SOLVED: Why is water running down my 3rd row seatbelt?

[2012sr5]

SOLVED Post #12

I've searched. The threads that I've found on the subject were posted by members who have a sunroof and/or an aftermarket roof rack. I have neither. And yet today while I was at work, my wife was driving the kids back home from Dinosaur World in KY (which is awesome) in the rain, and water was running into my kid's lap. She says the rear window was all the way up. The water is running out of the slot pictured below and down the seatbelt. I think it has been happening for a while because the inside of the 4Runner smells like water was spilled after it rains. I kind of always assumed it was my kids spilling a little bit of their water bottles (we don't go anywhere without full water bottles), but I could never find the spill.

If I have my factory roof rails (never been removed) and no sunroof, what could be the issue?

I will probably start with taking off the factory rails and resealing them, unless there is something else I should check.

 

[Jhalko]

The only leaks folks have reported that I remember seeing have been the holes where the roof rack (or after market rack) attaches. It would be easy to take off and check as there are instructions on here.

I do recall a couple folks having their sunroof drain channels get blocked and cause a leak. I thought those caused leaks by the sunroof though.

If it’s the 3rd row seatbelt my bet would be the rear roof rack attachment. Once you take it off you will probably know. I had a larger than average gap around one of mine that had to be sealed.

Edit for link that has great pics:
DIY: Roof Rack Delete (w/ pics)

 

[2012sr5]

If it’s the 3rd row seatbelt my bet would be the rear roof rack attachment. Once you take it off you will probably know. I had a larger than average gap around one of mine that had to be sealed.

Yeah, that's what I'm thinking, too. I can't imagine what else it could be. But I also thought that leaking only came from removing the factory rack and installing a new one incorrectly.

Thanks!

 

[KingTaco]

I think it absolutely has to be water coming in through the roof rack mounting points. I'd bet $100 if you remove the rear crossbar, seal those 4 bolt sleeves with gusto, and reinstall, your problem will go away. The existing seal has probably deteriorated over time. The smell, photo, and description are identical to what I experienced when mine was leaking. Good luck.

 

[cb1111]

Before you start taking things apart, you may want to look for rust in that area because that may impact how you tackle the issue.

 

[wcjeep]

Low pressure, high volume water hose to recreate the problem. Verify the leak.

 

[Beaver_94]

New 4-runner owner here. I haven’t looked to see how it’s attached to the roof yet but we had a leak in our minivan through the roof mounted antenna. Just thought I’d throw that out as a place to look as well.


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[2012sr5]

I took the passenger side roof rail off yesterday. There was some debris under the mount in the rear and what looked like evidence of water running down into the front bolt’s plastic threads. I added Teflon tape to the bolts front and rear and carefully sealed around the plastic bolt mounts with silicone. I’m giving the silicone a day or two to set up before I run a hose over it because it’s super humid here. Thanks for the help everyone!

 

[2012sr5]

Well, problem NOT solved. Drove home from church today in a torrential downpour, the kind where people drive with their hazards on through standing water on the highway. That was fun. Noticed that despite my efforts, water is coming in through the passenger side 3rd row seatbelt. But wait—there’s more! It’s coming through on the driver side 3rd row seatbelt, too!!

I’m just going to order all new parts for all four roof rack mounts, including the plastic thread housing that the bolts screw into. Stay tuned.

 

[flyrv9]

You could take off that square piece that the seatbelt runs through and look in there and maybe see where the water is coming from.

 

[Blu42]

If I had water coming from an unknown place like that I'd probably want to drop the headliner (just drop the rear down) and verify where its coming from and the extent of the damage. If there is any kind of damp smell it could be a mildew/mold situation. It should be obvious once you can see in there.

 

[2012sr5]

Found it

It's the weatherstripping that seals the liftgate when it's shut. This is why it only happens when we're driving and it's raining REALLY hard. Lots of water has to be running on the roof from front to back for it to leak. And even then, it doesn’t leak very much. The weatherstripping leak is in the middle, but the water runs into the channel formed by the edge of the headliner and down into the D pillar like this:

Then the water pools in these areas and runs over down the seatbelt and down into the fuzzy foam on the inside of the bottom of the D pillar panel.

It's interesting that the headliner, where it's molded around the edges, has this hardened material on the inside that seems like a thin layer of dried glue (you can see it in the above pic...it's the part that looks more yellow on the edge of the inside of the headliner). Whatever that stuff is, it kept my headliner dry and made it harder to figure out where my leak was coming from.

If you find water coming down the 3rd row seatbelts or wet spots in the back corners of the cargo area, this might be the culprit. Run a hose over the roof. Pull the headliner down enough to check the roof rack screws. We had the hose going for probably 3-5 minutes before it started leaking the way it does when we're driving through heavy rain.

 

[andrew4r]

I recently installed an aftermarket roof rack. When I removed the factory rails, I noticed there was dirt underneath the plastic piece that is bolted to the vehicle. If dirt can get under there, water surely can.

 

[KingTaco]

It's the weatherstripping that seals the liftgate when it's shut. This is why it only happens when we're driving and it's raining REALLY hard.

I'll be damned. Good find OP. Glad you got it tracked down.

 

[2012sr5]

I'll be damned. Good find OP. Glad you got it tracked down.

Thanks! What a pain.

Ordered some parts:
OEM lift gate w'strip: 67881-35060
OEM rubber grease: 08887-01206

If I find any rust, I'll shoot it with a little Rust Reformer in black.

 

[2012sr5]

Replacing the lift gate weatherstripping is pretty easy. First, I removed the old weatherstripping slowly while cleaning the edge where it's mounted. There was a bit of rust on the bottom edge, so I taped it off to spray a bit of rust reformer on it:

After that set up, I smeared some of the Toyota rubber grease all around the rim and started to install the new weatherstrip. First of all, there is a seam in the strip that goes in the middle of the bottom edge. Center that seam with the lift gate latch. To make sure you have it oriented correctly, there are three orange marks and one white mark on the strip. The three orange marks go in the bottom corners and the top driver side corner. This white mark goes in the top passenger side corner of the lift gate opening:

Use that mark and the seam at the bottom middle to make sure you have it oriented properly. It goes on pretty easily.

NOTE: I did not use any kind of weatherstripping or gasket adhesive. But I'm reading a few more threads and thinking that I should. I'll probably order some from Amazon.

 

[2012sr5]

Bought a little tube of adhesive from Walmart for $2.49. This stuff is immediately tacky and very stringy. Like Venom from Marvel Comics. You gotta work fast. And keep the stringy stuff from getting on your headliner or anywhere else.