2016 1500 Sun Roof leaking in floorboard.

[Davans]

Ok guys. I’m pulling whats left of my hair out over this one.  We have been getting a lot of rain lately. A couple of months ago I noticed my passenger side floor board was soaked. I checked the evap core drain and it was fine.  I’ve done a lot of research and have followed the flow of water from the sun roof into the floor board. There are 2 drains in the front of the sun roof that drain through plastic tubes down the pillars. I can’t tell if they’re  drains in the rear of the sun roof or not. All water seams to drain out the front and into a channel on the firewall. It then leaks out either side of this channel and spills down the firewall. From there is following the wiring harness back into the floor board. Most of it does drain behind the inner fender and spill onto the ground. But a considerable amount it leaking back in. It seems to me that the water leaking out of this channel on the firewall should have a better drain to keep the water out of the truck. 

So

1- are there drains in the back of the sun roof that may be clogged cause too much water to drain out the front?

2- is this channel on the firewall the proper place for the water to exit or is something somewhere else stopped up causing the draining at both sides of the channel? 

[Lsgun1]

Clogged drain tubes are common. Open the sunroof and use compressed air to clear them. They shouldn't dump into the cab at all so if they are then you need to find where they would normally route. I've never looked at one of these trucks roof drains but yes there could be some in the rear.

[Jaychevy81]

The front drains on the A pillars are 2 pieces there is a connection about half way down. Maybe one got disconnected. There are also 2 rear drains down each back corner.


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[Davans]

1 hour ago, Jaychevy81 said:

The front drains on the A pillars are 2 pieces there is a connection about half way down. Maybe one got disconnected. There are also 2 rear drains down each back corner.


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I don’t suppose you have a diagram of these tubes and the connectors? 

Any experience with them draining into the firewall? 

[Jaychevy81]

This is behind the A pillars.



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[Davans]

59 minutes ago, Jaychevy81 said:

This is behind the A pillars.



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Ok. I have tracked it beyond that point. Do you know where the tube ends? 

I do get water leaking out of an enclosed channel on the firewall, below the wiper blades. The water is dripping down behind the battery on the passenger side and in the same spot on the drivers side. Most of it flows behind the inner fender to the ground but a good bit soaks through the insulation or tracks along the wiring harness right back into the floor board. I’ve pulled everything except the dash. I have no interest in doing that chasing this ghost. I do not get any water running out of the back of the cab. I do see 2 ports in the cab that I believe may be the drains.  

I appreciate your help. 

[Jaychevy81]

The drains dump out behind the inner fender I wonder if it’s not the sunroof at all. Maybe the front cowl by the wipers water leaks suck. If the sunroof was leaking it would leak on the roof. There is a tray around the sunroof with a gutter system. 4 drains one each corner. Anything more then that it’s leaking on the headliner. My only other thought it’s leaking down the corners inside the frame. Which would find its way to the corner kicks by the E brake. If just throwing things out there to help lol. Jay


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[Davans]

1 minute ago, Jaychevy81 said:

The drains dump out behind the inner fender I wonder if it’s not the sunroof at all. Maybe the front cowl by the wipers water leaks suck. If the sunroof was leaking it would leak on the roof. There is a tray around the sunroof with a gutter system. 4 drains one each corner. Anything more then that it’s leaking on the headliner. My only other thought it’s leaking down the corners inside the frame. Which would find its way to the corner kicks by the E brake. If just throwing things out there to help lol. Jay


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I actually used food coloring to dye the water. I poured it into the drain gutter in the sun roof. I had the a pillar cover removed and saw it drain through. It also made its way to the ground behind the tire. Seemed good until I got in the floor board with a flashlight and could see the colored water running in.  I back tracked it to the channel on the firewall. It’s enclosed so I cannot see the water draining into it. But it drains out on both sides of the channel. It seems to me like it should not be spilling out here. It runs down the firewall, some of it makes its way to the ground. Behind the inner fender.  Some flows back into the floor board. 

[Davans]

On 3/23/2020 at 8:46 PM, Jaychevy81 said:

The drains dump out behind the inner fender I wonder if it’s not the sunroof at all. Maybe the front cowl by the wipers water leaks suck. If the sunroof was leaking it would leak on the roof. There is a tray around the sunroof with a gutter system. 4 drains one each corner. Anything more then that it’s leaking on the headliner. My only other thought it’s leaking down the corners inside the frame. Which would find its way to the corner kicks by the E brake. If just throwing things out there to help lol. Jay


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I actually used food coloring to dye the water. I poured it into the drain gutter in the sun roof. I had the a pillar cover removed and saw it drain through. It also made its way to the ground behind the tire. Seemed good until I got in the floor board with a flashlight and could see the colored water running in.  I back tracked it to the channel on the firewall. It’s enclosed so I cannot see the water draining into it. But it drains out on both sides of the channel. It seems to me like it should not be spilling out here. It runs down the firewall, some of it makes its way to the ground. Behind the inner fender.  Some flows back into the floor board. 

[Davans]

I checked the rear drains and they are fine. 

Does anyone know exactly where the front lines exit? Do you need to pull the inner fenders to see where they Exit?

[Jaychevy81]

Let me look at my truck and see what I can test.


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[kickass audio]

I cannot offer assistance in regards to where that drain tube runs through the cab to get outside in the fender but here is something to try.

 

If you can get someone to help you out, disconnect the tube connection that is in the A pillar and put that piece of tube in a bucket. Have someone dump the water in the channel of the sunroof and see if any water makes it to the floor board. If it doesn't then you definitely have a problem with where the hose goes from the connector in the pillar to the outside, maybe the tube leading outside has a small tear in it or was pulled inside some to make it leak.

[Davans]

10 hours ago, kickass audio said:

I cannot offer assistance in regards to where that drain tube runs through the cab to get outside in the fender but here is something to try.

 

If you can get someone to help you out, disconnect the tube connection that is in the A pillar and put that piece of tube in a bucket. Have someone dump the water in the channel of the sunroof and see if any water makes it to the floor board. If it doesn't then you definitely have a problem with where the hose goes from the connector in the pillar to the outside, maybe the tube leading outside has a small tear in it or was pulled inside some to make it leak.

The water is making its way into a channel on the firewall, under the hood and running out both ends, behind the battery on the passenger side. Leaking down onto the wiring harness that leads back into the floor board. Im just not sure if the tubes are supposed to dump into that channel or if they are stopped up and backing up into it. If I could get to it. I’d cover it up and duct tape it.  

[Tom M]

Did you find a fix? My 2017 Chevy truck sun roof front drain tube is flowing to the ground drain but also leaking where the tube goes into the fire wall and soaking the floor I see it behind the passenger side fuse box but unable to reach back there