What is the maximum allowable depth for a groove in a drum or rotor?

The maximum allowable depth for a groove in a drum or rotor is critical for maintaining the proper functioning of the braking system. A groove that is too deep can compromise the surface area of the brake pads or shoes, leading to reduced braking efficiency and potentially unsafe driving conditions.

The correct depth, which is .015", allows for minimal wear while ensuring that the brake components maintain adequate contact. This depth helps in dissipating heat and maintaining a stable braking performance without causing excessive wear on the pads or shoes.

Choosing a depth greater than .015" might lead to issues such as decreased braking effectiveness, increased vibration during braking, or premature wear of brake components. This is especially significant during inspections, where ensuring parts are within recommended specifications contributes to overall vehicle safety.