6.2. Precautionary measures and recommendations at repair of the brake system

Possible malfunctions of the brake system, their reason and ways of elimination

When performing repair operations follow the following rules.
1. Stack details, washed out and ready to assembly, on the white and glossy paper (which is not leaving fibers).
2. Do not wipe a detail with rags.
3. From a surface of collected knot it is possible to apply a gauze to removal of brake fluid.
4. Do not sort knots if it is not connected with need of their repair.
5. Do not use for repair of a detail, working in other knots.
6. Not to damage a detail, you carry out dismantling and assembly works by the special tool and devices.
7. Do not mix brake fluids of various brands. At repair work apply liquid which brand corresponds to brand of the liquid which is filled in in the brake system.
8. At maintenance or repair replace brake fluid on new in two years of operation.
9. It is recommended to replace irrespective of a state all rubber details applied in brake knots, new through 60 thousand km of a run or in three years of operation of the car to prevent failures of knots because of aging and fatigue failures of rubber.
10. Replace flexible hoses of brakes on new through 60 thousand km of a run or in three years if a run small.
11. Not to do excess work, at elimination of malfunctions of the brake system before dismantling works, and also before direct dismantling of knots try to define estimated defect correctly.

Fig. 6.2. The main brake cylinder with the vacuum amplifier: 1 – case cover; 2 – connecting ring; 3 – diaphragm; 4 – case basis; 5 – basic ring of a diaphragm; 6 – basic plate of a disk; 7 – sector of a basic disk of a diaphragm; 8 – the fixing washer of sectors; 9 – central valve; 10 – the directing piston ring; 11 – sealing cuff of the case of the piston; 12 – lock washer of a sealing cuff; 13 – piston case; 14 – clamping plug of a support of a pusher; 15 – air filter; 16 – piston pusher; 17 – adjusting screw; 18 – piston emphasis; 19 – locking ring of a diaphragm; 20 – returnable spring of the piston; 21 – persistent bracket; 22 – rod of the amplifier; 23 – returnable spring of sectors; 24 – adjusting bolt; 25 – backpressure valve; 26 – tank of the main cylinder; 27 – tank cover; 28 – tube of the connecting plug; 29 – connecting plug; 30 – persistent pin; 31 – piston of the second camera; 32 – returnable spring of the piston of the second camera; 33 – persistent washer of a cuff; 34 – main cuff; 35 – piston valve; 36 – case of the main cylinder; 37-dividing cuff of cameras of the main cylinder; 38 – returnable spring of the piston of the first camera; 39 – piston of the first camera; 40 – sealing ring; 41 - cap; And – the first camera; In – the second camera; With – a compensation opening



Table 6.2   Maximum permissible wear in the main interfaced details of brake mechanisms and the drive to them

12. It is easy to determine the malfunctions causing leak of brake fluid, and also some malfunctions of brake mechanisms by external survey. If fire of a control lamp testifies to malfunction, and external survey did not succeeded to find liquid dribble, then for definition of malfunction on the standing car with the idle engine press a brake pedal; when the control bulb lights up, holding a pedal in the pressed situation, unscrew the valve of production of air from the cylinder of a forward left or back right brake. If the pedal of a brake receives the additional course at the same effort, so the second contour of the brake system is faulty. The most probable malfunction in this case – an unsatisfactory condition of a cuff of 37 (fig. 6.2) of the second camera or a mirror of the main cylinder in a working zone of this cuff. Perhaps also damage of a seat of the specified cuff on the piston.
13. In the absence of the additional course of a pedal unscrew the valve of production of air from a forward right or back left brake. If the pedal in this case received the additional course, look for damage to consolidation of cuffs 34 pistons of the second camera and the 37th piston of the first camera. If the cuff 34 is faulty, brake fluid will be pumped over in a tank from the cavity close to the amplifier, in other cavity. In the cases described above remove the main cylinder, disassemble it and eliminate malfunction.
14. Overlapping of compensation openings cuffs can be the cause of a spontaneous zatormazhivaniye of the car. For check remove a tank of the main cylinder and a soft wire with the blunted end probe edges of cuffs through compensation openings. If the wire, without encountering elastic resistance, passes on depth much more 2 mm, then the opening is not blocked by a cuff edge. Otherwise remove the main cylinder. Release of a compensation opening after removal of the main cylinder indicates the wrong adjustment of the amplifier. As the main cylinder is removed, it is necessary to press several times a hand the piston of the main cylinder for the purpose of definition of intensity of return of pistons to a starting position. If compensation openings on the main cylinder removed from the car remained the blocked edges of cuffs, then the reasons of the described defect can be: swelling of cuffs of the main cylinder; pollution of a mirror of the main cylinder; breakage of a returnable spring. Repair the main cylinder.