ELDT - Entry Level Driver Training Vehicle Systems and Malfunctions Questions and Answers 2

Question 1

What should a CMV driver do if the low air pressure warning activates while driving?

Accepted Answer

Immediately pull over safely and stop; do not drive until the air system is repaired

Answer

A low air pressure warning indicates the air brake system may fail. The driver must stop immediately because below a certain pressure, the spring brakes will apply automatically and the vehicle will have no service brakes.

Question 2

What is the function of the governor in an air brake system?

Accepted Answer

It controls when the air compressor pumps air into the storage tanks

Answer

The governor controls the air compressor by cutting it in when tank pressure drops to about 100 psi and cutting it out when pressure reaches about 125 psi, maintaining proper system pressure.

Question 3

What causes brake fade and how can it be prevented?

Accepted Answer

Overheating the brakes from continuous use; prevented by proper gear selection on downgrades

Answer

Brake fade occurs when brakes overheat from continuous or excessive use, reducing their friction and stopping power. It is prevented by using proper gear selection and engine braking on long downgrades.

Question 4

What should you do if your engine overheats while driving?

Accepted Answer

Pull over safely, keep the engine idling to circulate coolant, and investigate the cause

Answer

If the engine overheats, pull over safely and let the engine idle (if safe to do so) to continue circulating coolant. Do not add cold water to a hot system as it can crack the engine block.

Question 5

What is the function of the slack adjuster in the air brake system?

Accepted Answer

It converts the push rod movement into the rotational force needed to apply the brake shoes

Answer

The slack adjuster is a lever that connects the push rod from the brake chamber to the camshaft. It converts the linear push of the rod into rotational force to turn the S-cam and apply the brake shoes against the drum.

Entry Level Driver Training (ELDT) Practice Test

Entry Level Driver Training (ELDT) Practice Test

ELDT - Entry Level Driver Training Vehicle Systems and Malfunctions Questions and Answers 2