Base Brake Valves (Normal Closed)

WARNING: This page is about a different car, the 2010 GMC Sierra and 2010 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The normally closed base brake valve is used to close off a passage which allows fluid from the back side (spring side) of the simulator and from the tank port of the boost valve to exit to the reservoir. In normal braking, turning this valve on (opening) allows the simulator to compress the spring and function normally. During failed system operation (push-through) the valve is left off (closed) keeping fluid from exiting the back side of the simulator, which in turn keeps master cylinder fluid from entering the front side of the simulator. In this way, fluid from the master cylinder during failed system, and push through operation is applied only to the wheel brakes, and not lost in the simulator. In normal operation the valve is turned on (opened).