between the fuel pump and the fuel inlet manifold in the
The fuel strainer and fuel filter are essentially the same in
cylinder head, operates under pressure Fuel enters through
construction and operation, and they will be treated as one in
the inlet passage in the cover and into the-shell surrounding
this section.
the filter element. Pressure or suction created by the pump
causes the fuel to flow through the filter element where dirt
particles are removed. Clean fuel flows to the interior of the
The filter and strainer, illustrated in Figs. 3 and 4, consist
filter element, up through the central passage in the cover and
basically of a shell, a cover, and a replaceable filtering
into the outlet passage, then to the fuel inlet manifold in the
element. The assembly is made oil tight by a shell gasket, a
cylinder head.
cover nut or bolt, and a cover nut or bolt gasket.
Fig. 1 Typical Mounting of Fuel Filter and Fuel Strainer
Fig. 2 - Fuel Filter Assembly
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