Brake squeal is one of those things that the forums either ignore or propose nonsensical solutions to. Sanding the pads or shoes, beveling them, using cleaners or glues or greases--all of that stuff is worthless, and anyone who has made a living working on these bikes every day for any length of time knows it.

Brake squeal may have more than one cause in general terms, but on the SOHC Honda fours just one thing is in view: pad or shoe oscillation. Address this and squeal goes away. And the best way to attack the problem on the disc brake end of the bike is with gaskets. Yes, gaskets. Not glue or grease or whatever. Honda themselves used gaskets in one or two years of the CB750. Yep. They did.

I make mine out of cereal box cardboard. Trace around the pad, cut it out, and place it between the back of the pad and the caliper piston. No squeal. After a few thousand miles the cardboard may compress a bit, and the brake give a peep or two. Just put in a new gasket. You can extend the life of the gasket by coating it with Gaskacinch or by using a coated form of card stock instead of Grapenuts, such as the cardboard license plates new cars and motorcycles come with. I used this material all the time I worked at dealerships.

For drum brakes of course the approach is different. Here the fix is to place an o-ring on the pivot pin behind the brake shoe. Just as with the disc brake pad gasket, the o-ring isolates the resonating shoe from the brake backing plate, eliminating the squeal.

Why haven't you heard of this before? Because forums ars not about helping. Forum influencers are not lifelong veterans of day-in-and-day-out maintenance careers. And the lifeblood of forums is to simply and numbly regurgitate whatever is currently streaming on the major powersports Internet--especially from the aftermarket--whose voices are, like those on forums, unqualified to speak about anything relating to vintage Honda maintenance.