Brake rotors do not need replacement as often as brake pads. But knowing when to replace brake rotors prevents costly damage and maintains braking performance.
Signs It Is Time
Vibration or pulsation. If the brake pedal vibrates when you press it, the rotor may be warped. Warped rotors cause uneven contact with the pads.
Deep grooves or scoring. Visible grooves on the rotor surface mean the pads have worn down to the metal. This damages the rotor and requires replacement.
Blue discoloration. Overheating turns the rotor blue. This means the metal has lost its temper and is weaker. The rotor may warp or crack during use.
Thickness below specification. Each rotor has a minimum thickness stamped on it. If the rotor is below that number, it must be replaced.
When to Replace vs Resurface
Thin rotors must be replaced. Rotors with minor surface wear can be resurfaced if they are still thick enough. But resurfacing removes material, so it can only be done once or twice. Many shops recommend replacing rotors instead of resurfacing because the cost is similar.
Replace with Every Other Pad Change
Many mechanics recommend replacing rotors with every other brake pad change. This prevents the rotor from wearing too thin and ensures the new pads have a flat surface to contact. If you install new pads on worn rotors, the braking performance is reduced and the pads may wear unevenly.
Cost
Replacing brake rotors costs $150 to $200 per axle on top of the pad replacement cost. This brings the total brake job to $250 to $500 per axle.
