The document provides instructions for disassembling and assembling the main hydraulic pump of an M313D Wheeled Excavator. It describes 34 steps to disassemble the pump by removing components like bolts, seals, springs, pins, and housing pieces. It then describes 22 steps for reassembly, including installing shaft bearings and seals, pistons, springs, and housing components in the reverse order of disassembly. Precise positioning and measurements are required to set component heights and clearances correctly.