CDL AIR BRAKES PRACTICE TEST #4
CORRECT 100%
1. Air loss in a straight truck or bus should not be more than ____ with the engine off
and the brakes on. - ANSWER 3 psi in one minute
2. To make an emergency stop with air brakes, using the stab braking method, you
should: - ANSWER C Brake as hard as you can, get off the brakes when the wheels
lock, get back on the brakes when the wheels start rolling again.
7. The brake system that applies and releases the brakes when the driver uses the
brake pedal is the: - ANSWER A Service brake system.
8. The most common type of foundation brakes found on heavy vehicles is the: -
ANSWER A Disc brakes
9. Vehicles with air brakes must have: - ANSWER C An air pressure gauge, to show air
used by the brake chambers for braking
C An air pressure gauge, to show air used by the brake chambers for braking -
ANSWER B 40 psi
11. Which of the following makes the total stopping distance for air brakes longer than
that for hydraulic brakes. - ANSWER A Brake lag distance.
12. Of the choices below, the first thing to do when a low air pressure warning comes on
is: - ANSWER Stop and safely park as soon as possible.
13. The braking power of the spring brakes: - ANSWER B Depends on the adjustment
of the service brakes.
3. You should know that your brakes are fading when: - ANSWER B You have to push
harder on the brake pedal to control your speed on a downgrade.
4. To check the free play of manual slack adjusters on s-cam brakes you should: -
ANSWER A Park on level ground, chock the wheels, and release the parking brakes.
5. If the air compressor should develop a leak, what keeps the air in the tanks? -
ANSWER C The one way check valve
. When driving down a long steep hill you should: - ANSWER Release the brake when
you are 5 M.P.H. below your safe speed.
CORRECT 100%
1. Air loss in a straight truck or bus should not be more than ____ with the engine off
and the brakes on. - ANSWER 3 psi in one minute
2. To make an emergency stop with air brakes, using the stab braking method, you
should: - ANSWER C Brake as hard as you can, get off the brakes when the wheels
lock, get back on the brakes when the wheels start rolling again.
7. The brake system that applies and releases the brakes when the driver uses the
brake pedal is the: - ANSWER A Service brake system.
8. The most common type of foundation brakes found on heavy vehicles is the: -
ANSWER A Disc brakes
9. Vehicles with air brakes must have: - ANSWER C An air pressure gauge, to show air
used by the brake chambers for braking
C An air pressure gauge, to show air used by the brake chambers for braking -
ANSWER B 40 psi
11. Which of the following makes the total stopping distance for air brakes longer than
that for hydraulic brakes. - ANSWER A Brake lag distance.
12. Of the choices below, the first thing to do when a low air pressure warning comes on
is: - ANSWER Stop and safely park as soon as possible.
13. The braking power of the spring brakes: - ANSWER B Depends on the adjustment
of the service brakes.
3. You should know that your brakes are fading when: - ANSWER B You have to push
harder on the brake pedal to control your speed on a downgrade.
4. To check the free play of manual slack adjusters on s-cam brakes you should: -
ANSWER A Park on level ground, chock the wheels, and release the parking brakes.
5. If the air compressor should develop a leak, what keeps the air in the tanks? -
ANSWER C The one way check valve
. When driving down a long steep hill you should: - ANSWER Release the brake when
you are 5 M.P.H. below your safe speed.
