Hitachi ZAXIS 130-6N Operator's Manual page 322

Service Recommendations for Hydraulic Fittings
Two hydraulic fitting designs are used on this machine.
 Flat Face O-ring Seal Fitting (ORS Fitting)
O-ring (1) is used on the sealing surfaces of adapter (2) to
prevent oil leakage.
Precautions for Use
1. Replace O-ring (1) with a new one when assembling
fittings.
2. Check that O-ring (1) is properly fitted in O-ring groove
(3). Tighten union (4).
Tightening union (4) with O-ring (1) out of the groove
may damage O-ring (1) and cause an oil leak.
3. When assembling fittings, take care not to make a dent
on O-ring groove (3) of adaptor (2) and sealing surface
(6) on hose (5) or the side of the valve. Failure to do so
may result in damage to O-ring (1) leading to an oil leak.
4. If oil leaks from a loose connection of union (4), do not
tighten fitting. Open the connection, replace O-ring
(1) with new one and check for correct O-ring position
before tightening the connection.
Tightening Torque:
Tighten fittings to the torque values shown below.
Wrench size (mm)
N·m
Tightening
(kgf·m)
Torque:
(lbf·ft)
MAINTENANCE
27 32 36
95 140 180
(9.5) (14) (18)
(70.1) (103.3) (132.8) (154.9)
±10%
41, 46
210
(21)
7-56
2 1 4
3 6
5
M104-07-033