Smoke in air gap of duravent

[mikhen]

I have smoke coming from the clean out cap between the 2 layers of pipe. Cap is siliconed, as is the rest of the joints. I'm thinking I will have to take the tee off, clean, inspect, maybe caulk any inside seams, then re caulk and re install.
Any other ideas before I start this project?
How can smoke be getting between the layers?
Thanx.

 

[rickwai]

fill that gap and see what happens. May just be a bad seal in the cap.

 

[mikhen]

Took everything apart and, based on a search of old posts on here, found the trouble. Inside of 90 and tee has failing caulking. Ever since the install, the venting has been the only problem. So, I took everything off and went and bought new vent, this time with the gaskets in it. Our old stuff had no gaskets. Letting the stove adapter silicone set up, then going to test it. Keeping my fingers crossed.