15 Suburban Roof Leak Found / Fixed

James Bryant · August 31, 2020

Hey all - new member here. Picked up a '15 suburban LS from a mechanic about 4 weeks ago. Though I bought a solid truck. 4 days after I brought it home the transmission started acting up. Replaced it. Then my wife found water in the drivers seat footwell after a rain storm. We thought maybe it was a fluke. Had a torrential downpour and lots of water in the footwell.

So I read about the shark fin issue. Pulled the headliner down - sure enough the bolt wasn't even finger tight. I cleaned everything up and applied urethane sealant around the gaskets.

Then I got the hose out and was baffled when water ran down the A pillar airbag. So I started pulling trim off the top of the truck.

I found a small "pucker" or void in the roof panel seal. I cleaned it out and poured some water into it and it ran straight into the truck and down the headliner to the A pillar.

So I cleaned that out and applied urethane there too.

Took the hose to the truck for a good 5 minutes. No water.

Strange factory flaw. Figured I'd share since I know water issues are a big complaint. If the sharkfin fix, sunroof drain fixes, and others haven't worked for you - check your roof panel seals.

For urethane I recommend Sikaflex, or Lexel, or even some of the Henkel roofing stuff. Silicone is fine - but it doesn't stick very well unless everything is perfect, and I don't like solving the same problem twice.

Cheers!

Tahoe02 · September 8, 2020

Good find and good info for proper sealer.

EXSlider400 · September 10, 2020

On 8/30/2020 at 8:25 PM, James Bryant said:

Hey all - new member here. Picked up a '15 suburban LS from a mechanic about 4 weeks ago. Though I bought a solid truck. 4 days after I brought it home the transmission started acting up. Replaced it. Then my wife found water in the drivers seat footwell after a rain storm. We thought maybe it was a fluke. Had a torrential downpour and lots of water in the footwell.

So I read about the shark fin issue. Pulled the headliner down - sure enough the bolt wasn't even finger tight. I cleaned everything up and applied urethane sealant around the gaskets.

Then I got the hose out and was baffled when water ran down the A pillar airbag. So I started pulling trim off the top of the truck.

I found a small "pucker" or void in the roof panel seal. I cleaned it out and poured some water into it and it ran straight into the truck and down the headliner to the A pillar.

So I cleaned that out and applied urethane there too.

Took the hose to the truck for a good 5 minutes. No water.

Strange factory flaw. Figured I'd share since I know water issues are a big complaint. If the sharkfin fix, sunroof drain fixes, and others haven't worked for you - check your roof panel seals.

For urethane I recommend Sikaflex, or Lexel, or even some of the Henkel roofing stuff. Silicone is fine - but it doesn't stick very well unless everything is perfect, and I don't like solving the same problem twice.

Cheers!

How did you remove the roof trim?

thanks

James Bryant · September 10, 2020

13 hours ago, EXSlider400 said:

How did you remove the roof trim?

thanks

The plastic trim closest to the windshield is attached to metal clips that pop down over some bungs / mushroom looking nubs that stick up from the roof panel. The nib is easiest to see in the last pic in my post. It pops off with regular trim removal tools. I'd go with plastic tools so you don't mark up the paint or plastic trim. On mine half the metal clips stayed stuck to the nubs on the roof and I had to pull them off and re-install on the trim piece before popping it back on when I was done.

-James