Combee1
Active Member
- Joined
- Aug 23, 2019
- Messages
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First, want to thank everyone who takes the time to post on here. I have gained a lot of valuable information by filtering through these forum threads.
There are a ton of threads on here regarding cab leaks, be it from the "rear backlight"/window, the third brake light, or the shark fin antenna. I wanted to share my experience with these problems over the past year, in hopes it may help someone troubleshoot the same in the future.
In Nov of 2021, I had water ingress from the area where the headliner meets the rear backlight (window). The water staining on the headliner extended to both sides of the sliding rear window. I was still under 3 year/36K, so instead of trying to troubleshoot it myself, I just took it to my local dealer. I bought my truck from this dealer and I always service it here. I believe that matters when it comes to getting good service on warranty items. The tech took about an hour to diagnose and came back to say that the entire rear window needed to be replaced. He added, they would replace the headliner as well at the same time. I was a bit surprised to hear it was the window, but glad it was going to be replaced without a hassle. This was before I read all the threads on here regarding this issue. It took some time to get the new window and headliner, but the dealer got the job done in one day, and everything seemed to be fixed.
Cut to 1 week ago, when I noticed the headliner was wet again, in about the same areas, and dripping after a couple days of heavy rain here in Florida. I am now out of warranty, but since this was a warranty issue that was supposedly resolved back in 11/2021, I immediately took it back to the dealer. Again, an hour later the tech comes back and says the rear backlight (window) has to be replaced again. At this point, I'm a bit confused, but a little better informed having read some of the threads on here. I now know that there is a FCA STAR online publicaton and a TSB on this issue (see links below). I read enough to know that the backlight they installed back in Nov 2021 was the redesigned backlight that was reinforced to prevent cracks. I also knew that there were no visible cracks on the inside of the window in the areas that the TSB instructed to look. So I asked the tech if he leak tested the cab, as instructed in the STAR pub, to rule out the third brake light and the roof shark fin antenna. The service rep stated, "the tech is sure it is the window because of the leak pattern. If it was third brake light or antenna the water would leak to the corners of the cab and not down the window".
So I think to myself... "Ok they have a bead on this because they have seen it a few times". So we order the parts. To my surprise, they schedule me just two days later. As I am driving home, I'm still not convinced it is the window, so when I get home I immediately leak check the cab as instructed by the STAR publication. The leak test definitively rules out the backlight. I poured water on those seams from a pitcher for a good 25-30 mins and not a drop of water inside the cab. However, within 10 mins of pouring water on the third brake light, water begins to appear, with the first spot collecting behind the driver side Airbag cap in the headliner. (see pics included).
So I call the dealer the next day. Inform them that their tech mis-diagnosed the leak, and that I would like to order a new third brake light (which has been redesigned with thicker weather sealing). That part is now $80 through the dealer, and would take 2 weeks to come in. Since a few guys on here had success replacing the weather sealing on the existing brake lights, I decided to do the same. Went to HD and paid $10 for the new weather sealing (link below), and $4 on some Goo Gone to remove the adhesive. It took about an hour in all to do the repair, and I am happy to report that after a week of daily torrential thunderstorms in our part of Florida, there is not a drop of water leaking into the cab.
I think the take aways from this experience are:
1. Not all cab leaks are from the same source. It is possible to have one or the other, or both. Make sure you read the STAR bulletin and follow their recommendation on leak testing to determine exactly where the water is getting in.
2. Just because a tech comes back with a diagnosis, does not mean that diagnosis is 100% correct. When I had my truck in a couple months ago, I was convinced I had an exhaust leak that was most audible from the front passenger side of the truck. The tech on that day told me there was no exhaust leak. When I brought the truck in for the cab water leak, I asked them to please look for the exhaust leak as well, because it had gotten worse. Sure enough, this time they found the exhaust leak, but misdiagnosed the water leak.
Links and Pics below:
TSB link: https://static.nhtsa.gov/odi/tsbs/2021/MC-10194060-9999.pdf
Star bulletin link: https://static.nhtsa.gov/odi/tsbs/2021/MC-10187092-9999.pdf
M-D Auto and Marine Weather Seal: M-D Building Products 5/16 in. x 17 ft. All Climate Auto and Marine D-Profile Weatherstrip 01025 - The Home Depot
First two pics are where the third brake light was leaking to. In the pics you can see that it appears the leak could be coming from the window seam because of how the water drips down on the window frame.
The next four pics are of:
1. The original cheap weather sealing on the third brake light. You can see how thin it is on the end corners.
2. Stripping the old weather seal, then using Goo Gone to remove adhesive.
3. New M-D Auto Weather Seal from Home Depot in place
4. Much better seal on re-installed third brake light.
Hope that helps someone.
