Michigan CDL — Air Brakes Practice Test 1

1.Why can a heavily loaded vehicle take a long distance to stop once the spring brakes apply on their own?

The parking brake overrides the service brakesThe compressor keeps the wheels turningThe heavy load pushes the linings away from the drumSpring brakes do not act on all axles, so a heavy load has less braking to stop it

2.On a trailer equipped with ABS, where is the yellow malfunction lamp located?

On the rear bumper, at the centerInside the cab on the dashboardOn the left side, at the front or rear cornerOn the right-side landing gear

3.In a spring brake system, what holds the powerful springs back while the vehicle is being driven?

A mechanical latch released by the pedalAir pressureEngine vacuumThe slack adjuster

4.The brake pedal on an air brake vehicle also goes by which other names?

The governor or cut-out valveThe wig wag or slack adjusterThe modulating valve or power screwThe foot valve or treadle valve

5.According to the manual, what is the defect turned up most often during roadside inspections?

Worn tiresCracked windshieldsBrakes that are out of adjustmentBurned-out lamps

6.On a vehicle with a dual air brake system, how is tank pressure shown?

One needle that averages both halves togetherA separate gauge for each half, or one gauge with two needlesOnly a warning light, with no gauge at allA gauge that reads the trailer's pressure only

7.What most directly causes brake fade on a long downgrade?

Draining the air tanks too frequentlyLow tire pressureRelying on engine braking instead of the service brakesExcessive heat from overusing the service brakes

8.What does the supply pressure gauge on an air brake vehicle tell the driver?

How much air pressure is currently stored in the tanksHow hard the brakes are being appliedThe temperature of the brake drumsHow many miles remain before the tanks must be drained

9.Why does an air brake system keep pressurized reservoirs on board?

They cool the brake drums during long stopsThey store enough air to work the brakes several times even if the compressor stopsThey take the place of a parking brakeThey lower the temperature of the compressed air

10.When the low air pressure warning first lights up and buzzes while you are driving, what should you do?

Stop the vehicle safely without delay, while you still have enough air to control the brakesKeep driving until the spring brakes apply by themselvesPump the brake pedal to rebuild pressureRelease the parking brake and speed up