Rust under rear window on tailgate repair? (1 Viewer)

[Jczajka]

I have rust around my rear window on the bottom, just under the seal. These patches are new since I bought the truck and are growing.

I had a cracked 3rd brake light that I replaced shortly after buying the truck. I sealed the light with 3M Window-Weld butyl sealer, taking my time to make sure it was the correct amount and I slowly torqued down the light on a warm day.

3M Window-Weld


What is the cause? What is the fix?

I assume pull glass, repair, replace seal, reinstall glass.

 

[2001LC]

These is common in rigs from the rust belt. Yes the 3rd brake light leak can contributor. But it's actually a sign, rust is into body panels.

Easiest fix, is find a used rear hatch from outside rust belt in your color.

 

[Jczajka]

Dang.

I was hoping it would be a simple fix.

My brake light should be sealed well. The truck came from the south and has very little rust otherwise. This bums me out since it means it happened since I've had the truck. The rust wasn't present when I purchased it, so moisture is getting in somehow.

 

[MongooseGA]

How does the underside of the truck look?

I've not seen body panel rust on these without frame rust present as well. But, as mentioned, a leaky 3rd brake light can accelerate it.

 

[Jczajka]

Underside is good for the most part, some light surface rust around weld areas of the frame, but that's it.

I have a feeling there is a leak somewhere or I didn't seal the brake light well. I cleaned everything thoroughly before adding the butyl, and used the 3m primer as well. Maybe it's still getting in.

I think at some point the rear glass was smashed an replaced. There are still little bits of broken glass rattling around in the tailgate bottom I couldn't get out. There was also issues with the rear defroster connection, so leads me to believe that the glass was replaced.

I have a buddy who owns a paint shop and was going to have him look at it. Is it really cheaper to replace the whole upper tailgate? I really have no rust elsewhere. Truck grew up in Florida, Georgia, Virgina maybe and I picked it up in April. I'm in Philly.

 

[MongooseGA]

I haven't priced tail gates, but you can likely find one for a few hundred bucks. I was going to have a dent in one door repaired; required more than just PDR. By the time I'd gotten pricing for the body work, blending the paint into adjacent panels, etc... I'm better off just buying a door in the same color for $3-400.

 

[Jczajka]

Dang. Ok

 

[MongooseGA]

Check out car-part.com if you decide to go that route.

 

[jLB]

Went through this on my son’s 2000 TLC. 3rd brake light leak (on an otherwise rust free southern vehicle). We found a rust free lift gate, in the correct OEM color, at CruiserYard.com.

 

[2001LC]

If glass was broken and paint nicked under molding during install of glass. That would cause this rust, even in a dry climate. It's the same issue we see in windshield install.

But unless you've had this 5 years. You just did not see the rust. I see paint bubbles all a long molding in your picture. Not just that one very bad spot. That bad spot will likely have holds in metal by now.

Rust we see from third brake light leak, isn't usually around the glass

 

[Jczajka]

@2001LC yeah, that's what it's so odd to me. I've had the truck less than a year and the spots are bubbling and growing. Maybe they were always there and just manifesting now or maybe there's a leak I can't find.

 

[CloudCity]

On the new one spray the ever loving crap out of the inside with Fluid Film to prevent a repeat, but I also think this was caused by chipping paint during a glass replacement since you found glass chips in the panel. They do still tend to rust at the very bottom so be sure to reseal the new one and add rust inhibitor inside.

 

[Jczajka]

I'm gonna stop by my buddies shop and see what he thinks. He does full paint and restoration and has done full frame off 60 series paint. If he isn't confident he can fix it, I'll look for a new tailgate.

 

[2001LC]

I'me sure he can fix. Any body man can.

 

[MongooseGA]

It's definitely fixable. The question is whether it's worth it. The down time for body work like that may be a week an cost you $1000. Replacing the hatch may take 2 hours and $500.

 

[kevin2i]

I have a small spot too, I pulled up the seal (between rubber and body) and noticed it was damp. I think the seal actually traps moisture - note how your rust follows the seal. Since mine is just a small dot, I took a dremel with small diamond bit and took it down to bare metal (shimmed up seal). Primed with rust stabilizer - curious what your body shop friend says. Are these glued in like the windshield?

Not sure what years this applies to, but if you don't have your VIN etched in your window, it is a replacement.

What is the cause? What is the fix?

I assume pull glass, repair, replace seal, reinstall glass.

View attachment 2138660



View attachment 2138659

View attachment 2138658

 

[gatormark91]

Found the exact same thing on my rust free Florida truck a couple weeks ago. Rust spot just showed up. The rubber seal was loose in that spot, guess it just dried up from age and sun. Looked to be letting water collect under the glass in that spot.