Take District Of Columbia CDL Air Brakes Test 2

QUESTION 1 / 25

Most heavy-duty vehicles use:

Choose one answer below.

ASingle air brake systems.✓BDual air brake systems.✓CTriple air brake systems.✓DQuadruple air brake systems.✓

QUESTION 2 / 25

Failing to drain the tanks in an air brake system can result in:

Choose one answer below.

AWater freezing and causing brake failure.✓BSquishy brakes.✓CToo much air collecting.✓DToo much fuel being carried.✓

QUESTION 3 / 25

To ensure normal stopping power, drivers of vehicles equipped with a front brake limiting valve should:

Choose one answer below.

ASet the control to normal.✓BSet the control to the off position.✓CSet the control to neutral.✓DKeep the control at the halfway mark.✓

QUESTION 4 / 25

While driving downhill, you should brake until you reach a speed that is ____ below your safe speed, then release the brake pedal.

Choose one answer below.

A5 mph✓B10 mph✓C15 mph✓D20 mph✓

QUESTION 5 / 25

What kind of force must emergency brakes use?

Choose one answer below.

AAir pressure✓BMechanical✓CHeavy✓DElectrical✓

QUESTION 6 / 25

During an applied leakage test, the maximum leakage rate for a triple combination vehicle is:

Choose one answer below.

A10 psi in a minute.✓B8 psi in a minute.✓C6 psi in a minute.✓D4 psi in a minute.✓

QUESTION 7 / 25

While driving, spring brakes are generally held in place by:

Choose one answer below.

AAir pressure.✓BChocks.✓CFoundation brakes.✓DSturdy ties.✓

QUESTION 8 / 25

How is water and compressor oil removed from the bottom of an air storage tank?

Choose one answer below.

AThe water and oil are siphoned out of the tank.✓BA drain valve is opened to remove the water and oil from the tank.✓CThe water and oil are removed automatically as the brakes are used.✓DA sponge is used to soak up the water and oil.✓

QUESTION 9 / 25

If using air tanks with manually operated drains, how often should you drain the tanks?

Choose one answer below.

AEvery day✓BOnce a week✓COnce a month✓DOnce every six months✓

QUESTION 10 / 25

When the brake pedal is depressed, air brakes work:

Choose one answer below.

AImmediately.✓BAfter a short delay.✓CAfter about a minute.✓DOnly if the green lever on the control panel is pushed down.✓

QUESTION 11 / 25

The air storage tanks:

Choose one answer below.

AHold only enough air for one braking cycle.✓BHold enough air for brakes to be used several times if the compressor stops working.✓CDo not hold air unless there is an emergency.✓DHold enough air for more than 1,000 braking cycles.✓

QUESTION 12 / 25

What can happen if a parking brake is used in very wet weather when temperatures are below freezing?

Choose one answer below.

AThe brakes will squeak.✓BThe brakes may freeze so the vehicle cannot move.✓CThe brakes may suddenly release by themselves.✓DThe brakes may explode.✓

QUESTION 13 / 25

When about to drive a vehicle with a dual brake system, a driver should:

Choose one answer below.

ALet the vehicle warm up to ensure the fuel reaches the engine.✓BWait for air pressure to build in both the primary and secondary systems.✓CBegin driving just after the engine starts.✓DPump the pedal about 20 times to build pressure, then begin driving.✓

QUESTION 14 / 25

What does the air compressor governor do?

Choose one answer below.

AControls when the air compressor pumps air into the air storage tanks.✓BControls how quickly air leaves the air storage tanks.✓CControls the temperature of the air entering the air storage tanks.✓DControls the temperature of the air leaving the air storage tanks.✓

QUESTION 15 / 25

Emergency brakes are:

Choose one answer below.

ANot required on trucks.✓BOnly required on trailers.✓CRequired on tractors.✓DOnly required when transporting hazardous materials.✓

QUESTION 16 / 25

The air pressure in a dual air brake system should build from 85 to 100 psi within:

Choose one answer below.

ATwo minutes.✓B15 seconds.✓C10 minutes.✓D45 seconds.✓

QUESTION 17 / 25

A vehicle equipped with an Anti-Lock Braking System (ABS) uses a ____ light to warn that the system is not working properly.

Choose one answer below.

AGreen✓BYellow✓COrange✓DWhite✓

QUESTION 18 / 25

In a dual air brake system:

Choose one answer below.

AAir tanks are shared by both systems.✓BEach system has its own air tanks.✓CYou must designate which system you are using.✓DBrakes on only one side of the vehicle will work.✓

QUESTION 19 / 25

Emergency brakes:

Choose one answer below.

AAre not required on trucks.✓BAre only required on trailers.✓CAre required on tractors.✓DAre optional.✓

QUESTION 20 / 25

Spring brakes come on:

Choose one answer below.

AWhen too much air pressure is lost.✓BWhen a control on the dashboard is activated.✓CWhen the tires have minimal tread depth.✓DWhen the brakes are noisy.✓

QUESTION 21 / 25

Some air brake systems use alcohol:

Choose one answer below.

ATo reduce the risk of ice forming in air brake valves.✓BTo make the compressor run more efficiently.✓CTo lubricate parts of the braking system.✓DTo reduce the risk of rust forming on air brake valves.✓

QUESTION 22 / 25

To stop in a vehicle that uses air brakes, the driver should:

Choose one answer below.

APull the air brake lever.✓BEngage the brake lever.✓CPush the brake pedal down.✓DPull the brake pedal up.✓

QUESTION 23 / 25

You should not use the parking brake:

Choose one answer below.

AIf your vehicle is stopped on a level surface.✓BIf your vehicle is stopped on a slight incline.✓CIf your vehicle's brakes are very hot.✓DIf your vehicle's other braking systems seem to be working adequately.✓

QUESTION 24 / 25

Test the low pressure warning signal:

Choose one answer below.

AOnce a month.✓BOnce a week.✓CTwice a week.✓DBefore every trip.✓

QUESTION 25 / 25

Vehicles with dual air brake systems:

Choose one answer below.

AMaintain full-capacity air pressure in the braking systems even when the vehicle is not running.✓BMaintain some air pressure in the braking systems when the vehicle is not running.✓CMust be run to build enough air pressure to brakes to operate properly.✓DDo not need time to build air pressure before a trip.✓