In a hydraulic brake booster, what does the spool valve do in the applied position?

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Multiple Choice

In a hydraulic brake booster, what does the spool valve do in the applied position?

The key idea is that the spool valve directs hydraulic fluid to the booster’s pressure chamber to create assist. When the brakes are applied, the valve shifts to route pressurized fluid from the hydraulic source into the pressure chamber. This builds pressure in the chamber, moving the booster piston to amplify the force on the master cylinder and reduce the pedal effort required by the driver. Venting or blocking flow would either release the pressure (no assist) or stop flow altogether, which is not what happens in the applied position.

The key idea is that the spool valve directs hydraulic fluid to the booster’s pressure chamber to create assist. When the brakes are applied, the valve shifts to route pressurized fluid from the hydraulic source into the pressure chamber. This builds pressure in the chamber, moving the booster piston to amplify the force on the master cylinder and reduce the pedal effort required by the driver. Venting or blocking flow would either release the pressure (no assist) or stop flow altogether, which is not what happens in the applied position.

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