The adjustment method is particularly intended for a hydraulic power system of a tractor, in which the thrust cylinder is supplied from a pump, the pressure and output of which are adjusted. After having converted it into a position-adjustment signal, with the aid of a position sensor, the adjustment quantity is conveyed to the adjustment device proper, in which the adjustment quantity is determined on the basis of a comparison with the reference quantity which is carried out by means of a controller mounted downstream. In order to be able to produce a behaviour of the adjustment circuit which is independent of the parasitic quantities acting on the adjustment section, throughout the whole load pressure range, the signal which is sent to the controller is formed from the difference between the position-adjustment offset and the modification in time of the position-adjustment signal. By choosing appropriate amplification factors for the adjustment circuit, the influence of all the parasitic quantities which act on the amplification of the adjustment segment are made to disappear. <IMAGE>
