Product Overview The swing hydraulic pump with part numbers 593-3840 and 593-3841 is a hydraulic power unit specially designed for the swing system of E374 and E395GC excavators. It supplies high-pressure hydraulic oil to drive the swing motor assembly. Built with a variable piston structure, precise flow control, wear-resistant alloy materials, and precision machining, this pump offers direct replacement installation and stable output performance for heavy-duty mining and