Leak at cab bed rail

I’m looking into buying a Tonneau cover. Doing some reading here I expect to need to do additional sealing. A friend bought a Gator Tailback a few weeks back and no leaks in a heavy rainstorm on a long drive but he has a Silverado. A fellow here has one on his Taco and likes it as well so I’m leaning toward that one. A tiny leak won’t bother me.

 

Honestly Diamondback covers are great and I have tried to defeat the locks on mine haven't yet. Yes expensive but quality is super. Not their fault that the rail is higher than the bed caps. I don't expect perfections in any cover but tons better than the one I had on my other truck.

 

Well, I took the cab bed rail off (T30). I cleaned it up and ran a bead of clear RTV alongside the 1/2" felt "gasket" mentioned in a previous post.

I reinstalled the bed rail and then pulled a hunk of HVAC sealant. I rolled it between my hands until it was the size of a big straw and then wrapped it all the way around the bed rail gap on both sides. I shaped it so that it feathered nicely into the side rails.

I then coated it with the same RTV so it will not stick to the Diamondback cover gasket. I think this is going to do the trick. Will report back

 

Yeah let me know. I may try to tackle this issue this holiday weekend since I am not traveling anywhere.

 

Curious to know if that bead of RTC worked. I plugged my gaps with butyl rope this morning. This stopped the leak I saw before, however, I now have a leak (maybe from the same place the OP had) I didn't have before that causes water to pool on top of the front wheel wells. I assume I might have had the leak here before too but assumed it was from the gaps. Did the RTV solve your issue?