Why Does the Brake Squeak?

[Judith]

Brake squeaking may be caused by the following reasons: 1. Poor quality brake pads: If the brake pads installed are not provided by a legitimate manufacturer, or if the owner purchased inferior quality brake pads, a squeaking sound may be heard when braking, and the brake disc may also be damaged. 2. Foreign objects in the brake disc: When driving on complex road conditions, it is easy for the wheels to fling up stones or other foreign objects. If a stone gets lodged between the brake pad and the brake disc, abnormal noises will occur during braking. 3. Severe wear on the brake disc: When the surface of the brake disc is uneven, the friction between the brake pad and the uneven brake disc will produce a squeaking noise.

[OKatherine]

Driving older cars often involves encountering squeaky brakes, a pattern I've noticed since driving taxis 20 years ago. When brake discs get rusty in rainy weather, they tend to squeak, and the same happens when they're wet after washing the car without drying properly. Newly replaced brake pads may 'sing' for the first 200 kilometers, which is the resin material breaking in. More commonly, sand or small stones get stuck between the brake disc and pad, causing a squealing noise like sand in a bearing. Additionally, when brake pads wear down to expose the metal, they emit a sharp warning sound, signaling it's time for a replacement. In such cases, I usually listen to whether the noise occurs during light braking at startup or only during hard braking, as identifying the type of issue can save on repair costs.

[JadeDella]

Last time I took my car for maintenance, I asked the mechanic about brake noises. He said there are two types. One is a high-pitched screeching sound, which usually means the brake pads have reached their replacement limit. The metal wear indicators will squeal when rubbing against the rotor to alert you - otherwise metal-on-metal contact can damage the brake disc. Dust and dirt on the brake discs can also cause this, especially after rain when rust forms easily. The other type is a low-frequency squeaking noise, often occurring when lightly braking at low speeds. This is most likely normal break-in noise from new brake pads that disappears after driving a few kilometers. Remember the front brake calipers need regular maintenance, otherwise sticking guide pins can also cause noise.

[VanKate]

Most brake noises in family cars are related to the brake pads. Recall when you last replaced them; if it's been over 25,000 kilometers, it's time for an inspection. Especially after rain when the brake discs rust, the first brake application will inevitably produce a squeak as it grinds off the rust. Additionally, many factory-installed brake pads now contain metal fragments—they're harder but prone to squeaking, though this doesn't affect safety. If a small stone gets stuck, it may cause a rattling sound, which can usually be ground away by braking hard a few times. Most critically, if you hear a metal scraping sound, you must inspect it immediately. If the metal wear indicator is exposed and not replaced, it can damage the brake disc, requiring a full replacement costing thousands.