This manual covers the Komatsu WA300-1 and WA320-1 models. These machines are engineered for demanding operational environments, representing robust construction and reliable performance. While specific production years are not detailed, the manual applies to units with serial numbers 10001 and up for both the WA300-1 and WA320-1. This Service Repair Workshop Manual provides comprehensive guidance for maintaining and repairing your Komatsu equipment. It details key areas including the general overview, engine, power train, steering system, brake system, work equipment system, and the electric and electronic system. The manual is presented in English and is designed to assist owners, mechanics, and technicians in ensuring the optimal performance and longevity of their WA300-1 and WA320-1 machines.