If it is not silicone impregnated and not straight polyester then I think Coghlans Seam Sealer that Arno mentioned should work. The other option would be Seam Grip, bit more expensive but pretty versatile stuff.
My understanding would be that you would have to peel off all of the old tape, then clean the seams with something like Isopropyl alcohol. Afterwards reseal all of the seams from the inside surface.
REI has a nice summary.