After replacing the brake pads, many people feel that the brakes have become soft, and some even suspect that the brake pads may not be properly installed. Actually, this is a normal phenomenon. Don't worry, the car will return to normal after driving for a period of time. But if the brakes become soft and there is abnormal noise, it is necessary to check, as there may be a situation where the brake pads are installed upside down. It is almost impossible for brake pads to be installed incorrectly. Below, I will explain the reasons why the brake becomes soft after replacing the brake pads under normal circumstances.

Simply put, it is caused by the uneven surface of the brake disc, which reduces the contact area with the brake pads. How did the brake disc become uneven? Braking is the braking force generated by the friction between brake pads and brake discs. Brake discs are made of metal, and the friction material of brake pads also contains metal powder. If the metal particles are relatively large, the brake discs will be severely worn. Friction between the same materials results in the greatest damage to each other. If there are more than one metal particles in the brake pads, the brake discs will be ground into deeper grooves. Although there are grooves, they are all worn out from old brake pads, and there is still a large contact area between the brake discs and the old pads.

If a new brake pad is replaced, the surface of the brake pad is very flat, while the surface of the brake disc is uneven. Only the protruding parts can contact the brake pad, and the groove parts cannot contact the brake pad, resulting in a smaller overall contact area between the brake pad and the brake disc. As the contact area decreases, the braking force will inevitably decrease. Therefore, after changing the brake pads, special attention should be paid to the braking distance within a few hundred kilometers. When parking, it is necessary to apply the brake a bit in advance. Generally, after driving two to three hundred kilometers in the city, it will return to normal. If you want to quickly return to normal, you can find an open area and press the brake a few times as the speed increases, and you can immediately return to normal. It's generally not necessary to do this, just use it normally and stick to a few hundred kilometers. After replacing the brake pads, some cars have noticeably softer brakes, while others are less noticeable, depending on the smoothness of the brake disc surface. If there are many grooves on the surface of the brake disc, the softening of the brake will be more obvious. If there are few grooves, it may not be very obvious, and even abnormal braking may not be felt.

Is it abnormal for the surface of the brake disc to have grooves worn out? Not necessarily, it depends on the depth of the trench. Most vehicles are normal. If there are two or three very deep grooves, it may be a quality issue with the brake pads. You should go to the 4S store for inspection and confirmation, and replace the brake discs if necessary. If the groove is not too deep, it is normal, and almost all cars will have slight grooves. Another thing to note is not to use fake brake pads. Genuine brake pads generally do not have problems, while fake brake pads often have more problems. In fact, there are many secondary brake pads on the market, so it is best not to replace them with too cheap ones, or go directly to the 4S store to replace them.

From: WONDEE Autoparts

2024-5-10