Air Brakes #2
Air Brakes Endorsement Test | Iowa 2026 #2 Page 4 of 4
Train for FREE online with our Iowa 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 IA 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 . If the low air pressure warning signal comes on in a vehicle with air brakes, the driver should:
If the low air pressure warning signal comes on while you are operating a vehicle with air brakes, you should stop and safely park the vehicle as soon as possible. It is essential that you are able to stop safely while you still have some braking power remaining.
20 . Brake fade is a result of:
If brakes are overused, they can become too hot. This overheating causes them to fade, making them less effective at slowing the vehicle.
21 . Manual air tank drains should be:
Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Manually operated air tank drains must be opened daily to remove this build-up.
22 . Once the air tanks are at an air pressure level of 125 psi, the air compressor governor will:
An air compressor governor will stop the compressor from pumping air once the air tanks are at an air pressure level around 125 psi. This air pressure level is referred to as the "cut-out" level.
23 . A slack adjuster should move no more than ____ from where it is attached to the push rod.
Before a trip, you should check each slack adjuster after parking, setting wheel chocks, and disengaging the parking brake. Pull the slack adjusters to make sure that they do not move more than about one inch from where the push rod is attached. If they move more than one inch, they may be out of adjustment and will need to be fixed.
24 . Air storage tanks:
In an air brake system, the air storage tanks hold compressed air to be used by the brakes. The number and size of air tanks varies among vehicles.
25 . Emergency brakes:
All trucks, truck tractors, and buses must be equipped with emergency brakes and parking brakes.
2026 Iowa | Frequently Asked Questions
To acquire a CDL Hazmat endorsement in Iowa, you need to pass the Hazardous Materials Endorsement Knowledge Test. Additionally, you must undergo a federal background check and fingerprinting. The TSA will assess your application and once approved, the Iowa Department of Transportation will add the endorsement to your CDL.
To obtain a CDL Hazmat license, you must first possess a valid Commercial Driver's License (CDL). You also need to be at least 21 years old, a U.S. citizen or have legal status, and be able to read and speak English. Additionally, you must pass the Hazardous Materials Endorsement Knowledge Test and undergo a federal background check and fingerprinting.
When applying for a CDL Hazmat endorsement in Iowa, you'll need to provide proof of U.S. citizenship or permanent residency, proof of identity, and proof of Iowa residency. Additionally, you'll need to bring your current CDL. A TSA background check and fingerprinting are also required, for which separate documentation may be needed.
Yes, there is a dedicated written test for the CDL Hazmat endorsement. This test is called the Hazardous Materials Endorsement Knowledge Test. It covers topics such as loading and unloading hazardous materials, bulk packaging marking, driving and parking rules, and emergency response procedures.
The written test for the CDL Hazmat endorsement in Iowa covers a wide range of subjects. These include understanding hazardous materials regulations, safety procedures, proper use of shipping papers, placarding, loading/unloading, bulk packaging marking, compatibility and segregation of cargo, and emergency response procedures.
Yes, there are additional fees associated with obtaining a CDL Hazmat endorsement in Iowa. These include a fee for the knowledge test, a fee for fingerprinting, and a fee for the TSA background check. The specific amounts can vary, so it's best to check with the Iowa Department of Transportation for the most current costs.
Yes, obtaining a CDL Hazmat endorsement in Iowa requires a background check. The Transportation Security Administration (TSA) conducts this check, which includes a review of your criminal, immigration, and FBI records. This ensures that you do not pose a security threat while transporting hazardous materials.
Yes, specialized training is required for the CDL Hazmat endorsement in Iowa. This involves understanding hazardous materials regulations, emergency response procedures, and safety protocols. After training, you must pass a written test to get certified. This ensures that drivers are equipped with necessary knowledge to handle hazardous materials safely.
No, you cannot legally transport hazardous materials in Iowa without a valid CDL Hazmat endorsement. This endorsement is required by federal law and ensures that drivers have the necessary knowledge and skills to safely transport hazardous materials. Violating this requirement can result in severe penalties, including fines and suspension of your CDL.
You can add a Hazmat endorsement to your current CDL in Iowa. You don't need to apply for a new CDL. However, you must pass a written test on hazardous materials and complete a TSA security threat assessment, which includes fingerprinting and a background check, to obtain the endorsement.