Taillight Gasket Exhaust Leak?

[chaseincats]

Well gang, here's a topic that's been beat to death...but let's give it another swing shall we?

I saw an old forum thread where a guy put a Halloween fog machine in his car and with all the windows up, turned it on which showed all the air leaks in the cabin.  Specifically, he did it to find where exhaust was sneaking into the cabin when driving with the windows were down.

I gave that a shot this evening and found that it is my taillight gaskets, but the strange thing is they are brand new from Motorsport.  We even removed the black trim surrounds and bolted them back to the body and you can see the smoke sneaking around the gasket edges regardless of how tight we make the bolts holding the gasket to the body.

The gaskets are reasonably squishy (I have no idea how gummy these are supposed to be but they are very pliable).  I did notice that the plastic housing has raised bumps where the mounting bolts come through which would mean the gasket wouldn't be laying flush in the areas between these bolt bumps, right?  Was I supposed to install these with gasket maker between the rubber gasket and housing?

Edited May 3, 2023 by chaseincats
added image

[dutchzcarguy]

4 hours ago, chaseincats said:

Was I supposed to install these with gasket maker between the rubber gasket and housing?

I used some pliable rubber kit that's also used when you put glass into the rubber seals and into your window. There a 2 types used (when installing windows), one does get hard and the other stays pliable, this last type you can use between the cars metall opening and the rubber! 🙂

[chaseincats]

5 hours ago, dutchzcarguy said:

I used some pliable rubber kit that's also used when you put glass into the rubber seals and into your window. There a 2 types used (when installing windows), one does get hard and the other stays pliable, this last type you can use between the cars metall opening and the rubber! 🙂

You didn't use the pre-made ones from a Z parts distributor?

[Yarb]

I think he may be talking about applying a sealant similar to windshield adhesive to the new gasket.

[chaseincats]

9 minutes ago, Yarb said:

I think he may be talking about applying a sealant similar to windshield adhesive to the new gasket.

So, something more like this?

[Jeff G 78]

All of the gaskets I have removed on old Z's were "stuck" to the body.  I would either use something like 3M trim adhesive, or maybe contact cement on the gaskets.  Glad to hear the smoke machine worked though.  Sealing the leaks is much easier than finding the leaks.

[cgsheen1]

13 hours ago, chaseincats said:

  Was I supposed to install these with gasket maker between the rubber gasket and housing?

Please NO!

For the sake of the next guy that has to remove them! (ask me how I know...)

I would also advise AGAINST 3M double stick as well. Instead get just some slim weatherstrip foam from Home Depot or Lowes (closed cell if they have it) and run it around the perimeter or just where you have leaks. It'll squish down to nothing where it needs to and fill the gap where it needs to. And it'll be easy to remove if necessary.

Edited May 3, 2023 by cgsheen1

[Jeff G 78]

15 minutes ago, cgsheen1 said:

Please NO!

For the sake of the next guy that has to remove them! (ask me how I know...)

I would also advise AGAINST 3M double stick as well. Instead get just some slim weatherstrip foam from Home Depot or Lowes (closed cell if they have it) and run it around the perimeter or just where you have leaks. It'll squish down to nothing where it needs to and fill the gap where it needs to. And it'll be easy to remove if necessary.

3M trim adhesive *should* come off the body in the future.  It's sticky and gooey, but it does come off.  Besides, who cares about the next guy?  🙂 Seriously though, I'd rather have a sealed panel than worry about what might happen to somebody else in the future if they try to remove the lights.

[chaseincats]

34 minutes ago, cgsheen1 said:

Please NO!

For the sake of the next guy that has to remove them! (ask me how I know...)

I would also advise AGAINST 3M double stick as well. Instead get just some slim weatherstrip foam from Home Depot or Lowes (closed cell if they have it) and run it around the perimeter or just where you have leaks. It'll squish down to nothing where it needs to and fill the gap where it needs to. And it'll be easy to remove if necessary.

Won't that deform when I wash the car and it gets wet?

[Yarb]

Adhesive doesn’t deform as far as I know.

[Jeff G 78]

Another option would be to get butyl rubber in a caulk gun and chase the leaks with the smoke machine again.  Rather than trying to seal the whole gasket, just put dabs where they are leaking while using the smoke.

[Captain Obvious]

7 hours ago, cgsheen1 said:

Please NO! For the sake of the next guy that has to remove them! (ask me how I know...)

I used "Seal and Peel" which is a clear silicone that is designed to be an easily removable temporary seal. I haven't had the pleasure of trying to pull the taillights out since (so I don't know how bad it would be), but I've done the same on other cars and it was fine. They came off without a fight. 

I would post up some pics o what I did, but I'm getting the same server error as other people.

But the tube looks like this: