11.3. Brake system

Fig. 11.5. The main brake cylinder and the vacuum amplifier: 1 – the main cylinder; 2 – a tank of the main cylinder; 3 – the vacuum amplifier; 4 – lock скоба; 5 – a finger

On the car the main brake cylinder 1 (fig. 11.5) with a tank 2 and the vacuum amplifier 3 applied on front-wheel cars VAZ can be established.

Fig. 11.6. The device of the vacuum amplifier of a brake: 1 – the case of the vacuum amplifier; 2 – a cup of the case of the amplifier; 3 – a rod; 4 – an adjusting bolt; 5 – a rod sealant; 6 – a sealing ring of a flange of the main cylinder; 7 – a returnable spring of a diaphragm; 8 – an amplifier hairpin; 9 – the plug of fastening of the return valve; 10 – the return valve; 11 – the union of fastening of a hose; 12 – a diaphragm; 13 – a cover of the case of the amplifier; 14 – a sealing cover; 15 – the piston; 16 – a protective cover of the case of the valve; 17 – the air filter; 18 – a pusher; 19 – a returnable spring of a pusher; 20 – a valve spring; 21 – the valve; 22 – the plug of the case of the valve; 23 – the rod buffer; 24 – the valve case; And – the vacuum chamber; In – the atmospheric chamber; With, D – channels

The vacuum amplifier. A rubber diaphragm 12 (fig. 11.6) together with the case 24 valves divide a cavity of the vacuum amplifier on two chambers: vacuum And and atmospheric V.Kamera And it is connected to an inlet pipe of the engine through the return valve of a tip 11 and a hose.

The case 24 valves the plastic. On an exit from a cover it is condensed by the goffered protective cover 16. In the valve case the rod 3 drives of the main cylinder with the basic plug, the buffer 23 rods, the piston of 15 cases of the valve, the valve 21 in gathering, returnable springs of 19 and 20 pusher and the valve, the air filter 17, a pusher 18 is established.

By pressing a pedal move a pusher 18 and the piston 15, and after them and the valve 21 against the stop to a saddle of the case of the valve. Thus chambers And and In are separated. At the further moving of the piston its saddle departs from the valve and through the formed backlash the chamber In incorporates to atmosphere. Air which has arrived through the filter 17, a backlash between the piston and the valve and channel D, creates pressure upon a diaphragm 12. At the expense of a pressure difference in chambers And and To the valve case moves together with a rod 3 which influences the piston of the main cylinder.

At the released pedal the valve 21 departs from a saddle of the case and through the formed backlash and the channel From the chamber And and In are informed among themselves.

Fig. 11.7. The device of the main cylinder of a brake: 1 – the case of the main cylinder; 2 – a sealing ring of low pressure; 3 – the piston of a drive of a contour the left forward-right back brake; 4 – races порное a ring; 5 – a sealing ring of a high pressure; 6 – a clamping spring sealing Rings; 7 – a spring plate; 8 – a returnable spring of the piston; 9 – a washer; 10 – the lock screw; 11 – the piston of a drive of a contour the right forward-left back brake; 12 – the connecting plug; 13 – a tank; 14 – the gauge of emergency level of a brake liquid; And – a backlash

The main cylinder with a consecutive arrangement of pistons (fig. 11.7). On the case of the main cylinder the tank 13 is fixed, in a stopper of which jellied mouth the gauge 14 emergency levels of a brake liquid is established. Sealing rings 5 main cylinders and similar rings of the back wheel cylinder are interchangeable.

1. Disconnect колодку with wires from the gauge 14 (fig. 11.7 see) emergency level of a brake liquid.

2. Turn away a nut of fastening of the main cylinder to the amplifier, remove it from hairpins and take aside, cautiously bending pipelines not to damage them.

THE NOTE At amplifier removal the main cylinder of a hydrodrive of brakes do not disconnect from hydrosystem that air has not got to it.

3. Disconnect a hose from the return valve of the amplifier.

4. Disconnect the vacuum amplifier from a brake pedal, having removed lock скобу 4 (fig. 11.5 see) and having taken out a finger 5.

5. Turn away a nut of fastening of the vacuum amplifier to an arm of a pedal of a brake and a body.

6. Remove the vacuum amplifier.

7. Establish the vacuum amplifier in an order, the return to removal.

THE PREVENTION The brake amplifier – the responsible knot directly influencing traffic safety. Repair of the amplifier demands the special assembly and control equipment and means high qualification of the executor. Therefore the faulty amplifier do not assort, and replace new.

The main cylinder remove from the car for replacement or repair. However if the executor does not possess skills of performance of razborochno-assembly works, the partition of the main cylinder often does not lead to desirable results, therefore we recommend to replace the faulty cylinder in gathering.

1. Pump out a rubber pear a liquid from a tank.

2. Disconnect pipelines from the main cylinder.

THE NOTE Muffle apertures at pipelines and at the main cylinder not to admit leak of a liquid and hit in them of a dust and a dirt.

3. Disconnect колодку with wires from plugs of the gauge of emergency level of a brake liquid.

4. Turn on two nuts of fastening of the cylinder to the vacuum amplifier and accurately remove the cylinder in gathering with a tank from hairpins.

5. Turn away a stopper of a jellied mouth and merge from a tank and from the cylinder the rests of a brake liquid.

THE NOTE If you have removed a tank from the main cylinder, examine rubber plugs of fastening of a tank. The plugs torn, cracked or lost elasticity replace.

6. Establish the main cylinder, wrap nuts of its fastening and fill in a brake liquid in a tank. Substitute under the main cylinder capacity or put a rag for gathering of a brake liquid.

7. Close aperture fingers under brake tubes in the main cylinder. The assistant should press slowly a brake pedal until from forward apertures of the cylinder the brake liquid will not begin to flow.

8. During this moment connect tubes to forward apertures of the cylinder and wrap nuts of their fastening. Thus the assistant should keep a pedal in the pressed condition. Similarly connect tubes to back apertures of the cylinder. Establish all removed details upside-down. Press a pedal of a brake and if it "soft", pump over brake system (see section 8 «the Brake system», «Prorolling of a hydrodrive of brake system»).

1. Remove the main cylinder from the car (Removal and installation of the main cylinder »see«).

2. Using a wooden shovel as the lever, remove a tank 13 (fig. 11.7 see) from the cylinder.

3. Take from the case of the main cylinder connecting plugs 12.

Fig. 11.8. Details of the main cylinder: 1 – the cylinder case; 2 – a sealing ring of low pressure; 3 – the piston of a drive of a contour the left forward-right back brake; 4 – распорное a ring; 5 – a sealing ring of a high pressure; 6 – a clamping spring of a sealing ring; 7 – a spring plate; 8 – a returnable spring of the piston; 9 – a washer; 10 – the lock screw; 11 – the piston of a drive of a contour the right forward-left back brake; 12 – a sealing lining

4. Turn out two lock screws 10 (fig. 11.8)

5. Effort of a hand take from the case pistons of the first and second chambers with cuffs, washers and springs. Thus the piston 11 second chambers can do not leave free. For its extraction with remained details blows by a case end face from outside the first chamber about a pure board advance it through the first chamber. For piston extraction it is possible to use also compressed air which needs to be brought to an exhaust outlet of the second chamber, having closed thus an aperture under a tank.

6. Attentively examine and be convinced of perfect cleanliness of a mirror of the cylinder and a working surface of pistons, in absence of a rust, рисок and other roughnesses. Otherwise replace details new.

7. Replace the cuffs torn, inflated or lost elasticity. It is recommended to replace at each dismantling of the main cylinder cuffs new irrespective of their condition.

8. Check up elasticity of springs of the pistons which length should be under loading 38,26–46,1 Н (3,9–4,7 кгс) – 41 mm, under loading 81,81–99,47 Н (8,34–10,14 кгс) – 21 mm, in a free condition – 59,7 mm. Replace the springs which have lost elasticity.

9. Linings 12 (fig. 11.8 see) under lock screws it is recommended to replace new.

10. Before assemblage wash out all details a pure brake liquid. Do not suppose hit on a detail of mineral oils, gasoline or diesel fuel as even residual traces of these liquids can lead to destruction of rubber cuffs.

11. Collect the cylinder in an order, the return to dismantling. Thus all details grease with a brake liquid.