Answer
Do not use coarse sandpaper to resurface brake rotors. For light surface rust only, use 400 or 600 lightly.
Why it happens
Rotors are safety-critical parts. Heavy rust or scoring needs proper mechanical inspection, not cosmetic sanding.
Recommended grit
For light surface rust only, use 400 or 600 lightly on non-critical cleanup areas.
Wet or dry
Dry.
Success check
Only light surface rust is reduced; braking surfaces are not gouged.
What to do
- Inspect the rotor condition first.
- Do not sand deep grooves or damaged braking surfaces.
- Use 400 or 600 only for light surface cleanup.
- Clean residue fully before reassembly.
Avoid: Do not use coarse grit to resurface brake rotors.