The Komatsu WA400-5H Wheel Loader is engineered for demanding work environments, offering robust performance and reliability. This versatile machine is designed for efficient material handling and is equipped with a powerful Komatsu S6D125E-2 diesel engine, delivering approximately 250 HP. Its advanced transmission system, the Komatsu Advanced Transmission with Lock-up (K-ATLS), provides both automatic and manual modes with 4 forward and 4 reverse gears, ensuring optimal control and fuel efficiency. With an operating weight of around 23,000 kg and a rated operating capacity of 14,000 kg, the WA400-5H is built to tackle substantial loads. Notable features include a ROPS/FOPS cabin for operator safety and pilot controls for precise operation, making it a dependable choice for construction, mining, and heavy-duty industrial applications. This Service Repair Manual provides comprehensive information for the Komatsu WA400-5H Wheel Loader, covering serial numbers WA400H50051 and up. It is designed to assist owners, mechanics, and technicians in maintaining and repairing the vehicle effectively. The manual details essential procedures, including safety guidelines, general information, structure and function of components, testing and adjusting, disassembly and assembly, and other critical maintenance topics. By following the detailed instructions and technical specifications within this manual, users can ensure the longevity, optimal performance, and safe operation of their WA400-5H wheel loader.