In the vacuum brake booster, during the applied position, which statement about the valve positions is true?

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Multiple Choice

In the vacuum brake booster, during the applied position, which statement about the valve positions is true?

Brake boost relies on pressure differences created by two control valves on the booster diaphragm. When the pedal is pressed, the valve actuators move so that the atmospheric valve opens and the vacuum valve closes. This allows atmospheric pressure to enter the booster chamber while isolating engine vacuum. The resulting pressure difference across the diaphragm pushes the booster piston toward the master cylinder, increasing hydraulic pressure with less pedal effort. That’s why the statement describes the atmospheric valve as open and the vacuum valve as closed during the applied position.

Brake boost relies on pressure differences created by two control valves on the booster diaphragm. When the pedal is pressed, the valve actuators move so that the atmospheric valve opens and the vacuum valve closes. This allows atmospheric pressure to enter the booster chamber while isolating engine vacuum. The resulting pressure difference across the diaphragm pushes the booster piston toward the master cylinder, increasing hydraulic pressure with less pedal effort. That’s why the statement describes the atmospheric valve as open and the vacuum valve as closed during the applied position.

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