The Komatsu PC400LC-8 is a robust excavator designed for demanding construction and earthmoving applications. Featuring a powerful Komatsu SAA6D125E-3 engine with a displacement of 11.04 L and an output of 224 kW (300 HP), this model exemplifies Komatsu's commitment to engineering excellence and operational efficiency. Its advanced Komatsu Hydrostatic Transmission with Power Mode and 4-wheel drive system ensure superior traction and control across various terrains. With an operating weight ranging from 40,000 to 42,000 kg and substantial dimensions, the PC400LC-8 is built for reliability and performance in challenging environments, meeting EPA Tier 3 and EU Stage IIIA emission standards. This Workshop Service Repair Manual provides comprehensive guidance for the Komatsu PC400LC-8 excavator, serial numbers A88001 and up. It covers essential maintenance procedures, detailed troubleshooting steps, and critical technical specifications, including engine oil, hydraulic tank, swing mechanism, and coolant capacities. The manual also outlines recommended filter replacement guidelines, ensuring optimal performance and longevity of the machine. This document is an indispensable resource for owners, mechanics, and technicians seeking to maintain, service, and repair the PC400LC-8 effectively and safely.