High performance car braking systems can in some cases lead to accidents. This is due to the fact that during sharp braking the wheels are completely blocked, and traction disappears from the roadway. And not always an inexperienced driver manages to cope with the car and quickly slow down. It is possible to prevent a breakdown in skidding and blocking the wheels by intermittent pressing the brake. There is also an ABS system that is designed to prevent dangerous situations while riding. It improves the quality of adhesion to the roadway and maintains the controllability of the car, regardless of the type of coating.
Principle of operation
The mechanism of the system can be compared with the actions of an experienced driver. This is especially noticeable with ice when the wheels are on the verge of blocking. In addition, it is worth noting the automated distribution of braking forces and maintaining transport stability.
The operation of the device is based on the influence of brake fluid on the wheel mechanism. This contributes to the appearance of braking force in the place of contact of the road and wheels. An increase in this effect occurs only up to the established moment; otherwise, the slip increases due to the stop of rotation.
This is what is becoming a frequent cause of loss of car owner control. The control unit of the device receives signals from the respective sensors, after which there is a decrease in pressure in the brake system, while the degree of pressing the pedal does not matter.
What you need to know
The ABS system of the car has one distinctive feature, which consists in determining the braking of each wheel individually. Normalization of fluid pressure occurs immediately after the movement becomes more stable. It is worth noting that driving a car without ABS and equipped with this system has some differences. In the latter case, you can calmly apply the brake without worrying about the likelihood of a lock occurring. This is especially important for drivers who have a short experience and are faced with a similar supplement for the first time.
Bleeding ABS
Before starting work, it is worth paying attention to the thread of the fitting. If there are traces of rust on it, it is necessary to treat the surface with a special composition, this will prevent damage to the thread.
A transparent hose is put on the cylinder fitting, the second end of which is lowered into the container. The gear lever must be in the neutral position. The pressure on the brake pedal is made before the start of resistance. In the process of holding the pedal, the fitting is unscrewed, after which it must touch the floor. It can only be released after tightening the fitting. In the process of work, the regular addition of brake fluid is of particular importance, this will prevent air from entering the circuit.
Quality control
Pumping brakes with ABS is performed on each wheel. In this case, the smallest bubbles should not be in the brake fluid. The last step is to check the pedal free play and add fluid to the desired level. It is also worth making sure that each part is tight and tight.
Performance can be checked by depressing the brake pedal for 15 seconds while the engine is running. At this time, for several seconds, the indicator should turn on, informing about the self-diagnosis. If nothing happened, this indicates that there is a malfunction in the ABS system. A race with systematic braking will further evaluate the quality of work.
Design
The system consists of several basic elements:
- hydraulic block;
- electronic control unit;
- wheel speed indicators.
As a rule, sensors operate on the electromagnetic principle. They consist of a coil with a special core. The magnetic current inside the sensor changes due to the movement of the grooves and the teeth of the crown during the rotation of the wheel. The electronic control unit receives the incoming signals and determines the speed of rotation. Using special tables, the computer calculates the optimal braking algorithm, the maximum degree of braking pressure and the quality of the road surface. The control unit is modulators that determine the appropriate level of pressure for the wheels. If a malfunction occurs, a malfunction indicator lights up, which informs the driver that an ABS diagnosis is required.
Advantages
The ABS system has gained its popularity due to the presence of many advantages, which include the following:
- there is no need to learn different ways of braking;
- the gas pedal does not require intensive monitoring, which is especially important for novice drivers;
- implementation of maneuvers with simultaneous braking;
- the possibility of braking on any part of the turn.
disadvantages
Despite the ease of use, the anti-lock braking system of the car is not able to become a panacea for all the troubles on the road associated with braking.
It is not without negative aspects, which include the lack of the ability to use when maneuvering in extreme conditions. It is also worth noting the following:
- there is a possibility of a delay in turning on the system, since its full-fledged operation is possible only after determining the coefficient of adhesion of the wheels and road surface and testing the quality of the canvas;
- the driver does not control the braking process, because of which the anti-lock braking system of the ABS becomes unpredictable;
- coefficient of adhesion can be calculated incorrectly with frequent changes in uneven road surfaces, which reduces efficiency;
- the ABS system does not work at a speed of less than 10 km / h, this is especially true for heavy or armored vehicles, since in this case the braking distance is significantly increased and there is a chance of an accident;
- the complexity of operation on loose and loose soil due to the elimination of the slightest blocking of the wheels.
When using, it is necessary to take into account all the features and negative aspects. The ABS system is designed to provide full control of the car during sudden braking. Thus, the driver can confidently control the vehicle and have the ability to maneuver during braking. The combination of these factors makes the system an effective assistant on the road and increases the safety of the driver and passengers. A car owner with sufficient experience can cope with difficult situations without the help of the system, but it is indispensable for inexperienced drivers.
Diagnostics
In the event of a malfunction, the vehicle’s ABS system instantly stops working, due to which the restrictions in the brake system of the car disappear. The driver can find out about the malfunction by the signal of the emergency lamp installed on the front panel. Diagnostics can be performed in several ways, depending on the type of device and the year of manufacture. The most common cause is a fuse malfunction.
First you need to inspect the block and make sure that there is no damage. It is also worth paying attention to the condition of the conductors and connectors. They must have a tight mount and a flat surface, without scuffs and scratches that can cause a short circuit.
The axle suspension (support and additional joints) and bearings must be checked for the presence of play and the quality of workmanship. Particular attention is paid to the high pressure pump. It is necessary to disconnect the connector and apply voltage to the pump, coming from the battery for a short time. To do this, you can use two conductors of any type. If it starts to work, you can proceed to a further inspection.
Sensors
The speed sensors and their components must be free from damage and stains. It is worth noting the increasing popularity of sensory active sensors. This is due to the presence of many advantages that passive analogues can not boast of. They are more accurate signal and the ability to determine the speed in two directions with maximum accuracy. Devices with similar measurement accuracy are used in various systems, including anti-theft devices and satellite navigation. Their indisputable advantage is their compact design.