Air Brakes #2
Air Brakes Endorsement Test | Colorado 2025 #2 Page 3 of 4
Train for FREE online with our Colorado 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 CO Class A/Class B driver license in 2025, 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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13 . How is water and compressor oil removed from the bottom of an air storage tank?
A sponge is used to soak up the water and oil.
Water and compressor oil are removed from air storage tanks through a drain valve. The water and oil can damage the brakes if left to accumulate in the system. Manually operated tanks must be drained every day to remove this build-up.
14 . What is a wig wag?
A part within the braking unit that allows air to move freely
A wig wag is a type of low air pressure warning device in an air brake system. It drops a mechanical arm into the driver's view when the air pressure in the tanks falls below 60 psi.
15 . Before driving a vehicle with air brakes, you should ensure that the spring brakes come on automatically when:
Driving uphill.
Before driving a vehicle with air brakes, you should ensure that the spring brakes come on automatically when air tank pressure falls to a level between 20 and 45 psi. You can do this by chocking the wheels and releasing air from the braking system by stepping on and off the brake pedal. Once the pressure drops to an unsafe level, the parking brake valve should pop out and spring brakes should come on.
16 . While driving downhill, you should brake until you reach a speed that is ____ below your safe speed, then release the brake pedal.
20 mph
While driving downhill, you should hold down the brake pedal until your vehicle reaches a speed 5 mph below your safe speed, then release the brake pedal. Repeat this process.
17 . If the brake pads rub against the brake drums and create too much heat:
The air compressor will kick on to cool the brakes.
Brakes heat up with use. If they are overused and become too hot, expansion and chemical changes will make them less effective and eventually cause them to stop working altogether. This is known as "brake fade."
18 . Anti-Lock Braking Systems (ABS):
Are illegal in some states.
ABS is equipped in addition to a vehicle's normal braking system and it neither increases nor decreases the vehicle's braking capability. ABS activates during hard applications of the brake pedal in order to prevent wheels from locking up.
2025 Colorado | Frequently Asked Questions
A CDL Class A license in Colorado is defined as a commercial driver's license that allows the holder to operate any combination of vehicles with a Gross Combination Weight Rating (GCWR) of 26,001 pounds or more, provided the GVWR of the vehicle(s) being towed is over 10,000 pounds. This typically includes tractor-trailers and truck and trailer combinations.
A Class A CDL license in Colorado allows you to operate vehicles such as tractor-trailers, truck and trailer combinations, tank vehicles, livestock carriers, and flatbeds. These are typically vehicles with a Gross Combination Weight Rating (GCWR) of 26,001 pounds or more where the towed vehicle(s) exceed 10,000 pounds.
To obtain a Class A CDL license in Colorado, applicants must be at least 18 years old (21 for interstate driving), possess a valid driver's license, pass a vision test, and successfully complete knowledge and skills tests. They must also pass a Department of Transportation (DOT) physical examination and provide proof of residency and social security number.
In Colorado, you must be at least 18 years old to qualify for a Class A Commercial Driver's License (CDL) for intrastate driving (within Colorado only). However, to drive a commercial vehicle across state lines (interstate driving), federal regulations require drivers to be at least 21 years old.
Endorsements are not required for a Class A CDL license, but they can provide additional driving privileges. These include H (Hazardous Materials), N (Tank Vehicles), P (Passenger Vehicles), S (School Bus), T (Double/Triple Trailers), and X (Combination of Tank Vehicle and Hazardous Materials). Each endorsement requires additional knowledge tests, and some may require skills tests.
The Class A CDL skills test in Colorado includes three parts: the pre-trip inspection, the basic vehicle control, and the on-road test. You'll need to demonstrate knowledge of your vehicle's components, show you can control your vehicle in various situations, and prove your ability to safely drive in traffic.
Yes, there are limitations. A Class A CDL holder may be restricted from operating certain types of vehicles or transporting certain types of cargo depending on their qualifications, endorsements, and any restrictions listed on their license. Examples include air brake restrictions, manual transmission restrictions, or restrictions related to wearing corrective lenses while driving.
No, according to federal regulations, the written Class A CDL test in Colorado must be taken in English. This is to ensure that all commercial drivers can read and understand traffic signs and signals, directions, and other driving-related documents in English, which is essential for safety on U.S. roads.
Yes, you can request accommodations for the Class A CDL written test if you have a disability. The Colorado DMV is committed to providing equal access to its services. You should contact your local DMV office in advance to discuss your needs and arrange for any necessary accommodations. This might include assistive technology or extra time to complete the test.
If you don't pass the Class A CDL written test in Colorado, you can retake it. However, you must wait until the next day to do so. There's no limit to how many times you can retake the test, but keep in mind, each attempt requires a new fee. It's advisable to study thoroughly before retesting.