This manual covers the Komatsu WA300-1 and WA320-1 wheel loaders, specifically for serial numbers 10001 and up. These versatile machines are engineered for demanding operational environments, featuring a robust diesel engine, a 4-wheel drive system, articulated power steering, and wet disc brakes. The hydrostatic transmission provides variable speed control, while standard loader arms and customizable bucket capacities ensure adaptability for various tasks. The electrical system operates on a 24V DC supply. These loaders are built for reliability and performance in construction, material handling, and other heavy-duty applications. This comprehensive Factory Service / Repair / Workshop Manual in English provides detailed, step-by-step instructions and highly detailed exploded pictures and diagrams to guide users through all aspects of maintenance and repair. It covers essential areas including engine specifications, powertrain details, lubrication schedules, fluid capacities, service intervals, diagnostic procedures, and electrical system information. The manual is designed to assist owners, mechanics, and technicians in effectively maintaining and repairing their Komatsu WA300-1 or WA320-1 wheel loaders, ensuring optimal performance and longevity.