I had a similar leak............but it was the windshield was not properly sealed from the factory.

 

That was another suggestion I kept finding. When I visited a body shop for quotes, he immediately latched on to the fact that I had my windshield replaced over a year ago.

That looks like some late-night investigating. Must have been a good case of the OCDs... thanks for passing on the info.

I remember finding the same thing about Cfans when I became active again this year since ~2008. That place was kicking then but dead now...

Sadly this truck is my daily driver and now that it gets dark at 7pm I was kind of forced.

Welcome to the Nation and thanks for taking the time to post the problem and the solution. Too many times problems are posted without the eventual solutions. Good "Search" info.

I've been on many forums and find the same thing, people bitch but people never post solutions.

Thanks for the comments guys, like I said, hopefully this will help someone someday.

 

That looks like some late-night investigating. Must have been a good case of the OCDs... thanks for passing on the info.

I remember finding the same thing about Cfans when I became active again this year since ~2008. That place was kicking then but dead now...

 

Welcome to the Nation and thanks for taking the time to post the problem and the solution. Too many times problems are posted without the eventual solutions. Good "Search" info.

 

It's gonna help me this evening. I've got water getting in my floorboard and after I seal the third brake light, I'm gonna check this out and make sure it's not coming in here too.

 

What view is the last two pictures? Is it looking down into that hole that's labelled "leak" in the third picture, or is it the view looking UP through the bottom of the fender well from the bottom?

 

down into the hole with the fender off, right where the picture with the fender off is labeled leak.

good luck

 

Thanks for sharing this!
I don't think I've seen this problem before, nice to see there's pictures to go with it.


*clicks on the Like button*

 

I'm glad you posted this I have a similar wet carpet and the majority of the water is near that kick panel so this must be my issue. I'll be drying mine out tomorrow and fixing it.

 

Just bought an '06 Colorado and have the same issue. After pulling the carpet and examining the pads, this makes the most sense. Back panel is actually dusty so I can't see it being the 3rd brake light although will reseal that on spec. Passenger side is wet also but much less so. It was a lot of water in those pads so this probably explains it. For anyone else there is a technical service bulletin on this if you look around, sorry I don't have the link.

Just want to thank the OP for the excellent post as an answer to what seems to be a common problem. The fender was off for accident repairs just a couple of weeks ago, a shame this problem wasn't addressed then. Oh well, the price was right, I knew just from the sniff test that there was a water issue before buying this truck.

 

It was in fact the 3rd brake light w/ my truck. As someone else mentioned an incredible amount of water, took days for the pads to dry out in the sun, should have turfed them as the odor lingers somewhat. Aftermarket rug/pad setup is available for relatively short money and I probably should have done this.

Now dealing w/ heater resistor switch issue but this is the wiring harness under the glove box as discussed in another thread. Spring project. Interestingly still on the OE battery after 140k and all these years. Probably just jinxed that.

 

So I got ambitious today and decided to tackle my water leak which was causing my drivers side carpet to be a puddle of water. After taking the cowl and fender off, and checking everywhere for water build up, I couldn't find where the water was coming in. Unlike the OP, there was no build up of water anywhere and everything seemed to be dry. I pulled the carpet and padding back from the fire wall and dried up all the water. While I was in the truck looking up under the dash, i had my brother pour water down the windshield and I saw the water coming in from the seal above the emergency brake where the firewall meets the cab. Here is a picture of the improperly sealed area.

 

I've also done the wireing harness and resistor for the speed settings for hvac. Very easy to change and works 100%. Make sure you follow the how to on fixing the ground behind the air intake box under the hood or you will/may have an issue with your fan working then not working which happend to me after installing the new harness. I believe this is what caused the original resistor and harness to melt in the first place. Good luck.

 

The resistor and connector problem is that the connector is just wimpy.
It can't handle the current drawn by the fan motor.

 

Very helpful post! Thank you! This has been driving me nuts for months...

 

Mine leaked in this same spot and the channel was full of dirt not allowing water to drain down like supposed to. I sealed up both sides and the antenna grommet on pass side had pulled out of wall and let water in so I put sealant on that and then pressed it back in. High and dry now for a year.

 

Mine is leaking again.. Sealed up that seam too.. We had a huge rain storm the other night.. Now I'm lost

 

Just bought my truck last month as a project truck. My carpet was ruined from water damage. So it looks like its time for me to try this. I'm pretty sure mine is leaking from both the cowl and the 3rd brake light though.

 

I have a leak on the pass. side :hulk:

 

Ever figure out why it leaked? Any repair? I just went through a car wash today and noticed pass floor mat was wet with water and leaked out both front sides of mat to the carpet. I found this of course when I parked to go into work and didnt have much time to take a look but I ran my hand along bottom of glove box and blower housing and it wasnt wet at all.

