Braking, the brake cylinder through the brake pads to the brake disc to exert a force F, and the rotation of the brake disc from motion to static, this time between the brake disc and the brake pad there is a relative speed V. F × V = vibration frequency, the sound is due to vibration caused. Here is the concept of a critical value, that is, when the vibration frequency is higher than the critical value, we will hear the brake produced abnormal sound.
When the vibration frequency does not reach this threshold, the resulting sound is that we can not hear it. This is the brake sound.
The noise generated during braking is shown in Figure A
Cause Analysis of Abnormal Sound of Brake
1, by the contact surface is not enough to cause abnormal sound (contact surface is not enough, the brake will increase the pressure per unit area)
A) because there is no disc caused by brake pads abnormal sound.
Brake pads abnormal reasons Summary:
1, the new car running, which brake pads run is a very important part, usually run hundreds of kilometers later, in order to feel the brake will be more comfortable;
2, the new brake pads also need to run through with the old disk to better combination, just put on the time, will feel very hard brakes, usually also need to open hundreds of kilometers to feel better;
3, the vehicle driving, there may be very small sand into the middle of the film and disk, and sometimes because of friction abnormal sound, this situation generally do not need maintenance, run a small sand to fall out All right;
4, for the non-running and abnormal sound, there are owners simply run up brakes, so you can run in a short time brake, but this will make the brake pads wear more powerful, that is, equal to the reduction of the brake pads Life, so it is recommended that you still run for some time to observe, do not go to the artificial wear brake pads;
5, the brake disc of the fixed screw is lost or damaged, will cause the brake abnormal sound;
6, the brake system failure, which requires inspection and maintenance.
Brake pads abnormal solution:
As the brake pads are abnormal for many reasons, for example:
A-brake pads are too hard.
B-brake pad wear level remains.
C-brake disc or brake hub wear is too large.
D-brake cylinder rust.
E-hand kill line does not live.
F-kill the main pump back to slow and so on.
So the method is not the same, the possible situation and approach are as follows:
Brakes are ringing:
If the brake is abnormal sound is screaming, the first thing to check is to despise the brake pads run out (alarm film sound). If it is a new film, then to check whether there is a foreign body was caught between the brake disc and the film.
When the brake disc wear abnormal, this is due to the brake disc surface dirty, brake disc material density is not uniform, too high operating temperature, brake disc installation torque does not match.
Check that the brake disc must be inspected before replacing the brake pads; check the brake disc thickness with a caliper; reinstall the fixed brake disc bolts; measure the brake plate work surface flatness.
High frequency sounds sharp, when the brake disc and brake disc vibration frequency of the same, they resonate produce screams.
Check the calipers: whether the rails are smooth, the piston oil seal is damaged; all the anti-noise clips and brake pads are suitable, the installation is correct; brake pads are too smooth, whether overuse.
If it is muffled, mostly brake calipers, such as the activities of pin wear, spring off and so on.
The caliper noise, caused by the vibration of the caliper assembly, may also be caused by the vibration of the suspension system. New car calipers or suspension systems have a slight shock, early morning sensitivity, such as winter morning, especially common. Check the calipers, suspension systems and bushings.