6.1.3. Repair

At wear of details of the brake system or other malfunctions sort system, check a condition of details and their suitability for further work. Replace the worn-out and damaged details. At repair of system use these tab. 19.
Lower brake shoes with the slips which are made oily in the course of work for 20–30 min. in gasoline (unleaded). Then carefully clear working surfaces of slips a metal brush and a skin.
Replace blocks on forward brake mechanisms at the same time (both couples of blocks). If on working surfaces of a brake disk there are deep risks, teases or uneven wear, its proshlifuyta on both sides on identical depth. When grinding a disk be based on a surface, being basic at installation of a disk on a nave. At wear of a disk to thickness less than 20,4 mm replace it new.
When replacing blocks of back brake mechanisms a surface of slips to a proshlifuyta so that diameter of slips was 0,2-0,4 mm less than diameter of a drum. If on the working surface of reels there are deep risks, teases or uneven wear, then chisel a drum. When boring a drum be based on a surface, being basic at installation of the reel on a nave. Increase in internal diameter of drums by 0,8 mm after boring does not demand change of diameter of brake
blocks. The most admissible diameter of the chiseled drum of the working brake mechanism of 281 mm.
When dismantling wheel and main brake cylinders and the regulator of pressure observe purity. Wash out rubber and metal details of cylinders only in alcohol or brake fluid. Do not apply kerosene or gasoline as it will put rubber details of the brake system out of action.
After a sink of a detail blow compressed air, but do not wipe fabric in order to avoid hit of fibers on a working surface of details and loss of tightness.
Before assembly of a cuff and sealing rings ship in brake fluid.

Removal, dismantling and assembly of working brake mechanisms
At repair brake shoes and wheel cylinders or details entering them for which removal there is no need to remove completely brake mechanisms usually are subject to replacement.
Assembled you carry out removal from the car of brake mechanisms only at their full replacement new or at full dismantling of bridges.
At installation of brake mechanisms of forward wheels pay attention to their correct situation to the car. The valve has to be screwed by Perepuskna in the top cylinder.
At installation on the car of brake mechanisms of back wheels the block with a long slip has to be ahead.

Removal and installation of brake shoes of forward brake mechanisms
1. Lift a jack the car and remove a wheel.

Fig. 256. Brake mechanism of a forward wheel:
1 – spring; 2 – blocks;
3 – bracket; 4 – support; 5 – protective cap; 6 – lock ring; 7 – sealing ring; 8 – protective cover; 9 – piston; 10 – plug; 11 – bolt; 12 – screw; 13 – cap; 14 – perepuskny valve; 15 – cap; 16 – bolt of fastening of a spring; 17 – block of cylinders


2. Turn off bolts 16 and remove a spring of 1 blocks (see fig. 256).
3. Before removal of blocks drown pistons 9 in cylinders for what move a bracket 3 against the stop of pistons to the internal surface of the block of cylinders.
Before movement of a bracket 3 uncover a tank of the main cylinder and do not allow transfusion of liquid from it when moving a bracket.
4. Remove blocks 2.
And assembly of brake mechanisms you carry out installation of blocks with new slips upside-down.
When replacing blocks check a state and landing in nests of protective caps 5 and covers 8. If necessary replace them or provide the correct landing in nests.
For leading of blocks to a disk press 2–3 times a pedal.

Removal and dismantling of wheel cylinders of forward brake mechanisms
1. Disconnect a hose from the block of cylinders and remove a support assembled with the block of cylinders.
2. Remove brake shoes 2.
3. Remove lock rings 6 and protective caps 5.
4. Having given compressed air through an inlet opening for liquid, push out pistons 9 of cylinders. At the same time not to damage pistons, establish between a bracket 3 and the piston a wooden lining.
You carry out assembly and installation of wheel brake cylinders upside-down.

