The self-propelled agricultural harvester (1) has a vertically movable mounting device for adapting an agricultural attachment device (3). The attachment device is supported in transport position by a supporting wheel (16) standing in contact with a base. A braking device is provided for braking the wheels of the harvester. A control device (25) is provided which regulates the support pressure of the supporting wheel on the base during operation of the braking device. The control device stands in operative connection with a lifting cylinder (28) arranged at the mounting device.
