Excavator Komatsu PC210-8K PC200-8K PC240-8K Main Control Valve Part Numbers 723-47-23400, 723-47-23404 Common Faults Slow and weak machine movements Weak operation of single actuator (boom / arm / bucket / swing / travel) Jerky and vibrating movement Interference during combined operation, poor flow merging External leakage of main control valve, oil seepage and oil leakage on valve body Severe internal leakage, rapid pressure drop and poor pressure retention Spool sticking,