F 150 2WD V8-4.6L VIN W (2007)
Vacuum Brake Booster: Description and Operation
Brake Booster
The vacuum-type power brake booster:
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is a dual diaphragm, vacuum-assisted power brake booster.
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reduces brake pedal force.
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is located on the LH side of the bulkhead in the engine compartment, between the brake pedal and the brake master cylinder.
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is divided into separate chambers by the diaphragms.
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will not operate if the vacuum is restricted or if any of the vacuum-related power brake components fail.
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is installed as an assembly.
If the power assist fails, the brake system continues to operate with increased brake pedal effort.
Hose and Check Valve
The power brake booster check valve:
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is located on the front of the power brake booster.
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is installed separately (install a new grommet when installing a new check valve).
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is positioned between the power brake booster and the power brake booster hose.
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closes when the engine is turned off.
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in the closed position, traps engine vacuum in the power brake booster.
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retains vacuum to provide a power assisted brake application with the engine off.
