This manual covers the Thomas 135, 137, 153, and 1300 ProTough Skid Steer Loader models. These heavy equipment machines are engineered for demanding tasks, featuring a robust hydrostatic drive system designed for reliability and efficient operation. The ProTough series embodies Thomas's commitment to quality construction and durable performance, making these skid steer loaders a dependable choice for a wide range of service and repair applications. This Factory Service Repair Workshop Manual provides comprehensive guidance for the maintenance and repair of your Thomas skid steer loader. It includes detailed information on the Hydraulic System, Hydrostatic Drive System, Final Drive, Controls, Electrical components, Main Frame, and Engine. With easy-to-read text, high-quality diagrams, step-by-step instructions, and detailed exploded views, this manual is an essential resource for both do-it-yourself owners and experienced mechanics seeking to perform complete disassembly and servicing.