Service brake system with ABS: 1 - front left wheel brake mechanism; 2, 5, 13, 18 - brake hoses; 3, 8, 12, 19 - brake pipes; 4 - master brake cylinder; 6 - front right wheel brake mechanism; 7 - Front right wheel speed sensor; 9 - master brake cylinder reservoir; 10 - vacuum booster; 11 - brake pedal; 14 - rear right wheel speed sensor; 15 - rear right wheel brake mechanism; 16 - rear left wheel speed sensor setting disk; 17 - rear left wheel brake mechanism; 20 - ABS hydraulic modulator.
Note: The left brakes also contain wheel speed sensors, which are not visible in the picture.
Some vehicles may be equipped with an ABS braking system (anti-lock braking system). A four-channel system is used. The channels are connected using a diagonal pattern. The actuator of the anti-lock braking system is the hydraulic modulator. This is a complex unit that has a built-in hydraulic pump and electromagnetic valves. It is installed in the engine compartment. The operation of the hydraulic modulator is controlled by an electronic unit installed on the hydraulic modulator. The control unit also monitors the serviceability of all elements of the ABS system. Front wheel speed sensors are installed in the front and rear brake mechanisms. Inductive type sensors. To operate the sensors installed in the front brake mechanisms, toothed rims are made on the housings of the outer hinges of the front wheel drives.
For the operation of sensors in the rear mechanisms...
...the brake discs 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, on command from the control unit, limits the pressure in the corresponding channel. If a fault is detected, the control unit informs the driver via a warning light on the instrument panel. The malfunction can be identified by the fault codes at a specialized service station. equipped with diagnostic equipment.
An ABS malfunction may be caused by a failure of the wheel speed sensors or a malfunction of the hydraulic valve block itself. If the ABS fails, the braking system remains operational, but braking efficiency is reduced, which is especially dangerous on slippery surfaces.
Warning! If the ABS malfunction indicator lamp lights up, contact a service station as soon as possible for diagnostics and repair.