PREVOST X3-45 Multiplex, Руководство по обслуживанию

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Section 03: FUEL SYSTEM
PA1562
3
1. FUEL SYSTEM WITH DETROIT DIESEL SERIES 60 ENGINE
1.1 DESCRIPTION
Figure 1 shows a schematic of the fuel system. Fuel is drawn from the fuel tank through a manual shut-off
valve, a primary fuel filter (fuel-filter/water-separator) before it enters the MCM and the fuel pump. If the
vehicle is equipped with the optional “Davco Fuel Pro 382”, this one replaces the primary fuel filter.
Leaving the pump under pressure, the fuel flows through a secondary fuel filter and a shut-off valve, then
to the cylinder head. The fuel reaches the injectors in the cylinder head through passages within the
head. Excess fuel exits at the rear of the head just above the inlet, through a restrictive return fitting which
maintains fuel pressure in the system. Finally, the fuel flows through the check valve and the fuel cooler
before it returns to the fuel tank. One preheater is available: 104 000 BTU. If the vehicle is equipped with
the 104 000 BTU preheater, the fuel is drawn from the fuel tank through the fuel filter to the preheater.
Excess fuel returns to the fuel tank.
FIGURE 1: FUEL SYSTEM SCHEMATIC (DDC SERIES 60 ENGINE)
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1.2 FUEL VALVES
Manual shut-off valves on engine fuel-supply
line are located on the R.H. side of engine
compartment. A manual shut-off valve is located
at the inlet side of the primary fuel filter under
the starter or at the inlet side of Davco Fuel Pro
382 fuel filter. Another manual shut-off valve is
located at the outlet side of the secondary fuel
filter. Shut-off valve are designed to prevent loss
of fuel prime at time of filter replacement. No
manual valve is required on preheater fuel-supply
line, since the positive-displacement fuel pump
(located close to the fuel tank) prevents fuel flow
when not activated.
FIGURE 2: MANUAL SHUT-OFF VALVES LOCATION
(DDC S60 ENGINE)
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