Hitachi ZAXIS 30U-5N Operator's Manual page 237

Bleed Air from the Fuel System (ZX50U-5N, 60USB-5N)
This machine is equipped with a electrical fuel pump.
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CAUTION: Fuel leaks may lead to fires.
1. Confirm that the fuel level is more than one-half of
the tank capacity. If the fuel level is lower, automatic
bleeding device will not operate. Add fuel.
2. Turn the key switch ON and hold it in that position for
approx. 3 minutes. Thereby, the electrical fuel pump
operates, starting to bleed air.
3. After the main filter is filled with fuel, hold the key switch
in the ON position for 30 seconds.
4. Start the engine. Check the fuel supply system for fuel
leaks.
IMPORTANT: Even if air is not thoroughly bled, do not
hold the key switch in the ON position for more than
5 minutes. In case air is not thoroughly bled, first
return the key switch to the OFF position. Then, after
waiting for more than 30 seconds, turn the key switch
ON again. Failure to do so may cause damage to the
electrical pump and/or discharging the batteries.
If Air Mixed After Common Rail
In case air mixed in the fuel system due to lack of fuel and
the engine is difficult to start, release air by following the
procedure given below.
1. Bleed air until the engine supply pump entrance enough
according to the above-mentioned procedures.
2. Operate starter motor for long cranking within 20
seconds. If engine falls to start, return key switch to OFF.
Wait more than about 60 seconds, and then try again.
MAINTENANCE
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