Product Overview Hydraulic main piston pump assembly engineered for Hitachi EX2500-5, EX2500-6, EX2600-5, EX2600-6, EX5500-5, EX5500-6, EX5600-5, and EX5600-6 mining excavators. This K3V280 pump is a direct replacement for part numbers 4455484 , 4455485 , 4347142 , 4449718 , 4424246 , YA00003083 , and YA00003084 , delivering reliable hydraulic performance for continuous heavy-duty mining operations. K3V280 Hitachi EX Series Mining Excavator OEM Replacement Key Specifications