There are a ton of threads on here regarding cab leaks, be it from the "rear backlight"/window, the third brake light, or the shark fin antenna. I wanted to share my experience with these problems over the past year, in hopes it may help someone troubleshoot the same in the future.
In Nov of 2021, I had water ingress from the area where the headliner meets the rear backlight (window). The water staining on the headliner extended to both sides of the sliding rear window. I was still under 3 year/36K, so instead of trying to troubleshoot it myself, I just took it to my local dealer. I bought my truck from this dealer and I always service it here. I believe that matters when it comes to getting good service on warranty items. The tech took about an hour to diagnose and came back to say that the entire rear window needed to be replaced. He added, they would replace the headliner as well at the same time. I was a bit surprised to hear it was the window, but glad it was going to be replaced without a hassle. This was before I read all the threads on here regarding this issue. It took some time to get the new window and headliner, but the dealer got the job done in one day, and everything seemed to be fixed.
Cut to 1 week ago, when I noticed the headliner was wet again, in about the same areas, and dripping after a couple days of heavy rain here in Florida. I am now out of warranty, but since this was a warranty issue that was supposedly resolved back in 11/2021, I immediately took it back to the dealer. Again, an hour later the tech comes back and says the rear backlight (window) has to be replaced again. At this point, I'm a bit confused, but a little better informed having read some of the threads on here. I now know that there is a FCA STAR online publicaton and a TSB on this issue (see links below). I read enough to know that the backlight they installed back in Nov 2021 was the redesigned backlight that was reinforced to prevent cracks. I also knew that there were no visible cracks on the inside of the window in the areas that the TSB instructed to look. So I asked the tech if he leak tested the cab, as instructed in the STAR pub, to rule out the third brake light and the roof shark fin antenna. The service rep stated, "the tech is sure it is the window because of the leak pattern. If it was third brake light or antenna the water would leak to the corners of the cab and not down the window".
So I think to myself... "Ok they have a bead on this because they have seen it a few times". So we order the parts. To my surprise, they schedule me just two days later. As I am driving home, I'm still not convinced it is the window, so when I get home I immediately leak check the cab as instructed by the STAR publication. The leak test definitively rules out the backlight. I poured water on those seams from a pitcher for a good 25-30 mins and not a drop of water inside the cab. However, within 10 mins of pouring water on the third brake light, water begins to appear, with the first spot collecting behind the driver side Airbag cap in the headliner. (see pics included).
So I call the dealer the next day. Inform them that their tech mis-diagnosed the leak, and that I would like to order a new third brake light (which has been redesigned with thicker weather sealing). That part is now $80 through the dealer, and would take 2 weeks to come in. Since a few guys on here had success replacing the weather sealing on the existing brake lights, I decided to do the same. Went to HD and paid $10 for the new weather sealing (link below), and $4 on some Goo Gone to remove the adhesive. It took about an hour in all to do the repair, and I am happy to report that after a week of daily torrential thunderstorms in our part of Florida, there is not a drop of water leaking into the cab.
I think the take aways from this experience are:
1. Not all cab leaks are from the same source. It is possible to have one or the other, or both. Make sure you read the STAR bulletin and follow their recommendation on leak testing to determine exactly where the water is getting in.
2. Just because a tech comes back with a diagnosis, does not mean that diagnosis is 100% correct. When I had my truck in a couple months ago, I was convinced I had an exhaust leak that was most audible from the front passenger side of the truck. The tech on that day told me there was no exhaust leak. When I brought the truck in for the cab water leak, I asked them to please look for the exhaust leak as well, because it had gotten worse. Sure enough, this time they found the exhaust leak, but misdiagnosed the water leak.
Links and Pics below:
TSB link: https://static.nhtsa.gov/odi/tsbs/2021/MC-10194060-9999.pdf
Star bulletin link: https://static.nhtsa.gov/odi/tsbs/2021/MC-10187092-9999.pdf
M-D Auto and Marine Weather Seal: M-D Building Products 5/16 in. x 17 ft. All Climate Auto and Marine D-Profile Weatherstrip 01025 - The Home Depot
First two pics are where the third brake light was leaking to. In the pics you can see that it appears the leak could be coming from the window seam because of how the water drips down on the window frame.
The next four pics are of:
1. The original cheap weather sealing on the third brake light. You can see how thin it is on the end corners.
2. Stripping the old weather seal, then using Goo Gone to remove adhesive.
3. New M-D Auto Weather Seal from Home Depot in place
4. Much better seal on re-installed third brake light.
Hope that helps someone.
