SYSTEM / Hydraulic System OUTLINE The hydraulic system is broadly divided into two cir- cuits, the main circuit and the pilot circuit. Pilot Circuit: Power Source Controller Pilot Circuit Pump Regulators Pump Control Circuit Pilot Pump Pilot Valves Operation Control Circuit Solenoid Valve Unit Valve Control Circuit Signal Control Valve Swing Parking Brake Release Circuit Accumulator Travel Motor Swash Angle Control Circuit Emergency Boom Lower Circuit Main Circuit: Hydraulic Oil Heat Circuit Power Source Controller Actuator Main Pumps Control Valves Motors Cylinders Front Attachmens (Optional) Fan Pump Fan Motor (For Oil Cooler / Radiator) T2-4-1