CDL Air Brake Air Brake Compressor and Governor 3

Question 1

What is the purpose of one-way check valves between air tanks?

Accepted Answer

To prevent pressure loss in one tank if another tank develops a leak

Answer

To allow air to flow freely in both directions

Answer

To prevent air from flowing back into the compressor

Answer

To regulate pressure balance between primary and secondary tanks

Question 2

What is the role of the supply tank (wet tank) in the air brake system?

Accepted Answer

It receives air from the compressor first, allowing water and oil to separate out

Answer

It stores water for the windshield washer system

Answer

It stores air exclusively for the secondary circuit

Answer

It powers trailer brakes only

Question 3

According to CDL requirements, how quickly should air pressure build from 85 to 100 psi at engine idle (600–900 RPM)?

Accepted Answer

Within 45 seconds

Answer

Within 15 seconds

Answer

Within 2 minutes

Answer

Within 5 minutes

Question 4

What does the supply pressure gauge in the cab indicate?

Accepted Answer

The current air pressure available in the storage tanks

Answer

The amount of fuel available for the air compressor

Answer

The governor cut-out setting

Answer

The pressure currently inside the brake chambers

Question 5

What should you do if the air pressure gauge shows a continuous drop while the vehicle is parked with the engine off?

Accepted Answer

Investigate for air leaks before driving the vehicle

Answer

This is normal — small drops are expected at idle

Answer

Pump the brakes to rebuild pressure

Answer

Increase engine idle speed to compensate

Question 6

Why must the air compressor be properly lubricated at all times?

Accepted Answer

To prevent mechanical wear and seizure of compressor components

Answer

To keep compressed air cool during operation

Answer

To improve brake response time

Answer

To increase the governor cut-out pressure