# Free North Carolina CDL Air Brakes Practice Test 2023

Do you need an Air Brakes endorsement or an L endorsement for your commercial driving license? The North Carolina CDL Air Brake test has some differences from other endorsements because your license will receive a mark of restriction if you fail the test. So having good preparation before exam day is very necessary. To ensure that our questions are relevant, all of our CDL practice test packs are based on the NC CDL Manual. Each question has a detailed explanation for you to thoroughly learn the format and the topic. Don't be afraid of having a restriction on your license. Let’s try our NC CDL Test to get ready to pass the North Carolina CDL Air Brake Test now.

Our CDL practice tests:
Based on 2021 NC commercial driver's license manual
Perfect for first-time, renewal applicants
NC CDL Air Brakes Test format:
25 questions
80% passing score
List of questions
1.
What can legally hold a parking or emergency brake in position for a truck, truck tractor, or bus?
2.
In case of emergency when driving a vehicle equipped with dual parking control valves, you should:
3.
The driver must be able to see a low air pressure warning which comes on before pressure in the service air tanks fall below ____ psi.
4.
A low pressure warning signal could be __________.
5.
A mechanical device that drops a low air warning into a drivers view is called a:
6.
Excessive heat caused by using your brakes too often can also cause:
7.
Spring brakes will generally come on at:
8.
The ____ shows how much pressure is in the air tanks.
9.
When the safety valve releases air this indicates ___________.
10.
In most newer vehicles, the parking brake control will be:
11.
Some vehicles are equipped with a control allowing you to apply the spring brakes gradually, called a:
12.
What happens when your brake drums get very hot?
13.
If you are driving down a steep downgrade and have reached your safe speed of 40 mph, you would apply the service brake until your speed dropped to ____ mph.
14.
Which of these is NOT a proper time to apply the parking brakes?
15.
16.
The brake pedal in an air brake system _______.
17.
If one air system is very low on pressure _______.
18.
In tractors and straight trucks spring brakes will come on fully when the air pressure drops to what range?
19.
Which of the following helps the stop light switch work?
20.
When driving an older vehicle that has a manual front brake limiting valve, drivers should:
21.
The spring brakes of a tractor will come on when the air pressure falls within _______.
22.
Vehicles without automatic air tank drains need to be checked manually to remove ________?
23.
What is the purpose of a supply pressure gauge?
24.
In a dual air brake system, one system will typically control the rear brakes, and the other:
25.
On a long or steep downgrade, how should vehicle speed be primarily controlled?