What causes a loud noise when pulling the electronic handbrake at low speed?
3 Answers
Reasons for a loud noise when pulling the electronic handbrake at low speed are as follows: Manufacturer's issue: For example, inconsistent friction block dimensions of the same model of brake pads, especially the width. Some manufacturers may have size deviations of up to three millimeters. This results in the brake disc surface appearing smooth, but if a larger-sized brake pad is installed on a brake disc previously used by a smaller-sized pad, it will still cause noise. In such cases, the brake disc needs to be resurfaced first. If not resurfaced, driving for a while until the marks align can stop the noise. Metal scraps stuck in the brake pads: If a sudden noise occurs after driving for a while, it is mostly due to hard objects like gravel or metal scraps getting stuck in the brake pads when braking. In such cases, cleaning at a 4S shop is recommended.
Having driven for many years, I've encountered similar situations. The loud noise when pulling the electronic handbrake at low speeds is usually caused by the sudden clamping of the brake caliper onto the disc, resulting in a harsh impact sound. The electronic handbrake is designed to be used only when the vehicle is completely stationary. Operating it while moving forces the system to perform emergency braking, causing the caliper to fully lock onto the disc, with metal violently rubbing against metal, producing a tremendous noise. Worse, such misuse can lead to scratches or deformation on the brake disc surface, and the drive motor inside the caliper may also be damaged. Over time, braking performance will decline, and repairs could easily cost thousands. Once, a friend did this and nearly caused an accident—fortunately, only parts were damaged, but the safety risk is too high. Remember, never operate any electronically assisted braking system while the vehicle is in motion; the parking function is only for static conditions. Develop good habits in daily use—safety should always come first.
The root cause lies in flawed design logic. The electronic parking brake is designed for stationary use. Activating it during low-speed driving may trigger the system to misinterpret it as an emergency demand, commanding the brake calipers to clamp abruptly. The result? The rotor and caliper collide violently, producing a piercing screech while potentially leaving permanent grooves on the disc or loosening caliper components. I've handled several similar cases where owners complained about severe brake vibration after the loud noise, later traced to warped rotors. Additionally, while the vehicle's electronic control unit may have protective measures, triggering during high-speed or hard braking will still cause noise. It's advisable to decelerate and stop promptly, then check for reduced braking effectiveness or persistent noise. Schedule a comprehensive diagnosis at a reputable service center, and always consult the owner's manual for proper operation guidelines to avoid such errors.
