How should you test that the low air pressure warning works during a pre-trip inspection?
a.By turning on the ignition and checking if the light comes on briefly
b.By pumping the brake pedal with the engine off to reduce air pressure and verify the warning activates before 60 PSI
c.By disconnecting an air line
d.By pressing the horn button
Explanation
To test the low air pressure warning, turn the engine off with a fully charged system, then repeatedly press and release the brake pedal to reduce air pressure. The low air pressure warning light and/or buzzer should activate before the pressure drops below 60 PSI.