2.5.5. Brake system

tc "23 Brake system"

The brake system of the considered cars is equipped by the vacuum amplifier allowing for braking with a certain intensity to put smaller effort to a brake pedal, than it would be required without amplifier. If the amplifier does not work (at the idle engine or for other reason), the working brake system remains serviceable, however it will be required to press on a brake pedal with a bigger force, and the brake way, as a rule, will increase.

At the idle engine by each pressing a brake pedal the additional effort of braking decreases therefore it is not necessary to press a brake pedal at the idle vacuum amplifier without need (for example, at deduction of the car on the slippery road).

In case of refusal brakes during the movement braking by means of the parking brake is allowed, however it is necessary to remember that the brake way in this case will exceed much more a brake way when using working brakes always.

Use of the parking brake at the movement of the car with a normal speed can cause driving loss therefore if it is necessary to use the parking brake for a stop of the moving car, act especially accurately.

It is not necessary to hold a leg on a brake pedal at the movement of the car since it leads to heating and premature wear of brake mechanisms and increase in a brake way. At the movement on a slope do not use brakes too long, instead use braking by the engine, switching to the lowering transfers. After the movement during a rain, and also after overcoming a water barrier it is necessary to dry brake mechanisms, having slightly pressed a pedal of a brake and holding it until productivity of brakes does not return on normal level.

Lobbies and back brake mechanisms

On the considered cars disk brake mechanisms are installed. Indicators of their wear which begin to make a high-pitched sound at the movement or when pressing a brake pedal are built in brake overlays of forward wheels if slips demand replacement. At the same time it is necessary to replace slips whenever possible rather to avoid further more expensive repair.

It is not necessary to confuse operation of indicators of wear of brake shoes and the scratch of brakes arising under certain conditions when pressing a brake pedal.

Parking brake

The lever of the parking brake is located on the central console, between front seats. For raising of the parking brake pull the lever up to an emphasis. For an otpuskaniye of the parking brake press the button located on the free end of the lever, and lower the lever down, holding the button of pressed.

Do not use the transmission established on transfer instead of the parking brake. On the parking surely you cock the parking brake and install the AT selector lever in situation "P".

At a stop on rise park the car as it is possible closer to the sidewalk or a roadside and turn wheels to the center of the road that at the casual movement of the car back forward wheels would rest against curbstone.

At a stop on descent park the car as it is possible closer to the sidewalk or a roadside and turn wheels to a roadside that at the casual movement of the car back forward wheels would rest against curbstone.

At each start of the engine check To/L the brake system – at the cocked KL parking brake has to burn, and after its otpuskaniye To/L has to die away. If after an otpuskaniye of the parking brake it To/L continues to burn, it indicates malfunction in the brake system which has to be repaired before to begin the movement. If To/L lit up during the movement, stop at the first opportunity and eliminate malfunction.

System of anti-blocking of brakes (ABS)

The ABS system constantly traces the speed of rotation of wheels of the car and at their blocking repeatedly modulates hydraulic pressure in the brake system.

When braking in conditions which can lead to blocking of wheels it is possible to hear clicks in brake mechanisms, or to feel brake pedal pulsations. The listed phenomena are a consequence of normal work of the ABS system and mean its activity. It is not necessary to change at the same time effort of pressure upon a brake pedal since it will prevent the ABS system to work with maximum efficiency.

It is necessary to remember the following precautionary measures always:

Check To/L the ABS system at start of the engine, - it has to light up for 2-3 seconds, and then go out. If To/L does not die away, ABS means it is faulty, at the same time the working brake system can normally function. To/L the ABS system can join also at long braking on the slippery road. If it occurred, stop and kill the engine. If after restart of the KL engine does not go out, drive away the car on HUNDRED for diagnostics and elimination of malfunction.

Systems of distribution of draft (TC) and electronic stabilization of stability (ESP)

These systems are installed as the additional equipment and use the ABS base understaffed with the additional pump, valves and sensors.

When determining pro-slipping of a wheel of the car moving with a speed less than 45 km/h the TC (TCS) system works. At the same time one of valves opens, allowing the pump to create pressure in one of contours until pro-slipping according to car speed stops. Thus there is a redistribution of traction effort. At the same time the butterfly valve is slightly closed, reducing draft of the engine.

Sensors of the ESP system give information on an angle of rotation of a steering wheel, pressure in GTTs, angular speed and cross acceleration of the car. Based on these data, the control unit calculates a trajectory of the movement of the car, compares it to the required trajectory and if necessary affects one or several brake mechanisms, correcting a trajectory.

Scheme of work of ESP

In case of an insufficient angle of rotation of a steering wheel the back internal wheel slows down; in case of an insufficient angle of rotation of a steering wheel external wheels slow down until the calculated and measured sizes of angular speed do not coincide.