Abstract: In a hydrostatic transmission comprising a pump and a hydraulic motor arranged in a main line having low pressure and high pressure sections, wherein an oil drain line of the hydraulic motor is connected to the low pressure section of the main line, the housing of the hydraulic motor is freed from excessively high pressures in the main line by arranging a valve having an adjustable passage cross-section which decreases with increasing pressure in the main line before--in the direction of flow--the line connection of the oil drain line.