The Komatsu PC800-8 and PC800LC-8 excavators represent robust engineering designed for demanding work environments. These machines, part of the 8 Series, are powered by the Komatsu SAA6D140E-5 engine, a 15.24 L diesel unit delivering 374 kW (501 HP) and meeting EPA Tier 3 / EU Stage IIIA emission standards. With a hydrostatic all-wheel-drive transmission, substantial operating weights ranging from approximately 77,800 to 80,900 kg, and impressive dimensions including a length of over 12 meters, these excavators are built for heavy-duty performance and reliability in construction and earthmoving applications. This workshop service manual provides comprehensive guidance for the maintenance and repair of the Komatsu PC800-8 and PC800LC-8 excavators. It covers essential technical specifications, detailed procedures for maintenance tasks such as lubrication with specific capacities for engine oil, hydraulic oil, and coolant, and information on component replacement. The manual is intended to assist owners, mechanics, and technicians in ensuring the optimal performance, longevity, and safe operation of their equipment through clear instructions and technical data.