Why do my brakes squeal when I back up?
Squeal in reverse only is a known quirk of disc brakes — the pad sits at a slightly different angle to the rotor going backwards, which can make it vibrate audibly. If it only happens in reverse and goes away in drive, it's annoying but harmless. If you hear scraping (not squeal) in reverse, that's worn pads and needs immediate attention.
Get a free AI-ranked diagnosis for your exact year, make and model — with fair repair cost ranges and DIY-vs-shop guidance.