New Hampshire CDL — Air Brakes Practice Test 8

1.The manual lists what puts the L restriction, no air brake equipped CMV, on a CLP or CDL. Which of these is NOT one of the triggers?

Not taking the air brake part of the knowledge testFailing the air brake part of the knowledge testTaking the skills test in a vehicle that lacks air brakesTaking the skills test in a vehicle with an automatic transmission

2.The manual lists several reasons you might need more application pressure than before. Which of these is NOT one of them?

An alcohol evaporator that has run dryBrakes that are fadingBrakes that are out of adjustmentAir leaks

3.The hand check of S-cam slack adjusters starts with parking on level ground and chocking the wheels. Why are the chocks needed for this particular check?

The parking brakes are released for the check, so the chocks are what keep the vehicle from movingThe chocks take the vehicle's weight off the slack adjustersThe chocks keep the air tanks level so the gauge reads trueThe chocks hold the brake shoes against the drums

4.On the vehicle inspection test, you check that the power unit's parking brake holds a combination vehicle. What state should the trailer brakes be in for that check?

SetDisconnected at the glad handsReleasedApplied with the hand valve

5.The manual says to use the parking brakes any time you park, with two exceptions. Which pair is it?

A heavy load, and a steep parking spotVery hot brakes, and very wet brakes in freezing temperaturesLow fuel, and a cold engineVery hot brakes, and a trailer equipped with ABS

6.Which gauge does the manual say all air-braked vehicles have, and which does it say is missing on some?

All have an application pressure gauge; the supply pressure gauge is not on every vehicleAll have both gaugesNeither gauge is on every vehicle; both are optionalAll have a supply pressure gauge; the application pressure gauge is not on every vehicle

7.In the manual's description of the air compressor governor, what is the "cut-in" pressure?

The tank pressure, around 100 psi, at which the governor lets the compressor pump againThe tank pressure, around 125 psi, at which the governor stops the compressorThe pressure at which the safety relief valve opens to protect the tanksThe pressure at which the low air warning signal has to come on

8.Which order matches the manual's service brake test at the end of the final air brake check?

Set the parking brake, pull against it in a low gear, then release itShut the engine off, hold the foot brake for a minute, then read the gaugeLet air pressure reach normal, take the parking brake off, ease forward at about 5 mph, then brake firmly with the pedalBrake firmly at highway speed, then check the gauge for pressure loss

9.The safety relief valve is usually set to open at a fixed pressure. Using the manual's usual numbers, about how far above the governor's cut-out level is that?

About 5 psiAbout 25 psiAbout 50 psiAbout 95 psi

10.After the low air pressure warning comes on, how long does the manual say controlled braking stays possible?

For as long as the engine keeps runningUntil the ABS malfunction lamp lightsFor exactly one more full brake applicationOnly while enough air is left in the tanks