ASE Brakes Certification Practice Exam 2025 – Complete Study Resource

Visible grooving or scoring on the surface of brake rotors is a crucial indicator of wear. This type of wear often occurs due to prolonged contact between the rotor and brake pads, especially when pads are worn down or there are contaminants on the braking surfaces. The grooves can increase stopping distances and reduce the effectiveness of the brakes, leading to uneven wear and potentially dangerous braking conditions.

In contrast, staining on the rotor surface may occur due to overheating but does not necessarily indicate functional degradation. The increased weight of the rotor typically does not correlate with wear; it could be related to the rotor material or design. Similarly, decreased friction material thickness pertains to the brake pads rather than the rotors themselves and does not directly indicate the condition of the rotor. Understanding these signs is essential for routine brake maintenance and ensuring vehicle safety.