The invention concerns a hydrodynamic coupling, having a pump wheel and a turbine wheel, which form together a toroidal working chamber which can be filled with working medium; with a closed working medium circuit, which extends from the working chamber via a working chamber outlet, an external circuit branch and a working chamber inlet back into the working chamber; with a storage chamber positioned outside the working chamber and outside the closed working medium circuit, for receiving the working medium evacuated from the working chamber for reducing the filling level of the working chamber, which is connected via a connection for conveying the working medium outside the working chamber to the closed working medium circuit. The invention is characterized in that the storage chamber is designed as a confined chamber which is pressure-tight to the environment, having a control pressure port so as to forcibly displace the working medium in the storage chamber with a control pressure.