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Brakes and auxiliary systems

General information and safety measures

general information

Scheme of the hydraulic drive of brake mechanisms for the three-channel ABS

5.04 - The main and auxiliary vacuum receivers 8.05 - the initial pressure valve 19. - Supports fixed type 19.03 - GTZ 19.05 - The rear wheel cylinders	26.03 - Pressure Regulator 27.04 - servo 31.01 - Electronic Control Module 31.05 - hydromodulator 34.02 - brake fluid reservoir

Scheme of the hydraulic drive of brake mechanisms for the four-channel ABS

5.04 - The main and auxiliary vacuum receivers 8.05 - the initial pressure valve 19. - Supports fixed type 19.03 - GTZ 19.05 - The rear wheel cylinders 26.03 - Pressure Regulator	27.04 - servo 31.01 - Electronic Control Module 31.05 - hydromodulator 34.02 - brake fluid reservoir X - Acceleration Sensor

Arrangement components ABS / BAS / ETS-4 / ESP (1 of 4)

A7 - hydromodulator ABS K1 / 2 - overload relays (petrol models) K1 / 1 - overload relays (diesel models)	L6 / 2 - Right front wheel sensor N30 - ABS control module

Arrangement components ABS / BAS / ETS-4 / ESP (2 of 4)

A7 / 3 - hydromodulator ASR / ETS / ESP A7 / 3k1 - relay e / m valve A7 / 3k2 - relay and pressure recirculation pump	K40 - Relay module (HFM-SFI, HFM-SFI with an air pump, ME-SFI, EDC) N47 / 7 - ABS control module

Arrangement of components ABS / BAS / 4-ETS / ESP, - three-channel ABS (3 of 4)

A1e17 - ABS warning lamp L6 / 4 - VSS right rear half-line	S76 - Switches locking differentials

Arrangement of components ABS / BAS / 4-ETS / ESP, - four-channel ABS (4 of 4)

A1 - Dashboard A1e17 - ABS warning lamp L6 / 3 - VSS left rear half-line (not shown) L6 / 4 - VSS right rear half-line H46 - Indicator light	S76 / 1 - Switch ABS N30 / 2 - the switch of management of functioning ASD B24 - Acceleration Sensor

The front and rear of all considered in this Guide models are equipped with disc brakes with fixed-type calipers front and rear floating type.

The brake system consists of a master cylinder, vacuum booster and disc brakes front and rear wheels, and is divided by a diagonal pattern on two independent hydraulic circuits. When failure of any of the circuits (for example as a result of pressurization failure) continues to operate in the second normal mode, providing adequate braking of the vehicle. Additionally, the contours of both rear brakes integrated pressure regulator valve provides a dynamic correction braking force of rear wheels in accordance with the change of the load on the rear axle of the vehicle. The fluid pressure in both circuits have created the tandem master cylinder design (GTZ). Activation occurs when the GTZ squeezing of a pedal of a foot brake.

A brief description of the principles of functioning of auxiliary electronic systems anti-lock brakes (ABS), strengthen emergency braking (BAS), traction (4-ETS) and protivozanosnoy (ESP) is shown in Part Receptions of operation and auxiliary systems.

Brake fluid reservoir is mounted on the master cylinder (GTZ) and provides all working fluid hydraulic path of brake system.

At petrol models braking power accumulates part of the vacuum created in the intake manifold of the engine. On diesel models, because of the lack of such a power vacuum, a special vacuum pump. If necessary, a special valve provides a connection corresponding to a vacuum source, thus providing increased exposure, developed by the foot brake pedal.

The parking brake with manual drive acts via cables to a special shoe assembly belonging to the disk brake mechanisms of back wheels.

Procedure control lamp ABS is activated while driving

PERFORMANCE ORDER

Stop the car, stop the engine and restart it. Check the battery voltage - if the measurement is less than 10.5, make recharging the battery. If the ABS warning lamp lights up at the beginning of the motion, and then some time later extinguished, it indicates a low battery voltage, which increases after the start of operation of the generator. Make sure of reliability of fastening of tips of wires on the pole terminals of the battery, if necessary, tighten the fasteners. Poddomkratte car and establish it on props, remove wheels and check the speed sensor wiring. More detailed diagnosis should be carried out in a service station with special equipment for reading stored in the memory control unit fault codes (DTC).

security measures

• Brake fluid is among the highly toxic and chemically aggressive compounds, and in contact with the body panels destroys the paintwork!
• Brake dust generated in the process of wear of the brake pads may contain harmful to human health asbestos - in any case, do not inhale it when cleaning the brake!
• Work on the brake system requires a high purity and precision of instructions. In the absence of the necessary experience it is advisable to contact the service station.

When driving on wet roads need to periodically press the brake pedal to remove moisture from the brake discs;

• During wheel rotation moisture centrifugally discharged from the brake discs, but leave a film of silicone rubber attrition, grease and other contaminants that reduce braking performance!
• After installing new brake pads last have earned extra - try to avoid sharp braking the first 200 km of run after replacement!
• Corroded disc brakes provide braking effect of shaking, do not disappear with time, - replace the wheels!
• Dirt sticking to the surface of the brake pad lead to formation of grooves on the surface of the brake disk, leading to a reduction in braking performance!