Vacuum pump
Saab 9-3 Turbo with automatic transmission and Saab 9-3 Diesel are fitted with a mechanical vacuum pump in order to further increase their braking force. The pump supplies the brake servo with negative pressure since the engine alone cannot fully achieve this.
The ring type pump is fitted on top of the cylinder head and is driven by the camshaft. As the pump is connected to the camshaft, it rotates at half the engine rotation speed and vacuum is produced continuously for the brake system.