Abstract: A process and apparatus for measuring the wear of a multiple disk brake while a wheel hub is rotationless. A measuring instrument is provided having a screw-like component and a spindle. A plug element located in a predetermined bore of the wheel hub is replaced with the screw-like component. The brakes are actuated, the spindle is moved while the brakes are actuated until the spindle comes into contact with a supporting disk that axially supports the multiple disks. The distance the spindle was moved is ascertained to form a first measured value. The brakes are then released, and the spindle is moved again, until the spindle again comes into contact with the supporting disk. The distance the spindle was moved is ascertained to form a second measured value. The difference between the first measured value and the second measured value is determined to ascertain a piston stroke, and the wear of the multiple disk brakes is ascertained from the piston stroke.