8.11. Brake mechanisms of back wheels

Fig. 8.7. The brake mechanism of a back wheel: 1 – the working cylinder; 2 – the top coupling spring; 3 – an overlay pad; 4 – a brake board; 5 – a back cable; 6 – an internal plate; 7 – a lobby brake колодка; 8 – the bottom coupling spring колодок; 9 – rivets; 10 – маслоотражатель; 11 – a spring Back hummock; 12 – a tip of a back cable; 13 – back brake колодка; 14 – a basic rack pad; 15 – разжимной the lever of a drive of a lay brake; 16 – распорная a lath колодок; 17 – rubber pillows; 18 – a finger of the lever of a manual drive колодок

The brake mechanism of a back wheel (fig. 8.7) drum-type, with automatic adjustment of a backlash between колодками and drums. The device of automatic adjustment of a backlash is located in the working cylinder.

Fig. 8.8. The working cylinder: 1 – an emphasis pad; 2 – a protective cap; 3 – the cylinder case; 4 – the piston; 5 – a sealant; 6 – a basic plate; 7 – a spring; 8 – crackers; 9 – a persistent ring; 10 – the persistent screw; 11 – the union; And – a cut on a persistent ring

Its basic element is the cutting persistent ring 9 (fig. 8.8), established on the piston 4 between a fillet of the persistent screw 10 and two crackers 8 with a backlash of 1,25-1,65 mm.

Persistent rings 9 are inserted into the cylinder with a tightness providing effort of shift of a ring on a mirror of the cylinder not less 343 Н (35 кгс) that exceeds effort to the piston from coupling springs 2 and 8 (fig. 8.7 see) brake колодок.

When because of deterioration of overlays the backlash of 1,25-1,65 mm completely gets out, the fillet on the persistent screw 10 (fig. 8.8 see) nestles on a fillet of a ring 9 owing to what the persistent ring moves after the piston on deterioration size. With the termination of braking pistons effort of coupling springs move against the stop crackers in a fillet of a persistent ring. Thus the optimum backlash between колодками and a drum is automatically supported.

Brake drum remove for its replacement at damage or deterioration of a working surface, and also for the control of a condition of brake mechanisms and for replacement brake колодок and working cylinders.

GOOD ADVICE Work carry out on the car with the hung out back wheels (on the lift or the car established by means of a jack on support). The lever of a drive of a lay brake should be lowered against the stop downwards (the car расторможен).

It be required to you: keys «on 12», a screw-driver, two assembly shovels.

1. Include I transfer and establish persistent бруски under forward wheels.

2. Check up: the lever of a lay brake should be lowered against the stop downwards (the car расторможен).

3. Remove a back wheel.

4. For convenience of work remove a decorative cap. However at replacement of a drum the cap can to be removed.

5. Moisten a backlash between a drum and a flange of a semiaxis any легкопроникающей a liquid (kerosene, WD-40, etc.).

6. Turn out two bolts (on a photo one is visible) fastenings of a brake drum to a semiaxis.	7. Shift a drum from a semiaxis easy blows of a hammer.

8. If the drum does not act in film effort of hands, bring down its hammer, using wooden брусок, or...	9.... Press, in regular intervals wrapping bolts in two carving apertures of a drum.

10. Remove a brake drum.

11. At installation of a former drum remove a file a fillet on a working surface of the drum, formed as a result of deterioration.

12. Establish a drum in an order, the return to removal. Preliminary smooth out from corrosion a landing corbel of a semiaxis, grease with its graphite greasing or greasing ЛСЦ-15 and reduce pad by means of two assembly shovels.

THE PREVENTION Consider that at cave-in of pistons in cylinders level of a brake liquid in a tank of the main brake cylinder raises. If necessary pump out a liquid.

13. Check up ease of rotation of a wheel. The lung задевание a drum about pad is supposed. On the car standing on the earth 2–3 times press a brake pedal to bring pad to a drum.

At damage of protective caps of the working cylinder the road dirt and a moisture causing corrosion of a mirror of the cylinder and a leak of a brake liquid get to an internal cavity of the cylinder. Therefore, if during check of a condition of brake system (Check and adjustment of brake system »see«) damages of caps are found out, necessarily replace them.

THE NOTE Timely replacement of protective caps will help to prolong service life of the working cylinders which replacement is much more difficult and more expensive.

It be required to you: a screw-driver, small beards.

1. Remove a brake drum (Removal and installation of a brake drum »see«).

2. Disconnect the top coupling spring 1 from колодок 2.

GOOD ADVICE There is one more way to deduce the top ends колодок from piston grooves, without disconnecting a spring. For this purpose it is necessary to take advantage of a lay brake («Replacement of the working cylinder of the back brake mechanism» see).

