3rd Gen diamondback owners…. I’m leaking. Need some input

I have a 2024 model (in case somethings possibly different this year). Cover is an hd model.

After a car wash (tunnel type wash, very high pressure) I have water in the bed. The water is,not leaking from the cover itself but I believe it’s coming in from between the bed rail, and plastic bed rail cap.

there is no water on the plastic cap of the bed rails, or tailgate inside of the diamondback gasket. The water is on the bed walls completely except where the middle section clamps to the rails.

anyone experience this? For a solution would you/should I:

1. remove bed rail and cap and put down some butyl tape? (Or other solution)

2. Just live with it? I park in a garage so I can leave the cover open and it’s dry after a few hours.

3. Wash with another method? I really like this car wash.

I haven’t tested the cover with a garden hose, or even used it in the rain (just got the cover and it’s winter). Was thinking of spraying the cover with a pressure,wand but further away to simulate rain.

 

I'm having hard time understanding your post. I re read it 3 times already.

Do you have a camper shell and water got into it after the car wash?

Can you take it to the place where you got your camper installed?

Pour water over it to see where it's leaking from and waterproof it...

 

Diamondback cover. It’s in the title.

water is getting in from under the rail caps (black plastic things)

 

Any high pressure water can easily cause your problem and hard to prevent. Do you have any hand wash place you can go to? Costs a bit more, but is better in the long run and someone else is doing it while you watch.

 

I could use a hand wash place, and just wash my own vehicle in the summer. But it really is convienient for me to use this place. The time savings far exceeds the water issue.

my box is basically empty most of the time, and I just wouldn’t wash the truck if I had cargo. Most of the water will go between the ribs, and then down the drain.

im just curious if other 3rd Gen has issues with water getting under the plastic bed rail caps

 

I am not sure I would worry too much ; there really isn’t anything that can replicate the force of a high pressure wash like that. I wouldn’t be too concerned about it unless you think a storm could cause the same issues. I do know that Diamondback recommends a gasket that installs under the bed rail caps. Do you have that installed by chance?

 

You may also want to add some weight to the top of each corner of the cover when adjusting the locking rods. I used 40 lbs. bags of birdseed, adjusted the locking rods, and have had no leaks. The weight assures a good seal for your cover.

 

there’s,nothing under the caps. Diamondback did supply a gasket for the cab side of the bed.

I was thinking (if I do anything) of removing the cap and running a bead of,caulk or some butyl tape.

or live with it. I’m pretty confident rain won’t be an issue.

 

the seal is fine. Water isn’t coming in between the diamondback and top of bed rail. It’s coming in from under the the plastic cap on top of the bed rail (not bed rail for adjustable cleats).

not sure the correct terminology here. Top of bed side is called? Rail is wrong.

 

I get a bit of water at the tail gate and at the front of the bed when the bed edge is lower. DB supplies a kit to go in the front area and fill that space.

You shouldn't get any water in from the sides at the middle section as those are super tight since they are holding the cover onto the truck. If your covers are not tight by adjusting the release handles, that could be a problem.

I also notice some condensation under the cover as the bed goes from hot to cold with the seasonal temps. It was bone dry last summer!

 

Did you receive and install any shims to place under the bed caps before installing your DiamondBack? DB started putting the shims in their installation kits because the bed caps were getting distorted (wavy) when the midsection was tightened down. The shims take up the voids so that the plastic caps don't get compressed in spots. The seal on your DB to the caps may be good but any compressed spots underneath the caps may be letting water get under them.

 

^ the shims are not needed for the 2022+ tundras. The issue is a high pressure wash is pushing the water under the plastic cap, and into the bed.

it seems a removal of the plastic cap, and a bead of caulk is in order. A summer job as I don’t want to break a clip and have to buy a new piece.

or I just live with it.

 

I just opened mine up after sitting for a while, the underside of the cover was soaked and the water rained off when the cover raised. It might be good to leave the cover open when it isn't raining to let out the moisture sitting in the bed air space.

 

After a car wash I park in an attached garage. I open the cover up over night. Once winter fully sets in I have a construction heater to heat the garage for an hour. Also a towel out the water.

 

Ok then, I got nuthin',

 

‘that’s ok. I appreciate your efforts, and you are still my best friend.

 

Does everyone have/know what this little black “block” is for? It actually sits on the rail cap and prevents the gasket from being compressed fully.

the cab panel doesn’t have this, so is it so the tailgate can open? Or is it an assembly item that was left on in error?

not sure if it has anything to do with the leaking??

 

Is that a shipping block? I don’t think I have that block.

 

I have no idea. It’s on both sides, and only on the tailgate panel. I’m pretty heavy so I couldn’t figure out why the tailgate panel wouldn’t compress like the cab panel. This is why.

it’s either not supposed to be there (unless everyone else has it) or it prevents over compressing so that the tailgate will still open?

I’ve emailed diamondback on this.

 

^ I think I’ve found my answer. DB has an instal instructions for a “compression limiting kit”. It appears my cover has this installed. It’s to prevent binding of the tailgate if a heavy load is on top of the tailgate.

 

I also have the "compression limiting kit" installed on my DiamondBack SE cover. I have no issue getting a proper seal between the weatherstripping and the bed rails.

 

I have the switchback and have not had any issues with water getting in during the few rainy days I have encountered since installing it. Been completely dry when it comes to the elements. I only had 1 instance where I had very minimal water enter the cab and that was from using my pressure washer as already stated.

 

Can someone confirm this before I take my rails off and install shims?

 

I have read that some owners have installed the shims. I didn't get any shims with my SE and installed it just like the previous HD cover (no shims with this cover either) on my Ridgeline.

The fit on the Tundra was pretty snug and the front and back sections were set with good compression on the seals. You just need to adjust the bars and lube the plastic coated bar ends so they slip into the end brackets. That way you can tighten the hardware to keep the sections tight when closed.

My Tundra cover is now on my 3500 Silverado and it works great there too!

 

I would just call Diamondback; they're very responsive. I realize I am a 2.5 gen, but I installed my HD cover on my 2019 and it leaked. After installing the shims it leaks MUCH less.

 

OP, I have the BakFip MX4 tonneau cover, so not an apples to apples, but I'm quite sure the majority of water that gets into my bed at the auto car wash is from the ridiculous gaps at the sides of the tailgate.

The water pressure is high enough, and the gaps are aligned so that it sprays the sides of the bed, and gives the appearance the water is leaking thru the top cap, as you described, but it's not.

 

I have a Diamondback SE cover. I use a pressure washer occasionally during the winter and I have only noticed very small amounts of water in the bed, mostly at the tailgate. It is important that you not over tighten the clamps. 5 to 6 ft-lbs is the recommendation from DB. I went 60 inch-lbs.