Tips on installing rear quarter window weather seal (1 Viewer)

[TheRealPoser]

I'm in the process of replacing the rear quarter window weather strip seal on my LC. I had a leak in rear cargo area that was leading to some water pooling in one of the 3rd row seat brackets. I pulled out the interior panels and carpeting, hit the window with the garden hose, and found water starting to come out under the weather strip on the inside. The seal is not damaged, so I'm not sure how it was getting through. I can only guess the contact cement may have broke down enough with age that water was able to get down into the bottom of the seal on the top and then run down into the inside of the seal.

Regardless, I decided rather than trying to clean up and reinstall a 18 year old seal I'd just put a new one in. I'm now looking for any tips I can find on how best to apply the weather strip sealant, as it seems like it could be a bit tricky. I found some nice youtube videos talking about how to properly use weather strip sealant. In those videos they applied a thin layer to the strip and metal surfaces, let it get tacky, then put together like a contact cement. That method resulted in a very solid adhesive bond.

However, in those examples they were also just gluing a flat rubber seal to a flat plate. Our weather strips have a "v" channel that sits over the sheet metal lip around the inside of the window. The problem I see is, if I use this technique I'm going to risk the gasket bonding to itself inside the channel in the gasket. Meaning if I hold the groove open and apply cement to each side in the channel and let it get tacky, if I don't perfectly hold that channel open it will snap shut and glue together on itself. I really don't want to ruin my new gasket screwing it up, as they are a bit hard to come by and not exactly cheap.

FWIW, the gasket comes from the factory with some sort of sealant, but the weather strip is not glued to the metal. It pulls of rather easily and there is a sticky black sealant of some sort that is still sticky 18 years later. So they clearly do not use the contact glue method in the factory.

Does anyone know what the technique is here, or if there is some other sealant that should be used? I was planning to use 3M black super weather strip adhesive. I can't tell if they used adhesive and just gooped it in at the factory so it never set up like contact cement, or if they use some other sort of sealant for these seals. From what I could find it seemed like the 3M adhesive is the gold standard these days.

I appreciate any tips. I searched the forums and youtube but I couldn't find an answer to this specific question. If it's out there please redirect me. Thanks!

 

[JunkCrzr89]

The FSM doesn’t spec adhesive or sealant for that weatherstripping.

 

[TheRealPoser]

Yet it comes from the factory with sealant... not meaning to be snide about it, I'm just not sure what to make of the fact that the FSM says no adhesive but they clearly used one in the factory I honestly didn't expect there to be any sealant, but there is gooey black stuff in there that I had to use adhesive remover to get out. I don't think it's the doing of the PO either, if you watch the install videos for the emu wing windows (for the LC 100 specifically) they talk about needing to clean the old sealant off prior to gluing in the emu wing frame.

 

[JunkCrzr89]

Then I would probably use 3M Super Black. That’s what I used when putting in new weatherstripping on the 40, and what is recommended for OEM Toyota weatherstripping where sealant is spec’d. However, for most side and back windows, Toyota does not spec any sealant or adhesive because the weatherstripping fit with the glass is tight enough to prevent water intrusion.

 

[saucebox]

I had a similar issue a year ago—no extra sealant required.

The cause for me was that with the vent windows open, dirt and crud would build up on the seal and get trapped when the glass was again closed. Over time the open/close action had worn the seal out. Now I just take extra care to wash it out after a trip and it's been leak-free.

 

[TheRealPoser]

Thanks for the tips JunkCrzr89 and saucebox. It's certainly easier and less messy to install without sealant. And if I get any leaks it's also easy to pop it out and add sealant and reinstall. Perhaps what I'll do is just put it in without and and do the old garden hose test and see if I get any leaks. If not, just leave it be. The only reason I get nervous about it is it's pretty soggy in my area for months on end. Doesn't get cold enough to freeze most of the time, but also seldom gets sunny enough to dry things out. Even small amounts of water can wreak havoc when it stays wet for months, causing all sorts of rot, mold, and mildew. Then the humidity can cause the mildew to spread to other places. Fortunately the leak was small enough that it didn't cause mold, though it did cause a bit of corrosion on the 3rd row seat brackets due to humidity trapped under the carpet.

