The Komatsu SK815-5N and SK815-5NA Skid Steer Loaders represent robust engineering designed for demanding work environments. These machines, equipped with either the 4D88E-5 or 4D84E-5 engine, feature a hydrostatic transmission for efficient power delivery. While specific production years are not detailed, these models are associated with serial numbers A30001 and up for the SK815-5N and A10001 and up for the SK815-5NA. Their construction prioritizes reliability and performance, making them suitable for a wide range of construction, landscaping, and material handling tasks. This Service Repair Manual provides comprehensive guidance for the Komatsu SK815-5N and SK815-5NA Skid Steer Loaders. It covers essential areas including foreword, structure and function, maintenance standards, standard value tables, testing and adjusting procedures, disassembly and assembly instructions, diagrams and schematics, and detailed specifications. The manual is intended to assist owners, mechanics, and technicians in performing routine maintenance, troubleshooting issues, and executing repairs to ensure the optimal performance and longevity of the equipment.