Correct answer
A rapid, unexplained drop in gauge pressure.
A rapid, unexplained drop in air pressure may indicate a leak. An air-brake circuit uses compressed air, not the fluid level in a hydraulic master cylinder. Stored pressure should not fall to zero simply when the pedal is released. Follow the manufacturer’s checks and tolerances and repair faults before using the vehicle.
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All options
A rapid, unexplained drop in gauge pressure.
Stable stored pressure during the check.
A pressure increase caused by outside air entering through the leak.
The real exam in English is a translation of the Spanish original; compare both here.
Show the Spanish original
En una comprobación conforme al fabricante, el camión está inmovilizado, el motor parado y no se está accionando el freno. ¿Qué puede indicar una fuga en el circuito neumático de frenos?
- Una presión almacenada estable durante la comprobación.
- Una caída rápida e injustificada de la presión indicada por el manómetro.(Correct answer)
- Un aumento de presión causado por aire exterior que entra por la fuga.
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