Wet floors
 

My 06 Explorer is leaking rain water under the dash behind the emergency brake assembly. I can see the water coming out at the bottom behind panel that is behind brake assembly, but cant find the source of the leak. Can anyone help?

You may have to remove the wiper arms and then the screws securing the cowl cover to get into the area below the windshield and above the firewall in the driver's side corner.
If you cannot see any possible place for water entry then check behind the driver's side door pillar where the door hinges are located . It isn't always the best solution ,but sometimes a can of undercoat spray with a soda straw will seal an invisible opening that is impossible to seal otherwise. Just remove as much dust and accumulated dirt with compressed air as possible. It may take a day or two for the smell of the solvent to go away. Last but not least check along the firewall itself to make sure there isn't an opening where a screw or plug came loose and the water is migrating to where you can see it.

I checked cowl, and could'nt see any possible leak area. But the leak is definately coming from water going into cowl. I unbolted the brake assembly so i could see better, and then poured water into the cowl again. I got a stream of water pouring out of the top right brake assembly bolt hole. So i got some permatex out and put some on bolts and around bolt holes and put brake assembly back in. I still have the same leak, so there must be another point of entry. Is something clogged that there was so much water building up and coming in through the bolt holes???? There is allot of water draining out behind fender like it should. I cant see where the cowl drains to. I'm thinking about taking the fender off next, but the bolts in the door piller are behind the support metal of the fender and look just about impossible to get to from the fender/door gap or from behind door. Do I need to remove inner fender well first, then reach back through to those bolts????

The undercoat spray will usually accomplish at least two things, end the leak problem, provide sound deadening, and act as a sealer to prevent any rust from taking hold. Was anything removed that might have left an opening for the water to enter?
I hope you know I'm referring to spraying the undercoat on the outside of the vehicle! Have had many leaks where that was the only way to seal them since you couldn't see the exact point of entry and no way could you get in the area to fix them. Many times when the vehicle is built the joints are just smeared with a sealer and sometimes it just dries out. Did you check if the windshield itself is allowing water to enter and drain into the vehicle?

Nothing has been removed, I had the windshield seal checked. It leaks when water is poured directly into cowl, with water not even touching windshield.
Do you think I will need to remove the fender to get in to seal everything, or maybe just remove plastic innner wheel well?

If you can spray the undercoat into the general area without removing anything , I would try that first.
When you spray that stuff it gets into everything and when it has a while to set you can try to see if you covered the area that had the leak. Just be patient and use a good quality product. If after it dries and you test it with the hose and if it still seems to be leaking, then I would try to pull the inner fender aside to gain access to the area you suspect is still leaking. If done carefully , one can should be more than enough. If you wish, you can pull the inner fender first and spray everything you can see in there. Unfortunately, once you stop using the nozzle on the can it may dry and now you may have to get another can because the nozzle plugs up . Make sure you check the windshield for any overspray so you can remove it while still soft or just cover the area where you don't want the spray to land on.

Thanks Hanky. I'm going to give that a try tomorrow.

Problem solved
 

I removed both innner wheel wells and stuck my finger in cowl drain holes. Both sides were clogged. I guess the water was just building up in there and found a way in.

I cleaned them out and poured about 10 gallons of water in the cowl.................no more Leak!!!

Glad you found a solution. Still wondering how the water found a way to get into the car.

Must just be a body seam in the lower cowl area near drain holes. Unfortunately there is no way to see down in there