The Bendix two-way -TW- series valves are manually operated, non-graduating, on-off valves The Bendix+ TW-12 is extensively used in hydraulic braking systems to control devices that are responsible for the application and release of the parking brakes Note: The TW-12 control valve can also be used in air brake system applications The most common configuration of the TW-12 control valve uses a levered cam that is manually, remote controlled A dash mounted lever or button may be connected to the aluminum lever cam via Bowden cable control or connected directly to the transmission selector