In my case the water comes out from under the seal on the bottom of the window. Between the window and the seal it's totally water-tight. I'm not sure how exactly the water is finding its way around the back side of the seal. I had some rust starting to form in 4 or 5 places on the metal lip the seal sits on, but all but one spot was early enough that little damage occurred to the metal. I ground them all down to bare metal and then primed with rust coverter / primer, so that was good to take care of. I will say it's a little tricky to tell there is a leak like that, as it comes down under the plastic panel and soaks into the foam padding under the carpet. There is a layer between the foam and the carpet, so even with the wet foam the carpet on top feels dry. It can hide it for a while.

At any rate, I'll try putting the window seal in without any sealant and then judiciously soak the heck out of it with the hose and see how it holds up. I'll report back after doing so. Hoping I'll get the seal by next weekend. Apparently there is a nation-wide shortage of the right rear seal in particular, so I've been on back order for about 2.5 weeks now already.

 

[TheRealPoser]

I'll also note in case anyone is reading this in the future and looking for leaks, another place for leaks to form is the black belt molding strip that runs under the window on the outside. There are 3 plastic clips under that molding that snap through holes in the metal body panel under the rear quarter window, and water can seep under the molding and drip down from those clips inside. The only way to see is to remove the plastic lower interior panel in the cargo area, then with some contortion you can look up underneath from the inside and see if water is dripping down while an assistant hits the outside with the hose. In my case I did not get any leaking there, but others have had leaks from the molding. That one is a pretty easy fix once diagnosed, so if you're trying to find a water leak in the back cargo area that would be a good place to check.
Also be aware that there is a video on youtube from a FJ80 showing to slide that belt molding forward and out. On the 100 series there is one screw on the forward end of that molding that is concealed by the window. To get to it you need to pull the upper trim panel and probably take off the lower nut that holds the window in place at the hinge in the front. I took my window all the way out, but you may be able to get to that screw holding the molding in out without taking the window all the way out. I'll see if I can upload a picture later of where that screw is. I wanted to mention it because if you try to get the belt out without getting that screw you're liable to just mangle the heck out of it and get nowhere.

 

[saucebox]

Thanks for the tips JunkCrzr89 and saucebox. It's certainly easier and less messy to install without sealant. And if I get any leaks it's also easy to pop it out and add sealant and reinstall. Perhaps what I'll do is just put it in without and and do the old garden hose test and see if I get any leaks. If not, just leave it be. The only reason I get nervous about it is it's pretty soggy in my area for months on end. Doesn't get cold enough to freeze most of the time, but also seldom gets sunny enough to dry things out. Even small amounts of water can wreak havoc when it stays wet for months, causing all sorts of rot, mold, and mildew. Then the humidity can cause the mildew to spread to other places. Fortunately the leak was small enough that it didn't cause mold, though it did cause a bit of corrosion on the 3rd row seat brackets due to humidity trapped under the carpet.

In my case the water comes out from under the seal on the bottom of the window. Between the window and the seal it's totally water-tight. I'm not sure how exactly the water is finding its way around the back side of the seal. I had some rust starting to form in 4 or 5 places on the metal lip the seal sits on, but all but one spot was early enough that little damage occurred to the metal. I ground them all down to bare metal and then primed with rust coverter / primer, so that was good to take care of. I will say it's a little tricky to tell there is a leak like that, as it comes down under the plastic panel and soaks into the foam padding under the carpet. There is a layer between the foam and the carpet, so even with the wet foam the carpet on top feels dry. It can hide it for a while.

At any rate, I'll try putting the window seal in without any sealant and then judiciously soak the heck out of it with the hose and see how it holds up. I'll report back after doing so. Hoping I'll get the seal by next weekend. Apparently there is a nation-wide shortage of the right rear seal in particular, so I've been on back order for about 2.5 weeks now already.

Totally understand. I figured out mine was leaking on a 3-week trip back home during monsoon season. It also wouldn't dry out (and stunk!), at least until I got back to the sunny desert that's home now.

