What would an excessive brake run out disc cause?

Excessive brake runout in a disc can lead to uneven braking performance, resulting in vibrations or pulsations felt in the brake pedal during use. This can cause premature wear on brake components, including pads and rotors, ultimately reducing their lifespan. Additionally, it may compromise vehicle safety by affecting the ability to stop effectively, increasing the risk of accidents. Regular inspection and maintenance are essential to mitigate these issues.