Audi A3

Since 1997 of release

Repair and car operation

Audi A3
+ The maintenance instruction
+ Current leaving and service
+ The engine
+ Systems of cooling, heating
+ The power supply system and release of the fulfilled gases
+ Engine electric equipment
+ Manual box of a gear change
+ Automatic transmission and models with a full drive
+ Coupling and power shafts
- Brake system
   Replacement of lobbies brake колодок
   Removal and installation of disk brake mechanisms of back wheels
   Check of a thickness of a brake disk
   Removal and installation of a brake disk/support
   Adjustment of a lay brake
   Brake liquid
   Removal of air from brake system
   Removal and installation of a brake hose
   Check of the amplifier of a brake
   Removal, installation and adjustment of the switch of a stoplight
   Removal and installation of the lever and cable of a lay brake
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ Electroschemes

Brake system




Separate characteristics are resulted also in the text of the Head and in case of compulsion of their performance are allocated by a bold type

The general parametres
Design Disk brake mechanisms on forward and back wheels. Disks of forward brake mechanisms – blown. Elektronno - hydraulic antiblocking system. Hydraulic system – two-planimetric, diagonal. Brake overlays – безасбестовые
Disk brake The forward The forward The back
The manufacturer FS - III FN - 3
Thickness brake Pads, mm
The new 14 14 11.5
Deterioration limit (with a back plate) 7 7 7
Deterioration limit (without a back plate) 2 2
Thickness of a brake disk, mm
Diameter 256/280 288 232
Thickness of the new 22 25 9
Deterioration limit 19 22 7
Brake liquid 1.5 l DOT of 4 specifications FMVSS 116
Diagnostic codes of malfunctions of electronic control are led by systems of braking and stability stabilisation in Specifications to Chapter 5.
Efforts of a tightening of carving connections
The moments of an inhaling of fixture are resulted also in the text of the Head and on some иллюстрациях*.

*Выделенные in the text a bold type the inhaling moments are subject to exact observance; the efforts not allocated with a bold type are resulted only roughly
Directing bolts of a brake support of forward wheels 28 Н•м
The holder of a brake support to a nave
Forward wheels 28 Н•м
Back wheels 65 Н•м
Brake support of back wheels to the holder 30 Н•м
Mudguard, ahead 10 Н•м
The lever of a lay brake on a body floor 25 Н•м
Brake hose on a support 35 Н•м
Bolts of wheels 120 Н•м

Elements elektronno - hydraulic system of stabilisation of dynamic stability ABS/EBV/EDS

1 – switch ASR
2 – the switch of feet - of a signal
3 – the gauge of number of turns back left
4 – the gauge of number of turns back right
5 – the gauge of number of turns forward right
6 – the gauge of number of turns forward left
7 – the block of management ABS/EBV/EDS/ASR
It is built in the hydraulic block of management
8 – control lamp ABS/EDS
9 – control lamp ASR
10 – a control lamp of level of a brake liquid
11 – the main brake cylinder, the brake amplifier, a brake pedal
12 – the hydraulic block

Elements of control system ABS/EDS

1 main brake cylinder and the brake amplifier
2 – the hydraulic block of management
3 – a diagnostic socket. In the central console under an ashtray.
4 – a cover
5 – a control lamp of a reserve of a brake liquid
6 – control lamp ABS/EDS
7 – the gauge of number of turns/wheels of the gauge. A back axis
8 – the switch of feet - of a signal. Over a brake pedal
9 – the gauge of number of turns/wheels of the gauge. A forward axis

The brake system consists of the amplifier of a brake, the main brake cylinder with connected hydraulic block ABS and disk brakes of forward and back wheels. The brake system has two contours, operating on a diagonal. One contour influences on forward right/back left, another on forward left/back right brakes. At refusal of one of contours car braking is carried out by one forward and one back brakes. Pressure of a liquid in both contours is created in the dual main cylinder by influence on a brake pedal.

