EGR tube seal (early version)

[js18018]

I have a 1997 Ranger with a 4.0 V6 that I'm replacing valve cover gaskets on. Not the most enjoyable job but part of that is removing the upper intake manifold. The EGR tube that goes into the manifold has a black rubber seal with two barbs on it that goes into the manifold but the old one was so old that it simply looked like two o-rings side by side even though it was one piece. The new gasket I got from the Ford dealer showed to Barb's on the outside edge but I'm not sure which way the barb should face when it's reassembled. Unsure if the barb should face into the manifold or away from the manifold. I'm thinking away from the manifold so that vacuum in the manifold would tend to pull them tighter and make them more effective seal but in the automotive world logic does not always prevail. So I thought I would ask the people here who have probably already been down this road before. Any thoughts or information to ease my pain would be much appreciated.

 

[franklin2]

Your seal lip theory is correct. As the pressure or vacuum pulls on the lip or barb, it should squeeze it tighter and make it seal tighter.

 

[js18018]

Appreciate the response. I have seen some people recommend some RTV on the seal on installation but see that as a bad idea. If RTV does survive the heat from the tube, it would make it a real bear if it ever has to come apart again.
Appreciate the information shared here.

 

[lil_Blue_Ford]

Moved to the appropriate location