SECTION 03: FUEL SYSTEM
DOB 2490-2789 | X3-45 Commuter PA1605 Maintenance Manual (Section 03 revised May 2018)
3
1.
FUEL SYSTEM DESCRIPTION
NOTE
For detailed service procedures and part replacement information, about Volvo D13 engine and
engine-related components, consult ’ Impact’ available under Volvo’s Premium Tech Tool Software.
FIGURE 1: FUEL SYSTEM SCHEMATIC (VOLVO D13 ENGINE)
03086
Fuel is drawn up the fuel lines by the supply
pump (1) through the pickup tube in the tank (2)
and through the Engine Electronic Control Unit
(EECU) cooling coil (3) and into the fuel filter
housing (4). The fuel housing is equipped with a
primary fuel filter (fuel/water separator)
consisting of a filter cartridge and a water
separation bowl.
The supply pump (1) forces the fuel into the fuel
filter housing through the secondary filter (main)
to a cylinder head longitudinal gallery (8). This
channel supplies each unit injector (9) with
pressurized fuel by a circular groove around
each unit injector in the cylinder head. The
overflow valve (10) controls the fuel supply
pressure to the unit injectors.
The return fuel from the overflow valve (10) is
returned back to the fuel filler housing and is
mixed with the fuel from the fuel tank in a
channel within the fuel filter housing (4).
Supply Pump Valves
Two valves are located in the supply pump (1).
The safety valve (11) allows fuel to flow back to
the suction side when the pressure becomes too
high, e.g., if the fuel filter is blocked or is too
restricted. The non-return valve (12) opens
when the hand-priming pump is used.
Automatic Bleeding
If air gets into the system, it is bled when the
engine starts. During bleeding, air is pressed out
through the fuel filter housing over to the fuel
tank through the return line (25). Bleeding for the
filter replacement is controlled by valves (17)
and (23).
Other
The fuel filter housing eliminates the need to
drain the fuel when replacing the filter. The valve
pegs (17) and (21) close when the fuel filter is
removed. It is not necessary to bleed the fuel
system after replacing the filter, since this is
