This document pertains to the Komatsu PC228US-3 and PC228LC-3 excavators, models from the US-3 / LC-3 generation. These machines are engineered for robust performance in demanding work environments, featuring a powerful Komatsu SAA6D107E-1 engine delivering 150 HP. With a hydrostatic, 4WD drive system and substantial operating weights, they are built for reliability and efficiency in construction and heavy-duty applications. The PC228US-3 has an operating weight of approximately 23,780 kg, while the PC228LC-3 weighs around 24,540 kg, both designed with impressive ground clearance and sturdy track dimensions for optimal stability and maneuverability. This comprehensive Workshop Service Repair Manual provides detailed guidance for the maintenance and repair of the Komatsu PC228US-3 and PC228LC-3 excavators. It covers essential areas including engine specifications, transmission details, fluid capacities, and service intervals for critical components like engine oil and hydraulic fluid. The manual is intended to assist owners, mechanics, and technicians in performing routine maintenance, troubleshooting issues, and conducting in-depth repairs, ensuring the continued optimal performance and longevity of these powerful machines.