WARNING: water leaks in NBS 07 silverado

[zekeman]

Just a heads up to all you owners of the new body style 07 and 08 Sierras and Silverados ...I just noticed my truck had a smell of mildew inside and I found that I had wet rugs in the front and a bit in the rear. I checked all the TSBs and found none decribing what I found. Behind the rear seats there are two plastic vents( one on the drivers side and one on the passenger side behind the rear seats) that snap into the body sheetmetal and they were leaking water into the truck and causing the smell and eventually would have rotted my truck. My fix was to pop out the plastic vents( they are easy to pop out) and run a bead of silicone around the rubber seal that had already worn out with only 8000 miles. Then crawl under the truck reach up between the cab and the bed and snap the vent back into place I had to unbolt the rea seats to access the vents. You can check to see if water is starting to trickle in if you remove the seats and using a hose run water between the cab and bed and look inside for leaks I was shocked to see lots of water getting in the seal of the vents. My rugs were more wet in the front than the rear because the truck sits lower in the front and the water would run down under the plastic step sill trim and pool under the front mats and be wicked up by the padding under the rug and it would stay wet and start to mildew. If I did not smell the mildew I would have never known I had a leak in a basically new truck.

[erskine]

why didnt you take it to the dealership? quad cab or extended

[zekeman]

why didnt you take it to the dealership? quad cab or extended

Dealership would never have taken the time needed to find the cause ..I fixed it and I feel much better especially because I did not have to tie it up at the delaership and it is fixed right.... replacing the vents with new parts (only $6.00 each side) would most likeley have leaked again at some point. It is an extended cab but all the pickup trucks use the same vent system..

[08sierra60014]

i have got the same problem and dealership told me its leaking thru the body panel?

[ace 14]

Wow, this is scary

[daddytech]

the more i learn about these new trucks the more i love my 99 tahoe.

[1slols1]

was re3ading on another site about this problem and it turned out to be the seal leaking around the third brake light hope this helps

[zekeman]

i have got the same problem and dealership told me its leaking thru the body panel?
Maybe it is leaking into your body panel somewhere but on mine it definitely was the vents and I have not had a single speck of water since I fixed the problem...Hope they fix your leak this is insane having a leak like this on a new truck.

[daddytech]

which vents are you talking about Zekeman? the ones where the air from outside comes into the cab through the wiper trough, or somewhere else???

[zekeman]

which vents are you talking about Zekeman? the ones where the air from outside comes into the cab through the wiper trough, or somewhere else???

There are two vents behind the cab between the bed and the cab you can see them if you look in the space between the cab and bed..They are plastic and mine fit very loose and were allowing water to leak into the cab and down along the floor pan to the front of the floor under the gas pedal and brake pedal the rugs were soaked everytime it rained. I thought it was a door seal or something buit it was those plastic vents.

[daddytech]

There are two vents behind the cab between the bed and the cab you can see them if you look in the space between the cab and bed..They are plastic and mine fit very loose and were allowing water to leak into the cab and down along the floor pan to the front of the floor under the gas pedal and brake pedal the rugs were soaked everytime it rained. I thought it was a door seal or something buit it was those plastic vents.

isn't there supposed to be some kind of rubber membrane in there that closes to keep anything from coming back into the truck???
I think i know what you are talking about now but you'll either need to look at that membrane or see if there is a gromet or something that the vents sit in.

[zekeman]

isn't there supposed to be some kind of rubber membrane in there that closes to keep anything from coming back into the truck???
I think i know what you are talking about now but you'll either need to look at that membrane or see if there is a gromet or something that the vents sit in.
There is a rubber flange around the outside of each vent but it was not seating good at all and therfore letting water into the cab everytime it rained..A bit of silicone around the flange and bingo problem solved..

[kevindsingleton]

I wonder if this has been fixed on the 09s? I guess I know what I'll be doing, this weekend!

[daddytech]

There is a rubber flange around the outside of each vent but it was not seating good at all and therfore letting water into the cab everytime it rained..A bit of silicone around the flange and bingo problem solved..

I think I'd be several kinds of pissed off buying that new of a truck and having those kinds of problems with it. hope you are able to get the musty smell out of it. that can be kind of hard to get rid of.

[winsonca]

dealership is not going to anything about it?

[mikew1273]

Thanks for the heads up...I have a mildew smell in my '07 NBS Silverado CC too. I haven't noticed any wet floor mats but I'll look more closely. I sure don't trust my dealership here either, I gave them 4 brand new TPMS sensors to put in my tires and they broke 3 out of 4 of them just trying to install them...and then told me it wasn't their fault. Idiots. Thanks for the post, I'm going to check mine out more thoroughly to pinpoint the source for sure.

[chevy2007]

Mine also leaked at the cargo light.

[TMRuiz]

was re3ading on another site about this problem and it turned out to be the seal leaking around the third brake light hope this helps


I have an 07 Quad Cab and it had a leaking 3rd light assembly. The dealership replaced the headliner, the carpet pad and the brakelight assembly. Took them over a week and they scratched the *&%( out of my truck but it doesn't leak anymore.:shocked:

[Glock2]

There are two vents behind the cab between the bed and the cab you can see them if you look in the space between the cab and bed..They are plastic and mine fit very loose and were allowing water to leak into the cab and down along the floor pan to the front of the floor under the gas pedal and brake pedal the rugs were soaked everytime it rained. I thought it was a door seal or something buit it was those plastic vents.
2007 Sierra 1500. Just bought used and really love the truck. I was pretty bummed out today when I went into the truck and found the front passenger floor saturated with water
I will locate the vents and seal up as you mentioned
Did you replace the padding. Mine is soaked and don't think I will be able to dry these out. Kids have bad allergies and I dont want to start rotting the truck from the inside out
Thanks for the suggestions.
This is great as I don't think it is covered by GM...although it should.

[zekeman]

2007 Sierra 1500. Just bought used and really love the truck. I was pretty bummed out today when I went into the truck and found the front passenger floor saturated with water
I will locate the vents and seal up as you mentioned
Did you replace the padding. Mine is soaked and don't think I will be able to dry these out. Kids have bad allergies and I dont want to start rotting the truck from the inside out
Thanks for the suggestions.
This is great as I don't think it is covered by GM...although it should.

I repl;aced the padding in the front under each foot area (went to Lowes and bought regulkar rug (JUTE PADDING) but wish I had done the whole truck or at least out back under the rear seats and up the back of the cab and along the side sills where it was wet also. I should have just replaced all of it because now I can smell a faint musty odor every now and then I know it's not wet anymore at all but the padding was wet for a long while before I found it and now it seems to have retained the smell of must/mold. It didn't smell it in the dead of winter here in New England at all but now the weather is just starting to warm up a bit and it's starting to bother me smelling like an old truck...It took me two days of leaving the rugs pulled up as much as I could and running electric heaters inside the truck for many hours to get the padding to dry but it was still a bit damp (very tough to dry). If your kids have allergies I think it would be wise to replace the padding especially more than I did or all of it, I know it will be a nightmare having remove the seats etc. but I you don't want any problems with your children down the road.

[merrick]

My trucks been in the shop for a week now. I had a "service air bag" message appear and took it into dealership. They told me water was getting in the cab and had was causing all sorts of codes being set off in the computer but they couldnt find the leak....i smell a lemon. Wish me luck.

[canislupis69]

I had to take my 08 to the dealer for water in the cab as well. The rear seats and rear carpet was wet. Turned out to be a bad seal on the 3rd brake light. The dealer replaced the light. So far so good.