Air Brakes #1
Air Brakes Endorsement Test | Massachusetts 2026 #1 Page 3 of 4
Train for FREE online with our Massachusetts 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 MA 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.
25
20
20
13 . Why do large vehicles use air brakes?
Air is free.
Air brakes are an effective and safe way of stopping large and heavy vehicles, as long as they are maintained and used properly.
14 . Air tank drains:
Must remain open while driving.
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.
15 . Before driving a vehicle with a dual air brake system, you must wait for the air compressor to build a minimum of ____ in both the primary and secondary systems.
100 psi
Before driving a vehicle with a dual air brake system, you should wait for the air compressor to build up at least 100 psi in both the primary and secondary systems.
16 . When you need to stop in an emergency, you should:
Expect your vehicle to slow down more quickly than usual.
If you need to make an emergency stop, you can use either the controlled braking method or the stab braking method. It's important to brake in a way that keeps your vehicle traveling in a straight line while still allowing you to turn, if necessary.
17 . 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.
18 . During a static leakage test, the maximum leakage rate for a single vehicle with air brakes is ____ in one minute.
4 psi
