the invention relates to a tube connection between a collector of a motor vehicle heat exchanger and a line using a connecting sleeve in which the free end of the line engages in a positive manner . an annular seal is accommodated in the annular gap between the inner surface of the connecting sleeve and the outer surface of the line . an outer flange is provided on the free end of the connecting sleeve , and a buckled outer bead is formed on the line . when the tube connection is completely assembled , said bead is tightened against the outer face of the outer flange by a clamping device . the seal forms an insertion sleeve . a sealing element is formed on the insertion sleeve in the peripheral area thereof situated close to the collector , and a sealing flange projects from the peripheral area of the insertion sleeve situated away from the collector . said sealing flange is axially clamped between the outer flange and the outer bead by the clamping device .