ONL843NW4 11/13
17
Servicing
SP10. BLEEDING THE FUEL SYSTEM
CAUTION: Escaping diesel fuel under pressure can penetrate skin causing serious personal injury.
Before disconnecting lines be sure to relieve all pressure. Before applying pressure, be sure all
connections are tight and lines, pipes and hoses are not damaged. Fuel escaping from a very small hole
can be almost invisible. Use a piece of cardboard or wood, rather than hands, to search for suspected
leaks. If injured by escaping fuel, see a doctor at once. Serious infection or reaction can develop if proper
medical treatment is not administered immediately.
Figure 9:
NL843NW3 Fuel System (for illustration purposes).
1. The fuel system is self-bleeding. However, any
system may need manual bleeding when:
a. A new fuel filter is installed;
b. The engine has run out of fuel;
c. The fuel lines, injection pump or any other fuel
system component has been removed and
installed.
2. Loosen bleed bolt “A” (
Figure 9
) on top of the filter.
Pump hand primer “B” on fuel lift pump until pure
fuel (no bubbles) escapes from bleed bolt “A”.
Tighten bleed screw “A”.
3. Loosen bleed screw “C”. Pump hand primer “B” until
pure fuel (no bubbles) escapes. Then tighten bleed
screw “C”.
4. If the engine does not start after the above bleeding
process, loosen a fuel line at the injector while
cranking the engine with the starter motor until pure
fuel escapes. Then tighten the connection. Do each
line
one-at-a-time.
5. After the engine has started, use a piece of cardboard
to look for fuel leaks.
