This manual pertains to the Caterpillar S4S Diesel Engine DP20N-35N and P4000-P7000 Forklift Trucks, identified by part number 99729-88100. These robust machines are engineered for demanding industrial environments, offering exceptional reliability and performance in material handling operations. Their design prioritizes durability and efficiency, ensuring consistent operation under heavy workloads. The purpose of this comprehensive service and repair manual is to provide detailed technical information for the maintenance and repair of your Caterpillar forklift. It covers critical systems including the engine, automatic transmission system, drive axle, brake system, steering system, and hydraulic system, among other components. This guide is an essential resource for owners, technicians, and mechanics to ensure the optimal performance and longevity of the vehicle through accurate procedures and specifications.