Hitachi ZAXIS 30U-5N Operator's Manual page 224

4. Rotate filter case (6) of pilot filter (4) counterclockwise to
remove filter case (6).
5. While rotating filter element (7), pull to remove filter
element (7) downward.
6. Replace O-ring (8) with a new one.
7. Clean the filter O-ring (8) contact area on filter head (5).
8. Securely install O-ring (8) in the O-ring groove on head
cover (5).
9. Coat the seal on new filter element (7) with clean
hydraulic oil. Completely install filter element (7) into
head cover (5) while rotating filter element (7) taking
care not to damage filter element (7).
10. Take care not to allow dust and/or water enter filter case
(6).
11. Install case (6) into head cover (5) while rotating case (6)
clockwise.
Tightening Torque: 2 5 to 35 N·m
12. After replacing filter element (7), bleed any remaining air
from the hydraulic circuit.
Check the oil level in the hydraulic oil tank. Add oil as
needed.
(Refer to the descriptions for "Bleed Air from Hydraulic
System")
If the machine is operated with air mixed in the hydraulic
circuit, damage to the pump may result.
13. Install under cover (2).
Wrench size: 17 mm
14. Tighten cap (1).
f
NOTE: Replace element (7) at the regular interval to keep
hydraulic oil clean and to extend the service life of the
hydraulic components.
MAINTENANCE
(2.5 to 3.5 kgf·m, 18.0 to 26 lbf·ft)
4
8
7
6
7-44
5
MADB-07-020
M503-07-031
MADB-07-004