Michigan State Brakes Certification Practice Exam

Squealing brakes are commonly associated with issues directly related to the braking system. Worn brake pads and glazed brake pads both commonly produce noise when brakes are applied. Worn brake pads can create a squeal as the friction material diminishes, and glazed brake pads, which can occur from overheating, tend to create a hard surface that may also cause squealing against the rotor.

Improper brake installation could also lead to squealing noises. If brake pads are not installed correctly, they may make contact improperly with the rotor or may not sit properly in the caliper, leading to noise during operation.

On the other hand, defective wheel bearings typically do not cause brake squeal. Instead, they might cause a grinding or humming noise, particularly noticeable when the car is in motion and especially when turning. Thus, while wheel bearing issues can affect vehicle operation, they are not a common cause of the specific noise associated with braking. Therefore, the least likely component causing the squeal when brakes are applied would indeed be defective wheel bearings.