Alabama CDL — Air Brakes Practice Test 5

11.Apart from leaning on the service brakes too much, what else makes brake fade more likely?

Tires inflated well above the recommended pressureUsing the engine to help hold your speed downBrakes that have slipped out of proper adjustmentDraining the air tanks more often than required

12.What does the application pressure gauge show?

The reserve air remaining in the tanksWhether the parking brakes are engagedHow much air pressure is being applied to the brakesThe compressor's cut-in and cut-out settings

13.In a dual air system, how quickly should pressure build from 85 to 100 psi with the engine at operating rpm?

Within 45 secondsWithin 5 minutesWithin 10 secondsWithin half an hour

14.On newer vehicles, how do you apply the parking (spring) brakes?

Pull out the yellow, diamond-shaped control knobPush in a round green buttonHold the brake pedal down and shut off the engineTurn a key beside the steering column

15.With the engine off and a fully charged system, what is the maximum acceptable air loss rate for a single vehicle?

Less than 10 psi in one minuteUp to 20 psi in one minuteAny amount as long as it stabilizesLess than 2 psi in one minute

16.You are pulling a trailer fitted with ABS behind a tractor that has none, and the tractor starts to jackknife. What does the manual advise?

Push the pedal harder to force the tractor back into lineHold the trailer hand valve down on its own until it straightensGrab a lower gear and let go of the steering wheelEase off the brake pedal, where it is safe, until control returns

17.While holding a steady speed you notice you must keep increasing the application pressure. What does this most likely mean?

The brakes are fading and you should slow down and use a lower gearThe compressor has switched to its backup settingThe air tanks are fully drained of moistureThe spring brakes are about to release on their own

18.How is the air compressor typically driven?

By exhaust gases passing through a turbineThrough gears or a v-belt tied to the engineBy an independent electric motorBy the rotation of the drive axle only

19.Why can the brakes still be used several times even if the compressor quits working?

The wheels generate their own air while rollingThe governor forces the engine to keep the brakes chargedThe tanks hold a reserve of compressed airThe spring brakes recharge the service system

20.With a manually operated tank drain valve, how often must the driver drain the tanks?

At the end of each day of drivingOnly once a monthOnly when the low air warning soundsEvery time the governor cuts out