TOTO Drake siphon line leaks

I installed a TOTO Drake in a bath remodel back in November 2007. Since then, after an hour or so after flushing, the BLACK siphon line coming from the top of the fill valve that dumps into the white fill pipe develops a steady drip drip drip.

I cant seem to find anyway to flush sediment from the valve assembly the way you can Fluidmasters. However, I have NEVER had any sediment issues before, there wasnt any sediment in the old toilet tank this replaced. I am assuming that perhaps some manufacturing debris may be present in the fill valve, but thats a guess.

Any suggestions?

If it's the Korky style, the repair instructions are here

https://terrylove.com/korky/

If it's the other style, check with Toto and they can send a repair part.

Depending on which refil valve is in your toilet, if it is the Korky version, it is quick and easy to replace the top seal. You can get it at a Lowes for a couple of dollars. Check out www.korky.com to see if your valve looks like that, if so, it will take about a minute or so to fix. Sometimes, just taking it apart and flushing it out works, but often it looks fine, but still leaks a little. The instructions are on the site, and come with the part.

When you say "Korky" style, is that a name i would see on the fill assembly, or just an assembly that looks like it?

I noticed that your instructions for the Korky style indicate that it "could" be a leaking flapper. Is this where I would put dye in the tank, and see if it enters the bowl?

Then I guess that means that I would have to disassemble the whole thing, tank and all from the base, and redo all that maybe one or two more times?