2003 Expedition EB. I am considering repairing the rusty driver side rockerpanel but can't seem to figure out where the water is getting in at. I want to figure this out before the repair but have had no luck. Is there any common place this could be coming in from? Drain from the sunroof- where does that go?

I don't want to do the repair without figuring how water is getting in there. It looks as though it is rotting from the inside out- not from the outside. It is rusted/rotted about 1/2 way down the floor board on the bottom of the cab door frame (not on the door).

I did some searching on here but couldn't find anything.

Any suggestions on where to look?

Thanks in advance.

 

i do a little auto body work myself, i've had 3 gen 1 expys. my '99 had a little of the similar prob. i found a small rust hole where the drivers side rocker goes in behind the front fender so it wasn't initially obvious at the time but the water was going in the front of the rocker, mostly due to a hole that was inside the front wheel well insert so salt and moisture was sitting in there to create the problem to start with. also something i have noticed on the expys is that the primer used appears to not stick well to the metal and paint will have a tendency to flake off sometimes right down to the bare metal. also here in mn where the roads are gritty and grimey during the winters there is accumulation of road grit towards the centerline which causes additional chipping and wear of the paint more on the drivers side than the passenger side. good luck w/your project !!!!

 

the water and dirt are coming in from the backside or inner rocker. as it is not and should not be completely sealed up. there are holes designed into the panel causing the issue. if you look underneath the truck you will see what I am talking about. and most likely the rocker braces that weld the floor ar rotted as well.

 

i probably should have been more specific. I was assuming d-ray probably knew that area was not a sealed chamber and was looking for an additional source of dirt, mud, and moisture. the hole in the front of mine caused accumulation of grime from the front wheel thru a hole in the wheel well insert and into a rust-through hole in mine. it was packed half full of grit etc...... the drain holes u speak of im sure were very plugged on mine, but in my case there were new drain holes not made by the factory. lol !!! cheers !

 

Thanks guys! I will take a closer look and get back with you. Any more tips on the repair? My plans were to treat the rust and prime everything and put undercarriage coating on it after cutting out and fixing the rotted place.

 

sorry my replys are slow, my inet went out and the phone comp. had to replace my lines into my house. i have a tip you may not find in an official body repair manual. I have been coating the backside of my body repairs (after a complete cleaning) with truck bed liner in a spray can to seal the back and prevent further rust thru's. it's like 10 bucks a can but it is thick and tough when dry and the can is pretty big. good luck !!!