Nowadays, the car braking system is very mature, and it is rare to see the brake failure of private cars. However, in the unfortunate event of a brake failure, what should I do? Let's talk about this today. How much do you know about the braking system of a private car? When you press the brakes, all four wheels brake together. The braking system assigns more braking force to the front wheels, with a typical front and rear braking force distribution ratio of 7:3 or 6:4. Private cars have a braking system with two tubing, each of which controls two wheels, and one failure does not affect the normal operation of the other. Most private cars have handbrakes that control the rear wheels, with handbrakes driving calipers directly with steel wire and electronic handbrakes driving brake calipers with electric motors. Once you understand the above, you can explain in detail how to deal with sudden brake failures.
1, the brake "does not work when the braking system occurs in special circumstances, inexperienced drivers are sometimes prone to think that the brakes fail, and some people pessimistically give up self-help and waste valuable opportunities. The following situations can easily be mistakenly judged as the brakes not working.
(1) Under special circumstances, the force of the brake is usually determined by the weight of the brake we step on. Gently stepping on the car to slow down slightly, or stepping down hard to slow down, you can clearly feel the deceleration sensation caused by stepping on the brakes with various forces. This is called the foot feel of the brakes. However, once ABS is launched, the situation changes. The ABS system actively controls the brake pressure. In particular, the ABS pump hardens the brake pedal when adjusting the pressure and shakes violently. At this time, the brakes did not feel like a foot at all. If the road condition is good, it is fine, but at this time, the braking force of the car is very large, and you can feel that the car is slowing down, so it will not be mistakenly judged that the brakes do not work.
In special circumstances, I was afraid to step on ABS, and it felt like the brakes really didn't work. The most common is to step on ABS on low adhesion roads. The friction on the road surface is too small, and the braking effect is not good. AbS also brakes frequently after starting, making it difficult to create effective friction between the wheels and the ground, with the result that the car has no brakes at all. It can be said that at least 80% of beginners who encounter this situation mistakenly believe that the brakes have failed. What should I do if this happens? This is handled on a case-by-case basis. The first is the snow-covered roads. In this case, honestly there is no good way but to prevent it. For example, slow down the speed, pay close attention to the road conditions, slow down first, and at the same time try to control the brakes with the throttle, and when decelerating, step on the brakes steadily, and try not to get out of ABS.
In addition, there are special cases such as road surface vibration lines and wet road surface markings. In this case, ABS is easily induced. The reason is also very simple, the wheel bounces violently when it passes the vibration line, the ground pressure is unstable, and the contact area between the wheel and the vibration line is not enough, and the brake is easy to clamp and induce ABS with a slight step on the key. The original friction on the surface of the road surface is small, and the friction is smaller after dipping in water, which is easy to induce ABS. The best way to deal with this situation is to first relax the brakes, stop the ABS, and jump out of the dead loop. Then re-brake. At this point, there is a considerable probability that the wheel will leave the vibration line or pavement marking line. The brakes will work fine.
2) The disappearance of the vacuum assist is also particularly easy to misjudge the situation that the brakes do not work. Many people mistakenly think that if there is no assistance, the brake pedal will become very hard, and the usual force will not be able to step on it at all, so the brakes will fail. In fact, the brakes do not work at all. The brake booster pump and the brake booster pump are still connected, but there is no boost. Generally there is no vacuum assist because the engine is turned off, and what should be done at this time is to restart the engine as soon as possible. If the engine really can't start fully because of the fault, the manual car can step on the clutch directly on the gear, release the clutch, and drag the drive wheel to the engine to force rotation. If the engine is running, the boost will soon be restored. If it is an automatic transmission car, you can fully step on the brakes, and if you do not have the strength to tie the machine on your hand, you can step on enough braking force. If your car is equipped with an electronic handbrake, it's easier to deal with. As long as the button of the electronic handbrake is lifted continuously, the emergency brake will start. At this time, the ABS pump actively provides braking pressure for emergency braking. This braking force is about 80% of the maximum braking force of the braking system and can be used in full emergency situations.
3) There is a problem with a single circuit I just said, the brakes of private cars are dual-circuit systems. If there is a problem with the circuit such as the rupture of the brake line during driving, the brake pedal will become lighter, the braking force will drop sharply, and there will be the illusion of brake failure. Please don't panic at this time. There are also two wheel brakes that work properly, and all we have to do is do our best to slam on the brakes. This is normal even if the brakes become softer or the brake pedal travels longer. A tube loses its pressure, don't worry, just press the brake pedal. However, at this point the distance to brake may be twice as far as before. 2, the real brake failure In addition, the brake system is really problematic, and the brake pedal may not be able to fully control the brake. This is a very dangerous situation. In this case, what should I do? There are still ways.
