I just noticed this as a result of your post. I don't know if all of the holes will ever clear by themselves. Even if they do, there's no guarantee they'll stay unclogged. Brake shoe compound will likely clog them again. Some of my holes are clogged with loose particles that can easily be cleared. However, some holes seem to be packed tight. I have more than twice your mileage and I'd say about 1/4 of my holes are clogged. Will they all clear over time? Your guess is as good as mine. I guess you could drill them, if you're that intent on clearing the holes. But I doubt if that would last very long. Personally, I'm not losing any sleep over this one.
Last edited by GLE43_Sube; Jun 5, 2017 at 04:34 PM.