15.2. Check of the vacuum amplifier of brakes

For simple check of the vacuum amplifier of brakes execute the following tests.

 PERFORMANCE ORDER

  1. Start the engine and in 1–2 minutes stop it. Several times press a brake pedal with usual effort. If the first course of a pedal the long and second course is shorter, than the first course – it demonstrates normal operation of the vacuum amplifier of brakes. If height of a pedal does not change, so the vacuum amplifier is damaged.
  2. At the switched-off engine several times press a brake pedal. Start the engine. If the pedal of a brake moves down at once after start of the engine, it demonstrates normal operation of the vacuum amplifier of brakes. If height of a pedal does not change, so the vacuum amplifier is damaged.
  1. Start the engine. Press a brake pedal with usual effort. Stop the engine. Slowly press a pedal of a brake and hold it pressed during 30 pages. If height of a pedal does not change, the vacuum amplifier of brakes works normally.

Otherwise, check the unilateral vacuum valve or a vacuum hose for absence of damage and check reliability of their fastenings.