Water leak

David12 · February 15, 2018

So I recently purchased a 2018 Chevy Silverado midnight edition. About A month after owning the truck I noticed water on the inside of my sliding back window. At first I thought that just maybe the widow wasn’t closed all the way and went about my day. A few days later i noticed it again but this time water was pouring in. I called the dealership and was able to get in. When I picked the truck up they said the body seam was leaking along with the third tail light. I was told it was good to go and was water tested and everything. Not even a week later here I Am again with the very same issue. I know things happen but I’m starting to loose my patience and faith very quickly. Has anyone had this issue and should I expect it to continue. I’ve heard it could take multiple trips to get it taken care of. Thanks

wforrest08 · February 15, 2018

I have a buddy that had a 13 that was leaking though the 3rd brake light. 3 or 4 times to the dealer and they never could get it to seal up. After it started to stink he traded it in on a Ford.

I have a 15 and replaced the cargo lights I almost didn’t want to do it because of my buddies truck but it worked out no leaks I took a good look at while I had it apart and I couldn’t really see how water would get in?

If it were my truck I’d put the blow tip on my air hose and have my wife run it while I sat in the truck feeling for air. The shop one of my other buddies works at has a smoke machine/tester they use to find vacuum leaks and air seal leaks might be worth asking the dealer if this is what they are using if not maybe call other dealers in your area and ask if they have one. I’d check the shark fin also as others on here have had it leak but I doubt it water would run all the way to the back from it?

I had a 98 Tahoe that developed a leak at the top of the windshield right above the mirror I used clear silicone in a tube from the home store to seal it on the outside temporarily for a couple months it peeled right off and didn’t damage the paint. Definitely not a fix but better than soggy carpet till you/they figure it out.

xps800doo · February 19, 2018

was putting in new floor mats on my new to me (3 weeks old) 15 sierra with 60,000 and sure as shit the entire floor front back and both sides is quite wet! i do not see any water stains on the headliner, i do NOT have a sun roof, the cab vents are not missing, i did notice the driver side a little wet when i took delivery but they said its must be from them shampooing the carpets for delivery detail.... the dealer is out of state about 6 hours drive. this truck is not a daily driver it has been sitting for 2 weeks!! where did this water come from!!! so disgusted!!!! the money you pay for these trucks and the shit you get for a product. shout be illegal!!

Buckshot556 · February 20, 2018

Wet driver floor board is the shark fin leaking.

Back window leaking is the third brake light or body seam.

water eventually will work it's way down to the lowest point in the cab (inner rocker panels) then sit and rot the truck from the inside out.

by the time it's rotted away they want you to sell it to the next guy and buy a new one.

No single manufacturer is guilty, every forum discusses these issues.

mjm-1957 · February 24, 2018

Check out document ID#4881898 (can't provide a link) If you google service update 17388 it will bring you to the correct document.It says it is for the pressure relief valve in the rear body allowing water intrusion into the cab on 2018 siverado and sierra, we have two 2016's in the shop right now leaking from the same area, carpets are soaked and stinks of mildew. It apparently affects other years also. If you remove the rear seat and trim , you can pull the padding away from the rear panel and you will probably see a puddle and rust stains from the lower portion of the vent. If your truck is brand new bring it back and give them this service update and doc id number.Let them deal with it under your warranty.

xps800doo · February 24, 2018

Check out document ID#4881898 (can't provide a link) If you google service update 17388 it will bring you to the correct document.It says it is for the pressure relief valve in the rear body allowing water intrusion into the cab on 2018 siverado and sierra, we have two 2016's in the shop right now leaking from the same area, carpets are soaked and stinks of mildew. It apparently affects other years also. If you remove the rear seat and trim , you can pull the padding away from the rear panel and you will probably see a puddle and rust stains from the lower portion of the vent. If your truck is brand new bring it back and give them this service update and doc id number.Let them deal with it under your warranty.

Definitely not new 2015 w/60,000 but I’ll for sure check that out as well, heard of rose missing but not faulty. Another thing to check Thanks!!

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btlgr · April 8, 2018

I have a 2015 sierra with same problem of all of floor soaked front and back. Checked everything for days before finding that both vents on back cab were leaking. Both were loose and the rubber seal was not keeping water out. Putting in new ones and applying sealer. Don't ever want to have to deal with this again.

Donnie Oliva · February 2, 2020

On 4/8/2018 at 2:16 PM, btlgr said:

I have a 2015 sierra with same problem of all of floor soaked front and back. Checked everything for days before finding that both vents on back cab were leaking. Both were loose and the rubber seal was not keeping water out. Putting in new ones and applying sealer. Don't ever want to have to deal with this again.

Seems it’s been a while since someone has posted on this topic, but I wanted to chime in for some thoughts.

