Driver's side leaking water

I have a first gen Tacoma, and after driving it for about 10 hours (through rain for maybe 1hr), and letting it sit in rain overnight, I have discovered the drivers floorboard and carpet is soaked. I have rubber floormats, and it was completely dry above and around it, I just realized it was wet after removing the floormat. Where can it be leaking from where it’s not wet anywhere besides beneath the floormat? I removed my carpet a couple months ago to clean everything and the floorboards are in phenomenal shape. Help would be appreciated!

 

What's the condition like on your windshield seals. Any gaps? Possible water intrusion entry points?

 

Just checked the windshields with soapy water and an air gun and windshield is sealed tight. Passenger side completely dry too.

 

check grommet under brake master cylnder, leads to drivers foot area, also check angled door seal, mine had a metal spur causing a leak, dealer could not replicate, i just removed seal, removed the spur, filed it down and fixed.

 

Hose test! Run the hose on top of the metal grate of the windshield cowl and look with a flashlight up along the firewall (passenger and driver side for that matter). If it's leaking, there's some threads on here about running sealant along the pinch weld of the body/firewall. Also check your door weatherstrips - I had a leak from the inner part not meeting up against the metal allowing water to trickle in and flow inside the car. Try running a very slow trickle all along the outside edge of the weatherstrip and seeing if any ends up pooling on the floor. Pull the kick panel and scuff plate so you can see better.

 

Thank you all this is some great advice. I ended up stripping out the entire interior as I was going to maybe put a new carpet in anyway. I will have someone run a hose all along the top, the bottom, and just in general mimic rain. I’ll sit on the inside of the stripped car and see if I can see anywhere water is coming in. I’ll let you al know what I find!

 

Well that worked a beauty. Found it’s the wiring harness grommet on the firewall that’s the issue. How would you all recommend fixing this? Just slap a ton of silicone on? Or is there a new OEM part I can buy that will fix it. Can imagine it would be tough to find the right part #.

 

I’ve fixed grommet leaks in the past with flex seal. Works great.

 

Good news. Side note I find it odd, only reason being in the 23 years of owning my truck I've never seen a lot of water accumulation under the hood. Even in a down pour for 6 hours. Wondering if you even have said factory grommet in place?!

 

Yes it is there you can see where it’s brittle. I found it strange why so much water is getting on the firewall in the first place too.. maybe that’s issue number one and the leak was issue number two. I’ll take a look at it tomorrow and update.