The Komatsu WA100-1 Wheel Loader, designed for serial numbers 10001 and up, represents a robust and reliable piece of equipment engineered for demanding work environments. Featuring a powerful Komatsu S4D105-1 diesel engine with a displacement of 5.5 liters and an output of 83 HP, this machine is built for efficiency and performance. Its advanced countershaft type, planetary gear power shift transmission with electronically controlled gear selection, offers four forward and four reverse gears for versatile operation. With an operating weight of approximately 7,200 kg and a bucket capacity of 1.2 m³, the WA100-1 is adept at material handling tasks, demonstrating Komatsu's commitment to quality and durability in its construction machinery. This Service Repair Factory Manual in English provides comprehensive information essential for the maintenance and repair of the Komatsu WA100-1 Wheel Loader. It covers critical areas including detailed engine specifications, transmission operation, dimensions, fluid capacities for engine oil, hydraulic oil, fuel, transmission oil, and cooling systems, as well as insights into the braking, steering, and work equipment systems. Furthermore, it outlines details of the electrical system, such as battery voltage and alternator output. This manual is an indispensable resource for owners, mechanics, and technicians, enabling them to effectively service, troubleshoot, and maintain the WA100-1, ensuring its optimal performance and longevity.