Vacuum pumps are a safety critical component, providing vacuum for:
- Central Locking and other safety/comfort systems
The different types of vacuum pump work through ‘positive-displacement’ to move air from the vacuum system, and then through the crankcase ventilation and into the air intake system.
Rotary Vane Pumps – consist of vanes mounted to an offset rotor that rotates inside a cavity. Vacuum pressure is provided as air is moved
from a larger chamber through to a smaller chamber. Click on the link
to the right to see a demo of the rotary vane pump movement.
Diaphragm Pumps – consist of a chamber sealed with a flexible diaphragm. As the diaphragm flexes, the volume in the chamber is increased/decreased to provide vacuum pressure.
Piston Pumps – consist of a piston and chamber assembly where the piston moves up and down to increase/decrease the volume of the chamber to provide vacuum pressure.
Troubleshooting and Diagnostics
Common reasons for vacuum pump failures include:
When a pump starts to fail, vacuum controlled systems as
outlined above will also start to fail and the OBD system may register a
fault by illuminating the warning lamp.