CDL Air Brake Air Tanks and Drains 3

Question 1

What prevents air from flowing backward from the primary tank to the supply tank if there is a failure?

Accepted Answer

A one-way check valve

Answer

The governor valve

Answer

The safety relief valve

Answer

The drain cock

Question 2

What could result from allowing oil contamination to build up in air tanks over time?

Accepted Answer

Damage to valves, seals, and brake components

Answer

Increased air pressure in the system

Answer

Faster compressor operation

Answer

Improved brake response time

Question 3

If a vehicle has automatic drain valves on the air tanks, what is still required of the driver?

Accepted Answer

Check that the automatic drain valves are functioning properly during pre-trip inspection

Answer

Manually drain the tanks each week in addition to the automatic draining

Answer

Replace the automatic valves with manual ones before long trips

Answer

Open the automatic drain valves manually at the end of each shift

Question 4

What is the purpose of having multiple air tanks in a split (dual) air brake system?

Accepted Answer

To keep the front and rear brake circuits separate so one failure does not disable all brakes

Answer

To allow higher maximum pressure in the system

Answer

To eliminate the need for a safety relief valve

Answer

To allow faster air pressure buildup after starting the engine

Question 5

What does it indicate if air tanks need to be drained more frequently than usual?

Accepted Answer

Excessive moisture or oil is entering the air system, possibly indicating compressor wear

Answer

The governor is cutting out at too low a pressure

Answer

The safety valve needs replacement

Answer

The air pressure is building too slowly

Question 6

An air dryer is sometimes installed in an air brake system. What is its role in relation to the air tanks?

Accepted Answer

It removes moisture from the compressed air before it enters the tanks

Answer

It pressurizes the air before it reaches the tanks

Answer

It regulates the pressure inside each air tank

Answer

It automatically drains the tanks on a timer

Question 7

What is the correct procedure when opening a manual drain valve on an air tank during pre-trip inspection?

Accepted Answer

Open the valve fully to drain water and oil, then close it securely before driving

Answer

Open the valve slightly and leave it open to allow continuous draining while driving

Answer

Open the valve only if the air pressure gauge shows below 60 psi

Answer

Only open drain valves when the engine is off and all pressure is released