How to Bleed Air from Fuel System for Hitachi ZX890LCH-7 Excavator

This instruction show you guide on how to bleed air from fuel system for Hitachi ZX890LCH-7 ZX890LCR-7.Air in the fuel system may make the engine hard to start or make it run irregularly. After draining water and sediment from the fuel filter,replacing the fuel filter element or running the fuel tank dry, be sure to bleed the air from the fuel system.

 

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IMPORTANT

Even if air is not thoroughly bled, do not hold the key switch in the ON position for more than five minutes continuously. If air is not thoroughly bled, first,return the key switch to the OFF position. Then, after waiting for more than 30 seconds, set the key switch to the ON position again. Failure to do so may cause damage to the fuel solenoid pump and/or discharging the batteries.

 

Check that fuel cock (1) near the fuel pre-filteris opened.

Set the key switch to the ON position and hold it in that position for approximately three minutes. The fuel solenoid pump operates and starts to bleed air.

 

 

CAUTION

Bleed air from fuel main filter(2) one side at a time. Loosen air bleed plug (3) on fuel main filter(2) while turning the key switch to the ON position. Run priming pump (4). When air is bled from fuel main filter(2), tighten air bleed plug (3). Return priming pump (4) to its original position.

 

Wipe offleaked fuel.

After fuel main filter(2) is filledwith fuel, hold the key switch in the ON position for 30 seconds.

Start the engine and check the fuel system for any fuel leakage.

 

Priming Pump Only

When a fault on the fuel solenoid pump or some other reason prevents air from being bled, air can be bled on only the priming pump.

Check that fuel cock (1) near the fuel pre-filteris opened.

 

Loosen air bleed plug (3) on fuel main filter(2).:10 mm

Run priming pump (4), and supply fuel. When air bubbles no longer come out, tighten air bleed plug (3). : 10 mm

After tightening air bleed plug (3), run priming pump (4) approximately 150 times.

Wipe offleaked fuel.

Start the engine and check the fuel system for any fuel leakage.

 

If Air Mixed Downstream from Common Rail

If air becomes mixed into the fuel system of downstream from common rail, bleed air by following the procedure below.

According to the air bleeding procedures, bleed enough air up to the engine supply pump entrance.

Operate the starter motor for cranking within 20 seconds. If the engine fails to start at a time, wait about 60 seconds, then try again.

 

More repair cases for Hitachi excavator,please refer to:Hitachi Excavator Trouble Repair.