Audi A4, S4

since 2000 of release

Repair and car operation

Checks of brake system. Adjustment of the parking brake

The dust being formed as a result of wear of slips and accumulating on components of the brake mechanism, can contain asbestos hazardous to health. Do not blow this dust by means of the compressed air and do not inhale it! Do not use solvents on the basis of gasoline for dust removal. The dust should be washed away a special cleaner of brake system or methyl alcohol in drain capacity. After rubbing the component of brake system a damp rag should be kept this rag and contents of drain capacity in the closed and signed container. Further, whenever possible, try to use components not containing asbestos.

Except checks through the established intervals of time a condition of brake mechanisms it is necessary to carry out each time at removal of wheels or at emergence of signs of malfunction in system. For driving safety the checks of brake system described below procedure are most important of all procedures made by you on car service.

Signs of malfunctions in brake system

Disk brake mechanisms can have the built-in indicators of wear of frictional slips which signal that wear of slips reached critical size. Thus slips should be changed immediately, differently brake disks will be damaged and they will need expensive repair.

Any of listed below signs can point to potential defect of brake system:

When squeezing a pedal of a brake the car "withdraws" in one party. Brake mechanisms when braking publish scraping or squealing sounds. The pedal of a brake has an excessive course. The pedal of a brake pulses (it normally only at ABS system work). Leakages of brake liquid (usually on tire or wheel inside) are observed.

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

Brake lines and hoses

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

PERFORMANCE ORDER

To Poddomkratta the car and reliably establish it on support. Remove wheels (address to the Section Check of a condition of tires and pressure in them. Designation of tires and disks of wheels. Rotation and replacement of wheels and to materials of head Governing bodies and receptions of safe operation). Check all brake lines and hoses on existence of cracks and attritions in their external covering, leaks, swellings and deformations. Check brake hoses in forward and back parts of the car on existence of signs of a softening, cracks, deformations or wear as a result of a friction about other components. Check all shtutserny connections on existence of signs of leaks and make sure of reliability of fastening of all bolts and clips of brake hoses. Bend hands in one and other parties a brake hose to reveal damages. To braid hoses does not follow. Watch the direction of the color line put on a hose! Turn a steering wheel to the right and to the left against the stop. Hoses should not touch elements of a design of the car thus. At detection of leakages of liquid or their damages it is necessary to eliminate immediately. For more detailed description of procedure of repair of brake system address to Head Brake system.

Check of thickness of brake shoes

The thickness of external brake shoes can be checked through an aperture in a wheel disk by means of a pocket small lamp. The internal block can be checked by means of a pocket small lamp and a mirror. If it is necessary to estimate more precisely thickness of a block, it is necessary to remove a wheel and to measure a block by a calliper.

Experience shows that wear of a brake shoe of a wheel from the forward passenger more than from the driver. Therefore for check of thickness of a brake shoe it is recommended to remove a wheel from the forward passenger.

PERFORMANCE ORDER

Note paint the provision of a forward wheel in relation to a nave. It will allow to establish the balanced wheel in the working situation. Weaken bolts of fastening of a wheel. Thus the car should stand on the earth. Lift a forward part of the car and establish on supports. Remove a forward wheel. Thickness (arrows on an illustration) internal and external blocks check through an aperture in a support. Limit of wear of thickness of brake shoes will reach, if the overlay of a block has thickness of 2.0 mm (7 mm together with a basis plate). In this case it is necessary to replace a brake shoe, address to the Sections Removal and installation of forward brake shoes and Removal and installation of blocks of brake mechanisms of back wheels. In practice, 1 mm of wear of a brake shoe corresponds at least 1000 km of run of the car. This rule corresponds to adverse service conditions of the car. In normal conditions wear of blocks is much less. At thickness of a block of 10.0 mm (with a basis plate) the block can be maintained still not less than 3000 km. Check possibility of leakage of brake liquid in supports. In the presence of a leakage urgently repair a support (work HUNDRED). Visually check brake disks on existence of flutes, traces of impact of corrosion and cracks. With cracks in thickness in a hair and length to 25 mm the raised loading can be which reason of emergence, it is not necessary to replace ventilated disks. At cracks and grooves brake disks it is necessary to replace more than 0.5 mm with depth. Check thickness of brake disks, address to the Section of Head Brake system. Establish into place forward wheels so that the labels put at removal coincided. Previously grease with a thin layer подшипниковойсмазки aligning belt of a disk of a wheel on a nave. Bolts of fastening of a wheel do not grease. Rusty bolts replace. Wrap bolts. Lower the car on wheels and tighten bolts cross-wise.

Check and extra earnings of the parking brake

Check

If the parking brake is pressed through further on distance to 5 teeth, it is necessary to regulate a brake.

Brake extra earnings

As the parking brake serve 2 drum-type brakes located in back disk brakes. Thanks to it the parking brake wears out slightly. Owing to corrosion of a brake drum or pollution of brake shoes the brake moment can decrease. For achievement of optimum action of its brake it is necessary to earn extra.

PERFORMANCE ORDER

Pass on the dry road not having heavy traffic. For the speed about 50 km/h establish a transmission in neutral situation. Extend the handle of the parking brake. Thus stop the car. When braking by the parking brake the signal of braking does not light up. For this reason be especially attentive in relation to transport moving behind. Continue movement on the car with constant speed about 50 km/h. Extend the handle of the parking brake, approximately on 10 seconds and release. If the parking brake is badly tightened, after its cooling repeat braking process. If the parking brake after check is released badly or after extra earnings and adjustments is tightened on the one hand, check brake shoes and cables, if necessary replace.