4.3.14. Check of operation of the vacuum amplifier of brakes

At increase in effort to a pedal of a brake it is necessary to check efficiency of the vacuum amplifier.
1. Press a brake pedal against the stop several times at the idle engine and, holding a pedal in the pressed situation, launch the engine. Due to difference of values of pressure in cavities of the amplifier the brake pedal has to move forward.
2. If it does not occur, check tightness of connections of a hose of the vacuum amplifier with the backpressure valve...
3. … and an inlet pipe, if necessary eliminate an air suction. If it does not yield positive result, then the amplifier is faulty and it needs to be replaced.
4. To check tightness of the vacuum amplifier, open a cowl and launch the engine for 1 min. Approximately through 30 from later stop of the engine press two times a brake pedal — characteristic hissing of the air entering in the amplifier has to be listened.
5. In addition check the backpressure valve of the amplifier at which malfunction depression in a vacuum cavity of the amplifier at change of loading of the engine does not remain or at its stop. For valve check disconnect from it a vacuum hose.
6. Take out the valve from a rubber sealant of a flange of the amplifier, put on the valve union (short, bigger diameter) a rubber pear (for example, from the areometer) and squeeze it. If the valve is serviceable, the pear will remain compressed. If the pear is straightened, replace the valve and repeat check of the amplifier.
7. Establish into place the removed details as it should be, the return to removal.

GOOD ADVICE
If malfunction of the amplifier is found, replace him new as works on repair of the amplifier are very labor-consuming, demand the corresponding skills and use of the special erection and adjusting facilities.