Please help identify what is behind this seam - water leak troubleshooting

[ramchol76]

These pictures show the condition of my seam seal in cowl.

btw, are these really sealing a seam or its just created for water barrier? asking this because it is raised by almost an inch. I am searching any thread about this seam seal.

 

[exp500]

Check the cowl drains at the bottom rear of the fenders. Are you able to easily break/crumble the existing seam sealer? If it's crumbly then you have alot of work to remove/clean. Another trick is a piece of 5/16-3/8 clear tubing on a caulk gun, use a self leveling urethane like osi quad so you dont make dams on the horizontals. Any resealing, you must be sure of a bond with new sealant, A bead on top may not seal,has to be stuck to whatever base you have so "stir" as you apply. An rv supply also has good urethanes that are easier to apply and flow nice.

 

[ramchol76]

Check the cowl drains at the bottom rear of the fenders. Are you able to easily break/crumble the existing seam sealer? If it's crumbly then you have alot of work to remove/clean. Another trick is a piece of 5/16-3/8 clear tubing on a caulk gun, use a self leveling urethane like osi quad so you dont make dams on the horizontals. Any resealing, you must be sure of a bond with new sealant, A bead on top may not seal,has to be stuck to whatever base you have so "stir" as you apply. An rv supply also has good urethanes that are easier to apply and flow nice.

yes, the seam sealer is crumbly in sections. thanks for the sealing inputs.

on the 'cowl drains at the bottom rear of the fenders' reference... In my case as in this picture, the cowl water just pours out between and inside fender. can you point which drain you are referring to?

 

[Doubeleive]

hard to say, if I had to guess I would say it is just a water barrier but freaking gm has decided to just glue a lot of things together anymore i noticed a lot of it on my yukon when looking under/behind stuff, I see less spot welds and more glue looking stuff.

 

[retiredsparky]

Sometimes leaks can be found by blowing high pressure, high volume air (shop vac or leaf blower) into the vehicle interior while using a soapy solution that can be spread around areas of possible leaks. Bubbles may show up at the location of water leakage. Hi volume air is needed because the HVAC external air source and the external air vents will leak out the air being introduced.

 

[ramchol76]

Sometimes leaks can be found by blowing high pressure, high volume air (shop vac or leaf blower) into the vehicle interior while using a soapy solution that can be spread around areas of possible leaks. Bubbles may show up at the location of water leakage. Hi volume air is needed because the HVAC external air source and the external air vents will leak out the air being introduced.

thanks for the idea, I am planning to try this method. it is easy to mount the shop vac (not sure CFM is enough), and I can close the HVAC air intake vent temporarily and conduct testing. mounting leaf blower can be difficult.

found this
https://cfnewsads.thomasnet.com/images/medium/827/827741.jpg
https://news.thomasnet.com/fullstor...tic-body-air-leakage-tests-on-vehicles-827741