Removal and installation of brake shoes of back brake mechanisms
1. Lift a jack the car and remove a wheel which brake shoes need to be removed.
2. Remove the brake drum from a nave.
For this purpose unscrew three screws of fastening of a drum to a nave. If the drum is removed hardly, then wrap removable bolts in three special carving openings which are available in a drum disk and, evenly wrapping them, remove a drum.

Fig. 264. Removal and installation of a coupling spring of brake shoes


3. Remove a coupling spring of brake shoes by means of special nippers (fig. 264).
4. Remove the top cups of squeezing springs, springs, the lower cups and take out cores.
5. Turn off nuts of basic fingers, take out basic fingers, clowns and remove brake shoes.
6. Before installation of new blocks pistons together with persistent rings need to be shifted in depth of the cylinder for free putting on of a drum on blocks.
And assembly of brake mechanisms you carry out installation of blocks with new slips upside-down.
Install brake drums after removal on the same naves. Shift of brake drums from one nave on another will lead to increase in a beating of working surfaces of the reel of rather brake slips.
At installation of the reel into place before wrapping screws of its fastening, it is necessary to press densely nuts of fastening of wheels the brake drum to a nave and only after that to wrap screws. It is necessary for more dense pressing of the brake drum to a wheel nave.

Fig. 257. Brake mechanism of a back wheel: and – tags on basic fingers; 1 – basic finger; 2 – board; 3 – opening caps for visual control of a condition of brake slips; 4 – wheel brake cylinder; 5 – perepuskny valve; 6, 12 – brake shoes; 7 – protective cap; 8 – piston; 9 – sealing rings; 10 – persistent ring;
11 – coupling spring


When replacing blocks check a state and landing in nests of protective caps 7 (see fig. 257). If necessary replace them or provide the correct landing in nests.
For leading of blocks to a drum press 2–3 times a brake pedal.

Adjustment of installation of brake shoes of back brake mechanisms
1. Lift a jack a wheel which brake mechanism needs to be adjusted.
2. Turn off nuts of basic fingers a little and establish basic fingers in initial situation (tags at end faces of basic fingers have to be located as it is specified fig. 257).

Fig. 265. Adjustment of brake blocks of a back wheel basic fingers


3. Pressing a pedal with constant effort 120–150 N (12–15 kgfs), turn basic fingers so that the ends of blocks from fingers rested against the brake drum (fig. 265). Determine the moment of contact of blocks with a drum by increase in resistance when turning a basic finger. In this situation tighten nuts of basic fingers, watching that at the same time fingers did not turn.
4. Having stopped pressing a pedal, check that wheels rotated freely without jamming of a drum for blocks.
At the correct installation of new blocks with not worn-out brake drums of a tag and on basic fingers have to be located, as shown in fig. 257, or with deviations from this situation in this or that party to 50 °.
At installation of new blocks when frictional slips were not earned extra to the surface of reels yet, brake drums after the specified adjustment can heat up a little. After several braking of a block will be earned extra and heating will stop.

Removal and dismantling of wheel brake cylinders of back brake mechanisms
1. Disconnect the pipeline from the cylinder and remove the cylinder.
2. Take off protective caps of cylinders, take out pistons with sealing rings and a lock ring.
You carry out assembly and installation of wheel brake cylinders upside-down.

Removal and dismantling of the main brake cylinder
1. Disconnect the pipelines going from the main brake cylinder.
2. Disconnect the main brake cylinder from the vacuum amplifier.

Fig. 260. Main brake cylinder: 1 – protective cap; 2 – a cover with the sensor of emergency falling of level of brake fluid; 3 – tank;
4 – case of the main brake cylinder; 5 – stopper; 6,13 – laying;
7 – stopper insert; 8 – spring; 9 – spring saddle; 10, 19 – washers; 11,
17 – pistons; 12 – the bolt is persistent; 14 – plug limiter; 15 – screw emphasis; 16 – the cuff is sealing; 18 – external cuff; 20 – lock ring; 21 – the plug is connecting


