Hi all,

My 1971 Cutlass 4 door has a trunk leak and it's beginning to damage the trunk floor that I want to eventually remove and use in my vert.

At first I thought there was a leak coming from around the rear trim so I caulked it up. However, I found it still leaking.

Next I bought replacement trunk weather stripping, thinking maybe a crappy seal that is the source. Today I removed the old weather stripping/glue and while it still could be the issue, I think it is actually leaking from the joint where the quarter panel is welded to the piece of metal that is between the bottom of the rear window and the trunk lid.

My plan is to install the new weather stripping but I am wondering if I should caulk up that joint before putting in the new weather stripping. Would there be any issues that anyone can foresee?

Has anyone out there run into this issue (trunk leak with that joint as the source of the water)? How did you stop the leak? Did you try caulking the joint before installing new weather stripping?

Or did you just rely on the adhesive/weather stripping to seal it up?

Also, when removing the old stripping, I used some 3M spray adhesive remover. I used a nylon tooth brush to help get the old adhesive off and it appears to have lifted up the paint. In some places I see bare metal. I don't want it to rust, should I primer it first? Or will the new 3M adhesive act like a layer of paint and stop any rust from forming?

Thanks.

 

My guess would be a rust hole around the rear window. The only way to fix it would be remove the rear window cut out the the rust and weld new metal in. If your going to cut up the car and use it for a parts car anyway. I wouldn't waste the time on it,. Looks like a good reason to get started on your other car.

 

My first thought was also the same, a hidden rust hole under the chrome trim pieces surrounding the rear window (as there are no rust holes anywhere else in the roof structure). That's why I caulked up around the rear window as my first step. Again, it's possible there could still be a hole and I didn't do a good job caulking, but it seems unlikely.

This will be a parts car kind of. It's also my guinea pig car that I'm using to get practice on before doing anything on my real project (which is to the point I'm now able to mount the body shell on a rotisserie once I acquire one). However, I do not plan on scrapping it out as it's in decent condition and my best friend's kid is interested in it after I'm done, so I want to do a good job on the weather strip install (and also as practice for me). So the questions remain:

1) Is that joint a commons source of trunk leaks in these cars?
2) When repairing it should I caulk that joint (in the area hidden underneath the weather strip) before installing the new strip?
3) Since that black 3M adhesive is so sticky, do I need to primer any areas of bare metal before installing the weather strip, or will a covering of the adhesive act to prevent rust (stuff was difficult as heck to remove even with that 3M spray remover and a nylon toothbrush)?

Thanks.

 

Agreed, most likely rust a hole in lower window to deck filler area, if it's just a parts car cover it, why bother repairing it?

 

Thanks for the responses but you guys are getting caught up debating why I'd fix a parts car. Please accept the fact that I want to repair it, no matter whether it makes sense or not.

Can anyone tell me if this joint is prone to being the cause of trunk leaks in these type cars or not?

Also, is there any drawback to caulking up the seam then installing the weatherstrip on top? Or will that cause issues with water retension or issues with the weatherstrip?

Finally, will that black 3M adhesive cover over bare metal spots and seal it from rust, or will I need to primer the area first?

Thanks.

 

best way to find out where the leak is coming from is jump in the trunk with a flash light and lock your self in and have a good friend with a hose mimic rain . I say good friend because at the body shop I used to work at I would get locked in lol. Then as the watter hits you can see where it's leaking from and repair accordingly. I used to have a knack for fixing water leaks on repaired cars that came through our body shop. Doing it this way you aren't guessing and you can pin point the leak.

 

The only rust on my entire car was on the trunk floor. I found the rear window was leaking, taillights where leaking, and there was a weld seam at the rear of the trunk that was leaking.
Getting in the trunk is a good idea, just make certian you use a not practical joker friend or your wife to let you out.

 

If you just want to stop a leak for a while, I have had some success with metal tape on cars outdoors. It won't keep coons & such out, but lasts much longer than say duct tape, and does keep the water out of the parts car.