Abstract: A tracked vehicle which is provided with an automatic track tensioning assembly of the type adapted to control the pressure in the hydraulic cylinders tensioning the endless track. This track tensioning assembly distinctively includes a main control circuit and a pilot control circuit which are hydraulically isolated from each other with the main control circuit being operatively closed and isolated from the supply pump to more freely optimize the distinct functions of these circuits such as the response of the main control circuit. This track tensioning assembly includes a pilot valve for each hydraulic cylinder, an accumulator, and a relief valve in the main control circuit for release of pressure from the cylinders to the accumulaotr through the relief valve. The pilot valves are selectively operable by control valves in the pilot control circuit.