Audi A4

Since 1994 of release

Repair and car operation

Audi А4
+ Running gear
+ Regular servicing
+ Engines
+ Turbo-supercharging
+ Exhaust system
+ Cooling system
+ Fuel tank and the fuel pump
+ The air filter and channels всасывания
+ Injection system
+ Coupling
+ Transmission and the main transfer
+ Suspension bracket of wheels and steering
- Brakes
   Independent work on brake system
   So the brake system works
   Check of brakes
   Brake liquid
   Check of level of a brake liquid
   Check of brake system on tightness and presence of damages
   Replacement of a brake liquid
   Disk brakes
   Measurement of a 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
   Manual brake
   Check of idling of the lever of a manual brake
   The main brake cylinder
   The brake amplifier
   Check of the brake amplifier
   Works on hydraulics of brake system
   Prorolling of brake system
   The help at malfunctions
   ABS and EDS
   What does ABS?
   Function of separate knots
   Electronic system of distribution of brake effort (EBV)
   Infringements in system ABS work
   Electronic blocking of differential (EDS)
+ Wheels and tyres
+ The electrotechnical equipment
+ Ignition system
+ Illumination
+ The alarm equipment
+ Tools and devices
+ Heating and ventilation
+ Body details
+ Salon
Search of malfunctions
Technical characteristics

Prorolling of brake system

The brake system should be pumped over after repair of a hydraulic drive if air gets to brake cylinders and in brake tubes.


  1. Fill a broad tank with a fresh brake liquid and during prorolling constantly watch (!) timely addition of a liquid before its level will fall. Otherwise air will again be soaked up.
  2. Sequence of actions: behind on the right; behind at the left; ahead on the right; ahead at the left.
  3. Remove a dustproof cap from the prorolling valve.
  4. Put on a transparent hose (as from system of washing of glasses) the wiped union and lower the free end of a hose in the capacity partially filled with a brake liquid.
  5. Let your assistant, swinging a brake pedal, will create brake pressure.
  6. Unscrew the prorolling valve on a corresponding wheel approximately on 11/2 turns and lower pressure. Thus the assistant holds a foot on a pedal and wrings out it.
  7. Close the valve and again pump up pressure.
  8. As open the valve.
  9. Repeat this process until in a hose air vials will not be visible any more. (If the hydraulic system has strongly become empty, pump over it twice.) In such a way through the valve the brake liquid and, certainly, together with it air is pumped over.
  10. If vials of air are not present more, let your assistant keeps a pedal in the lowest position, and you at this time close the prorolling valve. Tighten it cautiously, differently will strip a thread.
  11. Pump over systems on other brakes of wheels in precisely same way.

 Council: If the brake system on the above-stated method is not pumped over, despite numerous repetitions of this process (air vials are still visible) you should close all valves of prorolling, start the engine and some times press a brake pedal. Then once again pump over system.

At the left: prorolling of brakes on a forward support. The valve of prorolling (1) opens key SW 7. The transparent synthetic hose is put on the valve (2) and the extorted brake liquid merges in the prepared capacity (3).

On the right: if brake tubes (2) and brake hoses (4) are connected by metal arms (3) to a running gear or with a body there should be a springing arm for a hose (1). For a detachment of brake tubes such key (5) approaches