This Service Shop Repair Manual covers the Komatsu WA400-5 Wheel Loader, serial numbers 70001 and up. Designed for robust performance in demanding environments, this equipment embodies Komatsu's commitment to engineering excellence and reliability. Its advanced systems, including a comprehensive hydraulic system, a powerful engine with an injection pump, and a robust powertrain, ensure efficient operation and durability for a wide range of heavy-duty applications. This manual provides essential information for the maintenance, repair, and servicing of your Komatsu WA400-5. It includes detailed repair instructions, step-by-step procedures, and troubleshooting guidance for all major systems such as the engine, powertrain, braking, steering, hydraulics, and electrical systems. With fully bookmarked navigation, detailed illustrations, exploded diagrams, and photographs, this comprehensive English language resource empowers owners, mechanics, and technicians to effectively maintain the equipment, minimize downtime, and reduce repair costs.