Audi A4

since 1994 release

Manual of the car

Audi A4
+ Running gear
+ Regular servicing
+ Engines
+ Turbo-supercharging
+ System of an exhaust
+ Cooling system
+ Fuel tank and fuel pump
+ Air filter and channels of absorption
+ System of injection
+ Coupling
+ Transmission and main transfer
+ Suspension bracket of wheels and steering
- Brakes
   Independent work on the brake system
   So the brake system works
   Check of brakes
   Brake fluid
   Check of level of brake fluid
   Check of the brake system on tightness and existence of damages
   Replacement of brake fluid
   Disk brakes
   Measurement of thickness of overlays of forward disk brakes
   Check of a condition of brake disks
   Replacement of overlays of disk brakes
   Back disk brakes
   Measurement of overlays of back disk brakes
   Emergency brake
   Check of idling of the lever of the emergency brake
   Main brake cylinder
   Brake amplifier
   Check of the brake amplifier
   Works on hydraulics of the brake system
   Pumping of the brake system
   The help at malfunctions
   ABS and EDS
   What does ABS?
   Function of separate knots
   Electronic system of distribution of brake effort (EBV)
   Violations in work of the ABS system
   Electronic blocking of differential (EDS)
+ Wheels and tires
+ Electrotechnical equipment
+ System of ignition
+ Lighting
+ Alarm equipment
+ Tools and devices
+ Heating and ventilation
+ Body details
+ Salon
Search of malfunctions
Technical characteristics


So the brake system works

  • When you press a brake pedal, the pusher connected with a pedal presses two pistons located one after another into the main brake cylinder (in a motive compartment).
  • Pistons force out the brake fluid concluded there. Pressure which is formed thus in the brake system via pipelines and hoses is transferred to cylinders of brakes.
  • In them pistons press brake shoes to brake disks.
  • Pressure of liquid is transferred by two systems of pipelines (brake contours) independent from each other, and for one forward wheel and an opposite back wheel (the double-circuit brake system divided on diagonal).
  • If one brake contour, then, despite it fails, two wheels are still braked.
  • The emergency brake affects back wheels by means of hummock drafts and in the mechanical way presses slips to brake disks.
  • All Audi A4 models since the beginning of release of a series have serial system of anti-blocking of wheels. It is told about ABS in the following chapter in more detail.

 Council: If one brake contour fails, then you have to press on a brake pedal much stronger (the free wheeling of a pedal of a brake also becomes longer) to achieve brake effect. The way of braking is extended too.