Bed Rail Prep

Looking at getting a used cap for the bed. I saw a thread a while back on the best way to prep under the top bed rails for a cap but I can’t seem to find it again.
And yes I used the search function.

Most of the hits I saw were people saying that they did the prep but didn’t find one where anyone laid out exactly what the best procedure is to do.

Any suggestions, advice, or best course of action to follow would be appreciated. Thanks.

 

I don't have cap/topper, just tonneau cover. I pulled mine, had to switch from oem cover rail cap to regular rail caps. I laid a bead of DAP Gutter/Flashing sealent close to out edge. So water couldn't migrate under into bed. Hope that helps you. Iget no water now going down road or in car wash. Did with oem tonneau. MX4 now.

 

The bead of sealant should be placed along the inner edge, underneath the bed cap. The reason is that water splashes up from underneath the truck, through the holes in the top of the sheet metal sides. This water needs to have a route to drain outboard of the truck, not into the bed.

 

Thanks for the responses. Is there anything that needs to be done to protect the metal under the rail caps from the weight of the topper? I’m used to all metal beds and rails. Should I remove the rail caps and put anything under them to prevent rubbing?

@NoVa TRD Sport : in VA here also. Just south of Fredericksburg.

 

@tonered has some beta.

 

I found paint wear just from me jumping over the side, so I put down heavy foil tape before the silicone.

 

I just noticed u made some straps to hold the back window open I need to do something like that

 

i removed the bedrail caps on the sides and front of the bed. i then applied a bead of exterior grade caulk along the full length and around each hole (there are lots and lots of holes) in the bed rails, like you would an RTV gasket.

after re-installing the bed rail caps, i then applied a heavy bead of caulk at the front corners, set the canopy, and neatly spread and wiped off the excess caulk after tightening the clamps.

i know others have a different experience but, after owning many trucks and canopies, i have never found two clamps per side to be adequate if you do even mild off roading like driving on a bumpy forest service road. i recommend at least three clamps per side even on a short bed. i use blue locktite on the threads of the clamps and snug those suckers tight.

 

I did, but almost never use them. Only in high winds.

 

Mine gets stiff when it’s cool out and always wants to shut on its own. I need to build some I think

 

Much thanks @tonered

 

You're welcome.

 

Mine seems to sit pretty well on the top, but I can understand that.

 

Yeah definitely worthy of a beer….or five.