3. Take away brake pad in the parties, clamping springs how much allow.

4. Hook a screw-driver a protective cap and remove it with проточки on the cylinder.

5. Remove a cap from the piston.

6. The second cap remove similarly.

7. Establish new caps so that their internal landing corbels have entered in проточки on the cylinder. Check up, that caps have been established into place without warps.

8. Reduce pad and with the help a small beard establish the removed end of the top spring in an aperture pad.

THE PREVENTION Check, that the top ends колодок have entered into nests on pistons of the wheel cylinder.

9. Establish a brake drum and a wheel.

If while in service there were traces подтекания a brake liquid on a brake drum and a wheel inside, replace the working cylinder. Repair of the working cylinder often does not lead to positive results, besides special adaptations are for this purpose necessary. Therefore it is recommended to replace the cylinder in gathering.

It be required to you: a key «on 10» and a special key for nuts of brake tubes.

1. Include I transfer and establish persistent бруски under forward wheels.

2. Remove a corresponding wheel.

3. Clear of a dirt a place of fastening of a brake tube and bolts of fastening of the brake cylinder from an underside of a brake board. That it is easier to turn away bolts of fastening of the cylinder and a nut of fastening of a brake tube, put on carving connections liquid WD-40.

4. Remove a brake drum (Removal and installation of a brake drum »see«).

5. Lift the lever of a lay brake, thus the top ends колодок leave piston grooves.	6. Turn away a nut of fastening of a brake tube to the working cylinder and...

7.... Muffle a tube aperture, for example a cap of the valve of release of air.	8. Turn away two bolts of fastening of the working cylinder, holding it on the other hand, and...

9.... Remove the working cylinder.

GOOD ADVICE After long operation the nut of a brake tube "grows together" with a tube in a single whole, and at attempt to turn away a nut the tube is braided and breaks. In this case only shift a tube nut a little, then turn out bolts of fastening of the cylinder and disconnect it from a tube, screwing together the cylinder from its nut. After a detachment of the cylinder from a tube mobility of the released nut can be restored, having moistened with its brake liquid and turning a nut a key alternately in both parties.

10. Establish the working cylinder in an order, the return to removal.

11. Pump over brake system (it is possible only the working cylinder on a replaced wheel).

12. Necessarily establish a protective cap on the valve of release of air.

Is minimum admissible thickness of frictional overlays brake колодок – 1,5 mm.

Replace pad in following cases:

– A thickness of frictional overlays of less admissible;

– The surface of overlays is made oily;

– The frictional overlay is unsteadily connected to the basis;

– Overlays have deep furrows and сколы.

PREVENTIONS Do not apply gasoline, diesel fuel or any other mineral solvents to clearing of brakes. Колодки replace in brake mechanisms of both back wheels simultaneously. Replacement forward and back колодок among themselves, and also between the left and right wheel is inadmissible. It can lead to non-uniform braking.

It be required to you: пассатижи or a screw-driver, two assembly shovels.

1. Include I transfer and establish persistent бруски under forward wheels.

2. Check up: the lever of a lay brake should be lowered against the stop downwards (the car расторможен).

3. Remove a wheel.

4. If level of a brake liquid is in a tank of the main brake cylinder on a mark «MAX» or comes nearer to it, pump out from a tank a liquid part. Otherwise at replacement колодок it can be splashed out.

5. Remove a brake drum (Removal and installation of a brake drum »see«).

6. Remove the bottom coupling spring flat-nose pliers or...	7.... A screw-driver.

8. Turn the top cup of a clamping spring on 90 ° and...	9.... Remove it together with a spring and the bottom cup. Take out from a board of a brake a core of a clamping spring.

10. Similarly remove the second clamping spring.

11. Remove pad in gathering with распорной a lath and the top spring and...

12.... Having taken away the lever, disconnect a cable of a lay brake.

13. Keeping a foot one of колодок, stretch a spring and remove распорную a lath.

14. Remove the top coupling spring.

15. For replacement back pad расшплинтуйте a finger of the lever of a drive of a lay brake.	16. Remove a washer, the lever and...

17.... A finger.

18. Establish the removed details of a drive of a lay brake on new brake колодку in sequence, return to removal.

GOOD ADVICE For prevention of jamming of a drive of a lay brake grease a working surface of a finger with a thin layer консистентной greasings.

19. Establish pad in an order, the return to removal.

THE NOTE Having established pad, reduce them, having pressed on them two assembly shovels.

20. Establish a brake drum.

21. Press some times a pedal of a brake for installation of pistons of wheel cylinders into position.

22. Establish into place a wheel. Check up ease of its rotation.

23. Similarly replace brake pad the brake mechanism of other wheel.

24. After installation brake колодок adjust lay brake system (Check and adjustment of a lay brake »see«).