The accuracy of hydromechanical systems used for the positioning is of high interest. The stiffness of the system must be known, especially when there is a variable load. This paper describes the structure of the computing modules which is configured on the computer for the purpose of revealing the influence of various parameters on the system's stiffhess. The model was subjected to a programmed step load and the systems' answers are presented in this paper. On the basis of this answers one may say which the influence of each parameter is.
