MA CDL Air Brakes study guide
MA CDL Air Brakes · Work through your exam, one topic at a time.
The Massachusetts CDL Air Brakes knowledge test is the written exam a commercial driver takes to be certified on air brake systems. Passing it removes the air brakes restriction (L) from a Massachusetts commercial driver's license, which you need before you can legally operate a vehicle equipped with air brakes - most heavy trucks, tractor-trailers, and many buses. The MA CDL Air Brakes study guide has 7 sections and about 2,562 words.
01Air Brake System Components and Operation
This domain tests whether you can trace compressed air from the compressor to the brake chamber and say what each part does. Massachusetts questions here are about function and identification, not repair.
413 words, about 2 min02Dual Air Brake Systems and Safety Features
This domain tests how the two circuits work together and what protects you when one fails. Questions usually ask what a specific valve does or what happens to the spring brakes.
371 words, about 2 min03Pre-Trip Inspection of Air Brake Systems
This domain tests whether you can find an air brake defect before the wheels roll. A defect you miss during the walk-around is scored against you, so know the order and the acceptance limits.
379 words, about 2 min04Air Brake System Leak Checks and Pressure Tests
These tests prove the compressor, governor, warning devices and spring brakes work before you drive. Chock the wheels, release the parking brake, and start at full system pressure.
336 words, about 2 min05Using Air Brakes While Driving
The foot valve must send air down the lines before anything happens at the wheels. At 55 mph that lag adds roughly 32 feet to stopping distance before the brakes begin to work, so you brake earlier than in a car and leave a bigger following gap.
325 words, about 2 min06Braking on Downgrades and Emergency Braking
Check the brakes at the top of the hill by applying them firmly while still at speed. If they do not hold, stop and find out why before descending.
374 words, about 2 min07Air Brake System Malfunctions and Warning Devices
A low pressure warning light and buzzer must activate before pressure drops below 60 psi. On many vehicles one light serves both circuits.
364 words, about 2 min