3. Turn off a persistent bolt 12 (see fig. 260).
4. Remove a lock ring 20 and take out a persistent washer 19.
5. Take out the piston 17 of the first camera assembled.
6. Turn off a stopper 5, take out an insert of a stopper 7, a returnable spring 8 and the piston 11 of the second camera assembled.
The tank 3 is not recommended to be removed needlessly. In case of need for its removal turn off a cover 2 with the sensor of emergency falling of level of liquid and carefully take a tank from connecting plugs 21.
Assembled take out the piston 17 only towards a flange, and the piston 11 assembled – towards an opposite end face. Take out pistons carefully not to damage sealing cuffs 16 and 18. If pistons are not taken out freely from the cylinder, at first slightly push the piston 11 the piston 17, and then carefully push out the piston 17 pressing (through the released cavity) the screw-driver or other subject on the plug limiter 14 or the screw 15.
You carry out assembly and installation of the main cylinder upside-down. At the same time install assembled pistons in the cylinder carefully and only from the cylinder end faces corresponding to them. In order to avoid damage of sealing cuffs and rings do not push pistons through all cavity of the cylinder.
At assembly of the piston 17 wrap the screw 15 against the stop in the piston. 12 wrap a persistent bolt in the case only after installation of the assembled piston 17, a washer 19 and a lock ring 20.
Moments of an inhaling, N • m (kgf • l):
persistent bolt       12 8-10 (0,8–1,0);
traffic jams       5 170-190 (17-19).
Removal, dismantling, assembly and installation of the main brake cylinder with two tanks are carried out similarly.

Removal, dismantling, assembly and installation of the regulator of pressure
 Removal and dismantling of the regulator of pressure
1. Disconnect the pipelines conducting to the regulator.
2. Disconnect the regulator from an arm (basis).

Fig. 261. Pressure regulator: 1 – piston; 2 – sealing ring of the piston; 3, 6 – basic washers of a spring of the piston; 4 – piston spring; 5 – case; 7 – piston head sealant; 8 – case plug; 9 – basic washer of the plug of a pusher; 10 – pusher plug; 11 – sealing ring of a pusher;
12 – basic plate; 13 – pusher plug spring; 14 – stopper; 15 – laying of a stopper; 16 – perepuskny valve; 17 – cap; 18 – piston plug;
19 – lock ring; 20 – protective cover


3. Turn off a stopper 14 (see fig. 261) from a case end face.
4. Remove a protective cover 20 and a lock ring 19.
5. Take out the piston 1 of the case with all internal details.
6. Unscrew perepuskny the valve 16.
The control cap 17 is not recommended to be removed without need. Take out the piston from the case carefully towards an end face under a protective cover not to damage sealing rings. If the piston is not taken out freely from the case, at first slightly push him from an end face under a stopper.
 Assembly and installation of the regulator
1. Collect the piston 1 with a sealant 7 (see fig. 261).
2. Install in the regulator case 5 the case plug 8, the subassembled piston with a sealant, a basic washer 6, a spring 4 pistons, a basic washer 3, a sealing ring 2, the plug 18 of the piston and a lock ring 19.
3. Install in the regulator case a basic washer 9, a sealing ring 11, the pusher plug 10, the second sealing ring 11, a basic plate 12 and a spring of the 13th plug.
4. Podsoberite a stopper 14 with laying 15 also wrap it in the regulator case.
5. Wrap in the case of the regulator perepuskny the valve 16.
6. Establish a protective cover 20, a cap of the perepuskny valve and a control cap 17 (if it was taken out).
 Moments of an inhaling, N • m (kgf • l):
traffic jams 14..... 44–58 (4,4–5,8);
valve 16..... 10–14 (1,0–1,4).
 Removal and installation of the drive of the regulator of pressure

Fig. 262. Pressure regulator drive: 1 – pressure regulator;
2 – arm (basis); 3 – drive lever; 4 – adjusting bolt; 5 – elastic lever; 6, 9, 13 – bolts; 7 – plug; 8 – lever rack; 10 – the plug is expansion; 11 – plug; 12 – rack arm; 14 – lever axis