 

[TheRealPoser]

Ok, time for an update. I finally got the new window seal and finished sanding/rust converting/priming the rust spots I found under the old seal. Regarding my original question, it's not really practical to use sealant as a contact cement on either side of the sheet metal flange that the window seal mounts over. The seal is very stiff and the groove is narrow - not enough room to apply sealant to both inner sides of the groove and have it get tacky and then glue it it. At the factory they definitely apply a sealant of some sort (black), my guess is they lay a bead in the groove and just install.

I opted to try without the sealant first to see how it worked since it's easy to pull it and reinstall if needed. The fit is very snug on the seal, you have to push it pretty firmly to get it to seat all the way over the metal flange. I firmly seated the seal all the way around, washed the window well so there was not dirt to trap between the glass and the seal, and reinstalled everything.

So now the big question is, did it work? Well, sort of. I put the garden hose right above the window and let it run low enough that all the water would follow the shape of the body above the window down into the window track, then flow right around the gasket on both the front and rear. Basically totally drenched the weather gasket from all sides. I'd guess it was maybe 1/2 gallon a minute or so flow rate, much more than a heavy rain. I let this go on for an hour. The result? I no longer have water coming from underneath the gasket on the inside. However, I did get a small bead of water along the inside between the glass and the seal, across the bottom. However, it didn't build up enough to spill over the top of the seal and into to back of the truck. My initial thought was, ok, that was a pretty severe test. A few drips for that much water is probably not that big of a deal.

BUT... just yesterday I took it out for the first time in the rain. Drove ~30 minutes in what I'd call typical rain, nothing to write home about. When I stopped I hopped in the back and guess what? The exact same amount of water inside the glass! The picture below shows what I'm talking about. To make matters worse, I looked at the other window, and it had even more water piling up, enough to start running over into the rear cargo area.

To say I'm a bit frustrated is an understatement. I'm not thrilled even the 18 year old seal leaked, but I can accept it's old and has seen better days (though honestly the seal I took out on the right side looked nearly the same as the new one). But a brand new seal leaking at the first sign of rain? That's pretty lame, and I expect a heck of a lot more. It rains 8+ months of the year here, and no Toyota I've ever owned has leaked so much as a drop, ever.

Any ideas what to try next? I will probably pull the new seal and put a bead of sealant in, but honestly it looks to me like the water is coming in between the glass and the seal, not under the seal. Also the left side still has the factory sealant and it's leaking just as much if not more. As such, adding sealant likely won't make any difference at all. I'm not sure what else to do to get a brand new seal to do it's job. I've heard some people suggest silicon treatment, but that's usually to help recondition an old crotchety seal, not to baby a brand new one.

In this first picture you can see a slight glint of the camera flash on the water circled in red. I suspect it's coming in the front edge at the hinge. The water runs all the way down the bottom on the inside of the glass like that. This window has the new seal. The blue circle is where the water was seeping out under the bottom of the seal previously but no longer.

This 2nd image is from the left side with the original seal. There is a drip up near the top of the circle and I'm guessing the water is entering there on this window and running down and piling up at the bottom.

 

[Gnarwgn]

Giving this a bump, as I think I may have a similar issue. Spoiler alert - I'm also in Seattle!

@TheRealPoser - have you figured things out yet or still chasing the leak?

 

[TheRealPoser]

Giving this a bump, as I think I may have a similar issue. Spoiler alert - I'm also in Seattle!

@TheRealPoser - have you figured things out yet or still chasing the leak?

I've been meaning to give an update. My situation is still the same. I've been out driving in a few more hard rains as well as having the LC parked out in the driveway overnight in a couple good rains. Each time I get a very small streak of water along the bottom of the seal inside the glass. It's only a few drips worth; enough to see the glisten with a light on it but otherwise hard to see. I haven't taken any multi-hour drives so i don't know if I'd get more. I have paper towels lining the inside of the fender well (interior panels are removed still) and I haven't seen a single drip below the window yet.

The other window with the old seal still gets a few drips pile up when I drive in the rain, just like the picture.

