| 1. On the idle engine press several times a brake pedal, the course of a pedal of a brake thus should not change. | 
 
 | 2. Press a pedal and start the engine. After engine start-up the pedal should be displaced a little forward. | 
 
 | 3. Press a pedal of a brake and stop the engine. Within about 30 seconds, the pedal should keep the situation. | 
 
 | 4. Again start the engine, later 1 mines stop and press several times a pedal. The pedal course with each pressing should decrease. | 
 
 | 5. If operation of the vacuum amplifier differs from described above, the unit is subject to replacement (see subsection 8.11). |