Figure 1-19.—Fuel filter operation.
The fuel filter operates by passing fuel through a
porous material that blocks particles large enough to
cause a problem in the system. Some filters also act as
sediment bowls; water and larger particles of foreign
matter settle to the bottom where they can be drained off
(fig. 1-19).
Figure 1-20 shows the three types of fuel filters in
common use. They are the replaceable in-line filter
(view A), the in-line filter element (view B), and the
glass bowl (view C).
Filter elements are made from ceramic, treated
paper, sintered bronze, or metal screen, as shown in
figure 1-21. A filter element that differs from the others
is a series of closely spaced laminated disks. As the
gasoline proses between the disks, foreign matter is
blocked out.
Diesel Fuel Filters
Diesel fuel filters are called full-flow filters,
because all the fuel must pass through them before
reaching the injection pumps. They are very important
because diesel fuels are more viscous than gasoline and
Figure 1-20.—Fuel filter configurations.
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