Before and after brake pad wear degree and service life in many times is not the same, under normal driving conditions, the brake pad by the braking force will be relatively large, often wear degree is larger, the service life is shorter, generally about 3-5 thousand kilometers need to be replaced; The rear brake pads bear less braking force, and can be used for longer, generally 60,000-100,000 km need to be replaced. When removing and replacing the coaxial must be returned together, so that the braking force on both sides of the symmetry. If the front and rear brake pads are worn to a certain extent, it can also be changed together with four.

The brake pedals should not be changed individually, preferably in a pair. If you run out of money, consider replacing it with four. All normal is the front 2 change together, after 2 together, but also around the left and right can be changed together.

The car brake pad is generally 50000 km for a change, every driving 5000 km to check the brake shoe once, not only to check the excess thickness, but also need to check the brake shoe damage, the level of damage on both sides is not the same, is not easy to return, found abnormal conditions need to be solved immediately.

So, when exactly should the brake pads be replaced? How to carry out brake pad self-test?

Method 1: Look at the thickness

A new brake pad thickness is generally about 1.5cm, with the use of continuous friction thickness will gradually thin. Professional technical personnel suggest, when the naked eye observation brake pad thickness has only left the original 1/3 thickness (about 0.5cm), the owner will increase the self-inspection frequency, ready to replace. Of course, due to the design of the wheel hub, individual models do not have the conditions to view the naked eye, the need to remove the tire to complete.

Each brake pad on both sides of a raised mark, the mark thickness in two or three millimeters, this is the limit of the thinnest replacement brake disc, if the brake pad thickness has been parallel to this mark, it must be replaced.

Therefore, when the brake pad thickness is close to the mark, the owner will be ready to observe at any time, but it is difficult to accurately observe by the naked eye without removing the tire. At present, many models in the brake pad is too thin instrument brake lamp position will be prompted, relatively self-inspection is convenient.

 When the naked eye observation found that the brake pad is thin, technical personnel should be required to check in the maintenance, because there will be errors in the naked eye observation, professional maintenance stations through the caliper is more rigorous than the naked eye observation.

Method 2: Listen to the sound

If at the same time with the light brake "iron rubbing iron" filar silk sound (may also be the brake pad in the beginning of the installation of the run-in), the brake pad must be replaced immediately.

Because the limit marks on both sides of the brake pad have directly rubbed against the brake disc, it proves that the brake pad has exceeded the limit. In this case, when replacing the brake pad, check the brake disc. When this sound occurs, the brake disc is often damaged. (as shown in the following figure) even if the new brake pad is replaced at this time, the sound still cannot be eliminated, and the brake disc needs to be replaced in serious cases.

In addition, some poor quality brake pads have hard points, which will also produce abnormal sound. In general, the abnormal sound generated by this will disappear after a period of time.

Tip: It is often too late to hear the brake sound, and the brake disc will be more or less damaged. The price of the brake disc is much higher than that of the brake pad, so it is recommended that we check the brake pad frequently to avoid damage to the brake disc.

Method 3: Feel the force

If the brakes feel very hard, it is possible that the brake pads have basically lost friction, this time must be replaced, otherwise it will cause a serious accident.

 In addition, the reduction of brake effect will lead to an increase in brake oil consumption, so the replacement of brake pads should focus on checking the brake oil.