Tailgate seal not sticking

So I finally got around to installing my tailgate seal now that the weather is getting warmer but after a few weeks the lower part isn't sticking. So I was wonderng if there is any adhesive or some sort of caulk that you guys would recomend to hold the rubber to the composit bed?

 

3M weather strip adhesive? Auto parts stores should have it.

 

On a related note, does anyone recommend any particular brand of tailgate seal over another? I just put a topper on my truck and would like to seal the tailgates as best as possible also.

 

Access cover, yes?

Email eallen@agricover.com with your situation, serial number (black and white label on rear bar), and mailing address. He will suggest you rough up the area and remove the sheen with a scotch brite pad. You will suggest he sends you a new seal under warranty. I will suggest you spread a thin coat of clear silicone on adhesive prior to applying new seal.