DETROIT DIESEL 53
to the extent that they should be changed is based on
the fuel pressure at the cylinder head fuel inlet
manifold and the inlet restriction at the fuel pump. In
a clean system, the maximum pump inlet restriction
minimum. Select the proper grade of fuel in
must not exceed 6 inches of mercury. Al normal
accordance with the Diesel Fuel Oil Specifications in
operating speeds (1800-2800 rpm), the fuel pressure is
Section 13.3. Open the drain at the bottom of the fuel
45 to 70 psi. Change the fuel filter elements whenever
tank every 500 hours or 15,000 miles to drain off any
the inlet restriction (suction) at the fuel pump reaches
water or sediment.
12 inches of mercury at normal operating speeds and
whenever the fuel pressure at the inlet manifold falls
to 45 psi.
Install new elements every 300 hours or 9,000 miles or
when plugging is indicated.
Remove the dirty oil and sludge from the oil bath type
A method of determining when elements are plugged
air cleaner cups and center tubes every 8 hours (every
6,000 miles for highway vehicle engines), or less if
operating conditions warrant. Wash the cups and
elements in clean fuel oil and refill the cups to the
level mark with the same grade and viscosity heavy-
duty oil as used in the engine. The frequency of
servicing may be varied to suit local dust conditions.
It is recommended that the body and fixed element in
the heavy-duty oil bath type air cleaner be serviced
every 500 hours, 15,000 miles or as conditions warrant.
Clean or replace the element in the dry-type air
cleaner when the restriction indicator instrument
indicates high restriction or when a water manometer
reading at the air inlet housing indicates the
maximum allowable air inlet restriction (Section 13.2).
With the engine running, check for flow of air from
the air box drain tubes every 1,000 hours or 30,000
miles. If the tubes are clogged, remove, clean and
reinstall the tubes. The air box drain tubes should be
SEC. 15.1 Page 5