1. Abnormal sound: When braking, if you hear a high - pitched squeaking or grinding noise, it could be a sign that the brake lining is worn. The squeaking sound is often an indicator that the wear - indicator tab on the brake lining is making contact with the brake rotor or drum, alerting you that the lining is approaching the end of its service life. The grinding noise may suggest that the brake lining has worn down to the point where the metal backing plate is in contact with the braking surface, which can cause serious damage to both the brake components and the vehicle's wheels.
2. Reduced braking performance: If you notice that your vehicle takes longer to stop than usual, or if you have to press the brake pedal harder to achieve the same braking effect, it could be due to worn - out brake linings. As the brake lining wears, the contact area between the lining and the brake rotor or drum decreases, reducing the frictional force generated during braking. This results in a longer braking distance and a less - responsive braking system.
3. Vibration or pulsation: When applying the brakes, if you feel a vibration or pulsation in the brake pedal or steering wheel, it may be related to uneven wear of the brake lining. Uneven wear can cause the brake pads or shoes to contact the brake rotor or drum unevenly, creating an inconsistent braking force. This can also lead to damage to other brake components, such as the brake rotor, which may become warped due to the uneven pressure.
4. Visible inspection: You can visually check the thickness of the brake lining. For disc brakes, you can usually see the brake pads through the wheel spokes. If the thickness of the brake pad is less than the recommended minimum (usually around 3 - 4 mm), it's time to replace the brake lining. For drum brakes, you may need to remove the wheel and inspect the brake shoes. However, this requires some mechanical knowledge and tools. If you're unsure, it's best to have a professional mechanic perform the inspection.
5. Indicator lights: Some modern vehicles are equipped with a brake - wear indicator light. When the brake lining reaches a certain level of wear, this light will come on, notifying you that it's time to check or replace the brake lining. However, not all vehicles have this feature, so it's important to be aware of the other signs of brake lining wear as well.