Air Brakes #2
Air Brakes Endorsement Test | Oregon 2025 #2 Page 2 of 4
Train for FREE online with our Oregon 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 OR Class A/Class B driver license in 2025, 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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7 . If one air system in a dual air brake system is very low on pressure:
Lights on the outside of the tractor will flash.
In a dual air brake system, if one of the air systems gets very low on pressure, either the front or rear brakes will not be operating fully. You should bring your vehicle to a safe stop and have the air system repaired.
8 . 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.
9 . To inspect slack adjusters on S-cam brakes, you need to:
Chock the wheels and disengage the parking brake.
Check each slack adjuster after parking on level ground, setting wheel chocks, and disengaging the parking brake. Pull the slack adjusters to make sure they do not move more than about one inch from where the push rod is attached. If they move more than one inch, they may be out of adjustment and will need to be fixed.
10 . What happens if the air pressure in a system's air tanks falls below 60 psi?
The vehicle should stop.
In an air brake system, a low pressure warning signal should activate if the pressure in the air tanks falls to a level below 60 psi. This signal may be in the form of a warning light or a wig wag.
11 . The emergency brake system uses:
Only parts unique to the emergency brake system.
