Air Brakes #2
Air Brakes Endorsement Test | Colorado 2026 #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 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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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.
