The design, technical characteristics and operation diagrams of hydraulic mounted systems of tractors MTZ-80, MTZ-82, T-150, T-150K, K-700 are described in detail. The design and principle of operation of new and modernized hydraulic power steering units, as well as hydraulic mechanisms for turning tracked tractors are considered. Particular attention is paid to the operation and maintenance of hydraulic mounted systems and hydraulic control mechanisms of modern wheeled and tracked tractors. Designed for engineering workers, machine operators and other specialists serving agricultural facilities. Equipment on collective farms and state farms.