Study Mode - Air Brakes Test

21

The air loss rate for a straight truck or bus with the engine off and the brakes on should not be more than:

1 psi in 30 seconds.

2 psi in 45 seconds.

3 psi in one minute ✓ CORRECT

22

The driver must be able to see a low air pressure warning which comes on before the pressure in the service air tanks falls below ____ psi.

50

60 ✓ CORRECT

80

23

The braking power of the spring brakes:

Is not affected by the condition of the service brakes.

Depends on the service brakes being in adjustment. ✓ CORRECT

Increase when the service brakes are hot.

24

The air brake lag distance at 55 mph on dry pavement adds about ___ feet.

12 feet

32 feet ✓ CORRECT

52 feet

25

Total stopping distance for air brakes is longer than that for hydraulic brakes due to ____ distance.

Brake lag ✓ CORRECT

Reaction

Effective braking.

26

It is accepted that too much heat caused by using your brakes too often can also cause:

Modulated control valve to wear out.

Brake linings to split up.

Brake to fade or fail. ✓ CORRECT

27

Repeatedly partially releasing and pressing the brake pedal may result in:

A loss of brake air pressure ✓ CORRECT

A build up of brake air pressure

No change of brake air pressure

28

The brake system that applies and released the brakes when the driver uses the brake pedal is the ____ brake system.

Emergency

Service ✓ CORRECT

Parking

29

A slack adjuster's free play needs to be adjusted if it is more than about ___ how many inches when you pull hard on it?

1/4 inch

1/2 inch

1 inch ✓ CORRECT

30

A slack adjuster's free play needs to be adjusted if it is more than about ___ how many inches when you pull hard on it?

1/4 inch

1/2 inch

1 inch ✓ CORRECT