I haven't had time to try anything else yet. Our van got major damage and has been in the body shop for weeks, so I've had to keep the LC in driving condition, which with all the rain we've had lately means keeping it water tight. As soon as the car is out of the shop I plan to attack the other window. Lately I've been on the witch hunt for leaks in my upper hatch... If anyone wants a tutorial on replacing the spoiler bracket rivnuts let me know LOL.

I bought the LC recently and the 3rd row seat brackets were all corroded, so I still consider this a success. It's dry in the bottom now at least. I've stripped and repainted all the brackets.

I still have the back end torn apart, so if you want to have a look at what underneath and how it comes apart DM me and I can show you. I can also provide the window seal part numbers if you want them. The seals are about $50 a pop.

Have you tried hitting the outside with the hose to see if you can determine where the water is entering? It's pretty tricky since the water can wick all around where you can't see it, but you might get lucky.

 

[2001LC]

Few thoughts come to mind:

1. Any accidents in history or signs of 1/4 panel or roof damage.
2. Is widow alignment spot on.
3. It does appear in pictures, as leak localize in the corner (red outline). But is it. When testing with water hose. Are you very careful to not get water in rain-gutter on roof. I ask, because I find, when roof rack removed for any reason. Then replaced or not (with OEM or whatever). We often get leaks.

We don't get the constant rain you do in PNW. But perhaps I need to be looking at this seal more closely. Although, I think we'd have more reports of this in mud!

 

[TheRealPoser]

Good thoughts, I appreciate the input. No history of body damage. Of course there could be some I wasn't told about, but I doubt it. The body is straight as an arrow, and I've looked very closely. I have not tested to diagnose the window with the old seal. I will try the window and the roof track separately on that side.

On the side I replaced the seal it was definitely the seal. I put the hose right into the rear window track, not on the roof. The water appeared UNDER the seal on the inside almost immediately. There is another thread about moisture inside the outer rear door seal where the person is seeing the same thing, just different seal. After replacing the seal I ran the hose directly into the window track again, not on the roof. Now I no longer get water under the seal, so the seal fixed that issue. I can reproduce the small amount of water I get inside the window along the bottom with the hose so I am certain it is coming through the window seal, likely between the glass and the seal. It appears to be happening on the front edge but unfortunately there is no way to see that section from the inside so it's hard to say for sure. I may just live with that one and keep an eye on it.

I'm getting more fogging than I think I should in the rain, so there may be a leak somewhere still. I have no wetness in the carpet anywhere or water stain on the roof. There may be a small leak somewhere still but it's going to be harder to find because I don't know where it is. I'll keep the roof rack track in mind.

 

[stubbs]

Any other progress to share? I'm watching what you find because I've also found signs of leaks on my rear windows, particularly the back right. I'm in Utah so it's not usually wet for weeks at a time, and mine's not terribly urgent. I'd hate to pull the window out and replace the seal and have no improvement!

What I've occasionally found on mine is a row of water spots on the inside of the window where water appears to have worked its way inside at the top of the seal and run down!

 

[TheRealPoser]

Any other progress to share? I'm watching what you find because I've also found signs of leaks on my rear windows, particularly the back right. I'm in Utah so it's not usually wet for weeks at a time, and mine's not terribly urgent. I'd hate to pull the window out and replace the seal and have no improvement!

What I've occasionally found on mine is a row of water spots on the inside of the window where water appears to have worked its way inside at the top of the seal and run down!

Hi @stubbs, sorry for the delay, somehow I managed to overlook the notification that you posted a question here (BTW, I love your BBQ sauce ). I have some updates, but probably not terribly helpful. As I noted in my original description, my passenger side quarter window had the leak that had water coming out under the window seal on the bottom on the inside. I replaced that seal and it seems to be working fairly well. I get a tiny bit of water between the seal and the window on the inside still as I noted, but I haven't seen any dripping down on the inside. I have not taken it on any multi-hour drives in the rain yet, but I did soak the heck out of it with the hose and it held up. Note that I did NOT use any gasket sealant on that seal. More on this below.

