Bleeding Air From Fuel Circuit - Komatsu 114E-3 Series Shop Manual

30 Testing and adjusting

Bleeding air from fuel circuit

a If fuel is used up or if a fuel circuit part is
removed and installed, bleed air from the fuel
circuit using the electric priming pump accord-
ing to the following procedure.
1. If fuel main filter (1) is removed and installed or
replaced, install it back without filling fuel into
the fuel main filter.
2. Remove fuel pre-filter (on the machine) and fill
it with fuel.
a Fill the fuel filter with clean fuel and take
care that dirt will not enter it.
a Check that the cap is fitted to part (a)
(central hole) of the fuel pre-filter, and then
add fuel through part (b) (holes around the
central hole).
a After filling the fuel pre-filter with fuel,
remove the cap from part (a).
a If clean fuel is not available, do not
remove the fuel pre-filter but fill it with the
fuel by operating priming pump.
a Do not add fuel to fuel main filter (1) from
outside.
114E-3 Series
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3. Fill up the fuel tank with fuel.
4. Keep the starting switch at the ON position for
30 seconds and keep it at the OFF position for
10 seconds.
5. Repeat Step 3 above four times.
6. Start the engine with the starting motor.
a The air in the high-pressure circuit is bled
automatically if the engine is cranked.
a If the engine does not start, there may be
still air in the low-pressure circuit. In this
case, repeat the above procedure from
step 2.
a Operating the machine with air left in the
fuel circuit may cause an fuel system error
(449/CA449, 559/CA559). If either error
occurs, run the engine at low idle after
performing the above steps, and continue
engine operation approximately 3 min-
utes. When air is bled from the fuel circuit,
engine speed becomes stable and the
error indication disappears.
SEN00455-01
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