isaac338

My 4runner tends to leak a ton of water onto the passenger floorboard in the rain - to the point where I've started traveling with a spare computer so when it gets soaked I can swap 'em out and wait for the other to dry. The water runs down the body behind the passenger kick panel, right where the computer bolts in.

Where's the best place to look for a leak? I've heard the seam underneath the cowl is a likely suspect, but do the 1st gen 4runners have the roof drains from the sunroof like the later ones?

Thanks for any advice

AZkid

just pop the cowl off and seal her up realy good with some all purpose sealer

4Crawler

iTrader: (3)

There are sunroof drains down both sides but they normally run a tube from the roof down the a-pillars, You could pull the a-pillar trim to see if the tube is intact.

isaac338

I was wondering what those tubes were behind the kick panel covers. Thanks Roger, I'll check to see if they're clogged and use some seam sealer on that seam under the cowl.

kiyobrown

Man, learn something new everyday.

isaac338

Good tip, thanks.

Thrasher_s

I know this is an old thread, but I'm having the same issue. Are there instructions somewhere for how to do this?

Jimkola

I'm not quite sure what taking the cowl off would do. But if I were to guess, once the cowl is off(easy once you pop the wiper arms off) then you can unscrew the bottom molding and slide out. If the metal under the molding had rusted through than maybe you could patch. Rust was prone to develop in areas where dirt, mud, and leaves got trapped. Even worse if you live in a winter salt region. I'm not familiar with that cavity itself where all the wiper linkage is installed being a leak spot. Would have to be seriously loaded with debris.
To pull the cowl you need to remove wiper arms. Unbolt, then rock gently back and forth using the arm for leverage until it pops free(it's a tapered fit.) Open the hood and remove the two screws and three retainers where the hood seal sits on top on the cowl edge. The two outer ones are the screws, The three inner ones are clips where you pull up on the center, then pull the hole clip out. Now you can slide the cowl out. Once out, you'll see the screws holding the bottom molding in place. Unscrew, then slide downward. you can pull out the lower corners, too.

The three more common things that could cause leaks on the right floor:
1. AC evap drain hose gets blocked and water backs up in the evap box, spilling onto the floor. More of a summer thing when humidity is bad.
2. Grommet for radio antenna cord is missing at kick panel. Water will follow the cord right into the passenger area. Unfortunately, it's right above ECU. Reinstall grommet and try and make the cord dip lower than the hole on the fender side. The water will follow the cord downhill, but not up. If you can't get the cord lower than the hole put a zip tie on it and have the tail hang down(don't cut off.) Water running down the cord will hit the zip tie and follow it.
3. Windshield rusted in channel, especially lower corners.. The only proper approach i can recommend is pull the glass, neutralize and repair the rust damage, primer and paint to seal the metal, and reinstall a glass. You can remove moldings and try and just goop in a bunch of sealant, but the rust will continue to grow, and all that sealant isn't a pretty sight.

The sunroof tubes did periodically clog, but that caused leakage visible at the headliner. So even if you have a sunroof I doubt water is coming from there.