1) When there is an electronic handbrake, please try the emergency braking function of the electronic handbrake, although this method is not guaranteed to be completely useful, it may be really useful in some special cases. For example, in some cars, air enters the brake booster pump and the brake fails, but the air is only present in the brake booster pump, and there is no air in the line between the ABS pump and the brake booster pump. At this time, even if the ABS pump is operated, it is theoretically possible to transmit braking force to the brake caliper. Moreover, the emergency braking of some electronic brakes is achieved by repeatedly driving the brake calipers with an electric motor, and as long as the brake pads or brake discs are not broken, the system will always work.
2) Handbrake can also be used for emergency braking If your car is handbrake, you can press the release button of the handbrake and pull the handbrake tightly to help slow down. Why do you want to press the release button of the Handbrake? This is to prevent rear wheels from being locked. Because if you don't press the release button, the hand brake will be pulled up and stuck. In case you pull too hard and the rear wheels are just hanging on to death, the car will soon be easy to tail. At this time, if you release the handbrake again, it may be too late. Press the release button to pick up the brake lever and no longer lock, you can correctly adjust the braking force, and stop safely.
3) Using engine brakes Engine brakes can be decelerated, but the process is longer, and the higher the speed of the car, the longer the deceleration time. Therefore, when road conditions permit, it is possible to use engine braking to slow down. If the road conditions do not permit, the engine brake can only reduce the speed as much as possible to reduce collision damage. The key to decelerating with engine brakes is that the lower the gear shift, the greater the power of the engine brakes, so try to use low gears. If you can put it in a lower microwave oven during operation, please only hang it. At this time, please do not worry that the engine speed is too high and has no effect on the engine. And the higher the engine speed, the greater the power of the engine brake, and the better the deceleration effect. Automatic cars don't have much skill. If there is manual mode, you can hang in manual mode and control the joystick downshift. Although there are also cars without manual mode, there are l-gears, low-speed gears such as D3 and D2, and you can hang them directly.
The manual transmission car is a bit complicated, and the owner needs to downshift itself, but fortunately, the current manual transmission is equipped with a synchronizer, and it is easier to downshift. At a speed of around 120, the fourth gear is easy to hang. At a speed of about 80 kilometers, the third gear is also easy to hang. After attaching the corresponding gear, the clutch is immediately released and then the engine is braked. At this time, please use the handbrake at the same time to slow down the vehicle as soon as possible. After the speed drops and the engine speed drops, it must be downshifted immediately to maintain sufficient engine braking power. If the manual gear cannot be hung, you can clutch it with both feet without panic and assist in gear reduction. At this time, the inability to enter the low gear is mainly because the speed is too high, the engine speed corresponding to the low gear is too high, and it takes time to complete the speed synchronization of the synchronizer. Speed synchronization is possible quickly via clutch operation on both feet. It's easy. For example, if you want to hang from 3rd gear to 2nd gear and find that the control lever cannot be pressed into 2nd gear, immediately release the clutch, make the lever neutral, and then press the throttle to the end, quickly releasing the throttle after the engine speed rises, at the same time
Although so many coping methods have been summarized, none of them are as good as the feet that the car steps on normally. Therefore, it should be reasonably maintained, regularly check the condition of the car, find the danger in time, and prevent problems before they occur. Otherwise, when the real brakes fail, even if we have so much theoretical experience, we may not be able to retreat. So how to check the brake system? I think the simplest and most effective methods are the following three: 1. Check the remaining amount of brake oil, ensure that the brake oil level is normal, and prevent the brake oil from being insufficient and causing the brake system to restart. 2. Regularly check the wear of brake pads, and replace the brake pads that reach the wear limit in time. 3. Check the brake booster pump tubing. This is where problems can easily occur. Since the brake booster pump follows the wheel, the separation pump and the brake piping of the body can only be connected with a rubber hose, and the rubber will age. The wheels of the car move frequently relative to the body during driving, and the rubber tube is also more likely to have problems with compression and elongation. Therefore, it is usually best to pay attention to checking the brake rubber pipe, if there is damage, cracks, replace it in time.