Truck Camper Shell seal

Hello fellow Tacoma Enthusiasts
Wondering if someone can help with a camper shell sealing issue
I have a 2015 Tacoma with box side rail caps. At the front of the box, beneath the rear slider there is no rail cap, but rather a drop down of about 1/2 an inch that runs from one side of the truck rail cap to the other(see pic)
So, I purchased a camper shell from ARE, installed by a local camper shell outfitter. The issue is even though the installers put a bulb gasket to fill in this drop down open space to prevent leaks, it leaks like a sieve. I bring truck back and they thought they cut it too short. So they pull it out and put in another. Same issue. Now I want to seal it myself. Does anyone know a good way to fill in this space? Perhaps Toyota makes a better fitting gasket that I am unaware about?

 

IFL. I have a 2005 with the exact same situation - rail caps on the sides, but not the front of the bed. I just bought the truck and am looking around for a good deal on a camper shell and this exact issue is one I have been wondering about.

One thought I had, but haven't found an answer to yet: Would it be best to remove the rail caps from the sides before installing the shell? That should level it out all the way around, right? Any reason not to do that?

 

JUST got an ARE truck cap on my 2014. Hear a lot of giggling going on, hasn't rained yet. Going to remove cap and plan to put down self sticking weather stripping, thickness dependent upon space needing sealed. Will let you know in a few weeks.

After reading another post I will apply to underside of cap instead of on rail.

 

Butyl tape. RTV.

Park the truck with the shell on in a dark garage and have someone shine a flashlight between the cab and bed.

Start shoving butyl tape in the gaps.

For other spots where it weeps, apply RTV.

 

I used foam backing and a couple of large tubes of clear silicone sealant between my bed and topper shell to stop my leaks. I thought it would only be "temporary" fix but it's lasted for 15 years so far on my '06. It probably would be a hassle if you planned on taking the topper off occasionally though.

 

You'll want this front rail bed seal:

$27 ESI Front Rail Seal XL 5 1/2' EPDM Rubber for Truck Caps—Fills a Height Gap from .488" to 1"

https://www.amazon.com/gp/product/B07147Y43J

It's a quality part and sized specifically for our trucks. You can see the part numbers I used for sealing my cap in post #7 in this thread: https://www.tacomaworld.com/threads/project-cap-acquired.687896/#post-24517586

I just carefully followed the instructions and everything worked out great, no need to caulk or stuff any gaps.

FWIW, I'd never tried sealing a shell before and it worked great. I have zero leaks. I can't even get water in with the pressure washer. I think prep was key, and using correctly sized gasket.

 

Quality bed seal, prep and putting the seal on the cap and not the truck are key to eliminating leaks.

https://extrudedsolutions.com/

 

Thanks for these tips. I found a Snugtop for my 05 DCLB and have managed to get it pretty well watertight thanks to this thread.

 

See this post:
Need Help Filling Gap Between Cap and Bed | Tacoma World
#5 is my solution.