Bontrager tubeless valve problem

After taking advice off you helpful people I turned my bontrager wheels into a tublesss setup. After initial problems getting my xdx tyres to inflate changed to some nevegals and they inflated like a dream however I have air escaping a very small amount between the valve and rim. No matter how tight I put the nut on there is still a small amount. I can complete a ride easily without having to reinflate but its getting a bit tedious having to pump up before every ride. Has anyone else had this problem and any solutions on a fix.
Regards Paul

Not with bontrager bits, but I wrapped ptfe tape around the base of the valve when I converted my wheels to tubeless.
I aimed to get it partly over the rubber ‘seat’ and a short way up the actual valve stem.

Not sure if it made a difference or not, as I did it from the start in a belts-and-braces type way. But it worked.

Yes, I’ve had this exact problem with two different causes.

The first thing to check is that the “oval” bit of the valve stem is properly seated into the shaped bit on the rim strip.

I have also had the edge of the rim strip split and fold over under the tyre bead. This had me scratching my head for ages as it appeared to be leaking at the valve but in the end wasn’t. The air was getting under the rim strip and exiting at the valve hole! The cure was to remove the tyre, push the folded rim strip back into place and refit.