Shop mans say to use sealer in rubber on glass side and metal side of strip. Even the new cars that still have/had rubbers get the sealer in them and they have to wipe down with solvent to get mess off when done installing.
On old rubber, it may have big cracks like mine and seperate and allow water in that way. That's where the metal edge gets rusty and needs repair quite often on these old trucks. I used black silicone on mine for now, squeezed it right into crack to push it thru to inside, then did more on inside. Old rubber won't give, it will just break off in big pcs, I don't reccommend messing with it much unless you want to replace whole thing.
