SYSTEM / Control System Pressure Sensor Boom Raise Boom Lower Arm Roll-Out Arm Roll-In Bucket Roll-Out Bucket Roll-In Solenoid Valve Unit Pilot Pump Boom Cylinder Arm Cylinder Boom Flow Rate Control Valve (Switch Valve) Pump 1 Pump 2 NOTE: The illustration shows during combined operation of boom lower and arm roll-in. T1J1-02-02-017 T2-2-53