direction of the arrow 21 to the cooling fluid discharge chamber 9 which exhibits a low pressure drop connection to the oil sump 12 this arrangement provides a sealing of the cooling fluid supply chamber 4 to the cooling fluid discharge chamber 9 through the support of the last outer disc and in the actuated case to the adjoining piston 13 an alternative embodiment provides elastomeric sealing elements for sealing on the piston side and the support side which may also be built into the tooth structure of the outer discs 5 in the embodiment according to fig1 pad discs with pad grooves are provided and placed on the inner disc carrier 7 through this designs a dynamic pressure is induced into the cooling fluid supply chamber 4 at a differential speed in the brake the magnitude of the pressure is a function of the square of the differential speed this pressure information is used for controlling the cooling oil volume flow and it can also be used to provide fail safe functions for emergency program circuits through the dynamic pressure which is provided as a control signal to a control or clutch valve that controls the clutch pressure in the respective brake or clutch a pure hydraulic emergency start up mode can move the vehicle from a dangerous spot e g a train crossing or freeway without the need for considerable additional expenditures e g pitot tube additional valves centrifugal governor etc in another embodiment of the invention the outer discs 5 can be designed as pad discs with no hydrodynamic pressure build up in the cooling fluid supply chamber 4 in this manner the cooling fluid can pass through the discs with an advantageous low pressure even.