air brakes

Question 1

Modern air brake systems combines three different systems. The are the service brakes, the parking brakes and the

Answer 1

Emergency brakes

Question 2

Oil and water usually collect in compressed air tanks. If you do not have an automatic tank drain, when should you drain the air tanks?

Answer 2

After every working day

Question 3

Why drain water from the compressed air tanks?

Answer 3

Water can freeze in cold weather and cause brake failure

Question 4

Air brake equipped vehicles must have

Answer 4

A supply pressure gauge

Question 5

What can legally hold a parking or emergency brake in position for a truck, truck tractor or bus?

Answer 5

Spring pressure

Question 6

Air loss in a straight truck or bus should not be more than ____ with the engine off and the brakes on

Answer 6

3 psi in one minute

Question 7

To make an emergency stop with air brakes, using the stab braking method, you should

Answer 7

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

Question 8

You should know that your brakes are fading when

Answer 8

You have to push harder on the brake pedal to control your speed on a downgrade

Question 9

To check the free play of manual slack adjusters on s-cam brakes you should

Answer 9

Park on level ground, chock the wheels, and release the parking brakes

Question 10

If the air compressor should develop a leak, what keeps the air in the tanks?

Answer 10

The one way check valve

Question 11

When driving down a long steep hill you should

Answer 11

Release the brake when you are 5 M.P.H. below your

Question 12

The brake system that applies and releases the brakes when the driver uses the brake pedal is the

Answer 12

Service brake system

Question 13

The most common type of foundation brakes found on heavy vehicles is the

Answer 13

S-cam drum

Question 14

Vehicles with air brakes must have

Answer 14

An air pressure gauge to show the pressure available for braking

Question 15

The driver must be able to see a warning that is given before air pressure in the service air tanks falls below

Answer 15

60 psi

Question 16

Which of the following makes the total stopping distance for air brakes longer than that for hydraulic brakes

Answer 16

Brake lag distance

Question 17

Of the choices below, the first thing to do when a low air pressure warning comes on is

Answer 17

Stop and safely park as soon as possible

Question 18

The braking power of the spring brakes

Answer 18

Depends on the adjustment of the service brakes

Question 19

The air compressor governor controls

Answer 19

When air is pumped into the air tanks

Question 20

The application pressure gauge shows the driver how much pressure

Answer 20

Is being applied to the brakes

Question 21

If your vehicle has an alcohol evaporator, every day during cold weather you should

Answer 21

Check and fill the alcohol level

Question 22

During normal driving, spring brakes are usually held back by

Answer 22

Air pressure

Question 23

Air braking takes more time than hydraulic braking because air brakes

Answer 23

Need to have airflow through the lines to work

Question 24

In air brake vehicles, the parking brakes should be used

Answer 24

Whenever the vehicle is parked

Question 25

The brake pedal in an air brake system

Answer 25

Controls the air pressure applied to put on the brakes

Question 26

If your truck or bus has dual parking control valves it means that you can use pressure from a separate tank to

Answer 26

Release the spring brakes to move a short distance

Question 27

A straight truck or bus air brake system should not leak at a rate of more than ____ PSI per minute with the engine off and the brakes released

Answer 27

2

Question 28

If your vehicle has an alcohol evaporator, it is there to

Answer 28

Reduce the risk of ice in air brake valves in cold weather

Question 29

If you must make an emergency stop, you should brake so that you

Answer 29

Stay in a straight line and can steer

Question 30

Your truck or bus has a dual air brake system. If a low air pressure warning comes on for only one system, what should you do?

Answer 30

Stop. Safely park, and continue only after the system is fixed