An exemplary paint material switching path includes first and second valve elements, each having an inlet and an outlet, and a hollow cylindrical intermediate piece arranged between the outlet of the first valve element and the inlet of the second valve element. The inlet of the first valve element is configured to be connected to a continuously pressurized paint material supply, and a manifold channel which is configured to be pressurized and into which the outlet of the second valve element opens. Furthermore, components are provided for measuring the pressure prevailing in the hollow cylindrical intermediate piece and an evaluation device for detecting leaks in at least one of the two valve elements based on the measured pressure with respect to time for a given pressure difference between the inlet of the first valve element and the outlet of the second valve element at the beginning of the leak detection.