This document provides comprehensive service information for the Komatsu PC45-1 Hydraulic Excavator, designed for a wide range of construction and earthmoving applications. Engineered for reliability and efficient operation, this compact excavator offers robust performance in its class, with an approximate operating weight of 4,500 kg. Its hydraulic drive system ensures precise control and power delivery for demanding tasks. This manual covers units with serial numbers 1001 and up. The purpose of this Workshop Service Repair Manual is to assist owners, technicians, and mechanics in understanding, maintaining, and repairing the Komatsu PC45-1. It details essential maintenance procedures, troubleshooting guidance, and technical specifications necessary for optimal performance and longevity. Coverage includes critical aspects of the hydraulic system, engine servicing, and general repair information, ensuring that the equipment remains in peak operational condition throughout its service life.