OTTO Hydraulic Main Pump Assembly (4437197) for Hitachi ZAXIS70 / ZX70 / ZX80 excavator - bolted to the pump drive on the engine, behind the coupling. It draws oil from the hydraulic tank and delivers it under pressure to the main control valve, which feeds the boom, arm, bucket and travel circuits. Supplied as an OTTO replacement, checked before packing, with 3-12 months warranty options. Send us your machine serial and a photo of the old part and we will confirm fitment before dispatch.