The same probelm I am facing, while I drive close to beach alot of water leaks under passenger feet floor.
it is realy big amount of water leaks inside car.

I tried to locate the water drain under the car, but no luck.....

Expedition is stupid turck.

 

If you lay under the truck on the passenger side and look up above the forward oxygen sensor you will see a black plastic shield on the firewall. This shield covers the A/C drain outlet tube. The tube is fairly flush with the firewall, hence the feedback into the insulation and passenger floor. To get to it for installing the elbow piece you have to either remove the oxygen sensor, or the right front wheel and inner wheelwell liner. There's a TSB out on it. http://ww2.justanswer.com/uploads/ti...sb05-20-07.pdf
... Either way its a huge pain in the butt.




Here's a pic, looking up at the drain shield....





-Mike

 

I've had this happen on a few different vehicles that I've owned, and blowing out the drip tube with some air always seemed to unclogg it from debris and solve the back up issue.

Looks like this is a little more involved than that.

 

Ha....glad I found you guys! I'm the new (less than two weeks now) owner of a 2012 Expedition, and had my passenger point out that her floorboard was soaking wet and hot! It appears after much delightful crawling around under that water from the AC slowly just drips out from a "random" spot between the black plastic piece and silver heat/sound barrier on the outside of the vehicle, BUT more appears to be finding its way INSIDE the vehicle?! It drips harder from between these same layers in the front of the wheel well on the inside of the car. Funny....how these is so much rust already near these same areas (CAT, exhaust, body frame) on the outside of the vehicle as well....co-incidence? NOT
Darn truck is 2K miles out of warranty, so its up to me to figure this one out

 

I have an '06 exedition and have the same issue. I bought the TSB elbow to put on the drain nipple but I can't find it on the firewall...My truck doesn't look like the picture above, there is no plastic cover I can find anywhere near either o2 sensor. All I see is a single piece of foil insulation that goes from half way down the firewall all the way to behind the cat. With the truck running I can see water dripping from above the exhaust heat shield from a couple holes cut into the silver insulation.

I'm assuming I need to drop the exhaust and heat shield, and pull that insulation down to find the drain nipple...How this wasn't a recall I don't know.Between the paint falling off the hood and tailgate, and the AC flooding the truck I'm ready to give up on Fords **** poor design skills.

 

I believe I have this issue as well. The other day I found the passenger side floor soaked under the floormat. No signs of issues with the heater core so I was wondering what was causing it.

 

I assume the plastic cover shown above is 1st gen and 2nd gen is a bit different. I'm pulling it apart again tonight since I found a PDF of the TSB that specifies 05-06 model years and the diagrams look like what I was seeing under my truck. I'll update this thread if I get it resolved.

 

Hello,

Digging this old thread up from the grave. I figured out what is causing the leak after I learned of a TSB for the same thing on the 2018-2020 F150/Expedition/Navigator. The A/C drain line from the evaporator behind the glove box is INCREDIBLY short. Maybe sticking 1/4 to 1/2 inch out of the firewall behind the engine. It also sits behind the firewall insulation between the firewall and the insulation. Its hidden from view by the insulation as well. Ive attach the TBS and explain the fix which works great for the 2007 to 2017 models as well.

What I discovered was the drain tube sticks out into the engine bay horizontally, like a nipple and water dripping from the end of the drain sticks to the bottom of the drain tube, runs backward along the bottom of the tube, saturates the foam insulation around the drain tube in the firewall and then drips back into the passenger side footwell. Also, the firewall insulation that the tube sits behind is close enough to the outlet of the horizontal drain tube it aggravates the situation by not allowing much water to drip out causing a bit of a back up in the line.

The solution is to cut a hole in the firewall insulation in front of the drain tube and add a rubber elbow (Dorman 46017 PCV End Assembly Compatible with Select Ford / Lincoln / Mercury Models https://a.co/hiyvY2T) to the end pointed down. 100s of leak free, dry, fully air conditioned miles await you my friends!