3.7. General checks of the brake system

The dust which is formed as a result of wear of slips and accumulating on components of the brake mechanism may contain asbestos hazardous to health. Do not blow this dust by means of compressed air and do not inhale it! Do not use solvents on the basis of gasoline for removal of dust.

Except checks through the established time intervals a condition of brake mechanisms it is necessary to carry out every time at removal of wheels or at emergence of signs of malfunction in system.

Signs of malfunctions in the brake system

Disk brake mechanisms have the built-in indicators of wear of frictional slips signaling that wear of slips reached critical size. At the same time slips should be changed immediately, otherwise brake disks will be damaged and they will need expensive repair.

Any of the listed below signs can indicate potential defect of the brake system:

In case of detection at least of one of these signs immediately examine the brake system.

Brake lines and hoses

In the brake system steel brake tubes, except for the flexible reinforced hoses at wheels are generally used. Regular survey of all these lines is very important.


  1. Park the car on the flat platform.
  2. The car also establish to Poddomkratta it on props then remove wheels.
  3. Check all brake lines and hoses for existence of cracks and attritions in their external covering, leaks, swellings and deformations. Check brake hoses in forward and back parts of the car for existence of signs of a softening, cracks, deformations or wear as a result of friction about other components. Check all nipple connections for existence of signs of leaks and make sure of reliability of fastening of all bolts and clips of brake hoses.
  4. Bend hands in one and other parties a brake hose to reveal damages. It is not necessary to twist hoses.
  5. Turn a steering wheel to the right and to the left against the stop. Make sure that hoses at the same time do not touch car design elements.
  6. At detection of leak of liquid or their damages it is necessary to eliminate immediately. For more detailed description of the procedure of repair of the brake system address the Head the Brake system.

Check of thickness of brake shoes and disks


  1. The car also establish to Poddomkratta it on props then remove the corresponding wheel.
  1. Check thickness of overlays of brake shoes and through an opening in a support of the brake mechanism.
  1. Thickness of an overlay of 1.0 mm is considered a limit of wear of a block (without metal substrate). In this case the brake shoe should be replaced (see the Head the Brake system).

As a rule, 1 mm of wear of a brake shoe corresponds to, at least, 1000 km of a run under adverse service conditions. In usual conditions of a slip are erased much more slowly. So, at a thickness of brake overlay of 3.0 mm (without a substrate) brake shoes will be enough still, at least, for 1500 km of a run.

  1. In case of doubt in correctness of measurement remove brake shoes and measure slip thickness by a caliper. If degree of wear is already reached, replace brake shoes. At the same time replace all 4 overlays of wheels of one axis, even in case only one slip wore out.
  2. Check supports of the brake mechanism for existence of leaks. At leaks urgently repair a support of the brake mechanism.
  3. Visually check brake disks from internal and outer side for existence of furrows, a rust, cracks, if necessary replace disks.
  1. Measure thickness of brake disks in several places by means of a micrometer or a special caliper. It is also possible to measure thickness of a brake disk by a usual caliper, having enclosed from each its party a lining of the known size (for example, two coins), and then having subtracted lining thickness from the measured value.
  1. Compare minimum of the received results to requirements of Specifications to the Head the Brake system. If the limit of wear is reached, replace surely both brake disks of wheels on one axis. The brake disk should be replaced also at big cracks or furrows with depth of more than 0.5 mm.
  2. Establish wheels and lower the car on the earth.

Check of the parking brake


  1. Park the car on a plain surface and release the parking brake.
  2. The car has to move manually, action of brakes should not be felt.
  3. Cock the lever of the parking brake on 1 click (the European models) or press a pedal of the parking brake (the American models), the car has to remain on the place in attempt to shift it manually.
  4. Completely cock the lever of the parking brake (the European models) – it should not be cocked more, than on 5 clicks. Otherwise adjust the parking brake (see the Head the Brake system).