Need some help: Water Leak behind back driver side side.

Hey all!

so I was having some issues with my subwoofer that I installed about a year and a half ago behind my back driver side seat. Took the seat out to find that my sub box was completely rotted and the carpet was quite damp. Was looking for the issue and determined it had to be the pressure vent (or air vent?) behind the seat that exits directly between the cap and the bed(I attached images). It is completely unsealed and has probably been letting in water for a significant amount of time. I’m not sure what to do. Should I seal it myself? Take it to the dealer for them to do basically nothing?

If anyone else has had a similar issue please give me your thoughts on what I should do to resolve this problem. Thanks everyone.

 

The leak is more than likely from the third brake light. Notice the water stains on the top side of the vents? If it is, Toyota will fix it and you’ll likely get new carpet for free. Those vents aren’t sealed on any of our trucks.

 

the leak is is coming from the pressure vent not the 3rd break light. I have confirmed that. Check the pictures

 

10-4 The third brake light is a known and extremely common point of leaks. Wasn’t sure if you knew that but it sounds like you’ve got it figured out. Good luck with the fix.

 

If your for sure that it is the vent. I would push it out towards the bed to make the gap a little bit bigger. Then take some black RTV sealant and squeeze it into the gap. Pull the vent back to make it tight. Wipe off extra with a wet finger. And don't wash, or get wet for 24 hrs. No more leak.

 

Currently in a storm right now. When out to check where the leak for sure. Looks like it’s also the 3rd break light as well. Water slowly coming through the headliner. Thanks for the help I really do appreciate it

 

Call your service department tomorrow. DO NOT attempt to fix it on your own. There is a recall and Toyota is going all out to fix it properly, including replacing any damaged carpet/seats. I wouldn’t even mention the vent to them.

 

just noticed water under my driver seat. noticed my vent leaking as well. can you share what you did to fix?

 

Toyota servicing center was useless so pulled out the rear seats and plastic storage and applied black rtv sealant around the vent to seal it from the inside. Seems to have worked perfectly. If the leaking is under the driver seat most likely coming from a different location. Check under your front and back driver side running boards for water damage and or holes.

 

thanks for the response. it was under the drivers seat because it came in from the back and made its way to under the seat. it wet everything on the way. after looking today while in a down pour, i saw the vent leaking, mine is very loose in the cab - like your picture - like it loosened up over the years. i have 130k miles on mine so i run it hard and we are in a very high rain area. i will try the silicone, bet that does it. i had the 3rd brake light done at the dealership. i put high jet water on the brake light and monitored it, no leaks.

 

there should be a rubber gasket around it. looks like it's there in second pic but not in the first. are those different sides?

 

Adding to the top center brake light discussion . . . when my 2018 was at the dealer getting a transmission fluid change, they changed the seal at the light. It was Dec 2021. no charge, but i didn't get a recall letter on this. i have gotten recall letters on this truck for two other issues though.

 

I have a leak in the back of my 2016 Double Cab Tacoma.
Dealer told me it was the rear vent, I took it apart and sealed those vents last week. We have had rain every day and no leaks that I noticed.

However this weekend a big storm and I check today and I still have leaks, but not from the vent. Something higher up.

I suppose it has to be the window because the 3rd brake light has been fixed on mine (if they did it right of course) but mostly because no water on the headliner.

I am finding the water almost in the back corner on each side of the cab with one side worse than the other, with some water ontop of my exaust vent .

I honestly cant tell where its comming from, I'll have to take the side plastic off with the seatbelts because the water is behind that area.

 

Also check moonroof lines if you have one,, doubtful as your headliner isn't wet, but still something to consider.

 

Just had to pull it apart a bit more today, so it seems light rain wont leak but HEAVY rain will, got that rain again today and water was everywhere. My vents look good except the water ontop of them from above.

I pulled back the headliner and noticed it was wet actually, never noticed that before.

I figured with all the terrible repairs the dealer has done so far, they botched the 3rd brake light fix that has already been done and that is the issue this whole time.

Still too soon to tell though I guess it could also be the top of the window.

With it constantly raining I cant do much of anything, I'll have to wait unil its dry and have someone spray a hose while I am inside to find exactly where this is comming from.

If I do find it to be the brake light... I wonder if I can expect any help. I just know the dealer after trying to charge me $1200 for a diagnostic and $3000+ to fix the leak is not going to own this botched recall job and fix the issue. They will say something like the damage could have been caused by the vent and its not covered even though the brake light is also leaking, or since its been fixed once they wont fix it again, who knows.

The dealer I dealt with is pure garbage, and the truck is still covered with the platinum warranty and I still got absolutely no help just bills from the dealership.

 

I am currently dealing with the exact same situation with water coming in from the rear vents. Had the 3rd brake light replaced last year with an almost whole new interior installed due to the water intrusion. Took it back to the same dealer to have the review the seal as water was showing up on my rear window and floor, they found that the water was coming in on the passenger side where the rear window is mounted to the cab and the pressure relief vents. Currently removing the plastics and headliner to seal everything up and may end up put some sound deadening since everything is removed.

 

I had the 3rd brake light replaced a couple years ago at Toyota after noticing rain pouring in the back. They redid my seats and carpet. About a year ago I started noticing water in the passenger side floor board front and back. Took it to Toyota 3 different times and spent hours waiting for them to figure it out. The put dye in the ac line to see if it was coming from there, checked clogged hoses, said it could be the ac evaporator or a seal on the roof but they couldn’t find the leak. Charged me $150 to diagnose but they never diagnosed anything. They basically said there is no leak even though they saw the water. My boyfriend started looking around and figured it out in 10 minutes. It was the pressure vent in the back on the passenger side. Water hose tested it and water was pouring through. Sealed it up with some weather sealant bc I be damned if I pay Toyota another dime to fix what they couldn’t diagnose in the first place.

 

I’m currently trying to track down where my leak is coming from. Mine is in the driver rear in my double cab. I’ll be checking that vent. I don’t notice any spots that are wet in the headliner. It seems to be in that rear corner and then water is pooling under the sill panel.