TX Air Brakes CDL 1

Question 1

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 1

After every working day.

Question 2

What is the S-cam used for?

Answer 2

To apply the brakes.

Question 3

What makes the total stopping distance for air brakes longer than that for hydraulic brakes?

Answer 3

Brake lag distance.

Question 4

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

Answer 4

Service brake system.

Question 5

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

Answer 5

Brakes as hard as you can, get off of the brakes when the wheels lock, get back on the brakes when the wheels start rolling again.

Question 6

Brake lag distance at 55 mph is ___ feet?

Answer 6

32

Question 7

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

Answer 7

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

Question 8

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

Answer 8

Spring pressure
- Air pressure can eventually leak away.

Question 9

The braking power of spring brakes:

Answer 9

Depends on the adjustment of the service brakes.

Question 10

Under which conditions are front wheel brakes good?

Answer 10

All weather conditions

Question 11

If your vehicle has a properly functioning dual air brake system and minimum-sized air tanks, the air pressure should build from 85 to 100 psi within ___ seconds.

Answer 11

45

Question 12

The air compressor will stop pumping air into the air tanks at ____ psi.

Answer 12

125

Question 13

Excessive heat caused by overuse of the service brakes can cause

Answer 13

the brakes to fade.

Question 14

Excessive use of the service brakes may result in overheating, which can lead to

Answer 14

expansion of the brake drums.

Question 15

A typical air brake system is fully charged at ____.

Answer 15

125 psi

Question 16

During normal driving, spring brakes are usually held back by

Answer 16

air pressure.

Question 17

During your final air brake check, if the air pressure does not build up fast enough,

Answer 17

the air pressure may drop too low during driving.

Question 18

To test the static air leakage rate, you should

Answer 18

turn off the engine, release the parking brake, and let the system settle.

Question 19

Air brakes use ________ to make the brakes work.

Answer 19

compressed air

Question 20

When you press the brake pedal,

Answer 20

compressed air enters the brake chambers.