New Hampshire CDL — Air Brakes Practice Test

The New Hampshire CDL — Air Brakes knowledge test has ~25 questions; you need ~20 correct (80%) to pass.

Or take one of 10 full-length practice tests

25 questions · pass with 20 correct. You get instant feedback and an explanation after every answer.

Choose your level

The full-length test, with feedback and an explanation after every answer.

New Hampshire CDL — Air Brakes practice tests

10 full-length practice tests, each with 25 questions and a pass mark of 20, like the real test. You see the answers and explanations after you grade.

Test 1
25 questions · pass with 20
While you are driving an air-braked truck normally, what keeps the spring brakes from applying?
Test 2
25 questions · pass with 20
In the manual's description of the air compressor governor, what is the "cut-in" pressure?
Test 3
25 questions · pass with 20
In the manual's description of the air compressor governor, what is the "cut-in" pressure?
Test 4
25 questions · pass with 20
Driver A's CDL carries the L restriction and Driver B's carries the Z restriction. Going by the manual's definitions, which of them may operate a commercial vehicle with air over hydraulic brakes?
Test 5
25 questions · pass with 20
The final air brake check gives roughly 100 psi for compressor cut-in and roughly 125 psi for cut-out. What reminder does the manual attach to those figures?
Test 6
25 questions · pass with 20
Two trucks both have alcohol evaporators. Truck A's air tanks have manual drain valves; Truck B's have automatic drain valves. Under the alcohol evaporator passage, which truck still needs its tanks drained by the driver every day?
Test 7
25 questions · pass with 20
On older vehicles, the manual ties the low air warning to the compressor governor instead of to a fixed 55 psi. If such a vehicle's governor cuts out at 120 psi, when must the visible warning come on?
Test 8
25 questions · pass with 20
The manual lists what puts the L restriction, no air brake equipped CMV, on a CLP or CDL. Which of these is NOT one of the triggers?
Test 9
25 questions · pass with 20
While you are driving an air-braked truck normally, what keeps the spring brakes from applying?
Test 10
25 questions · pass with 20
On older vehicles, the manual ties the low air warning to the compressor governor instead of to a fixed 55 psi. If such a vehicle's governor cuts out at 120 psi, when must the visible warning come on?