9.10.7. Repair of the vacuum amplifier
It is easy to check efficiency of the vacuum amplifier on the car (see above).
It is necessary to be convinced also of tightness of the vacuum amplifier and backpressure valve. For this purpose it is necessary to kill the engine, to make endurance of 1 — 2 min. and to press several times a pedal. During the first three pressing noise of the air entering in the amplifier has to be heard. If it does not occur, the vacuum amplifier or the backpressure valve are faulty.
Completely it is necessary to sort the amplifier only when necessary.
To remove the amplifier from the car and it is necessary to sort in the following order:
- to clear the amplifier of dust and dirt, to disconnect a rubber hose from the backpressure valve, and the main cylinder from the amplifier;
- to fix the main cylinder with a tank that from it liquid did not pour out (it allows to exclude pumping of system after repair);
- to take out the forelock, to turn off a nut of fastening of an axis of an eye of a pusher to a pedal of a brake and to remove a spring washer, an axis and plastic plugs;
- to turn off four nuts of fastening of the vacuum amplifier to a cabin front guard, to take out the amplifier from podkapotny space;
Fig. 8.9. Device for dismantling and assembly of the amplifier: 1 — laying; 2 — a tube; 3 — the screw; 4 — adaptation; 5 — a cap; 6 — a cover; 7 — the case; 8 — a vice
- to fix by two nuts on hairpins of a cover of 6 (fig. 8.9) of the case a special cap 5 with the handle for turn of a cover and with a tube 2 for connection of the vacuum gage;
- to install the vacuum amplifier in the special adaptation 4 fixed in a vice 8;
- screwing the screw 3 in adaptation, to drown a cover of the 6th vacuum amplifier before emergence of a small gap in connection a cover — the case 7;
Fig. 8.2. Vacuum amplifier: A1, A2, A3, A4 and A5 — cavities of the vacuum amplifier; A6 — openings; 1 — the backpressure valve; 2 — the sealing plug; 3 and 16 — pushers; 4 — an adjusting bolt; 5, 10, 17 — pistons; 6 — a cover; 7 and 8 — diaphragms; 9 — a persistent ring; 11 — the case of the amplifier; 12 — the directing rings; 13 — sealing cuffs; 14 — the filter; 15 — the case of valves; 18 — a diaphragm of valves; 19 — the screw; 20 — a jet washer; 21 — a spring; 22 — a connector of pistons
- to insert the extender into the cap handle and to turn the handle before coincidence of ledges on the case with cuts on a cover. To unscrew the screw on several turns and to uncover 6 with a spring 21 (see fig. 8.2);
- to turn off a nut of a connector of pistons and to remove the piston 5 with a diaphragm 7, a plate and a persistent ring;
- to remove the amplifier from adaptation and to take a persistent cover and other details of the amplifier from the case, to take a lock washer and to take out a pusher from a connector;
- to turn off three bolts with spring washers and to remove a connector, the piston 10 with a diaphragm 8 and a diaphragm 18 with a spring. To take out from the piston 10 a jet rubber washer 20; to turn out two screws 19 fixing the pusher piston 17 in the case of 15 valves and to take out a pusher with the piston;
- to turn off a pusher eye, previously having weakened a lock-nut;
- to slightly squeeze a pusher spring, to take out a lock washer and to remove other details from a pusher. The pusher with the piston is a non-demountable connection. To take out lock washers and to take from a persistent cover and the case 11 of the amplifier the directing plastic rings 12, and also sealing rubber cuffs 13;
- to remove a sealing rubber ring from a connector of pistons;
- to take out the backpressure valve 1 of a cover of the case and if necessary to replace it.
To clear all details of the amplifier of dirt and to examine. To replace the details having damages or excessive wear. Special attention should be paid to check of rubber details of the amplifier, and also a condition of the external polished surfaces of a connector of pistons and cases of 15 valves. In the presence of scratches and zadir these surfaces should be smoothed out accurately a small skin and to wash out.
If the filter 14 is littered, it needs to be replaced.
Before assembly all details of the amplifier have to be absolutely pure. If necessary all details, except for rubber, can be washed out in pure kerosene and to dry up a stream of compressed air.
It is necessary to collect the amplifier in the sequence, the return dismantling.
At assembly it is necessary to consider the following features:
- the rubber sealing ring in the case of 15 valves needs to be greased with TsIATIM-221 lubricant;
- after installation of sealing cuffs 13 in the case and a persistent cover to grease their internal surfaces with a thin layer of TsIATIM-221 lubricant;
- to install a collected pusher with the piston in the case of 15 valves. To press slightly a pusher, overcoming spring resistance and to screw two fixing screws 19. To wrap screws against the stop, then to turn off everyone on 0,5 turns and to zakernit them for prevention of an otvorachivaniye. The pusher with the piston has to move without jammings and distortions to 1 — 2 mm;
- to grease the external polished surfaces of a connector of pistons and the case of 15 valves before assembly with a thin layer of TsIATIM-221 lubricant;
— 7 and 8 before assembly to cover a surface of diaphragms with a thin layer of talc, and 7 for simplification of turn of a cover concerning the case to grease a flute of a fillet of a diaphragm with a thin layer of castor oil or NG-213 liquid;
- 7 at assembly to straighten a diaphragm so that its fillet came for ledges on the case of the amplifier and nestled on the internal diameter of the case;
- to tighten the nut fixing the piston 5 the moment of 5,5 — 8 N · m (0,55 — 0,8 kgfs · l);
- inserting a cover 6 into the case 11, to watch that the diaphragm 7 was not wrapped.
After assembly to check efficiency of the amplifier in the following order:
- to connect the backpressure valve of 1 amplifier a hose to a depression source, for example, with an inlet pipe of the working engine; 2 (see fig. 8.9) in a cap 5 to connect the end of a tube a hose to the vacuum gage;
- to create in the amplifier depression about 70 kPa (0,7 kgfs/cm2) and to close the crane on the vacuum pipeline. During 10 about depression more than on 4 kPa (0,04 kgfs/cm2) should not change.
After check to establish distance of 131 — 133 mm between the privalochny surface of the case of the amplifier and the center of an eye of a pusher as it is specified fig. 7.6 and to tighten an eye nut.
The correct operation of the main brake cylinder is possible if the gap between a head of an adjusting bolt 4 and the privalochny plane of a cover of the 6th vacuum amplifier is equal to 1,35 — 1,65 mm. For installation of this gap to weaken a lock-nut and to rotate a bolt 4. After adjustment to tighten a lock-nut.
To collect the amplifier with the main cylinder and to install it on the car it is necessary as it should be, the return to dismantling.