The Komatsu WA420-3 Avance, including the WA420-3H variant, is a robust wheel loader engineered for demanding operational environments. Built with Komatsu's renowned commitment to quality and reliability, this machine features a powerful Komatsu S6D125E-2 diesel engine delivering 205 horsepower, coupled with a 4-speed forward and 4-speed reverse power shift transmission. Its substantial operating weight of 22,700 kg and a bucket capacity of 3.5 m³ make it well-suited for heavy-duty material handling tasks. The articulated frame steering ensures excellent maneuverability, further enhancing its utility in construction, mining, and industrial applications. This comprehensive Service Repair Workshop Manual provides essential information for the maintenance and repair of the Komatsu WA420-3 and WA420-3H wheel loaders. Covering over 800 pages in English, it details critical procedures, technical specifications, and troubleshooting guidance. Owners, mechanics, and technicians will find in-depth instructions on engine service, hydraulic systems, transmission maintenance, fluid capacities, and recommended service intervals. The manual is designed to facilitate efficient upkeep and ensure the longevity and optimal performance of your equipment.