I have been another one of the lucky guys to find water on drivers side of vehicle. Not sure how long it’s been leaking but has soaked the entire drivers side of vehicle.

I brought truck to dealer and they have stated they need to do a water test to find the leak and this would be 6 hours and 800$ to try to find the leak. Yes of course I bought the extended bumper to bumper warranty from the Chevrolet dealer. And yes they will NOT cover water leaks. Now that’s money well spent to insure my 70k truck is protected.

I’ve owned the truck for 1 year 10 months and have put 50,000 miles on it, and it has been awesome till now. I have asked my insurance to help and they will accrue some of the cost, but typical Louisiana insurance and warranty’s apparently don’t like cover anything to do with water.
From the post I’ve read seems this vent has been giving ppl a lot of problems. I checked the back carpet under the back window and didn’t really notice water. Seems mine is dominant to the entire drivers side. Could this water travel to the edge from these vents? I’m curious to what ppl have found only because I feel that this project is gonna cost me thousands, because this dealership already seems to be expensive just to find the leak. And I don’t really trust them.

firechief3930 · February 9, 2020

Yes I have a 2015 Silverado and have the same issue , noticed it in middle of July 2018, only drivers side front. took it to chevy, 1st time claimed it was clogged drain, problem still existed, switched dealers first time they claimed could not find anything, brought back when floor was wet-- they said it was the fin antenna - replaced --- problem still there, back in Sept this time they said they sealed areas in firewall etc-- problem still there - back in Oct they sent to auto body - took whole interior out found loose rear vent --- (they had truck 1 month) other times about week at a time

then in beginning dec looks like it came back again.. they had it whole month dec - supposedly had GM eng look at it and end of month said they could not find anything... seems to have been good most of 2019 but stopped looking fast forward to Jan 2020 issue is back..... and Chevy now saws not there issue out of warrenty etc...…….

CarNovice · March 6, 2020

We just had our Chevy Silverado in for an issue with the drivers side window not rolling down or up. The dealer took apart the drivers door and found that there was water damage. My husband mentioned that the floor by the drivers side door had been wet before but he didn't think much of it since it wasn't consistent. Thanks to the gentleman above mentioning TSB's I found that there was an exact TSB for this issue in the 2015 chevy Silverado (on this website https://www.nhtsa.gov/recalls#vehicle the NHTSA ID Number is 10137306 to search) and it explained the exact issue and claimed a repair time of 1.4 hours (so I am a bit pissed they are charging for 3 hours since this would be a simple search on the dealership side, since we took it to a chevy dealership for repair). It is a common problem for this water damage on the drivers side. I hope this helps you firechief3930! They are currently quoting us $1,200 to rip out all the seats and carpeting to find where the water is coming from. Now after reading that TSB I am assuming the best place to start would be the driver window, not starting with ripping out the center console as our repair guy has suggested.

Now my mission is to find if there is manufacturer information with a place to check for where this leak is coming from, since it is a common leak spot.

davester · March 6, 2020

That's sad funny. The center console would be the LAST place I would look for a water leak, even without that TSB.

Edit: ...unless that console is the one in the roof...I was thinking about the console between the two front seats...but even then, if it's leaking enough to soak the floor, you would notice dripping from the console...

Edited March 6, 2020 by davester

Golfhacker64 · June 25, 2020

I have a 2015 Silverado 2500 that had the same issue. I ended up ordering this gasket from Amazon for the 3rd Brake light. I have not had an issue since.

https://www.amazon.com/MOFORKIT-Gasket-Compatible-Silverado-Sierra/dp/B07H3S4GHM/ref=sr_1_1_sspa?dchild=1&keywords=2015+3rd+brake+light+gasket+silverado&qid=1593105011&replacementKeywords=3rd+brake+light+gasket&sr=8-1-spons&vehicle=2015-47-491------------&vehicleName=2015+Chevrolet+Silverado+1500&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExUlBNTExEN1hCN1NFJmVuY3J5cHRlZElkPUEwMzMyMTg2MVM1VDhLTVZHSUlOMiZlbmNyeXB0ZWRBZElkPUEwNTcyNzQyMTFDRERPUk5KMjAyNSZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

eric17 · July 14, 2023

I have a 17 2500 silverado and at 40k I started noticing when heavy rain mainly water dripping off my e brake pedal from behind dash and a couple times out of the handle to pull you in on driver side . I only found because I have weather techs and catches everything. I haven't found location yet

newdude · July 21, 2023

On 7/14/2023 at 10:35 AM, eric17 said:

I have a 17 2500 silverado and at 40k I started noticing when heavy rain mainly water dripping off my e brake pedal from behind dash and a couple times out of the handle to pull you in on driver side . I only found because I have weather techs and catches everything. I haven't found location yet

Onstar antenna. Its mentioned in the thread here as are some other possible leak points.