So again, I just bought this truck a month or so ago. Last time it rained I noticed where there was water on the passenger side by the foot rail. At home, i removed the screws and took up the rail. The whole pass side padding was wet. Dripping. Pooling. BTW, I have a final floor, not carpet. Anyway, my friend said that his Ram 2500 leaked from the 3rd brake light cover. So I removed mine, cleaned it up, replaced the weatherstripping. Tested it (wife sprayed with water while I stayed inside the truck to watch for leaks) and it worked out fine. Great. Sucked all of the water I could get out with the shop vac. A few days later, it rained again. More pooling??? So yesterday I removed the seats, vinyl, and padding. I set it out in the sun all day and let it dry. The floor of the truck wasn't too bad. There were some top-level rust happening but nothing too serious. So I sanded those and then sprayed Rustoleum rust stop / primer (2 coats). Then I sat in the truck with a flashlight while my wife sprayed the whole cab. No leaks. My conclusion had 2 options....water is getting in around the seat bolts / foot rails OR the weatherstripping is bad on the doors.

The issue with the weatherstripping is that after she sprayed the truck, there was no water on the inside of the weatherstripping...water didn't get to the truck. Could that still be the issue?

Regarding the bolts, I don't think enough water would get into the truck via the bolts, but I put some silicone around them upon reinstallation.

Question. Is there another common place for water to enter? I didn't see any evidence of water coming from the firewall. There was evidence that the driver's side leaked at some time in the past, but someone must have corrected it.

Regarding the Rust Stop spray stuff...I saw "undercarriage" spray paint when I picked up this stuff for the cab floor. My undercarriage has a little rust on it. Should I spray it as well? does this stuff work?

 

If you have been using the A/C check the drain for it.

 

Thanks Charlie. Where is that located?

 

Should be just a metal tube sticking thru the firewall in the area of the heater hoses I think.
Poke something like maybe a pipe cleaner in it and see of water comes out.

 

The rear window seals are known to leak. On either side of the window( driver and passenger) on the exterior, there are small holes that allow the water to drain out. Make sure those are clean otherwise the water drains into the cab. This is more prevalent if you have the sliding rear window.

 

I had water leaking onto my floor on the passenger side for a long time whenever I ran the A/C and eventually I stuck about 10" of hose (can't remember what size) on the little nub on the firewall under the a/c accumulator and ran it down out of the way. Haven't had any problem with it since

 

I've been using POR-15 for rust. My local Carquest puts it in spray cans. It works great, but you need to use it right away. I tried keeping some on hand, but it sets up in the valve and won't spray. I've got 4 cans I'll have to poke a hole in and then brush it on.

 

As I mentioned in one of my other posts, the shop has my truck right now because of the rear gear issue in the differential. Maybe the location of the AC drain port will make more sense when I can look at my truck again, but right now I can't picture it.

If I raise the hood and look under the AC compressor, can I see it or do I have to look behind the glove box from the inside? Where did you connect the tubing from? I have several types of clear tubing due to brake bleeding on bikes. I should be able to do something similar as you. It won't hurt and may solve my issue.

 

Yep. I have a sliding window, but the previous owner somehow permanently shut it (i think he was in a high-crime area...just off MLK by the air force reserve base). I can't figure out how to reopen it. Since my rear seat was in the bed of the truck, my wife didn't spray the rear window too much. When I get my truck back, I'll do another water test and check the drain holes (which I didn't know were there).

 

Drain is for the heater box, so, on the firewall, relatively low, passenger side somewhere. Use a bright light, shouldn't be too hard to find.