The drive of the regulator of pressure is not recommended to be removed without need from the car not to break its adjustment. In case of dismantle at assembly it is necessary to sustain the adjusting sizes given on fig. 262. At the same time install the size N (position of the elastic lever 5 concerning a point And an arm 2) by an adjusting bolt 4 on pressure regulator subassembled with an arm 2, the drive 3 lever, the elastic lever 5 and the plug 11 (before installation on the car).
 Moments of an inhaling, N • m (kgf • l):
bolt 13 and nuts of bolts 4, 13 and axes 14..... 28–36 (2,8–3,6);
bolts of fastening of the regulator to an arm 2 and nuts of a bolt 9..... 14–18 (1,4–1,8);
nuts of a bolt 6..... 6,5–8,0 (0,65–0,8).

Removal, dismantling and assembly of the vacuum amplifier

Fig. 259. Vacuum amplifier: 1 – cover of the secondary camera; 2 – piston of the secondary camera;
3 – return valve; 4 – spring; 5 – nut; 6 – emphasis; 7 – rod; 8 – washer; 9 – rod sealant; 10, 12, 37 – lock washers; 11 – sealing ring; 13 – sealing cuff of a cover; 14 – plate of a diaphragm; 15 – the directing cover ring; 16 – cover of primary camera; 17 – basic ring; 18 – diaphragm of the piston of the secondary camera; 19 – connector; 20 – buffer; 21 – spring of a diaphragm of the valve of management; 22 – diaphragm of the piston of primary camera; 23 – case of the amplifier; 24 – piston of primary camera; 25 – valve case; 26 – persistent washer; 27 – the directing case ring;
28 – sealing cuff of the case; 29 – valve piston; 30 – air filter; 31 – protective cover; 32 – pusher fork; 33 – pusher; 34 – spring plug; 35 – valve spring; 36 – sealant of the valve of management; 38 – forelock-provoloka; 39 – valve diaphragm; 40 – screw-upor; I, II – atmospheric cavities; III, IV – vacuum cavities


At an exit of the amplifier out of operation on pistons of the main cylinder only the effort from the driver's leg is transmitted through a pusher 33 (see fig. 259), the valve of management, the buffer 20 and a rod 7.
The increased effort to a pedal indicates the need of survey and, perhaps, repair of the amplifier.
At an exit out of operation of sealants, springs and other details the amplifier remove from the car, having disconnected previously from it the main brake cylinder, a hose, a pedal, and sort. Before dismantling put tags on the case and a cover that at assembly to establish them on initial places.
Sort and collect the amplifier in special adaptation by means of a small press.
The amplifier establish in openings of not movably established plate by four bolts with the rubber plugs which are put on them for protection of a carving from damage. On two bolts of a cover of the second camera, having also protected previously their carving, install the special lever with openings under these bolts and, pressing on it with small effort a press, turn a cover before combination of ledges on the case of the amplifier with hollows on a cover.
Other operations do not demand special devices.
At assembly 6, 17, 24, 25 and the contacting surfaces of a cover 1 with a diaphragm 18 grease the working surfaces of friction of details with lubricant
TSIATIM-221.
After assembly the amplifier check for working capacity and tightness. For this purpose attach a hose to the return valve and at the working engine apply effort of 200-300 N (20–30 kgfs) to a pusher 33. Thus the case of the valve of management together with a pusher has to move to an emphasis.
After removal of effort from a pusher the 33rd case of the valve of management has to come back to a starting position. After 2–3 min. after an engine stop when pressing a pusher 33 hissing of the air arriving in the amplifier via the valve of management has to be listened.
Before installation of the main brake cylinder on the amplifier adjust a departure of a rod of the 7th rather privalochny plane of a cover 1 at a size of 7,78-8 mm and a departure of a pusher of the 33rd rather privalochny plane of the case 23 at a size of 134,7-136,3 mm.