Wheel Loader Komatsu WA150-5 WA150-6 Hydraulic Pump Piston Pump Main Hydraulic Pump 416-18-31600 416-18-31601 Common Faults & Diagnostic Analysis Slow Boom Lifting & Bucket Retraction Insufficient pressure and weak performance under heavy load caused by wear of gears, side plates, and bushings. This reduces volumetric efficiency and increases internal leakage, preventing pressure buildup. Hydraulic Pump Whistling & Abnormal Noise Heavy vibration resulting from clogged suction