Air Brakes #1
Air Brakes Endorsement Test | Illinois 2026 #1 Page 4 of 4
Train for FREE online with our Illinois CDL air brake test. The official exam test consists of several obligatory parts, with all of them checking your knowledge of different blocks of road rules. If you need to obtain a IL Class A/Class B driver license in 2026, practice as much as possible. Free sample tests published on our website will help you check and improve your knowledge and boost your grades. Please bear in mind that the requirements for CDL may vary from state to state.
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19 . Air tank drains:
Clean the air in the passenger compartment.
In an air brake system, air tanks have drains to remove accumulations of water and compressor oil. Allowing water and oil to accumulate in the system could cause damage to the brakes. Manually operated drains should be used daily.
20 . In a vehicle with dual air brakes, what happens if one system is low on pressure?
The low system will use an auxiliary system to fill the tank.
In a dual air brake system, if one of the air systems gets very low on pressure, either the front or rear brakes will not be operating fully. You should bring your vehicle to a safe stop and have the air system repaired.
21 . You should not use the parking brake:
If your vehicle's other braking systems seem to be working adequately.
A parking brake should not be used if the vehicle's brakes are very hot from use on a steep downgrade or if the brakes are very wet and temperatures are freezing. Using the parking brake when brakes are hot could cause damage to the brakes, and using the brakes when they are wet in freezing weather may cause the brakes to ice up, rendering the vehicle immobile.
22 . In a newer vehicle, you apply the parking brake:
By using a black round knob.
In a newer vehicle with air brakes, the parking brake is controlled by a diamond-shaped yellow knob. The knob is pulled out to apply the parking brakes and pushed in to release them.
23 . How is the parking brake released?
By tapping the accelerator twice
In newer vehicles with air brakes, the parking brakes are controlled by a diamond-shaped yellow knob. Pull the knob out to activate the parking brakes and push it in to release them.
24 . Emergency brakes:
Are optional.
All trucks, truck tractors, and buses must be equipped with emergency brakes and parking brakes. These brakes must be held by mechanical force.
25 . Most heavy-duty vehicles use:
Quadruple air brake systems.
Most heavy-duty vehicles use dual air brake systems, in which there are two separate braking systems operated by a single set of controls. Each system operates the brakes on different axles.
See the exact questions that will be on the 2026 Illinois DMV exam.
99.2% of people who use the cheat sheet pass the FIRST TIME
Lillian MCcranie explains how our CDL study guide was helpful in passing the exam and recommends it to everyone.
Cameron tells us how he purchased the CDL exam, and found it to be a useful tool which helped him pass the exam and find a job.
2026 Illinois | Frequently Asked Questions
To acquire a CDL Tank endorsement in Illinois, you must first have a Commercial Driver's License (CDL). Next, study the Tank Vehicles section of the Illinois Commercial Driver's License Study Guide. Once prepared, schedule and pass the written tank vehicle endorsement test at a Secretary of State Driver Services facility. The endorsement will then be added to your CDL.
To obtain a CDL Tank license, it is essential to have a Commercial Driver's License (CDL) first. Then, you need to study the Tank Vehicles section of the Illinois Commercial Driver's License Study Guide. After studying, you must pass the written tank vehicle endorsement test at a Secretary of State Driver Services facility in Illinois.
While specific training or experience isn't legally mandatory for a CDL Tank endorsement in Illinois, it is highly recommended. Understanding the operation of tank vehicles and handling of liquid cargo is crucial. Studying the Tank Vehicles section of the Illinois Commercial Driver's License Study Guide and passing the written test at a Secretary of State Driver Services facility is required.
Yes, to obtain a CDL Tank endorsement in Illinois, you must pass an additional written test. This test covers specific knowledge related to the safe transport of liquid and gaseous materials in tank vehicles. The information for the test can be found in the Tank Vehicles section of the Illinois Commercial Driver's License Study Guide.
The written test for the CDL Tank endorsement in Illinois covers various subjects including: high and low center of gravity and its impact on vehicle stability, how to inspect tank vehicles, how to drive vehicles loaded with liquids or gases, and special safety considerations for hazardous materials. All these subjects are detailed in the Illinois Commercial Driver's License Study Guide.
The CDL Tank endorsement assessment evaluates your understanding of tank-specific operations. You'll be tested on handling liquid surge, inspecting tank vehicles, managing a high center of gravity, and the implications of carrying a full or partial load. However, it's primarily a knowledge test, so specific driving maneuvers aren't typically assessed in this endorsement.
Yes, drivers with a CDL Tank endorsement must comply with specific requirements and regulations. These include maintaining a clean driving record, undergoing regular medical examinations, and adhering to hours-of-service regulations. Additionally, drivers must follow safety procedures when loading and unloading tanks, and comply with hazardous materials transportation regulations if applicable.
No, you cannot legally transport liquid or gas materials without a valid CDL Tank endorsement in Illinois. This endorsement is necessary for operating a commercial vehicle designed to transport any liquid or gaseous materials within a tank or tanks having an individual rated capacity of more than 119 gallons and an aggregate rated capacity of 1,000 gallons or more.
Yes, the CDL Tank endorsement can be added to your current license in Illinois. You don't need to apply for a fresh license. However, you must pass the Tank Vehicle endorsement test. Once passed, the endorsement will be added to your existing CDL, allowing you to legally operate tank vehicles.
Yes, handling hazardous materials with a CDL Tank endorsement requires adherence to specific regulations. Drivers must pass the Hazardous Materials (HazMat) endorsement knowledge test, undergo a federal background check, and submit fingerprints. They must also follow safety protocols for loading and unloading hazardous materials, and comply with shipping paper requirements.
