As we all know, there are two sets of braking systems in the car, the foot brake and the hand brake. They have different functions, the foot brake is used to brake while driving, and the hand brake, also known as the parking brake, is only used after stopping to prevent rolling. They also act on different tires, the foot brake is the four wheels brake at the same time, while the foot brake only brakes the two rear wheels, and the front wheel is not braked. There are many people who have this question, is the rear wheel foot brake and the handbrake use the same brake pads, why I only changed the brake pads of the foot brake but never changed the brake pads of the handbrake?
In previous vehicles, if the rear wheels were disc-braked, almost all vehicles did not use the same brake pads as the handbrake. There are two sets of brake pads on the rear wheels, one is the two-piece type used for our foot brakes, which moves through the piston of the brake cylinder when braking, and pushes the brake pads to move, so that the brake disc can be tightened to achieve braking.
The handbrake pads are hidden in the bulging position in the middle of the brake disc, which is a drum brake. When we pull up the handbrake, the handbrake cable will pull the driving mechanism to open the brake shoe outward, and be in close contact with the brake drum around it to generate braking force and realize the parking brake. Therefore, there are both brake pads for foot brakes and hand brake pads for hand brakes at the rear wheels.
And some low-end models, the rear wheel is not a disc brake, but a drum brake, commonly known as the front disc and rear drum. The foot brake pads and the handbrake pads of such models are the same brake pads, because the handbrake is a drum brake, and the foot brake is also a drum type, so it is okay to share the brake pads. However, the control mode is still two sets, the foot brake is still pushed by brake fluid transmission, and the hand brake is still pulled by the cable.
In recent years, there have also been models with disc brakes on the rear wheels, but sharing brake pads, that is, the foot brake pads and the handbrake pads are the same brake pads. However, the control mode is still separated, and the handbrake is still pulled by the pull cable. Now the electronic parking brake has also been widely used, and all vehicles that use the electronic parking brake, the foot brake and the handbrake are also the same brake pads. The electronic handbrake does not need to pull the cable, but is a switch, which controls a motor, and relies on the rotation of the motor to drive the brake pads to hold or release.
Therefore, it can be summarized that some models of foot brake and handbrake share brake pads, and some models are separated. However, the control system is separate, and the foot brake is a system with brake fluid. The handbrake is either a pull cord or a motor. Therefore, in the event that the footbrake fails, the handbrake is still effective.
Of course, if you don't have a certain amount of experience, if the speed exceeds 40km/h, it is best not to brake with the handbrake, and the poor control is likely to cause the vehicle to flick out of control, rush to the side of the road or even roll over. Of course, the electronic handbrake does not require the driver to control the strength, so it can be used when the foot brake fails. To activate the handbrake while driving, you only need to continuously pull the handbrake switch or pull the handbrake switch and hold it for more than three seconds.
Why does the handbrake feel that the braking force has decreased after a period of time, isn't it time to change the handbrake pads? How often should the handbrake pads be changed? For most vehicles, the handbrake pads alone can be kept unreplaced for life. Because it is only used when it is stationary, the wear and tear of the handbrake pads is very small, and many cars have run 100,000 kilometers, and the thickness of the handbrake pads is about the same as new. Generally, the handbrake will only be replaced if it is not used properly, for example, if you often forget to let go of the handbrake, it will cause serious wear and tear after driving for a few kilometers, and it may need to be replaced. For vehicles in normal use, there is generally no need to change the handbrake pads.
So why does the braking force of the handbrake drop? It's because the handbrake line is stretched. The handbrake line is all steel wire, the frequency of handbrake use is high, or it is pulled very tightly every time, and the handbrake line will be stretched after a long time, and then the same height will be pulled up after being stretched, and the power of the handbrake will become weaker. At this point, you only need to adjust the effective length to solve the problem.
All cable-type handbrakes can adjust the length of the cables after the braking force drops, some of the operation is very simple, there are adjustment screws near the rear wheels, and you can rotate a few times. Some are more complicated, and the adjustment screw is behind the handbrake control lever, and the central armrest box needs to be removed to adjust. Of course, no matter how you adjust, the length of the adjustment is limited, if you adjust to the shortest or can't brake, then you should replace the handbrake cable. The price of a pull wire is also very cheap, and the labor fee may be slightly expensive.