Power valve transfer bushing?

[Hoss]

There is a rubber seal between the power valve and the bushing, but none where the bushing goes into the Barrel.
What keeps it from leaking air?  Should I put some kind of sealant on it, or maybe a small o ring? Looks like it should be made air tight.

Thanks!

[Sweller]

Theory: The sleeve relies on the pressure from the gasket pushing it against the barrel. Assuming the two mating surfaces are both smooth enough, the seal should be good. They don't even need to be perfectly parallel because there's enough give in the gasket to make up for any misalignment. A thin film of oil should help a lot, too.
End of theory.

Ever played with two wet microscope slides? I recall the phrase "stiction." Once the bane of all hard disk drives.

[BillK]

I have used these for a few years.  I don't know if they make much difference.  Seems like a good thing to do.
https://www.gmaccustomparts.com/epages/BT3197.sf/en_GB/?ObjectPath=/Shops/BT3197/Products/007-0902