The document provides instructions for removing and installing a piston pump on a 257D Multi Terrain Loader. It describes disconnecting hoses and harness assemblies, using various tools to support the pump during removal, and reversing the steps for installation. The pump must be disassembled by removing valves, coils, cartridges, seals and other components. Assembly is the reverse of disassembly, including pressing bearings into place and installing retaining rings.