Steering Hydraulic Pump Part Numbers 708-1U-00163, 708-1U-00161, 708-1U-00162 Compatible with Komatsu WB93R-5, WB93R-8, WB97R, WB97S-5E0, WB146-5, WB156-5 series backhoe loaders Common Axial-Piston Main Pump Failure Modes Most axial-piston main pump failures result from gradual wear and contamination rather than catastrophic failure: Internal Leakage: Wear of cylinder block, port plate, or pistons causing flow and pressure drop - results in sluggish, weak, or jerky machine