Classification of brake pads and requirements for replacing brake pads
Car brake pads can be divided into two types according to different braking methods: drum brake pads and disc brake pads.
Automobile brake pads can generally be divided into five types according to different materials: asbestos type, semi-metallic type, low metal type, ceramic type, and NAO type (that is, non-asbestos organic type) brake pads.
1. Asbestos brake pads
It was first used on brake pads to improve the strength. Because of its low price and certain high temperature resistance, it is widely used. However, asbestos materials have been confirmed by the medical profession to be carcinogens and are now banned.
2. Semi-metallic brake pads
From the appearance, it has fine fibers and particles, which can be easily distinguished from asbestos type and NAO type. Compared with traditional brake materials, it mainly uses metal materials to increase the strength of the brake pads. At the same time, the temperature control ability and heat dissipation ability are also superior to traditional materials. However, since the material of the brake pad contains more metal components, especially in a low-temperature environment, it will cause the surface wear between the brake disc and the brake drum due to excessive brake pressure, resulting in noise.
3. Low metal brake pads
From the appearance, low-metal brake pads are somewhat similar to semi-metal brake pads, with fine fibers and particles. The difference is that it has a lower metal content than semi-metal, which solves the problem of reducing the wear of the brake drum. The noise is reduced, but the life of the brake pads is lower than that of semi-metal.
4. Ceramic brake pads
The brake pad of this formula uses a new type of ceramic material with low density, high temperature resistance and wear resistance, which has the advantages of no noise, no dust, no corrosion of the wheel hub, long service life, and environmental protection. It is currently popular in North America, Europe and Japan. Its thermal recession is better than that of semi-metallic brake pads. What's more, it improves the average service life of brake pads and is non-polluting. This kind of brake pads has strong market competition in recent years. force.
5. NAO (non-asbestos organic matter) type brake pads
It is mainly developed as a substitute material for asbestos. It has the advantages of no dust pollution, less wear, less noise, and the service life is obviously extended. Compared with asbestos brake pads, its performance is better, especially non-polluting, and the cost is higher, but it represents the current development direction of brake pads.
At present, world-renowned brands such as Ben Deshi and Ferodo are using the third-generation NAO materials. Can brake freely at any temperature, maximum protection, driving safety and prolong the life of the brake disc.
When replacing the brake pads, try to use the same or higher grade of material and friction coefficient as the old brake pads (or the manufacturer's standard requirements). If conditions permit, try to use high-performance brake pads from large manufacturers. Although the price is higher than economical brake pads, the materials are much better, the service life is longer, and of course the safety is much stronger. You can't just pick cheap ones for this kind of thing.
Automobile brake pads refer to the friction material fixed on the brake drum or disc that rotates with the wheel. The friction lining and friction pad in it are subjected to external pressure to generate friction to achieve the purpose of vehicle deceleration. The friction block is the friction material that is pushed and squeezed on the brake disc by the clamping piston. Due to friction, the friction block will gradually wear out. Generally speaking, the lower the cost of the brake pad, the faster the wear. The friction block is divided into two parts: the friction material and the bottom plate. The friction material part can still be used after wear and tear. After the friction material is used up, the bottom plate will directly contact the brake disc, which will eventually lose the braking effect and damage the brake disc. Brake discs are relatively expensive to repair or replace.
For ordinary car owners, the basic requirements for the replacement of brake pads are as follows:
1. High-speed performance and highway performance.
2. High temperature performance and heat recovery performance.
3. Water wading performance.
4. Initial performance.
5. Low temperature performance.