1995-2001 of release
Repair and car operation
1.1. Periodicity of maintenance
+ 2. FE DOHC engines and Т8 DOHC
+ 3. Greasing system
+ 4. Cooling system
+ 5. Power supply system and release
+ 6. Fuel system
+ 7. Ignition system
+ 8. Coupling
+ 9. Mechanical transmission
+ 10. АКП G4A–EL
+ 11. АКП 50–40 LE
+ 12. Axes and power shafts
+ 13. Steering
+ 14. Wheels and tires
+ 15. Suspension bracket
+ 16. Body
+ 17. Central air
+ 18. Electric equipment
- 19. Brake system
19.2. Pumping of hydraulic system of a drive of brakes
19.3. Check of brake tubes and hoses
19.4. Replacement of brake hoses
19.5. Height of installation of a pedal of a brake
19.6. Free wheeling of a pedal of a brake
19.7. Distance of a pedal of a brake from a floor
19.8. Brake pedal
19.9. Check of the switch of a stoplight
19.10. Main brake cylinder
19.11. Check of the vacuum amplifier of brakes
19.12. Forward disk brake
19.13. Back disk brake
19.14. Pressure regulator
19.15. Parking brake
19.16. Anti-blocking system of brakes (ABS)
19.17. List of codes of malfunctions of brake system
19.18. Precautions at carrying out repair
19.19. Pumping of hydraulic system of a drive of brakes
19.20. Hydraulic control unit (HCV)
19.21. ABS control unit
19.22. Sensors of frequency of rotation of a wheel
19.23. Rotor of the forward sensor
19.24. Main survey
19.25. Check of functionality
19.26. Search and elimination of malfunctions
+ 20. Electric circuits
Arrangement of elements of anti-blocking system of brakes (ABS) on the car
Principle of work of brake system
Hydraulic scheme of brake system
The anti-blocking system of brakes is intended for an exception of blocking of wheels at intensive braking.
Main ABS functions:
– reduction of a brake way at the expense of an exception of blocking of wheels at intensive braking;
– improvement of stability of driving in the course of braking.
The three-channel anti-blocking system with four sensors works in such a manner that each of forward wheels copes independently, and back wheels cope by a principle of a choice of the smallest speed (management of hydraulic pressure is made from that party from which sliding came earlier).
Principle of work of ABS
Braking is carried out as in usual brake system until the ABS control unit will not find out that the wheel is blocked.
In a standard mode of braking electromagnetic valves do not work, the inlet valve is normally open, and final – is normally closed.
When ABS works, the hydraulic device operated by the ABS control unit, operates each valve in three stages, supporting, reducing or increasing pressure.
The ABS control unit by means of sensors of frequency of rotation of wheels fixes frequency of rotation and delay of each wheel. At braking implementation frequency of rotation of wheels decreases and calculated a difference between frequency of rotation of a wheel and speed of the car. If delay of frequency of rotation of some wheels exceed expected value (a point And), the ABS control unit considers that there was a blocking of the corresponding wheel and opens the final electromagnetic valve to reduce pressure of brake liquid. If pressure of blocking on the corresponding wheels is exceeded (a point In) and frequency of rotation of a wheel increased to a point With, the ABS control unit again closes the final valve to increase pressure of brake liquid.
Principle of work of ABS
In cars with ABS the following symptoms testifying, however, to serviceable work of ABS can be observed.
1. Standard braking (braking without ABS)
By pressing a brake pedal under the pressure of the liquid, the raised vacuum amplifier of brakes, closes the central valve of the main brake cylinder and pressure in the hydraulic highway of a brake is created. During this moment the inlet electromagnetic valve is open, the final valve is closed and hydraulic pressure from the main cylinder is transferred to the wheel cylinder.
2. Braking with ABS
2.2 Pressure reduction
2.3 Increase in pressure