Service brake system with ABS: 1 - brake mechanism of the front left wheel; 2, 5, 13, 18 - brake hoses; 3, 8, 12, 19 - brake pipes; 4 - main brake cylinder; 6 - brake mechanism of the front right wheel; 7 - front right wheel rotation speed sensor; 9 - reservoir of the main brake cylinder; 10 - vacuum amplifier; 11 - brake pedal; 14 - rear right wheel rotation sensor; 15 - brake mechanism of the rear right wheel; 16 - setting disk of the rear left wheel speed sensor; 17 - brake mechanism of the rear left wheel; 20 - ABS hydraulic modulator.
Note. Wheel speed sensors are also installed in the left brake mechanisms, which are not visible in the figure.
Some vehicles may be equipped with an ABS brake system (anti-lock system). A four-channel system is used. The channels are connected diagonally. The executive element of the anti-lock braking system is a hydraulic modulator. This is a complex assembly in which a hydraulic pump and solenoid valves are built. It is installed in the engine compartment. The operation of the hydromodulator is controlled by an electronic unit installed on the hydromodulator. The control unit also monitors the health of all elements of the ABS system. The front and rear brake mechanisms are equipped with front wheel speed sensors. Inductive sensors. For the operation of sensors installed in the front brake mechanisms, gear rims are made on the housings of the outer hinges of the front wheel drives.
For the operation of sensors, in the rear mechanisms...
...drivers are installed under the brake drums.
Pulse signals from the sensors are sent to the control unit. When one of the wheels is blocked, the hydraulic modulator, at the command of the control unit, limits the pressure in the corresponding channel. If a malfunction is detected, the control unit informs the driver using a warning lamp on the instrument panel. You can determine the problem by the fault codes at a specialized service station. with diagnostic equipment.
An ABS failure can be caused by a failure of the wheel speed sensors or by a failure of the hydraulic valve block itself. If the ABS fails, the braking system remains functional, but braking efficiency is reduced, which is especially dangerous on slippery surfaces.
Warning! If the ABS malfunction indicator lamp comes on, contact a service station as soon as possible for diagnosis and repair.