Free Iowa CDL Air Brakes Practice Test 2022

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

Our CDL practice tests:
Based on 2022 IA commercial driver's license manual
Full answers + detailed explanations
Perfect for first-time, renewal applicants
IA 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.
"A slack adjuster’s free play needs to be adjusted if it is more than about ______ when you pull hard on it."
3.
A low air pressure warning signal is ________.
4.
During normal driving, spring brakes are usually held back by:
5.
Emergency stab braking is:
6.
The application pressure gauge shows how much air pressure you:
7.
When should the spring brakes activate?
8.
When the mechanical arm of a wig wag drops into your view that means the pressure in your system has dropped below what psi?
9.
Air governor cut-out should be at around:
10.
If the air compressor should develop a leak, what keeps the air in the tanks?
11.
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.
12.
The safety valve reduces pressure at ___ psi.
13.
The level at which the air compressor stops pumping air is:
14.
Which of these is NOT a proper time to apply the parking brakes?
15.
If your vehicle has an alcohol evaporator, every day during cold weather you should:
16.
Under normal braking conditions, the vehicle:
17.
In case of air pressure loss, a mechanical means of preventing the vehicle from moving is called:
18.
At what level will the low air warning usually take effect?
19.
The service brake system ________.
20.
Why should you check the brake adjustment often?
21.
Initial air leakage rate for combination vehicles should be:
22.
Automatic adjusters should ________.
23.
What does ABS stand for?
24.
Required on all vehicles with air brakes, what tells the driver that air pressure is too low?
25.
What is an alternative name for a brake pedal?