The amount of energy losses in hydraulic systems, determined directly by the efficiency parameter, becomes one of the basic aspects related to the design of these systems. Recently, reducing the energy consumption of hydraulic drives has become one of the most important factors in, and sometimes even the main reason for, development works focused on hydrostatic drive systems in newly designed and already deployed types of machines. The article presents an approach to improve the efficiency of such a hydraulic system based on the analytical model and also includes a case study of redesigning a hydrostatic drive system in a stationary rock breaking machine. The analysis of the calculation results showed benefits resulting from two different concepts of modifying hydraulic systems with an aim at reducing their energy consumption.