Hitachi ZW 120-6 Operator's Manual page 253

5. Pour new hydraulic oil into cartridge type element (5).
6. Coat O-ring (7) on new cartridge type element (5) with
hydraulic oil. Install cartridge type element (5) to filter
head (6) by turning the hexagonal section on the bottom
of cartridge type element (5) with a spanner. After O-ring
(7) comes in contact with the seal surface on filter head
(6), further tighten the element by 3/4 turns. Take care
not to damage cartridge type element (5) as it may
become deformed if overly tightened.
f
NOTE:
 When installing the element, take care not to allow O-ring
(7) to break due to twisting.
Check for oil leaks around the mounting surface of
cartridge type element (5).
 Replace the element at the regular intervals. The element
keeps transmission oil clean and to extend hydraulic
components service life.
MAINTENANCE
7-35
6
7
5
M4FG-07-030