A stent graft delivery system including a tip assembly, a middle member tube, a sheath assembly, a threaded assembly, and a unitary endoseal. The tip tube is disposed in and longitudinally slideable within the proximal portion of the endoseal lumen, the middle member proximal end of the middle member tube is disposed in the distal portion of the endoseal lumen and fixed to the longitudinal cylindrical endoseal body, the first cylindrical portion of the transverse cylindrical endoseal body is disposed in the first sidewall port of the threaded assembly, the second cylindrical portion of the transverse cylindrical endoseal body is disposed in the second sidewall port of the threaded assembly, and the longitudinal endoseal cylindrical body is disposed in the threaded assembly lumen.