CDL Air Brake Test exam questions and answers update

CDL Air Brake Test exam questions and
answers 2024-2025 update

The parking or emergency brake on a heavy
vehicle can only be held in position by
something that cannot leak away, like:


a. Fluid pressure
b. Spring pressure
c. Air pressure
d. Any of the above - CORRECT b. Spring
pressure


A straight truck or bus air brake system should
not leak at a rate of more than psi per
minute with the engine off and the brake
released.


a. 1

,b. 2
c. 3
d. 4 - CORRECT c. 3


Your vehicle has dual air brake system. If low air
pressure warning comes on for the secondary
system or for one system, you should:


a. Bring the vehicle to a safe stop and continue
only when the system is fixed.
b. Reduce your speed, and test the remaining
system while under-way.
c. Reduce your speed, and drive to the nearest
garage for repairs.
d. Continue at normal speed if only the
secondary system fails. - CORRECT a. Bring
the vehicle to a safe stop and continue only
when the system is fixed.

, If your vehicle has an alcohol evaporator, it is
there to:


a. Rid the wet tank of alcohol that condenses
and sits at the bottom.
b. Eliminate the need for daily tank draining.
c. Boost tank pressure the same way that
superchargers boost engines.
d. Reduce the risk of ice in the air brake valves
in cold weather. - CORRECT d. Reduce the risk
of ice in the air brake valves in cold weather.


Air braking takes more time than hydraulic
because air:


a. Brakes use different brake drums.