plug to nowhere driver's side floor & moisture under the carpet....

I am putting in body mounts & when I pulled back the carpet on the driver's side, there is moisture. I can't find any holes. Of course there's a story. I had brought this to a mechanic & he put the mounts in wrong, so I am doing it myself. I would have tried it to start with, however I had concerns about the rusty bolts. The mechanic took care of that, so hopefully I'll be all set now. Anywho, he did the job by using a lift to lift the body, therefore he had to disengage a bunch of stuff. All this to state that maybe the water coming through something he had to undo? The moisture is concentrated around the area where the body mount plug is, however there is none under the plug. & it seems dry alongside the door. I take this back. It is along the door, although it goes from up near the dead pedal to about 1/2 of the driver's seat. Pic posted in next post. & not sure if I should have made this two different threads?
Also there is a plug in the middle of the driver's side floor that seems to go to nowhere. I pulled it up & was looking at asphalt. Why is it there? It has a bit of rust around it so I figured I'd spray it & seal the plug.

 

Have a pic of the plug?

 

Funny you should ask. I had headed out to take pics.

 

That's just a body plug, should leave it in to keep water from getting in the cab.. You must live in the salt belt, looks like the floor near the wiring harness is rusted out pretty bad..

 

Massachusetts. It appears to need some work, however no holes, so I can't understand why the moisture would be concentrated toward the front. & I imagine if it had been doing this for a while, there'd be a musty smell.

 

the only way to know for sure if you have a leak somewhere is to spray around the cab with a garden hose. Removing the carpet will help a lot, letting you see much clearly where it's coming from.

I really doubt it comes from the body mount. Looking at the rust on the dead pedal (footrest), it seems to be coming from above. If this is the case, it can either be water entering around the wiper motor or a windshield leak on driver's side. Water drips down the firewall and onto the floor. Or it could be coming from somewhere in the cowl (like plugged drain holes, or the seams themselves)

I had a leak in the same area and it ended up being the windshield - top left corner. Water dripped down the A pillar (behind the plastic with the handle), then down onto the wall behind the plastic kick panel, then pooled on the floor at this exact place.

*edit*
if that can help you:
https://www.tacomaworld.com/threads...-before-water-pooling-passenger-floor.502204/
includes lots of links about leak problems, including driver's side

then a toyota service bulletin about leaks in the cab

 

Makes sense. Sucks. But makes sense. Just seemed weird to me that I hadn't had a musty smell. I'll give 'er a look underneath tomorrow & see what the rust looks like from there. Been trying to tackle it while painting the frame. Guess I hadn't gotten there yet....

 

You know, I read this & went "ok". Then three hours later.... Wait a minute.... I realized maybe I was just as confusing as ever. Soooo, lemme try this again. I got that it was a plug & serving a purpose, however what I am wondering is whether it is necessary to be able to pull the plug or have the hole there at all. I was more questioning what the hole is for, not the plug. Just seems like another source of rust startage....

 

I believe the hole is there as a drain hole in case the cabin were to ever become flooded.

 

yes, this is a drain plug, in case your cab gets flooded or an important amount of water gets in. You should leave the plug there, because letting the hole open can allow dust, debris, and water to get in the cab and stay trapped under the carpet (if it's moist or water, say hello to floor rust!).

Unfortunately, rust tends to form around the edge of the hole, because of moisture being trapped between the edges of both the rubber plug and the sheet metal. So that's why you should grease all around the edge, to keep moisture and rust away

 

K. Yeah, I wasn't going to remove it permanently, so much as treat the rust & maybe seal the plug with silicone. Nine + years with the truck & had it flooded I wouldn't have known that was there anyway, unless I removed the carpet.... which I probably would have done if it flooded.... eventually.... at least to dry it out....

 

Maybe it's irrelevant, but in other cars I've seen floors get soaked with water thanks to a windshield seal leak.

 

Holes in the body that serve no purpose and have hole plugs are generally there for several reasons: unused hole for option not present, say wire harness passage but option not on that truck; datum holes for stamping or welding equipment from when the body panel was made/assembled; drain hole for the factory dipping process to coat the body with the "ED", or electro-deposition primer coat. They let the ED coating material drain back into the dip tank. You should leave the hole plug in place.

As for the leak, another possibility is the grommet from the firewall where the engine room wire harness passes into the cabin. If that was leaking, the water would run right where you are showing in the picture. It is right beside the master cylinder booster. You could spray it with a hose, but it may be obvious if it is out of place.