Top of the day people. Got a major problem that I hope some one here can help with. I have two 2013 E350 chassis cabs that are leaking water from the wind shield area that has rotted the floor out on the drivers side. A little back ground. Both units came from Supreme Body in PA. There vin numbers end in 02 and 03. So yea they came off the line one after the other. I yanked the wipers and pulled the crowl. Blew out all the dirt and even dumped some water in there which seem to drain away just fine. I don't think the leak is coming from this area. The real shame of this is one van has 28k on it and the other 6k. Help! Thanks in advance, Bob L

 

Bob, I'm not familiar with your 2013, but on the older models if your air conditioner condensation can't drain it will run back into the cab thru the heater box and soak the floors. Yours may be the same. Hopefully someone who is familiar with your chassis will chime in on this.

 

Carefully reading the OP its clearly seen this problem is NOT related to the A/C which is on the right or passenger's side---his issue is centered on the left or driver's side.



Questions for the OP: how did you discover this issue? Does this van have the factory "rubber" floor covering with spun fiber backing? Have you removed that floor covering on both sides of each van checking if both or either have soaked floor coverings? By that I mean the metal floor will be wet and the spun fiber backing full like a sponge. IF that's the case this is simply a rather common problem where humidity is absorbed by the factory floor covering and rust forms.

Are the current windshields factory original or replaced by someone in the aftermarket glass business, aka "glass shop"?

As a windshield installer its possible the upper corners of the windshield are leaking from a bad installation or the body joint at the top of the A-Pillar has separated, a somewhat known issue with the E-Series. You can run a water hose NOT under pressure with a squirter nozzle along the bottom of the windshield while looking under the dash for signs of water. If none are found slowly move the hose along the outside of the windshield where it meets the body while looking under the dash for water streaming inside--it might be only a drip. Its best to have another pair of hands for this because moving the hose upwards will show if a particular area along the sides is the problem. Do this on both sides but be patient because it sometimes takes a little while for water to appear IF the windshield is leaking.

If nothing can be found there then move the hose to the roof allowing water to cascade down, again looking under the dash for water coming in. I've dealt with this rusted front floor pans as well as significant surface rust due the soaked factory floor covering on my full bodied E-Series. The cab-chassis will only have floor pans under the front seats affected naturally.

HTH

 

I have experienced water intrusion on my 2000 van when the door weatherstriping went bad,

 

That will happen however in this instance it doesn't explain how the metal floor under the floor covering would be rusting.

 

My '13 E350 leaked here, i guarantee this is your problem! This is where the firewall, wiper tub, and drivers inner fender all meet up and is poorly sealed/aligned. Take coolant tank loose and moved aside, Stand on stepladder, stick your head in there and this is what you'll see! That round dimple in firewall, lower in photo, watch it from the inside while running water on it outside, down the windshield. Same size hole in black insulation reveals round dimple. You can watch it entering here. Mine was pouring in here, getting under carpet/insulation, never felt wet except at edges depending how van was sitting. I used YamaBond sealant as im a dirtbiker, made by 3M, I believe. Only seal up small horizontal crack at top,not the drain holes! If this isn't your problem, I'll buy the beer!

 

@Pingpop I am having exactly same issue on the driver side. I used a flexible scope camera and saw that there is a hole behind dashboard. The tried to seal the area you have shown both here and below the cowl seal which stopped it temporarily though it came back , I think the seals were weak. I am in the process of removing dashboard to fix the hole that I see behind the dash which is the cause of water leak. It dripped drop by drop but has caused rusting of the bolt beneath driver side carper.