SBS120 Hydraulic Main Pump Assembly Part Numbers: 272-6955, 173-3381 Compatible with: E321D, E320C, E320D, E323D Excavators Purchasing and Installation Guidelines Verify OEM part number compatibility, including regulator and servo valve assembly Require hydraulic bench test report for pressure, flow, and case drain leakage For remanufactured units, confirm replacement of pistons, cylinder block, valve plate, slippers, bearings, and all seals Inspect pump housing for pores and