This Service Repair Workshop Manual covers the Komatsu WA120-3 Avance wheel loader, including variants WA120-3A and WA120-3 Eu Spec auto shift. These machines are powered by a Komatsu S4D102E-1 diesel engine, offering approximately 82 kW (110 HP) and featuring a 3.9 L displacement. The transmission is a Powershift type, with 4-speed options for most models and a 3-speed for the WA120-3A. Designed for demanding operational environments, the WA120-3 series is recognized for its robust construction and reliable performance in various material handling applications. Its operating weight is approximately 8,700 kg, with dimensions including a length of about 5.7 meters with the bucket and a width over tires of roughly 2.0 meters. This comprehensive manual provides essential information for the maintenance and repair of your Komatsu WA120-3 series wheel loader. It details critical procedures, including engine oil and hydraulic oil capacity, transmission oil specifications, and recommended service intervals for oil changes and filter replacements. Furthermore, it outlines daily lubrication requirements for key components and offers guidance on preventive maintenance practices. With over 700 pages of detailed instructions and technical specifications, this manual is an indispensable resource for owners, mechanics, and technicians to ensure the longevity and optimal performance of their equipment.