1998 4runner; water accumlating on drivers side floorboard. Have checked the AC drain, removed cowling to check drains and windshield, checked heater core; all were okay. Water appears to be coming in from the outside somewhere,any suggestions.

 

do you have a sunroof? I think there is a fron sunroof drain that runs through that a pillar.

 

Check your heater lines and see if the windshield is leaking anywhere

 

There is a rubber grommet on the firewall near the brake booster under the hood where the wires come through. Have you made more holes in the grommet to pass extra wires through or anything? Check to see if it's installed properly. Take a garden hose and spray the grommet from the engine compartment side, and check to see if water is coming into the cab.

 

the above mentioned items are all possibilities. I would also check your door seal, sometimes they get compressed to the point it won't work. fix it so you don't end up with this on my driver's side:

found this after fixing a leaky windshield and pulling up my carpet.

Good luck..and welcome to Yotatech!

 

In mine it was a tiny bit of rust in the wiper tray beside the hump for the air intake for the blower motor. I've actually seen rust there on 3 toyotas so far. You may have this same rust on the driver's side. This caused water to get in and rust out the fire wall and the floor around the body mount. To repair it properly I took off the fender. Drilled out the spot welds for a little plate covering the end of the tray. You'll then see where its rusted. Before going this far, you can do the garden hose test before getting to this point. Put water in the loovers around your wipers. Pull up your carpet and have a look at the fire wall and see if water is comming in.

CT