ELDT - Entry Level Driver Training Air Brakes Questions and Answers Flashcards

How long should a driver wait after the air compressor builds pressure before performing a brake check?

Answer: Until the governor cuts out around 125 psi

Drivers should wait until the compressor governor cuts out (around 125 psi) to ensure the system is fully charged before testing.

What is the purpose of air tank drain valves in an air brake system?

Answer: To drain water and oil from the air tanks

Drain valves remove moisture and compressor oil from air tanks, preventing corrosion and freezing in cold weather.

What is the air pressure range within which the air compressor governor normally operates?

Answer: 100–125 psi

The governor causes the compressor to cut in at approximately 100 psi and cut out at approximately 125 psi.

Why should a driver never push the brake pedal down with the service brakes if a front wheel brake failure is suspected?

Answer: It could worsen steering instability

Without front brakes, heavy brake application shifts weight rearward and can cause severe steering instability or loss of directional control.

What does a failing air compressor typically cause first?

Answer: Gradual drop in air pressure over time

A failing compressor causes pressure to gradually drop as brakes are used and not enough air is replenished.

What is the correct way to use brakes on a long steep downgrade?

Answer: Use a proper braking application to reduce speed by 5 mph then release

Select a low gear before starting the descent and use the service brakes in a controlled application to reduce speed by about 5 mph, then release and repeat.