so i did a little reading and i found... does the track inside the cab that the slider slides on, does that track fill with water and then overflow down? you can test this with a hose and a second person or even setting up your camera phone to be your inside the cab eyes. i read that there are actually two tiny drain holes at the bottom of that track that can drain water back outside but get clogged. heres the article and kinda how to if this is the case....
Do you have a wet rear carpet? Possibly some water in the under seat storage bins? 1st place to check is the infamous 3rd brake light. I checked mine and that was not the source of the leak. I sprayed water on the rear window and found the U shaped channel the rear sliding window panel glides in was taking on water. The water gets past the outside rubber seals and makes its way into the U shaped channel and depending on the ground the truck is parked on will run to the driver or passenger side (in my case passenger side). After some reading and spending 2 hours outside this morning I have found out this is suppossed to happen! There is a drain in that channel on each end that allows water to exit the channel and down the back of the cab between the bed and cab. My issue was the drain was clogged so the channel would fill up (I witnessed after a heavy rain my channel was full) with water and eventually overflow out of it and down the inside of the cab behind the rear seats onto the carpet or into the bins. It dont matter where its going problem is its inside the truck. I took my compressor and blew air into the channel and eventually cleared both drains. Here is a picture of my drain location on the passenger side from the outside you will see in the picture I took a small piece of metal wire and have inserted it into the drain hole.
I put a tape measure for reference from the glass edge. It is a pain in the ass to see if you use a flashlight you can look up between the pane of glass and the truck cab and see the hole. There is another in roughly the same spot on the other side of our trucks. I have a power slider and when you look on the inside to try and see the hole you have a black plastic cable cable anchor block that looks like this.
It comes almost to the end of the U channel there is a small section of U channel after it. This plastic block does not sit on the floor of the U channel it is raised just a little and water can run underneath it and that is where the drain hole is. There is a plastic block on each side of the truck that cable comes out of for the power slider. If you have a manual slider wich my daughters boyfriend does there is nothing in the way and you can see the drain hole alot easier it looks like this.
As you can see its fully exposed I circled the drain hole in red. I have owned an 04 with a manual slider and now this 09 with the power slider and had no clue about these drains. If they clog with debris over time you will have a water issue in the cab. I have also read if the factory was sloppy with the window sealent that can also block the drains. With my truck I blew air under the plastic cable block and was eventualy able to feel air escaping on the outside. Ran the wire in and out a few times as well. After I was all done I opened the slider and poured some water into a funnel and directly into the U channel.
And now the proper result is this!
I was ready to have the entire window replaced for no real reason. I sure hope someday a member here thru the search function finds this thread and it saves them alot of grief and money!
