My DC is leaking - what is the root cause?

Long story short - a few weeks ago I washed my truck and noticed later in the day that a cleaning towel that was on my back seat was wet - I thought I must have left a window cracked when washing on accident and didn’t think much of it.

We’ve had a lot of run the past two days and I noticed yesterday and again today some water drops on my back seat. Tonight it finally stopped raining for a bit so I went to get a closer look and it appears to be coming from around the XM antenna fin, or perhaps the top of the rear sliding window as you can see the headliner is only wet in the the back center. I can’t see anything amiss with the seal around the windows and the tracks appear clean. Is there a drain line in the rear that can be plugged? I know the ones near the front door and cause water to leak in that area.

thanks in advance for any tips or info on what to check for.

 

Third brake light? Known issue. Mine leaks.

 

your headliner looks wet. Go jiggle the third brake light. Bet it’s loose...

 

More than likely. Effected 16-17s right? Fixed on 18

 

Not sure, mine is a ‘16. Toyota denied warranty on it.

 

Denied probably because of mileage or time?

 

Thanks guys, will check the third break light tomorrow. Is there any simple fix for it?

 

Look for the tsb (or the thread about it)- it might have the process/steps

 

https://imgur.com/a/COCsLHq

 

They said I broke it. Had 30k on it.

 

Warranty or rtv

While you’re at it, don’t forget to check the brake light. For the break in the brake light

 

I didn’t realize 18s were included

 

I wouldn’t accept that unless I actually did break it.

 

What a crappy warranty TSB on that light, 30K miles/3 years only for coverage on that is bad.

 

36k same as everything else. I wonder if you have an extended warranty if this would apply

 

Whaddya gonna do?

 

True, but when water is coming into the cab because of some dumb design or part they should fix it.

 

A thin line of clear RTV around the third brake light housing (clean up all the excess - you only need enough to fill the void between the housing and the gasket which is a couple MM inside from the outer edge of housing) will do the trick. Or you can replace the housing. If you're out of warranty, Toyota will likely tell you to kick rocks, otherwise get it covered under warranty.

 

The only way to tighten it is if you drop the rear of the headliner which is a bit of a project. I had my headliner down because I was taking a look at my shark fin antenna that I ripped off on a garage door so I tightened the third brake light as well. Didn't have a lot of faith in it because it didn't look like it closed the gap between the light and body so I used some gasket maker and put a bead around the entire light. Hasn't leaked since.

 

Ask for proof of damage. From my understanding it’s the seal on the back so if there’s not physical damage on the lens it’s bs right. Then talk to the service manager or higher up. Then Toyota. Like I said I wouldn’t drop it if I know that I didn’t cause damage. Persistence and a relative calm but firm attitude