If your cab corners are getting rust you should get them fixed. I had that problem with my 08 king ranch and ignored it, before I knew i was driving around with two big wholes in my cab corners. I ordered mine online and had them spray some bed liner on the inside of the cab corners since that's where the rust originated from. Hopefully I won't have to deal with this problem again.

 

Read the entire thread. I did have it repaired and glad I did. I wanted to contain the rust before it got out of control. I knew it would only get worse and the cost for repair would only go up.

 

This could possibly be the culprit of all the cab corner problems<br/>

 

That is if you have a moonroof and dont clean your drains regularly anyway

 

My truck does not have a moon roof. It doesn't appear anything is wet on the interior like the 3rd brake light or rear slider would be leaking. It did appear as if the rust started on the inside, though. The underneath or inside of the rocker panel looked to be ok too. I have no idea what initiated it.

 

Well that's strange I haven't seen many non moonroofs rust out like that mine are getting fixed next week and we are putting in proper moonroof drains

 

I have the exact same problem in exactly the same area on my '08 F-150 SCrew except I don't have $1,300.00 to fix it. I have to do this all myself...

 

Good luck. I have repaired many rust spots myself on my vehicles over the years. Fortunately, they have always been in the wheel wells prior to this. I wouldn't be able to make it look good enough for the exterior.

 

Have had this 2010 Platinum for just under 2 years. Everything looked solid when we had it on the lift and my mechanic inspected it. Last year we had some hellacious rainstorms in Kansas City and I noticed the rear corners of the headliner were wet. Traced the problem to the gasket on the 3rd brake light.

Fast forward to this year and noticed the sheet metal peeling off on the rocker panels. Getting an estimate but my body shop first said it could be poor drainage from the sun roof. Then I pointed out the 3rd brake light issue I'd discovered and fixed.

Not very pleased as I got rid of a 1999 F-150 with 265,000 miles that had very little rust when I sold it in 2017.

 

I know, old thread up to last post. Repair looks Great!

I've seen some rusty corners, usually on moon roof trucks. It's not common and I cringe when I see it. Keep mine parked in a carport I had erected a year after getting the truck to protect interior from sun and …. maybe prevent this. I am retired so when snow / ice / salt on roads, not a lot of reason to be on the road myself.

 

I think my rust issues were related to a 3rd brake light leak. It has since been replaced. Unfortunately, a little too late.

 

Since you had it fixed there is a way to prevent it from happening. I live in the NE the rusty truck capital. What i did was to put a little motor oil in the hollow spaces. Ie: doors, fender walls, etc. This prevents the water from sitting there. The oil doesn't rust your panels. I know your thinking thats crazy but it is an OLD trick that has worked fantastically for me. Just saying it couldn't hurt and might save you $900 in the future.