Hitachi ZW 550-6 Operator's Manual page 361

6. Slightly loosen air bleeder valve (7) of the EGR
(Exhaust Gas Recirculation) cooler.
IMPORTANT: Be sure to loosen the plug before
supplying the coolant.
7. Prepare a container of more than 5 liters (1.3 gallons)
capacity under the outlet (8) of the hose from air
bleeder valve (7).
8. Supply low impurity soft water or tap water together
with the specified LLC. When adding coolant, do so
slowly (less than 5 L (5 quart)/minute) to avoid mixing
air in the system.
Tighten valve (7) when coolant comes out from
outlet (8).
Tightening torque: 23.5 N·m (17.3 lbf·ft)
9. Continue to supply coolant up to the bottom level (4)
of the radiator filler port.
10. To drain any residual air pockets from the EGR
coolers, open air bleeder valve (7) again and allow 4
liters (1.0 gallon) or more to drain out of outlet (8).
Tighten valve (7) after the bleeding is complete.
Tightening torque: 23.5 N·m (17.3 lbf·ft)
11. Refill the coolant to the bottom level (4) of the
radiator filler port.
f
NOTE: The drained coolant in the above step 9. can be
used.
12. Tighten radiator cap (1) firmly.
13. Supply the LLC up to "FULL" level line (5) of the
radiator sub tank.
14. Start the engine and run the engine at low idle for
about 5 minutes, and stop the engine.
The coolant level should be lowered as the mixed air
in the coolant is released.
IMPORTANT: Take care the coolant temperature not
to reach 75°C (167°F) or higher while idling the
engine.
15. Wait until the engine and the coolant are cooled.
Remove radiator cap (1) and supply the coolant to
the bottom level (4) of the radiator filler port.
If the coolant level in the radiator is abnormally low,
check for possible leakage.
16. Tighten radiator cap (1) firmly.
17. Add the coolant in the sub tank to 3/4 level (6).
MAINTENANCE
8
6
7-77
7
5
3/4
115Z7B-7-75-1
4
115Z7B-7-71-2
95Z7B-7-75-3