Leak!! HELP ME!

Juicy-J · December 1, 2020

So three days ago I bought a 2019 GMC Denali 2500HD and absolutely love it. It has around 35,600 miles on it so the factory bumper to bumper will expire very soon! I live in Virginia and it DUMPED rain all day today and I went outside to show off the truck to co workers in a break in the rain and my cab is completely soaked and the back seats are like a soaked sponge. I attempted to remove the third brake light but it has so much silicone on it that it won’t brake free. (The rear window had been replaced for leaking before I bought it). My entire floor boards are soaked, my seats are soaked, the dealership is being very shady and I’m getting the impression they aren’t going to help me out. I take it in tomorrow morning (December 1st, 2020) and I’ve been calling asking for the GM reps info and no one will give me anything. The rear window is “sealed” with clear caulk. This is a serious problem after spending 65k! Someone help me please!!

OnTheReel · December 1, 2020

Good luck is all I can say.

Jac365 · December 1, 2020

The rear window leak is primarily seen in the 1/2 ton trucks with the sliding rear window. They suffer from hairline cracks developing in the plastic window frame. (very thin). Just got mine back today after attempt # 2. Pouring buckets here and it appears to have been successful (so far) Spray soapy water along the outside of the window frame then use an air hose/nozzle and blow air along the inside of the window. Check the entire window along the edges. You see bubbles forming you have found a leak. Sounds like you have multiple areas to deal with.

In the above thread some have mentioned using flowable silicone on their rear windows.

Juicy-J · December 1, 2020

I feel as though my problem is much deeper rooted and worse than just the rear window. There is obvious dripping water from the roof of the cab but only in the back of the can.

OnTheReel · December 1, 2020

Just re-read and noticed you have a 2019 HD truck. That’s on the old (K2) platform, so nothing in the thread I linked to applies. You may get more assistance in the 2015-2019 HD forum.

gearheadesw · December 3, 2020

Sounds like an issue with the dealership, they sold you a truck with a pre existing problem, it;s on them.

Juicy-J · December 3, 2020

So update here, I reached out to any sort of GM rep I could find even by contacting fleet services and other dealerships. The reps put pressure onto the dealership and they are now going in and removing and replacing anything damaged like the headliner, carpet and floor liners. Hoping to get them to replace the rear seats as well but they should be able to dry that up safely. Currently sending the truck to a specialist to check all the seals on the cab completely and verify it’s all good. Then remove everything completely and check all the metal for rust. Getting it taken care of correctly. They’ll have the truck for a long while but it’s worth it in the end. Thank you to all on this site that recommended contacting the local GM service representative.