Arkansas CDL — Air Brakes Practice Test 3

1.Your truck's brake system is designed so that pressing the pedal while the spring brakes are on will not hurt anything. What does the manual still advise?

Make a habit of not pressing the pedal while the spring brakes are on anywayYou may press the pedal freely, since the design protects the brakesPress the pedal firmly whenever the spring brakes are on to test the protectionOnly avoid it when the truck is loaded

2.You want to pull a trailer that has air brakes. Besides the Air Brakes section, which section of the manual must you also study?

Section 6, Combination VehiclesSection 4, Transporting Passengers SafelySection 9, Hazardous MaterialsSection 10, School Bus

3.On the CDL vehicle inspection test, what is the air brake check designed to confirm?

That the compressor can build pressure to 150 psiThat the air brake safety devices work properly as pressure falls from normal to low airThat the vehicle can stop from 55 mph within 450 feetThat the ABS lamp comes on at start-up

4.What form does the low air pressure warning usually take in the cab?

A yellow light that blinks only when the truck is parkedA green light that goes out when pressure is lowA horn that sounds outside the vehicleA red light, sometimes with a buzzer

5.In a typical dual air brake system, which brakes does the secondary system run?

Only the spring brakesThe regular brakes on all the rear axlesOnly the trailer brakesThe front-axle brakes, and sometimes the brakes on one rear axle

6.Some automatic air tank drains come fitted with electric heating devices. What are the heaters for?

Keeping the automatic drain from freezing in cold weatherWarming the brake linings so they grip betterDrying the air before it reaches the compressorRaising tank pressure faster after start-up

7.In a wedge brake, what does the brake chamber push rod do?

Turns a power screw that clamps a rotorTwists an s-shaped camshaftDrives a wedge between the ends of two brake shoes, spreading them against the drumPulls the shoes away from the drum to let the wheel roll

8.Which vehicles does the manual say must have emergency brakes and parking brakes held on by mechanical force?

Only vehicles built after 1998Only vehicles that haul hazardous materialsOnly combination vehiclesAll trucks, truck tractors, and buses

9.Which statement about the application pressure gauge is true?

It shows how much air is in the tanks and is required on every air-braked vehicleIt shows how much air pressure you are putting to the brakes, and not every vehicle has oneIt shows the governor's cut-in and cut-out settingsIt lights up only when the spring brakes are applied

10.How is a manually operated air tank drain valve opened?

By pressing the brake pedal three times with the engine offBy pushing the yellow parking brake knob inBy loosening the bolts that hold the tank to the frameBy giving it a quarter turn, or by pulling on a cable