Subaru Legacy

Since 1990-1998 of release

Repair and car operation

Subaru Legasi
+ 1.1. Identification numbers
+ 2. Maintenance service
+ 3. Engines
+ 4. Heating, ventilation
+ 5. Fuel system
+ 6. An exhaust system
+ 7. Systems of start, ignition
+ 8. Transmissions
+ 9. Coupling, shaft
- 10. Brake system
   10.1. Introduction
   10.2. Technical characteristics
   10.3. Replacement brake колодок on disk brakes
   10.4. A support of disk brakes
   10.5. A brake disk
   10.6. Replacement brake колодок drum-type brakes
   10.7. The working brake cylinder
   10.8. The main brake cylinder
   10.9. Brake pipelines and hoses
   10.10. Replacement of a regulator of pressure
   10.11. Prorolling of hydraulic brake system
   10.12. Adjustment of a manual brake
   10.13. Replacement of a cable of a manual brake
   10.14. Replacement brake колодок a manual brake on back disk brakes
   10.15. Additional brake system
   10.16. The vacuum amplifier of brakes
   10.17. The stoplight switch
   10.18. Antiblocking system of brakes (ABS)
+ 11. A suspension bracket
+ 12. A steering
+ 13. A body
+ 14. An electric equipment

10.18. Antiblocking system of brakes (ABS)

Arrangement of elements of antiblocking system of brakes on the car

1 – the hydraulic block of management and the control block
2 – the pressure terminator
3 – a diagnostic socket
4 – a control lamp of the alarm system
5 – an electric socket of the data
6 – the management and control block on the car with an automatic transmission
7 – a rotor of the gauge of speed
8 – gauge ABS
9 – a support of brakes
10 – the G-gauge (only models 4WD)
11 – the stoplight switch
12 – the main brake cylinder

Arrangement of the hydraulic block of management and the control block on models since 1997

Arrangement of forward gauge ABS

Arrangement of back gauge ABS

Efficiency of braking the greatest, when coupling of the tyre with a surface of road the maximum. In the course of braking the tyre slides on a surface and district speed of a wheel becomes less speeds of the car.

Sliding minimum (0 %) when the wheel slides freely and maximum (100 %) when the wheel is blocked. Peak efficiency of braking is reached, when sliding makes 15 %. This size also allows to keep stability and controllability the car.

The role of antiblocking system consists in restriction of the pressure created in hydraulic system of brakes so that size of sliding was kept about optimum size (15 %). Action of this system should be immediate and separate for each wheel. The system should answer immediately each change of a surface (coupling factor) and loading on the car. The antiblocking system interferes with blocking of wheels at sharp braking. Thanks to it the brake way decreases, especially at low coupling with a road covering at a rain and snow. Cohesive force between wheels and road in this case is more, when at wheel braking continue rotation. Besides it even at full braking the car remains operated. Gauges of turns on one on each wheel measure speed of rotation of a wheel. On signals from gauges of turns of a wheel in the electronic operating block the average speed approximately corresponding to speed of movement of the car is calculated. Comparing speed of rotation of each separate wheel with the average calculated speed, the electronic block defines a condition проскальзывания a separate wheel and by that establishes, what wheel is in a preblocking condition. When one of four gauges of speed of rotation transmits a signal about blocking of a corresponding wheel, immediately the electronic actuation device gives out a closing signal to corresponding inlet electromagnetic valve which immediately blocks giving of a brake liquid through the brake pipeline to a brake of this wheel therefore force of braking remains to a constant. If nevertheless sliding proceeds, the final valve and pressure in hydraulic system of the given brake opens decreases, therefore wheel braking decreases. As soon as the wheel again will start to rotate, at once there is an opening of the inlet valve and closing of the final valve. Pressure increases in a contour also a wheel is again braked. Such cycle of braking and free rotation of a wheel occurs very quickly (some times in a second) and proceeds to a car stop, or to отпускания brake pedals. This process repeats at sharp braking separately for each wheel until the pedal of a brake will be released or at reduction of speed of the car to several km/h. The driver defines work of antiblocking system on a pulsation of a pedal of a brake.

The system of emergency switching-off provides system ABS switching-off at any malfunction or at a low voltage in an electric chain of the car. The electronic actuation device carries out also autodiagnostic function, warning the driver fire of a control bulb about registration of malfunction of electric chains or elements of antiblocking system. At faulty system ABS of a brake nevertheless are serviceable and function as if this system is not present in the car.