17:27. Check of the brake system
Annually or each 20 000 km of a run
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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. Dust should be washed away a special cleaner of the brake system or methyl alcohol in drain capacity. After rubbing of components of the brake system a damp rag this rag and contents of drain capacity should be held in the closed and signed container. Further whenever possible try to use the components which are not containing asbestos. |
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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. For driving safety the procedures of check of the brake system described below are the most important of all procedures for service of the car made by you. |
Signs of malfunctions in the brake system
Disk brake mechanisms have the built-in electric indicators of wear of frictional slips which cause inclusion of an alarm lamp on the dashboard in case wear of slips reached critical size. After inclusion of an alarm lamp of a slip it is necessary to change 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:
- When squeezing a pedal of a brake the car "takes away" in one party
- Brake mechanisms when braking make the scraping or squealing sounds
- The pedal of a brake has the excessive course
- The pedal of a brake pulses (it normally only during the work of the ABS system)
- Leak of brake fluid is observed (usually on inside of the tire or a wheel)
In case of detection at least of one of these signs immediately examine the brake system.
Brake lines and hoses
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In the 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. |
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- Park the car on the flat platform and switch off the engine. Take off caps from wheels. Weaken, but do not remove bolts of fastening of all four wheels.
- The car and reliably establish to Poddomkratta it on axial support.
- Remove wheels (see Poddomkrachivaniye's Section, towage and change of wheels or the Operation manual on your car).
- 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.
- 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.
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Disk brake mechanisms
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- If it was not made yet, the car and reliably install to a poddomkratta it on axial support.
- Now it is possible to see supports of disk brake mechanisms in which there are blocks. In each support there are external and internal blocks - it is necessary to check both that and others.
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- Estimate thickness of blocks, having glanced in a viewing opening in the support case. If thickness of frictional slips makes 2.0 mm or less or if they are worn-out on the one hand more, than with another, then blocks should be replaced (see the Head the Brake system).
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- Remember that frictional slips are usually pasted on a metal substrate of a block - its thickness should not be considered at measurement. Always replace blocks on both parties of the car (in a set on one bridge) even if only one of them is worn-out, otherwise process of braking will be uneven.
- Remove supports, without disconnecting brake hoses (see the Head the Brake system).
- Check a condition of a brake disk. Examine it on existence of furrows, deep scratches and sites of an overheat (they look as the blue or decoloured spots). At detection of signs of damages or wear the disk can be removed and pierced in a mechanical workshop; if there is no such opportunity, it should be replaced. Both in that and in other case it is necessary to replace or pierce both disks even if only one of them is worn-out. In more detail the procedure of survey and repair is described in the Head the Brake system.
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Drum brake mechanisms
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- Using instructions of the Head the Brake system, remove back brake drums.
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- Measure thickness of frictional slips on boots of back brake mechanisms and examine them on existence of signs of pollution by brake fluid or lubricant. If the slip has thickness within 2.0 mm over heads of rivets or the metal basis, replace boots. Also the boots polluted by brake fluid or lubricant are subject to replacement also burst, zapolirovanny to gloss. The procedure of replacement is described in the Head the Brake system.
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- If slips are pasted to a boot substrate, measurement of their thickness is performed from a substrate surface, as shown in the figure (A); in case overlays of a priklepana to boot metal, measurement is performed from a slip surface to tops of heads of rivets
- Check a condition of the coupling and holding springs of boots, and also the adjusting mechanism. Make sure that all these components are correctly installed and are in working order. The worn-out or deformed springs can serve as the reason of premature wear of frictional slips.
- Check wheel cylinders for existence of signs of leaks, having accurately removed protective rubber covers. Existence of insignificant traces of moisture under covers is allowed. If under them brake fluid is found or it follows from the wheel cylinder, then cylinders should be repaired or replaced capitally (see the Head the Brake system).
- Check drums for existence of deep scratches, furrows of cracks and superheated sites which look as the decoloured spots. If the revealed defects cannot be eliminated by means of an emery paper, the drum should be pierced in a workshop (see the Head the Brake system for more detailed information).
- Following indications of the Head the Brake system, install brake drums.
- Establish wheels, but do not lower the car yet.
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Parking brake
To protozoa, and it is possible, the most obvious way of check of operation of the parking brake is installation of the car on a steep slope with the cocked brake and transmission in neutral situation (when checking you should be in the car). If the parking brake does not keep the car from rolling, it is necessary to make its adjustment as it is described in the Head the Brake system.
