Maintenance
61
Bleeding air from the fuel system
Air in the tubes of the fuel circuit will make the engine
difficult to start. Air may enter the circuit when the
filters and tubes are demounted, during long periods
of inactivity or when all the fuel in the tank is used
(something that should never be allowed to happen).
The tank should be kept full and the taps open.
Proceed in the following way to bleed the air from the
system:
1. Make sure that the fuel tank contains a sufficient
quantity of fuel.
2. (Fig. 50) Slacken off the bleeder fitting at the top of
the filter body (1) by a couple of turns. Operate the
fuel pomp lever (2) until bubble-free fuel flows out
of the bleeder. Re-tighten the bleeder.
3. Slacken the bleed screw (3) of the injection pump
in a similar way (Fig. 51-52-53).
4. Slacken off the other bleeder screw (4) by a couple
of turns and loosen at least two of the injector
unions (5). Turn the engine using the starter motor
until bubble-free fuel flows out of the tubes. Re-
tighten the unions and leave screw (4) slack.
CAUTION:
do not operate the starter motor for more
than 20 seconds at a time to avoid overheating the
windings. If the engine fails to start, wait a while to let
the starter motor cool down before trying again.
5. Start the engine and re-tighten the screw (4) as
soon a bubble-free fuel flows out of it.
6. Check all the fuel lines and seals for leaks.
Fig. 51 - 5860
Fig. 52 - 6060
Fig. 50
Fig.53 - 6860 - 7860 - 8860
Routine Maintenance
See operations 5, 31, 33, 41 and 44 in the Routine
Maintenance Guide.
