I've told the story before but worked on a friend's Mustang, decades ago, she'd been calling me for weeks telling me how the brakes were making a terrible noise. Kept urging her -bring it to me so I can fix it- but she'd put it off. Warned her the longer she waits, the more expensive it gets. Eventually calls and says well the noise stopped but the car is also really hard to stop. Big surprise right?
On those older Fox body Mustangs there's an ignition module that when it goes bad a common issue is it raises the idle to around, oh, 1200rpm. Hers was bad. Couple that with her driving the front brakes metal-on-metal until the calipers ate all the way through the rotor face and literally broke the rotor away from the hubs, so the rotor rings were hanging on the control arms, both sides, calipers locked up on them with the piston hyperextended. She was stopping that 1200rpm idling POS with just the back brakes.
When I pulled the rotors off, I could pry little triangular pieces of them out of the cooling vanes on the back side where they hadn't been completely eaten through, front side went first. Replaced rotors, put new pads in, and went to compress the piston. POW seal blown and brake fluid sprayed all over the place including the fender of my '69 Chevelle parked next to it.
Some quick action with the water hose kept damage to a minimum.
Rebuilt the calipers as parts-house rebuilds didn't exist back then.. popped them apart, cleaned everything up, new seals and boots, everything back together, replaced the ignition module which requires that weird little stubby screwdriver tool, and DONE..
Richard