Water leaking from A-pillar airbag cover in heavy rain

[flip]

Not going to say I found your problem but I'm going to say there is some seal skip going on around this plastic cap. Without taking the top seal off to inspect, I'm going to say the water runs down the holes, into a big channel that is capped at both ends and sealed with the pink "foam". It doesn't have the same consistency as true seam sealer and is more like "Great Stuff".

I bet the channel is filling but some is getting around the foam, running down a pillar and either catching a push pin hole (Christmas tree) or following it down until there isn't enough surface tension with the metal and it starts dripping on the trim then out through the panel seams.

Not sure how far down the A-pillar I was but in enough to come up with a good theory.

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[Mattbar1]

Not going to say I found your problem but I'm going to say there is some seal skip going on around this plastic cap. Without taking the top seal off to inspect, I'm going to say the water runs down the holes, into a big channel that is capped at both ends and sealed with the pink "foam". It doesn't have the same consistency as true seam sealer and is more like "Great Stuff".

I bet the channel is filling but some is getting around the foam, running down a pillar and either catching a push pin hole (Christmas tree) or following it down until there isn't enough surface tension with the metal and it starts dripping on the trim then out through the panel seams.

Not sure how far down the A-pillar I was but in enough to come up with a good theory.

I do not know where that plastic cap is.

Once the water passes the foam dam. If the water overflows the gasket it will fall directly onto the non-roll-bar. It then drips down the roll bar onto the backside of the plastic covering the air bags.

This isn't really a sealant issue. The gasket can't hold enough water. And it can not drain it quickly enough.

 

[stuston]

The real problem is that you shouldn't be getting that much water in that channel to begin with. Those look more like they were designed to be weeping holes, only to drain condensation and incidental water that makes it past the seal. If you're getting multiple ounces of water in there, look higher up at the seal between the roof panel and the windshield header - you're probably not getting the seal that you should be there.

The same thing happens with sunroofs. They are supposed to seal around the perimeter to the roof, but they also have a drain for incidental water, or for the little bit that may get in when it's open and you forget to shut it. It's not meant for a typhoon. From what's been described, it sounds like that's what this drain was designed for as well.

 

[Buddy Lee]

1/4 to 3/8 inch.

Glad I refreshed before replying. Flip, you are amazing. Was going to say typical sunroof tubing runs about 1/4 to 1/2 inch internal diameter, so that would be in line if the measurements you gave were ID and should handle typical runoff that makes it past a properly sealed top (yes, pouring water directly to channel will overwhelm, but that much water should not be getting past seals).

What Flip found is a sound theory. Without having better pics or being hands on the Bronco, my initial thoughts were improperly sealed tubing allowing water to track on outside of tubing and accumulating in A pillar, a tear or defect in tubing in the A Pillar, or broken/disconnected connector where tubing transitions to cowl or further down interior to drain outside.

 

[Mattbar1]

The real problem is that you shouldn't be getting that much water in that channel to begin with. Those look more like they were designed to be weeping holes, only to drain condensation and incidental water that makes it past the seal. If you're getting multiple ounces of water in there, look higher up at the seal between the roof panel and the windshield header - you're probably not getting the seal that you should be there.

The same thing happens with sunroofs. They are supposed to seal around the perimeter to the roof, but they also have a drain for incidental water, or for the little bit that may get in when it's open and you forget to shut it. It's not meant for a typhoon. From what's been described, it sounds like that's what this drain was designed for as well.

I don't disagree with this.

The top and/or the gasket will have to be redesigned to prevent as much water from getting in this channel.

 

[Mattbar1]

Glad I refreshed before replying. Flip, you are amazing. Was going to say typical sunroof tubing runs about 1/4 to 1/2 inch internal diameter, so that would be in line if the measurements you gave were ID and should handle typical runoff that makes it past a properly sealed top (yes, pouring water directly to channel will overwhelm, but that much water should not be getting past seals).

What Flip found is a sound theory. Without having better pics or being hands on the Bronco, my initial thoughts were improperly sealed tubing allowing water to track on outside of tubing and accumulating in A pillar, a tear or defect in tubing in the A Pillar, or broken/disconnected connector where tubing transitions to cowl or further down interior to drain outside.

These are good ideas but not what is happening here.

We are seeing more of these, there is another thread on it now too.

There is no damage, no pinches, no tears. The top lets water in this channel. The channel can not hold enough water. The drains can not drain quickly enough.

The water overflows inside the cabin.

 

[flip]

I do not know where that plastic cap is.

Once the water passes the foam dam. If the water overflows the gasket it will fall directly onto the non-roll-bar. It then drips down the roll bar onto the backside of the plastic covering the air bags.

This isn't really a sealant issue. The gasket can't hold enough water. And it can not drain it quickly enough.

This is inside the roll-bar tube at the corner of the windshield. My assumption is this cap seals the trough inside. If it is leaking inside the tube it would be another path to that area.

 

[flip]

These are good ideas but not what is happening here.

We are seeing more of these, there is another thread on it now too.

There is no damage, no pinches, no tears. The top lets water in this channel. The channel can not hold enough water. The drains can not drain quickly enough.

The water overflows inside the cabin.

Wonder what taking the foam dams out would do? If it can drain from the corners through a different path, wonder if that would be enough to alleviate the surge.

 

[Mattbar1]

Wonder what taking the foam dams out would do? If it can drain from the corners through a different path, wonder if that would be enough to alleviate the surge.

I am not following you.

Once the section that has the small hole that you found overflows. It is already too late. Anything below that won't matter.

 

[flip]

I am not following you.

Once the section that has the small hole that you found overflows. It is already too late. Anything below that won't matter.

Water is supposed to go down yellow hole. Foam dam in blue keeps that channel from bleeding over. If you take the foam block out and snip the rubber flap, wouldn't the water flow out to the small drain in the corner of seal? I don't know this for sure, just wondering how to increase the amount of flow so it doesn't get to the point of overflowing the chanel.

 

[Mattbar1]

Water is supposed to go down yellow hole. Foam dam in blue keeps that channel from bleeding over. If you take the foam block out and snip the rubber flap, wouldn't the water flow out to the small drain in the corner of seal? I don't know this for sure, just wondering how to increase the amount of flow so it doesn't get to the point of overflowing the chanel.

Yes, unless it is too much water for the snipped flap and drain hole (the one you found, not in the photo, not the yellow one) to handle.

If the channel is filled. And water is draining in the yellow hole as designed. And the vehicle shifts to an angle and the water runs down the channel toward the blue foam block. It will pass the yellow hole and overflow the block no matter if it is there or not...

I think cutting the rubber flap would just send the water down the inside of the window, into the car. I think more water would get inside doing this.

 

[Broncodave]

Man, I hate water sometimes. That damn stuff is so good at getting in anywhere and everywhere.

I will never understand why anyone would build, buy, or live in a flat roof house. I don't care how good it looks. The water will find its way in. Just give it time.

 

[RednWhite89]

Looks like Car and Driver may have had a similar issue...
https://www.caranddriver.com/features/a37302593/dyer-new-ford-bronco/

 

[Buddy Lee]

Tech bulletin - Fill A pillar with damp rid and discard of gel mess every oil change interval. In cooler climates, use jello pudding for a tasty snack.

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