Why is there still abnormal sound after new brake pads are replaced?

Usually, the abnormal sound and vibration of the brake system are not caused by the defects or quality defects of new parts. The reason that is often neglected may be that other parts of the brake system are abnormally worn. As time goes by, they are constantly deteriorating, thus causing poor operation of the brake pads and brake discs in the end.

During the operation of replacing brake discs and brake pads, we always recommend that not only the two main worn parts of the brake system should be replaced simply, but also the system itself should be inspected and maintained more comprehensively.

In general, the following operations are recommended:

If the brake pads are replaced, the wear state of the brake discs shall be inspected.

If the brake discs are replaced, the brake pads shall also be replaced.

Clean the fitting surface of the brake disc/hub (rust or dirt).

In case of any accumulated material or dirt (other than the new brake disc), it is also necessary to clean the brake surface of the brake disc.

Check the vibration of the brake disc installed on the hub. Generally, the value shall not exceed 0.10 mm. In case of any problem, check the vibration value of the hub. The value shall not exceed 0.05 mm.

Anti-noise gaskets are used correctly when the brake pads are replaced. If the new brake pads have been equipped with anti-noise gaskets, never reuse the old gaskets.

Check the piston, seal, dust cover and sliding parts on the brake caliper, to ensure that they are not damaged or corroded and can slide. Use special grease suitable for each part and avoid affecting rubber parts. Replace deteriorated parts.

Clean the contact surface between caliper bracket and brake pad, and apply anti-noise grease.

Check and clean the circlip of the brake caliper. In case of aging or wear, replace it with a new part.

Check and ensure that the circlip is in the correct position.

Check and ensure that the brake fluid level is between the lowest and highest marks. Brake fluid shall be replaced every two years or according to the manufacturer's regulations.

Use a torque wrench to tighten the hub screws as per the correct tightening torque in the correct order.

Carry out a short test drive on the road, to ensure that the equipment can run correctly, without vibration or noise. The crucial point is that the driver should drive in the running-in period of about 300 km. During this period, try to avoid vigorous and rapid braking, so as to ensure that the brake disc and the brake pad can fit effectively.

These simple but important inspection and maintenance operations performed on the brake equipment can effectively avoid the common problems that affect the comfort. Such problems sometimes occur even when driving only a few kilometers after parts are replaced.

These necessary operations involving active safety components of vehicles are simple but often ignored. Therefore, in addition to selecting high-quality parts, very detailed and professional procedures shall be adopted for operation.