Detailed interpretation of brake disc and brake pad
The surface of the brake disc is usually coated with a black or blue substance, which is used to prevent rust. The brake disc is generated by friction during braking, and its surface temperature can reach more than 500 ℃. The brake disc will generate high temperature during friction. Because the friction surface does not fit the brake drum or brake pad well, it may cause heat recession, resulting in brake force reduction. When driving at low frequency for a long time (the braking frequency is generally not higher than 30 km/h), the braking effect may be reduced, the brake failure, and the brake pad wear may be accelerated. In this case, be careful not to brake for a long time or keep the vehicle at a standstill to avoid danger. The brake disc and brake pad should be checked more often at ordinary times. If they are seriously worn, they should be replaced. We need to remind you that the vacuum tyres can only be installed on cars with tyres of 16 inches and above, so the brake pads must be replaced. New vehicles must be equipped with wheel alignment angle device, and the working condition of wheel alignment angle device shall be checked regularly to ensure that the wheel alignment angle device is in good working condition.
1. Look at the color
This is the most direct identification method. There are different color marks on the brake disc or brake pad to distinguish the added color, but there are also marks on the brake disc or brake pad to indicate the hardness. Generally, the hardness of the brake pad is 35-45 degrees, while the hardness of the brake disc is 60-70 degrees. The thickness of the brake disc is usually about 3 mm, while the thickness of the brake pad is usually about 2 mm. If you find that the thickness of the brake disc or brake pad is less than 1/3 of the original thickness, or if you see a small hole in the brake disc, you should replace it in time. This is not only a sign of insecurity, but also a sign that the brake disc or brake pad is approaching its service life. But please note that if there is only a small hole in the brake disc, it should be worn out.
2. Listen to sound
As we said, the brake disc and brake pad will make friction noise during braking. When you hear the friction noise, you must replace it in time. The quality of a brake disc or pad can be judged mainly from the following aspects: (1) Brake disc: its surface hardness and thickness. Good brake discs have high hardness and uniform surface; Uniform thickness and smooth surface; (2) Brake disc: mainly depends on whether its surface is smooth; Whether there are scratches and damages; Whether the thickness is consistent; The contact surface of good brake pads is flat, free of burrs, and the thickness is uniform. If the brake pad is thin, it will make noise even if it is not used frequently. As brake discs and brake pads are consumables, their thickness will gradually become thinner with the use in normal driving, leading to weakening of braking effect and even brake failure. Therefore, it is very important to check the brake discs and pads regularly during daily maintenance.
3. Look at wear
Touch the brake disc with your hand. If there is a bumpy feeling, it means that the brake pad is too worn and must be replaced; If it is very smooth, it is necessary to check whether the clearance between the brake pad and the brake disc is normal. When it is worn to 0.2mm, it must be replaced. When you feel slight resistance on the brake pedal, it also means that the brake pads need to be replaced.
4. See thickness
When the brake pads of the car are worn to a certain extent, they should be replaced in time. This is because there will be obvious protrusion after the brake pad is worn to the limit. At this time, there is a high probability that the brake will fail and cannot drive normally. To determine whether the brake pads need to be replaced, you can check the thickness of the brake pads. Generally, the brake pad thickness of each vehicle is fixed, and must be replaced when it is worn to a certain extent.
5. Check the wear condition
The replacement cycle of the brake pads will be indicated in the vehicle operation manual. If a new brake pad is found to be worn to the limit mark, or the two pads are almost worn, it needs to be replaced immediately. The thickness of the new brake pads is generally about 1.5 cm. After reaching this thickness, it is suggested that the owners should consider replacing them, otherwise the problem of brake failure may occur. If the wear reaches the limit mark, or both discs are almost worn out. Then it can only be replaced. In this case, it is necessary to repair or replace the tire. So you should pay attention to observe whether your brake discs and pads are worn.