FAA Aviation Mechanic Airframe (AMA)Landing Gear SystemsHard
A technician is troubleshooting a hydraulic brake system that uses a component to reduce full system pressure to a lower, regulated pressure suitable for the brakes, since the aircraft's brakes cannot tolerate full hydraulic system pressure. Which component performs this function?
- ADebooster valve
- BShuttle valve
- CRestrictor valve
- DPriority valve
Show answer & explanationAnswer & explanation
Correct answer: A. Debooster valve
A debooster (deboost) valve reduces high system hydraulic pressure to a lower, controlled pressure and increases volume flow to the brakes, protecting the brake assembly from excessive pressure while still providing adequate braking force.
Why the other options are wrong
- B. A shuttle valve selects between two pressure sources (normal/emergency), not pressure reduction.
- C. A restrictor valve slows flow rate but does not proportionally reduce and regulate pressure like a debooster.
- D. A priority (sequence) valve controls the order of actuation between systems, not pressure level.
Debooster (Deboost) Valve
A hydraulic valve/cylinder that reduces high system pressure to a lower regulated pressure for brake application while increasing fluid volume delivered to the brake.
- Protects brakes from full system pressure
- Increases volume while reducing pressure (piston area ratio)
- Common on aircraft with high-pressure hydraulic systems and lower-rated brakes
Memory trick: 'Deboost = de-boosting the pressure down to brake-safe levels'