Originally Posted By: HTSS_TR
No, brake rotors are not needed to be replaced when you need to replace brake pads. You may need to resurface the rotors when you replace brake pads. If it is at minimum thickness before resurfaced, then it is needed to be replaced.
Actually, a rotor that is at or below minimum thickness after resurfacing should be replaced.
I prefer to replace the rotors at every brake job. Resurfacing the rotors costs between 15-20/rotor, and for an additional $60/axle, I can have new parts.
But generally, the criteria for rotor replacement is the following:
1. Excessive corrosion
2. Rotor at or below minimum thickness
3. Heat damage
4. Damage due to operating with worn-out pads.