COMPONENT OPERATION / Pilot Valve OUTLINE The pilot valve controls pilot pressure oil in order to move spool in control valve. The pilot valve outputs pressure according to the control lever stroke by PPC (Pressure Proportional Control Valve) function and moves the spool in control valve. The 4-port pilot valves for front attachment/swing and for travel are standard. The 2-port pilot valve is for counterweight (optional) and for auxiliary (optional). NOTE: As for the pilot valves for front attach- ment/swing and for travel, the structure of cam to push in the pusher is different and that of pressure-reducing valve is same.
Front Attachment / Swing Pilot Valve P 4 T105-02-07-020 3 1 T1V1-03-04-001 2 T T3-4-1 Port No. ISO Control Pattern Hitachi Pattern Right 1 Bucket Roll-Out ← 2 Boom Lower ← 3 Bucket Roll-In ← 4 Boom Raise ← Left 1 Right Swing Arm Roll-In 2 Arm Roll-Out Right Swing 3 Left Swing Arm Roll-Out 4 Arm Roll-In Left Swing ulic P T l 1 3 2 4 Hydra Symbo ulic l