Handbrake is not a universal insurance high-speed driving hand brake deceleration risk

During the use of the car, the use rate of the handbrake is very high, but the handbrake is not "universal insurance", and its performance will decrease with the increase in the number of uses. In many cases, the handbrake has been pulled up, but due to system failure or improper use, it does not achieve the desired effect. This is also a major hidden danger. Therefore, the owner should regularly maintain and check the handbrake of the car. For this purpose, the reporter interviewed Liu Gang, director of the workshop of the special service center of Shanghai General Motors of Hubei Guosheng Industrial Co., Ltd. He introduced to the reporter that checking the handbrake mainly pays attention to the following points:

Determine the working position of the handbrake handle

Like the foot brake pedal, the handbrake handle also has a pulling stroke. “Usually, when the handle is pulled up to 70% of the full stroke, the handbrake system should be in the normal braking position. Therefore, before checking the braking force of the handbrake, the 70% working point should be found. This work point can be Determined by the ratchet of several rattles.” Liu Gang suggested that the majority of owners can park their cars in a relatively quiet place and slowly pull up the handbrake, pulling the rattling sound from the ratchet until the handle is pulled to the end. Then calculate the 70% position of the total number of sounds, this position is the effective working point of the handbrake handle.

Check the hand brake mechanism performance

Put the car on a slope with a large gradient and a good road condition (preferably an asphalt road), slam the brakes and hang the neutral gear (if it is an automatic transmission, hang it in the N range) and pull the handbrake handle to the working point just determined. position. Then slowly release the brake pedal. If the car does not slip, it means that the handbrake is effective. Because there is a gap in the brake, sometimes the car will slide slightly after releasing the pedal, and then it will stop. As long as this sliding distance is small, the performance of the handbrake is also normal. Uphill and downhill should be done once.

Test handbrake sensitivity

“Besides the braking performance, the handbrake's sensitivity should also be checked. This is especially important for starting a slope. Slowly on a slopeless road, slowly lift the handbrake handle and feel the handle's sensitivity and juncture. The inspection method will cause the handbrake mechanism to wear, so the number of inspections should not be too much.” Liu Gang introduced that in the inspection process, if the handbrake's braking performance or sensitivity is found to be unsatisfactory, it can usually be solved by adjusting the handbrake operating cable. There is an adjustable compensation mechanism at the connection of the bottom of the handbrake handle with the copper cable (usually covered by the interior trim). With a wrench to loosen the lock nut, the length of the brake copper cable can be stretched. Some car adjustment mechanisms may be located at the bottom of the vehicle. If adjustments are inconvenient, they should be handled by professional maintenance personnel.

High-speed driving without a brake

Liu Gang also explained that many owners think that if the brake system fails, you can pull the handbrake to slow down. In fact, this approach is very dangerous. Since the handbrake mechanism is not precise, the braking forces on the left and right sides are unevenly distributed. When the handbrake is pulled at a high speed, it is easy to cause the rear wheels of one side to lock up and slip sideways. Here, to remind owners, the correct approach is to slow down through the downshift, to pull the handbrake to stop the car until the speed is very low.