On the driver's side I was getting a little water coming in between the seal and the glass, so I decided to replace that seal as well just for good measure. After all, I already had all the interior panels out and at that point it's trivial to get the glass out. On that side I decided to put a small bead of 3M gasket sealant in the gasket. I realize by saying that I'm inviting the "that's not in the FSM" beat down, and probably rightly so in this case. In my defense I will reiterate that the LC's come from the factory with sealant inside that gasket, and it's a bit of a bugger to clean off (3M general adhesive remover works well for it though). I figured if they put it in at the factory there must be a reason, so I did as well to see if it would work better.

Unfortunately when I hit that window with the hose, after maybe 5 min or so water started to trickle from under the seal on the bottom on the inside, just like the passenger side window did before. You can't see that leak when the body panels are in, and so you end up with soaked carpet and corrosion without even realizing it. I pulled that window again and am in the process of cleaning the adhesive back off. Unfortunately there really isn't a way to clean the adhesive out of the groove in the rubber seal, so I'm just hoping I can clean it up and put it back together and it won't leak this time. I honestly got tired of dealing with it and so I parked it in my garage so I could work on my suspension and bumper install instead with the window still out, realizing I'm only delaying the inevitable!

If you decide to replace it, feel free to post questions or DM me if you want any tips on the removal. I still have the panels out so I can take pictures of where the connectors are or whatever. I don't think you need to actually remove the panels all the way, but I did. There are two nuts on the front edge of the window that are the main thing holding the window in place. I can also post the part number of the seal if that's of use. It was around $50-60 if I remember right.

 

[MrA]

Hi @stubbs, sorry for the delay, somehow I managed to overlook the notification that you posted a question here (BTW, I love your BBQ sauce ). I have some updates, but probably not terribly helpful. As I noted in my original description, my passenger side quarter window had the leak that had water coming out under the window seal on the bottom on the inside. I replaced that seal and it seems to be working fairly well. I get a tiny bit of water between the seal and the window on the inside still as I noted, but I haven't seen any dripping down on the inside. I have not taken it on any multi-hour drives in the rain yet, but I did soak the heck out of it with the hose and it held up. Note that I did NOT use any gasket sealant on that seal. More on this below.

On the driver's side I was getting a little water coming in between the seal and the glass, so I decided to replace that seal as well just for good measure. After all, I already had all the interior panels out and at that point it's trivial to get the glass out. On that side I decided to put a small bead of 3M gasket sealant in the gasket. I realize by saying that I'm inviting the "that's not in the FSM" beat down, and probably rightly so in this case. In my defense I will reiterate that the LC's come from the factory with sealant inside that gasket, and it's a bit of a bugger to clean off (3M general adhesive remover works well for it though). I figured if they put it in at the factory there must be a reason, so I did as well to see if it would work better.

Unfortunately when I hit that window with the hose, after maybe 5 min or so water started to trickle from under the seal on the bottom on the inside, just like the passenger side window did before. You can't see that leak when the body panels are in, and so you end up with soaked carpet and corrosion without even realizing it. I pulled that window again and am in the process of cleaning the adhesive back off. Unfortunately there really isn't a way to clean the adhesive out of the groove in the rubber seal, so I'm just hoping I can clean it up and put it back together and it won't leak this time. I honestly got tired of dealing with it and so I parked it in my garage so I could work on my suspension and bumper install instead with the window still out, realizing I'm only delaying the inevitable!

If you decide to replace it, feel free to post questions or DM me if you want any tips on the removal. I still have the panels out so I can take pictures of where the connectors are or whatever. I don't think you need to actually remove the panels all the way, but I did. There are two nuts on the front edge of the window that are the main thing holding the window in place. I can also post the part number of the seal if that's of use. It was around $50-60 if I remember right.

Hey, whats the part number for the passenger side weather seal? I'm having an identical issue of water pools in one of the 3rd row seat brackets. Replaced with belt molding, but now I notice it coming under the weather seal.

 

[TheRealPoser]

Hey, whats the part number for the passenger side weather seal? I'm having an identical issue of water pools in one of the 3rd row seat brackets. Replaced with belt molding, but now I notice it coming under the weather seal.

