A method for simplifying the conventional pressure monitoring and/or adjustment method for a mounted assembly for a vehicle, in particular for a two-wheeled vehicle, and, more precisely, reducing the number of steps in the method, and a pressure monitoring and/or adjustment device for the use of this method. A mounted assembly (31) is composed of a tire (32), preferably tubeless, mounted on a rim (33) and inflated to an initial pressure, the tire comprising an inner surface forming the wall (34) of the tire cavity, in contact with the internal air, the wall of the tire cavity being at least partially covered with a self-sealing material (35). An inflation interface (36) is introduced into the tire cavity by piercing a hole in the wall of the tire cavity in an area covered by the self-sealing material, the inflation interface is extracted from the tire cavity after inflation, and the pierced hole in the wall of the tire cavity is sealed spontaneously by the self-sealing material, after the extraction of the inflation interface.