This document provides instructions for disassembling and assembling the main hydraulic pump on a M315D Wheeled Excavator. It lists 34 steps for disassembly, removing components like pistons, springs, seals and housing pieces. It then lists 36 steps for assembly, installing components in reverse order and noting proper orientation of marked parts. Precautions are provided regarding contained fluids, released spring forces, and keeping parts clean from contaminants. Required specialty tools are also listed.