# Free Delaware CDL Air Brakes Practice Test 2023

Do you need a Delaware Air Brakes endorsement or an L endorsement for your commercial driving license? The CDL Air Brake 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 Delaware CDL Practice test questions are based on the Delaware 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 free CDL practice test to get ready to pass the Delaware CDL Air Brake Test now.

Our CDL practice tests:
Based on 2021 DE commercial driver's license manual
Perfect for first-time, renewal applicants
DE CDL Air Brakes Test format:
25 questions
80% passing score
List of questions
1.
The parking or emergency brake on a heavy vehicle can only be held in position by something that cannot leak away, like:
2.
What can legally hold a parking or emergency brake in position for a truck, truck tractor, or bus?
3.
The driver must be able to see a low air pressure warning which comes on before pressure in the service air tanks falls below ____ psi.
4.
At 55 mph on dry pavement, the air brake lag distance is how many feet?
5.
An air brake system is fully charged at what psi?
6.
When parking a vehicle with a modulating control valve ________.
7.
When using a vehicle with air brakes, the parking needs to be used _______.
8.
When your brake's main air pressure is lost ________.
9.
Some vehicles are equipped with a control allowing you to apply the spring brakes gradually, called a:
10.
If the low air warning comes on while you are driving, you should:
11.
Spring brakes will come on automatically, but the parking brake can also be applied _____.
12.
It is not safe to drive a vehicle that has brake drums with cracks that are longer than _____ of the width of the friction area.
13.
If the spring brakes are on, when should you push the brake pedal?
14.
Repeatedly partially increasing and pressing the brake pedal may result in:
15.
If you need to make an emergency stop, you should brake so that you can ________.
16.
Automatic air tanks _______.
17.
On newer vehicles what color is the parking brake knob?
18.
At what level will the low air warning usually take effect?
19.
The air compressor is connected to the engine through ______.
20.
Why should air tanks be drained completely?
21.
You should use the parking brake _____________.
22.
What does the air compressor governor control?
23.
What is proper braking technique for drivers travelling down a hill or any other downgrade?
24.
Air tanks should be drained:
25.
Vehicles with ABS have malfunction lamps that are what color?