Air Tightness Check
- Start the engine and keep it running at idle until vacuum pressure indicates 66.7 kPa (500 mmHg, 19.69 inHg) while the brake pedal is not depressed.
- Stop the engine and check the vacuum pressure.
If the value matches the following standard, the vacuum booster assembly function is normal.
Vacuum pressure: standard
The range of vacuum pressure drop within 15 seconds after stopping the engine is 3.3 kPa (25 mmHg, 0.98 inHg) or less
If a faulty part is detected after inspection, it may results from one of the following causes.
- Check valve malfunction
- Leak from vacuum hose
- Leak from shell joint section or stud bolt welded section
- Damaged diaphragm
- Leak from valve body seal and bearing section
- Leak from plate and seal assembly section
- Leak from poppet valve assembly section