Going to share a bunch of information here in case someone goes searching for it later.
So, right before my trip last year to NAFO and YFO I discovered my left front caliper sticking and dragging badly. I had a mad scramble to get a rebuild kit to my house in time and had a caliper pulled and split in half the night before the trip. The motorcycle gods took pity on me and after torturing me right up to the last minute, I got it all back together and the bleeding process went off without a hitch.
I didn't tempt fate and rebuild the right one at the same time. So those parts have been sitting in my garage. Sitting much like my poor FJR. I finally decided that the temperatures were tolerable in the garage and I really wanted to play with brake fluid again, so this past weekend I started pulling the right side apart.
Now let me tell you. You see these little rubber seals?
DO NOT f@$king LOSE THEM!
I won't go into details but yes, one of them went missing. When you split the calipers there is that little donut seal that gets smashed between the two halves to allow fluid to go between the halves without leaking out and going everywhere. Guess what is NOT included in the brake caliper rebuild kit? Yup, those seals. Guess what isn't on the Yamaha parts fiche and can't be ordered? Yup, those seals.
Some searching of the internet led me to a forum, maybe it was advrider, don't know, can't find the thread again, where someone else had the same problem. Turns out Suzuki easily sells these and they are a direct freaking replacement.
It comes with two, I put the third Yamaha one in there for comparison purposes. Then I put them all side by side.
I can tell which one is the Yamaha one because it has a little ridge in the center where it was smashed by the calipers for 15 years, but that's it. Anyway, if anyone needs it, Suzuki part number 69107-17C00 is a suitable replacement if you lose one. Before you freak out, it's only the right one that has two seals because of the linked brakes. This part was available fairly inexpensively and with quick shipping on ebay.
Now this weekend we'll see if she bleeds as easily as she did last year. This might help someone but I hope you don't find yourself in this situation.