Hitachi ZAXIS 450LC-3 Operator's Manual page 224

7. After installing the bottom side of the left-hand boom
cylinder to the main frame, lay the rod side of the boom
cylinder onto supporting stand (7).
8. Install the right-hand boom cylinder in the same
procedure as taken in the steps 2 to 5 above.
d
WARNING:
• Stop the engine. Move the control levers back and
forth, and right and left several times to release
the remaining pressure in the hydraulic line.
• Before connecting hoses between the boom cylin-
der and the machine, gradually loosen bolts secur-
ing the covers to the ends of the hydraulic piping
on the machine to release the trapped oil pressure
in the piping.
9. Gradually loosen bolts securing the covers to the ends
of the hydraulic piping on the machine to release the
trapped oil pressure in the piping. Then, remove the
covers.
10. Connect four hoses between both the right and left
boom cylinders and the machine.
Tightening torque: 180 N•m (18 kgf•m, 130 lbf•ft)
11. To prevent the seal from damage, bleed the air from the
boom cylinder in the following procedures:
(1) Run the engine at slow speed.
(2) Slowly extend or retract boom cylinder rod (8).
(3) Repeat the same operation of the step 2 above until
cylinder rod (8) moves smoothly.
ASSEMBLING
6-32
7
M116-07-028
8
M116-07-028