This manual covers the Komatsu PC78MR-6, a versatile compact excavator from the MR-6 Series. Engineered for reliability and performance, this machine is designed for a wide range of construction and landscaping applications. Its robust construction and efficient operation make it a valuable asset for professionals requiring precision and power in confined spaces. The PC78MR-6 embodies Komatsu's commitment to quality and innovation in heavy equipment. This comprehensive workshop manual provides detailed information essential for the maintenance and repair of the Komatsu PC78MR-6, covering serial numbers 1001 and up. It includes three distinct manuals: a Shop Manual, an Operation and Maintenance Manual, and another Shop Manual, all focused on the PC78MR-6 and its Komatsu 95-3 series engine. This resource is invaluable for owners, technicians, and mechanics seeking to ensure the optimal performance, longevity, and safety of their equipment through accurate procedures and technical specifications.