kyk007

Hello boys and girls in LS land. I have recently developed a phantom leak in the trunk area of my LS400, unbeknownst to me at the time. A few days ago, I opened up the trunk to find a huge puddle of water underneath my spare tire.

As they say, "Houston, we have a problem." Indeed. I first thought water might be splashing up into and through the plugs in the trunk, but after sealing them with silicon, drying out the trunk and letting it sit overnight, I now know that is not the source of the water getting into the trunk.

Once again, I opened up the trunk this morning to find a small puddle that had built up overnight. I have taken a couple pictures of the area, and although it's hard to make out in great detail, it shows where the water is pooling.

In the second picture, I tried to show a view of where it seems the water is coming from. It's right in the middle of the wire loom area. Are there any brighter minds that can shed light on this for me? Any input or information you could give me would be greatly appreciated.

With all the rain we get in Seattle, it's not something I want to endure for any longer than I have to. Thanks to everyone in advance.

timmy0tool

iTrader: (7)

the common causes of leaking trunks is the trunk seal itself, and the drain tubes from the sunroof. the drain tubes run on each side of the c-pillar into the side of trunk and drains right behind the rear tires. make sure the tubes are not misplaced or clogged.

kyk007

Timmy0tool - thanks for the timely information. I checked the trunk seal and it looked OK to my eyes. As for the drain tubes, at the risk of sounding ignorant, what's the best way to check to see if they're clogged. I haven't done that yet.

timmy0tool

iTrader: (7)

don't be afraid to ask ! you will need to pull back the trunk liners on each side. start with the trunk floor and work your way around. there are various clips that need to be removed using a flathead screwdriver or trim panel removal tool, then each liner comes out. the sides of the skid guard on the lower part of the trunk opening may need to be peel back (again by removing clips) to remove the side trunk liners. you do not need to remove the back liner covering the gas tank, but you can to see more of the leak source.

kyk007

Timmy - I'll try to get to it this weekend to see if I can find the source of the leak. If it's the drain tubes that are clogged, I'll let you know. Much thanks . . .

dicer

It will be the trunk seal. And until you get a new one, remove one of those plugs in the spare tire well to drain any water. I always put a little bit of Vaseline on the threads for the hold down for the spare to keep the rust away.

GH5T

Do you have to buy a new seal? Or will cleaning the old adhesive off and reusing the rubber seal with new adhesive work?

lexmoose

I've cleaned mine and used 3M Weatherstrip Adhesive (08011)

GH5T

It should be in the 70's here today I will give it a go. Thanks Ichouinard

lexmoose

just make sure you get all the water out using compressed air before putting the new adhesive

kyk007

Gentlemen, it seems from reading the last 3 or 4 posts that the consensus is that the trunk seal is the culprit. Am I to understand that it's acceptable to use the existing trunk seal, and to just replace the old adhesive? If so, I can definitely do that. In checking the seal, it seems to be in good condition, but maybe a little loose.

Appreciate all the feedback.We have sun here in Seattle today, so maybe a good day to try and tackle this job.

dicer

Its not an adhesive per say from the factory. The seal comes new with the sealer already in the groove (and it never hardens), it is more of a butyl type sealer, if you use an adhesive it will be a mess to remove if you have to do that. Any petro base solvent removes the butyl pretty easy, no scraping off paint etc. to remove it. Resealing may or may not fix the problem. Since there are air holes in the seal water can get in and travel to a torn area of the seal and continue to leak. All you can do is try it.

sha4000

iTrader: (1)

Or you can do what munday did in this thread. Cheaper than buying a factory seal and he seems to vouch for it. I'll probably go this route when i get around to it.

https://www.clublexus.com/forums/ls4...the-trunk.html

kyk007

Sha4000 - I read over the whole thread and Munday's solution to the problem. Sounds like an affordable alternative to a problem I never would have guessed is so common on our LS400. I very well might swing for that, and given the success he and his counterparts have had with this particular seal, it could be worth it.

Thanks for the heads up.

sha4000

iTrader: (1)

Your welcome and that's why we all come here.