Air Brakes #2
Air Brakes Endorsement Test | South Carolina 2024 #2 Page 3 of 4
Train for FREE online with our South Carolina CDL air brake test. The official exam test consists of several obligatory parts, with all of them checking your knowledge of different blocks of road rules. If you need to obtain a SC Class A/Class B driver license in 2024, practice as much as possible. Free sample tests published on our website will help you check and improve your knowledge and boost your grades. Please bear in mind that the requirements for CDL may vary from state to state.
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13 . What can happen if the air pressure gets too low in an air brake system?
The brakes will be very sensitive.
Pressing and releasing the brake pedal unnecessarily can let air out faster than the compressor can replace it, reducing the available air pressure. If the air pressure in an air brake system gets too low, the brakes will no longer work.
14 . At what psi is the safety valve set to open?
500 psi
In an air brake system, the first tank that receives compressed air has a safety valve that releases air if the pressure gets too high. It is usually set to open at 150 psi. If the valve must open, there is a fault in the system that should be repaired by a mechanic.
15 . An alcohol evaporator in an air brake system:
Some air brake systems include an evaporator that introduces alcohol into the system. The alcohol can help prevent ice from forming within the system.
16 . A low air pressure warning signal should activate:
When tank pressure falls below 5 psi.
In an air brake system, a low air pressure warning signal must come on if air pressure in the tanks falls below 60 psi. This warning signal may come in the form of a light, a buzzer, or a wig wag.
17 . An air brake-equipped vehicle traveling at a speed of 55 mph under ideal driving conditions will need approximately ____ to come to a complete stop.
450 feet
