I had zero squeal for a long time, then changed out the tire (had to remove the pads and calipers) and got squeal. Bought new pads as the old ones were done, ends up the scraper was actually touching the disk, but no metal to metal contact yet. Still have the squeal.

Before installing the new pads, I cleaned the pads with Walmart’s brake cleaner spray as well as the disks.

Removed the pads and sanded them with a DA 220 grid sander and scuffed the disks with the same.

Worked great for a 1/2 day, then back to squeal.

Each time a full cleaning of the contact surfaces (pads and disks).

These were supposed to be the same exact pads as I ordered last time (based on Amazon order history). I did notice that these didn’t come with the metal scraper and were a single section (no divider in the middle of the contact patch).

Q. What caused squeal and what can I do that I haven’t already done?

What about that blue goop stuff they used to put on the back of pads back in the day?

Note: Honda 919 motorcycle, all stock braking system and suspension.