Why does the front brake rotor get hot after driving? Is it normal?
Disc brake rotors are made of cast iron not steel. Rotors act as a heat sink. Thicker and larger diameter rotors carry more frictional heat from the brake pads. During normal driving even though your foot never touches the brake petal, pads are lightly contacting the discs as you drive. This is to keep dust dirt and moisture off the pads and rotors. If we were all lucky enough to have an optical pyrometer, you could quickly take the temperature of your brake rotors after a drive to see if both front rotors were the same temperature, and how closely the two rears matched. If both front rotor temperatures didn’t match, the slider pins or calipers may be sticking which causes excess heat. Same with the rear rotors. If you have sensitive hands, you could feel any difference in rotor temperature by opening both palms, 6″ away from the street side spokes on your aluminum wheels and compare the heat with the opposite rotor.