I don't have the packaging anymore, but I looked it up again and found 62741-60091 for the right side rear quarter window seal. FYI, I finally seem to be leak-free under the seal. I installed the new one with some 3M weatherstrip sealant and had a small leak still. Took it out and cleaned all the sealant out (huge PITA), reinstalled, leaked like crazy. Took it out again, reinstalled with some 3M sealant again and this time no leak under the seal. If that had not worked I was going to put clear silicon around the outside edge of the seal as the nuclear option. Sounds stupid but you can't actually see that under the glass so I think it's a workable last resort.

I have done a lot of leak testing on it and I found that now I get an occasional drip that comes down from the top between the glass and the seal. Seems like a design flaw. Happens in 2 places on the top at nearly the exact same spot on both sides. However, it appears to wick out the bottom and it hasn't yet spilled over the seal on the inside to drop down. It's annoying but the carpet is staying dry so I'm calling it a success.

 

[MrA]

I don't have the packaging anymore, but I looked it up again and found 62741-60091 for the right side rear quarter window seal. FYI, I finally seem to be leak-free under the seal. I installed the new one with some 3M weatherstrip sealant and had a small leak still. Took it out and cleaned all the sealant out (huge PITA), reinstalled, leaked like crazy. Took it out again, reinstalled with some 3M sealant again and this time no leak under the seal. If that had not worked I was going to put clear silicon around the outside edge of the seal as the nuclear option. Sounds stupid but you can't actually see that under the glass so I think it's a workable last resort.

I have done a lot of leak testing on it and I found that now I get an occasional drip that comes down from the top between the glass and the seal. Seems like a design flaw. Happens in 2 places on the top at nearly the exact same spot on both sides. However, it appears to wick out the bottom and it hasn't yet spilled over the seal on the inside to drop down. It's annoying but the carpet is staying dry so I'm calling it a success.

Do you remember what 3M sealant worked the 2nd time? Was it 03602 Black sealant or something else?
Many thanks for the replies. Doing this exact repair myself this weekend.

 

[TheRealPoser]

Do you remember what 3M sealant worked the 2nd time? Was it 03602 Black sealant or something else?
Many thanks for the replies. Doing this exact repair myself this weekend.

Yes, that is the stuff I used. I replaced the weatherstrip/gasket on both drivers and passenger sides. As someone noted above, the FSM doesn't mention using adhesive, but there was adhesive from the factory on both sides when I removed the originals. I can't say what it was exactly, but it was very similar to the 3M adhesive. I also found an install video on youtube about gull-wing windows where the guy had to clean off the factory adhesive as well, so it doesn't seem to be a fluke on my LC.

A couple things about the adhesive. It's supposed to be a contact cement. I think the normal use is for applying weatherstrips that have to glue flat onto metal. You put a thin layer on the strip and the metal, let it dry, then stick them together. That is not very practical to do with the quarter windows because the weatherstrip has a channel that pushes over a sheet metal lip all the way around. What I did the 3rd time was actually pry the channel open a bit (it has metal or something inside that causes it to hold its shape). Then I put a bead of sealant along the top edge of the lip, which is sort of a messy affair. Then I put the seal down and crimped it together. My theory was to try and get contact in the bottom of the channel in the weatherstrip with sealant on the tip of the metal lip. It will probably make more sense when you pull things apart. I'm not sure I'd recommend this method, but it's what I did and seemed to work this time. If you don't pry it apart it has a very tight friction fit on the metal lip. I thought this would be good enough but it leaked crazy when I didn't use any sealant. Because it's a contact cement it doesn't seem to really dry if you just smear it in there. That said, the sealant in the original weatherstrip installed at the factory was still gooey 20 years later, so I figured if Toyota was good with it it must not be all bad.

I will say, if you have any desire to try without sealant, try it that way the first time so you don't end up with a mess of tar-like sealant to clean up like I did. Oh, and use gloves, that stuff is sticky and hard to clean.

 

[MrA]

Did your weatherstrip come with any sealant preinstalled? I took off my old weatherstrip, spent a long time cleaning it, test fit the new weatherstrip and when I went to take it off, it was already nearly stuck again with sealant that had been preinstalled. It was a little unexpected.