This manual covers the Clark ECS 17-30 HI Performance Supplement, an electric forklift designed for a wide range of industrial applications. Engineered for reliability and efficiency, this forklift is built to handle demanding tasks in assembly, disassembly, servicing, and repair environments. Its robust construction and advanced electric power system ensure consistent performance and operational longevity, making it a dependable choice for material handling needs. The purpose of this comprehensive 431-page service repair manual is to provide detailed guidance for the maintenance, troubleshooting, and repair of the Clark ECS 17-30 HI Performance Supplement. It includes essential information on key systems such as the battery, electric motors, hydraulic system, and brake system, along with specific procedures for planned maintenance, lubrication, and battery handling. Furthermore, the manual offers troubleshooting guides, safety practices, and electrical and hydraulic schematics, equipping technicians and owners with the knowledge to keep the forklift in optimal working condition.