Headliner soaked after rain - 2014 GMC CC

[Spendit]

The truck was simply parked in driveway and headliner is soaking wet. Its only the rear cab portion and this is above the window and break light line.....maybe a crack somewhere in cab top? I noticed some water line marks from a previous soak but did not catch it when wet....anyone find something as strange as this

[mikeyk101]

It's actually a common problem and usually occurs at the third brake light. The foam gasket starts to get old and leak. I would suggest replacing the gasket and it will probably fix the leak. 

[mikeyk101]

Just to add, another point to pay attention to in the event you start to experience a leak in front part of headliner is the shark fin antenna. It is another common source of leaks.

[Chriselton88]

I had the same issue, my third brake light gasket was cracked and brittle. Just used silicone around the old gasket and good as new. Did the shark Fin antenna also and found the bolt that secured it to the roof was damp so it was starting to go also. 

[mikeyk101]

7 hours ago, Chriselton88 said:

I had the same issue, my third brake light gasket was cracked and brittle. Just used silicone around the old gasket and good as new. Did the shark Fin antenna also and found the bolt that secured it to the roof was damp so it was starting to go also. 

I probably would have done the same thing on the 3rd brake light but the dealer replaced the gasket under warranty several years back. It's been fine ever since.

[JimCost2014]

Is it a sunroof truck?

[mikeyk101]

31 minutes ago, JimCost2014 said:

Is it a sunroof truck?

Oooo, good question. I have to admit that I didn't even think about that.

[Spendit]

It is not a sunroof vehicle - the dampness on the headliner is above the 3rd brake light level....but I will start there