A hydrostatic drive system has a travel drive (4) and working hydraulics (6). The working hydraulics (6) have a variable delivery pump (5) connected to the driving engine (1). The pump (5) is connected to a container (10) on the inlet side and delivers to a delivery line (11), to which at least one consumer of the working hydraulics (6) is connected. The pressure medium delivered by the pump (5) is feedable to a pressure valve (9). The pressure valve (9) is arranged in the delivery line (11) from the pump (5) to a control valve device (13; 15; 17; 18). A container branch line (29), which is connected to a container (10) and in which a circulating device (31) is arranged, is connected to the delivery line (11) downstream of the pressure valve (9).