The tank of a brake liquid is located in an impellent compartment over the main brake cylinder, it provides with a liquid all brake system.

On forward wheels the disk brakes having for the best heat-conducting path aeration are established. Back wheels are braked by continuous disk brakes.

The amplifier of a brake of the engine accumulates a part of the vacuum created in the soaked up pipeline of the engine. At influence the effort to pedals through the brake amplifier increases by a pedal of a brake thanks to vacuum action.

Disk brakes are supplied by so-called rigid supports. At these supports one piston is necessary for pressing on brake Pads only.

The lay brake operates through cables on brakes of back wheels.

Work with brake system demands special cleanliness and exact observance of instructions. In the absence of necessary experience it is expedient to address on HUNDRED.

Brake Pads are intended for use in concrete model of the car. It is recommended to apply brake Pads, resolved by the manufacturer or Federal department under the control over vehicles. Such brake Pads have corresponding marks KBA.

At movement on wet roads it is necessary to press periodically a pedal of a brake for drying of disk brakes. In the course of rotation of a wheel the moisture under the influence of centrifugal force is dumped from brake disks, but there is a film of silicone, a product истирания rubbers, greasing and the other pollution reducing efficiency of operation of brakes.
Пригары to a dirt on a surface brake колодок and rain flutes lead to formation of furrows on a surface of brake disks, a consequence of that is decrease in efficiency of braking.
At cleaning of brake system the dust which can harm health of the person is allocated, therefore to inhale a brake dust it is impossible.



The antiblocking system, interferes with blocking of wheels at sharp braking. It promotes preservation of controllability in the course of braking and raises reliability of movement.


The system of electronic distribution of brake effort, by means of ABS hydraulics distributes brake effort to back wheels. As EBV adjustment works essentially more sensitively, than the mechanical regulator of brake effort, is used considerably больший a regulation range.
At movement on a straight line the effort of braking is transferred to back wheels completely. That at braking on turns also to provide stability, it is necessary to reduce effort of braking to back wheels. Through gauges of number of turns ABS the system defines, whether the car directly moves or it turns. At movement on turns the effort of braking of back wheels decreases. Thanks to it back wheels can receive the maximum lateral directing effort.
EDS: the Electronic blocking differential, brakes turned wheels at трогании the car from a place. Thanks to it the twisting moment is transferred to driving wheels.
Electronic blocking of differential operates at трогании from a place and is disconnected automatically at achievement of speed of 80 km/hour. Special advantages of this system: it does not render negative influence on dynamic qualities of the car and on comfort of management.
Recommendations about systems ABS/EBV/EDS
The special switch in the electronic block of management watches that the system in the presence of damage (for example, cable breakage) or a voltage reduction of an onboard network more low 10 In was disconnected. The situation is displayed on the panel of devices by fire of control lamps. The usual system of braking thus keeps the working capacity. In the course of braking the car behaves as if system ABS is absent.

If during movement control lamps ABS and braking systems at strong braking back wheels can be blocked as distribution of brake effort does not operate light up.
If during movement on the panel of devices one or several control lamps light up, it is necessary to mean the following:

1. Stop for a short while the car, switch off the engine and again start it.
2. Check up pressure of the storage battery. If pressure is less 10.5 In, charge the battery.

If control lamps light up in a start of motion and then after a while die away, it specifies that pressure of the storage battery at first was too low, and then during movement as a result of gymnastics the generator has again raised.

3. Check up, whether plugs of the storage battery are reliably fixed and whether they have reliable contact.
4. Put the car on supports, remove wheels and check up the electric wires going to gauges of number of turns of wheels on presence of external damages (retyranny). More detailed check ABS/EBV/EDS should be spent in conditions HUNDRED.

Before performance of electrowelding works it is necessary расстыковать a socket of the block of management. Connection undocks only at the switched off ignition. At performance of paint and varnish works it is authorised to heat up quickly the block of management to temperature no more + 95°С, and it is long (макс. 2 hours) to temperature +85°С.

On the main page