# Free Idaho CDL Air Brakes Practice Test 2023

Do you need an Idaho Air Brakes endorsement or an L endorsement for your commercial driving license? The Idaho 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 Idaho 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 Idaho CDL practice test to get ready to pass the Idaho CDL Air Brake Test now.

Our CDL practice tests:
Based on 2021 ID commercial driver's license manual
Full answers + detailed explanations
Perfect for first-time, renewal applicants
ID CDL Air Brakes Test format:
25 questions
20 correct answers to pass
80% passing score
List of questions
1.
If you do not have automatic tank drains, how often should you drain the oil and water from the bottom of compressed air storage tanks?
2.
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.
3.
An application pressure gauge shows how much air you are applying to the brakes. Increased application pressure to maintain the same speed indicates that __________.
4.
The reduced stopping power caused by overuse of the service brakes and excessive heat is called:
5.
Total stopping distance for air brakes is longer than that for hydraulic brakes due to ______ distance.
6.
If your vehicle has an alcohol evaporator, it is there to:
7.
The brake system that applies and releases the brakes when the driver uses the brake pedal is the ________ brake system.
8.
To make sure that the spring brakes come on automatically, do all of the following except:
9.
When the engine is off and the parking brake released, a single vehicle air loss rate should be less than ________ psi in one minute.
10.
When you need to apply more pressure to help your brakes work normally effectively, this means that your brakes are fading. Which of the following can cause fading brakes?
11.
If you must make an emergency stop, you should brake so you:
12.
To check the free play of manual slack adjusters of S-cam brakes, you should park on:
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.
In case of air pressure loss, a mechanical means of preventing the vehicle from moving is called:
15.
In order to make contact with the brake drum, the brake pads and linings are pushed outward by the:
16.
Brake drums (or discs) must not have cracks longer than ____ the width of the friction area.
17.
Pushing the brake pedal down harder __________.
18.
The service brake system ________.
19.
Stab braking should only be used:
20.
You should use the parking brake _____________.
21.
During a normal drive, the spring brakes are held back by _____.
22.
How often should alcohol containers be checked during cold weather?
23.
What is proper braking technique for drivers travelling down a hill or any other downgrade?
24.
A warning to drivers behind you that the air brakes have been applied is the:
25.
Water and oil _______.