Abstract: The invention is based on a hydraulic system, in particular of an engine brake for an internal combustion engine, having at least one hydraulic actuating element, a positive displacement pump by which pressurized fluid can be pumped from a low-pressure region into a high-pressure region, and a distributor unit (14) having a control output (13) which is connected via a control line with the actuating element, which control output can be pressurized from the high-pressure region and connected to the low-pressure region. In order to obtain the desired control of the actuating elements over a wide range of cycle times and speeds of rotation of the internal combustion engine with a pump of relatively small displacement, a return valve which opens towards the high-pressure region is provided, via which the control line can be connected to the high-pressure region after it has been pressurized from the high-pressure region and before it is connected to the low-pressure region.