Final answer:
Brake dust and dirt can cause reduced braking efficiency, increased component wear, and noise due to acting as abrasives between the brake lining and drum.
Step-by-step explanation:
Brake dust and dirt between the lining and the drum can cause several issues for a vehicle. These contaminants can lead to reduced braking efficiency, increased wear and tear on the brake components, and can generate noise. When brake pads press against the rotors to slow down the vehicle, heat is produced due to friction. Just as a book sliding across a floor loses kinetic energy to heat by friction, a car also dissipates kinetic energy to heat in various parts, including in the braking process. Brake dust and dirt can act as abrasives, compromising the contact between the brake pads and rotors, thus requiring more force and time to stop the car. This extra force and time not only lead to inefficient braking but also can cause extra heat, which further reduces the system's effectiveness.