the pressure vacuum fluid are connected the robot 8 is now again introduced into the pipe 1 through the inspection shaft 3 for the repair of the place of leakage 4 and advanced up to the place of leakage 4 after the sealing off of the place of leakage 4 the robot is re equipped with a milling and or grinding tool and possibly a spray water cleaning nozzle in order accurately to calibrate finely machine or clean the place of patch a set of compressed air hoses 12 of different length is preferably present on the vehicle 11 this has the advantage that the length of the pressure line can be selected in accordance with the distance of the point of leakage 4 from the vehicle 11 by the selection of the shortest possible pressure line 12 the pressure drop and the amount of patching material remaining in the pressure line 12 after the spackling can be kept small similarly in this way the cleaning of the pressure line 12 is simplified fig2 shows a known robot bjr trading dk roskilde type bearer cutter having a part 15 which can be locked in position relative to the pipe 1 and a movable part 16 which is displaceable relative to the lockable part 15 in the direction of the longitudinal axis 17 and is turnable around said axis on the lockable part 15 there is firmly attached a ring 18 to which several longitudinal bars 19 are fastened spaced with radial symmetry apart from each other with respect to the axis 17 two additional rings 20 and 21 are firmly attached coaxially to the longitudinal bars 19 spaced from the ring 18 the rings 18 20 21 and the longitudinal bars 19 form a.