Abstract: A fusible thermally responsive device (20) for mounting in a bore (12) provided for it in a wheel (10) to vent an overpressure condition caused by heat generated in an aircraft wheel and brake assembly comprises a rod-shaped length of a thermally activated virgin eutectic alloy (34) exhibiting a tolerance within .+-.1.degree. F. of a specific melt temperature established for the alloy, which rod-shaped eutectic alloy in its virgin solid form has one end (34b) machined to a self-holding taper such as to be press-fit into a mating bore (28,48) having the same self-holding taper (28b,48b) in a cylindrical carrier member (22,42). The carrier is mounted in the wheel bore, either from the inside (22) or the outside (42) of the wheel, and a pair of O-ring type seals (32,52,62) provide a positive sealing relationship between the virgin eutectic (34) and the carrier (22,42) and between the carrier (22,42) and the wheel (10).