Here's a bizarre doodle I've had to draw 3 times over the life of my truck.
Ya see, somethin' broke in the drum brake assembly of my rear passenger wheel. My dad and I JUST replaced the brake shoes and hardware kits on both rear wheels over the summer. But somethin' broke, and miscellaneous pieces were rollin' around squealing in the brake drum for a couple days. The day after Christmas we fixed it, but brake drums are completely asinine in structure - they require a drawing so we know the order in which all the pieces and springs go together. It's a delicate house of cards with all the parts holding on to each other with springs and cables. The whole mechanism floats around and it hardly seems like a precision piece of equipment that's responsible for your brakes.
And so, I guess that's why they invented disc brakes.