Hydraulic Circuit And Electrical Circuit; Hydraulic System - Hitachi Zaxis 850LC-3 Operator's Manual

HYDRAULIC SYSTEM

IIMPORTANT: Hydraulic equipment such as hydraulic
pumps, control valves, and relief valves have
been adjusted at the factory. Do not attempt
to disassemble or turn the adjusting screws,
as they are very difficult to readjust. Consult
your authorized dealer if any trouble should
occur.
• The excavator is equipped with the "O. H. S" (Optimum Hy-
draulic System) developed by Hitachi.
The "O. H. S" features:
Quick response of the actuators.
Improved precise swinging.
Improved combined operation of each functions.
• The control valve and each circuit are provided with relief
valves of sufficient capacity to protect the actuators and
other equipment from damage caused by the surge pres-
sure and filter plugging.
• Travel parking brake is automatically released when the
travel lever is operated. When the control lever is placed
in NEUTRAL, the brake is automatically applied.
• Swing parking brake is automatically released when any
control levers except for the travel levers are operated.
When the control lever is placed in NEUTRAL, the brake is
automatically applied.
• The excavator is equipped with an accumulator in the hy-
draulic system in order to operate front attachment for a
few seconds after the engine has stopped. The accumula-
tor is charged with high pressure gas: do not attempt to
remove or disassemble it, and do not expose the accumu-
lator to flame.
HYDRAULIC CIRCUIT AND ELECTLICAL CIRCUIT
8-1