 

Okay guys let me get in this please, I just noticed water on my driver side. Things that I have done I had my windshield replaced about 2 years ago. But I just about a month maybe two had to replace my third brake light because it was out. I am sure that I sealed it back really good. I will look again and make sure that its not leaking again, but I don notice the wet spot above the window anymore. But with all of this rain here in Oklahoma I really don't know what to think anymore and from some of the things that it could be I really don't feel like taking fenders off but if I have to then so be it. I will look under the dash above the emergency brake and look under there. I am also thinking that it could be from where I ran my power for my light bar that I installed also or maybe the power to stereo also. Just have to take the time to narrow it down and find the source of this dam leak

 

A leak would piss me off beyond words.

-note though, if the fenders come off, would be the PERFECT time to replace "ground-packs" and eliminate that stupid multi-pin ground connector.

I know I would.

.

 

First thing to suspect is always the 3rd brakelamp.
It will leak eventually. Not if, but when.

Water has been known to come in by the 3rd brakelamp and run down into the front floorboards.
Better that than ruin your headliner, which it may also do.

A few here have had leaks at the front cowl though.
And of course the windshield and backglass.

 

I sealed the third brake light and I still have a leak. I am going to check the cowl tomorrow.

I noticed the seal for the sliding back glass is curling up.

 

Im gonna assume its from the front cowl since it was on top of the rubber floor mat. The truck is still under the CPO warranty so guess I will be going back to the dealership. Will have to wait til after the MESM in May though.

 

Sliding rear glass?
I'd be suspicious of that.
I've never even seen an OE sliding rear window, but I can imagine them maybe developing leaks.

I'm on my 2nd 355, and I never had any front leakage problems.
Others here have though, and one item on my "things to do" list is do a through inspection and add additional sealant to the front fender/cowl areas before I put in the time to do an interior. To be sure...

 

I have an OEM sliding rear glass.

I also recently discovered a large amount of water on the driver's side floorboard. It's bad enough I'm going to have to find the leak and fix it asap.

I wish I had another set of hands to hold the water hose while searching for the leak. I suspect the seal the OP posted, but I'm going to do my homework before removing the fender.

My firewall is bone dry but the drivers floor has standing water. I already sealed my third brake light a few years ago.

I hate leaks!

 

I too have a factory slider rear window. I layed down some absorbing towels on pass floor over the weekend. I will check today to see if wet since it rained and iced all weekend here. I also parked on a slight incline facing forward so any water will roll towards back of truck. Just the incline of my driveway to be clear I didn't place any boards or anything under the front tires.

 

I removed the driver's fender and the windshield cowl. It only took about 20 minutes to complete the disassembly.

I ran water down the windshield and looked closely where the water was flowing. I noticed that water was flowing toward the firewall grommet where I had ran a few wires through. The water was running through the grommet onto my driver's floorboard.

The strange thing is that the firewall padding and carpet was completely dry. The water ran behind the parking brake assemble and was actually hard to see without sticking your head under the dash.

I let the truck dry and I then added a liberal amount of silicon to a few areas including the grommet.

Removing the fender was worth the effort because it allowed me to silicon a place where the seam adhesive was allowing water to go from the cowl to the engine bay.

I reassembled the truck and ran the water hose again. The water is no longer running into the cab.

I'm going to find some type of adhesive weather stripping to replace the "seal" on the cowl that has turn to dust. I don't think the "seal" that touches the windshield does much to help water flow, but mine looks kinda bad. I can't afford a new one right now. It will probably just turn to dust like the first one anyway.

Thanks to the OP for taking the time to post this advice.

 

I have a 2006 Chevy Silverado and found this issue/ solution via Google searches. My problem sounded familiar to this post but my solution was very different. The hood release cable has a "rubber stopper" surrounding it near the "firewall". This rubber stopper should be fully seated in a hole (about the size of a nickel) in the "firewall". My rubber stopper was not even touching the hole. Once it was fully inserted into the hole my leaks stopped. The attached pdf (assuming I can get it to attach) is an annotated picture of the area after the fix was completed.

 

Sorry, I don't. I just went to my local PullAPart looking for something that might work and was surprised to find it's the same seal. Most yards will have a bunch of F-150's in there so you get your pick of them, maybe even a Colorado. It would have been nice to have a new seal but in this case they let me have the seal for free. Can't complain since the factory slider costs a grand. Have had no leeks since installed.

 

I'm tempted to yank the slider window and replace it with a fixed back glass actually. An aftermarket PGW window is relatively cheap, whereas moldy carpets and entire days spent tearing out the interior to dry everything is definitely not cheap.