Trunk Gasket Installation, round 3

[joebarthlow]

OK, I've searched the FAQ, read the posts, bought a new trunk gasket (BMW), cleaned off the old adhesive, used 3M rubber adhesive, pinned down gasket to dry, let it cure... only to leak again. repeated the steps, leak again. Now I'm at the stage to put down adhesive again for the third time. then clamp, let cure. 

 

Am I missing something? I'd really like a dry trunk.

 

I've searched and now I cannot find the right thread. help 

Edited March 10, 2022 by joebarthlow

[Tommy]

I don't think it's about the gluing if it has stayed on place. I have not been able to make my trunk watertight either with aftermarket or OEM seal. The profiles just are not as the original was so it's not sealing against the lid.

[Mike Self]

Presume you're placing the gasket seam (where the ends meet) at the 6 o'clock position--just above the latch.  If placed at 12 o'clock in a heavy rain, the gutter that drains runoff from the roof and backlight will overwhelm the metal gutter edge and leak through that joint.  And it's not easy to really get the gasket glued down tightly on the four corners.  

 

You can adjust just how tightly the trunk lid seals against the gasket--both the latch and hinge mounts can be adjusted.  A car that's been hit in the rear can have an uneven perimeter surface (where the seal attaches) .  You can pinpoint low spots by closing the trunk lid on a sheet of paper and then seeing if you can pull the paper out.  Work your way around the lid, looking for low spots.   You can also dust the inside of the gasket with cornstarch or talcum powder, then spray water on the closed trunk and look for water streaks in the powder.  

 

Finally--water can leak in around the flow-through ventilation outlets at 11 and 1 o'clock,  Make sure they're firmly seated in their holes, and if you have a sunroof, make sure the grey plugs are also tightly seated.  A little strip caulk applied around the hole, and then reinstalling the outlets/plugs can seal things up.

 

I've never had problems with a leaky trunk on either of my cars so they did come watertight from the factory--and can continue to be.

 

mike

[joebarthlow]

good stuff, Mike, thanks

[BarneyT]

Not clear on real problem, is the seal coming loose from body and leaking?…or is the trunk just leaking?

[joebarthlow]

2 hours ago, BarneyT said:

Not clear on real problem, is the seal coming loose from body and leaking?…or is the trunk just leaking?

a little of both. water comes off the rear window and overwhelms the seal, it appears. two of the corners, which I thought were sealed, popped up.

 

Perhaps I need to degrease the rim after using the adhesive remover. I just wiped it dry before. I'll use a mild degreaser this time around. Also look at adjusting my trunk lid height

[NYNick]

Something is amiss here. Did you stretch it too much when applying? I just loosely pushed it on after applying cement and attached 100 clothes pins to hold it in place for a day. Zero issue. 

 

I think you need to closely inspect your trunk lip to see if it's bent, out of shape or misaligned from a hit. If not, check the seal. 

[mvliotta]

Sooo where should the seam sit? 
 

Mike mentions above that it should be at 6 o’clock to avoid seepage while almost every trunk I’ve seen has it at 12 o’clock. 

[Schnellvintage]

The seam should be at 6:00 directly above the trunk lock/latch. I also spread the seam, (after the seal has cured well for a couple days), and add to little bit of super glue to the seam and I haven't had an issue.  Another place to check is the trunk lid adjustment.  Make sure it is making contact around the seal. 

 

Fwiw

[danco_]

12 hours ago, mvliotta said:

Sooo where should the seam sit? 
 

Mike mentions above that it should be at 6 o’clock to avoid seepage while almost every trunk I’ve seen has it at 12 o’clock. 

12 o'clock gang checking in. 

6 o'clock placement is blasphemy to the eyes

 

[Mike Self]

15 hours ago, mvliotta said:

Mike mentions above that it should be at 6 o’clock to avoid seepage while almost every trunk I’ve seen has it at 12 o’clock. 

Both of my cars (69 & 73) came from the factory with the seam at the 6 o'clock position, next to the trunk latch...that's all I know.  And neither trunk has leaked.  Ever. 

[Conserv]

23 hours ago, mvliotta said:

Sooo where should the seam sit? 
 

Mike mentions above that it should be at 6 o’clock to avoid seepage while almost every trunk I’ve seen has it at 12 o’clock. 

Vince,

 

My ‘76 certainly had the seam at 6:00 from new. I have plenty of photos of it going back to 1983 — I never thought much about photographing the car’s un-glamorous bits until I was taking it out of daily driver service in 1983.

 

Your comment makes me wonder if those 12:00 seams are all replacements, or suggest an alternative factory installation. I’d guess that virtually all re-painted cars have had the original gasket removed (and replaced or reinstalled).

 

Absent threads or discussions such as this, the 12:00 seam seems logical as it places an ugly joint further from view — but the price for that aesthetic judgement might be a leak. May I add that, without comment or input from me, Korman placed the new gasket at 6:00, thank heavens… ?

 

Anyone here have an original owner car, trunk gasket never removed?

 

Below, my ‘76 before it’s repaint, sloppy factory seam well in sight! ?

 

Best regards,

 

Steve

 

[NYNick]

My gasket came seam welded together. I undid the back hinge of the trunk and slipped in under it so it remained circular. I'm not with my car today so I can't tell you where that seam ended up: 12 or 6? But if it's still welded together, I'm guessing it can't leak?

[02Les]

Water/rain runs down the rear window and under the trunk lid and is stopped by the trunk seal and directed toward the sides. This being the high point the water would then probably run down the side of the car. For sure the lower portion of the trunk/seal on the rear panel between the taillights is pretty much protected by the overhang of the trunk lid. Water entering the trunk is probably because the seal and the lid are not completely touching along the top/higher edge.

 

IMHO:  Logically you would position the join in the seal in the lowest position where it should, basically, remain dry. I.e., just like BMW did back in the day.

[joebarthlow]

My gasket is welded together.

 

On previous installs, after gluing it down, I used about 40 large document clips (like clothes pins) to hold it down.

 

Now that I have cleaned off the old glue and degreased the surfaces, I loosely stuck the gasket back on to do the paper test. the window-side, where some water had come in passed the paper test. the bumber-side, where it's not leaking, the paper was a little loose. go figure.

 

I went to glue down last night and determined my glue had expired. it was not too pliable, rather stringy and gooey. I double checked any general tips for applying the product and found this. No new info, but reenforced the application process

 

 

Here goes... hopefully third time is a charm.

Edited March 12, 2022 by joebarthlow