My brothers 1976 Honda motorcycle CB750K6 has squealing brakes. Already sanded rust and used Brake Clean.
Front brakes, or rear brakes? Score up the brake pads, or shoes with coarse sand paper. Then clean them with brake cleaner. Even though you used brake cleaner, the brakes can become glazed and not grab the disc, or drum. That would cause them to slide around and vibrate.
The brakes squealed from brand new on my '75 CB750F. I later had a '69 with aftermarket pads that didn't squeak as much. On the front, try loosening the little lock nut and turning the caliper adjusting screw until the stationary pad just barely touches the disc. That may or may not help.
OK so what's the question? or are you just stating a fact.
