New Mexico CDL — Air Brakes Practice Test 8

11.The Step 7 check times air leakage twice, once with the brakes released and once with the foot brake held down. What do the two tests have in common?

The engine runs at a fast idle and the parking brake is setThe electrical power is off and the air tanks have been drainedThe vehicle is rolling forward at about five mphThe engine is off and the parking brake is released

12.You have just finished inspecting the brake components at one axle on the vehicle inspection test. What does the note in Section 11 tell you to be ready for?

Skipping the remaining axles once the first one has checked outRepeating the inspection on the steering axle and nowhere elseRepeating the same brake inspection at every axle, power unit and trailer alikeRepeating the inspection only if the examiner points out a defect

13.On a pre-1975 truck, a brake application would normally send 80 psi to the front brakes. With the front brake limiting valve control set to "slippery," about how much reaches them?

About 40 psiAbout 80 psiAbout 60 psiNone at all

14.Whichever emergency braking method you choose, the manual wants your braking to accomplish two things. What are they?

Keep the vehicle in a straight line and still let you turn if you have toStop in the shortest distance possible, even with the wheels lockedLock the drive wheels while the steering wheel is held perfectly stillBring the spring brakes on a moment ahead of the service brakes

15.A trainee makes four statements about drum brakes. Which one does NOT match the manual?

The shoes and linings press against the outside of the drumThe drums are found at each end of the axlesThe wheels bolt onto the drumsThe friction that slows the vehicle at the drum also produces heat

16.Your truck's air compressor is gear-driven, so there is no compressor belt to show the examiner on the vehicle inspection test. What does Section 11 require instead?

Nothing; a component that has no belt is left out of the engine compartment inspection altogetherTell the examiner it is not belt driven, then check that it works, is undamaged, is not leaking and is secureTake off the gear cover so that the examiner can see the compressor drive and judge its conditionRun the engine at a fast idle and time how quickly the air pressure builds to governor cutout

17.Section 5 of New Mexico's manual has the low air pressure warning come on before tank pressure falls below 60 psi. Which figure does the air brake check in Section 11, the vehicle inspection test, use for the same warning?

60 psi, the same as Section 5, with no manufacturer alternative55 psi, or the level the manufacturer specifies45 psi, or one half of governor cut-in80 to 85 psi on every vehicle

18.Section 5 lists the checks that make up the Step 7 final air brake check. Which one does it list first?

The rate of air pressure buildup at operating rpmThe parking brakeThe low pressure warning signalThe governor's cut-in and cut-out pressures

19.You are building pressure in a New Mexico truck with a dual air system. The low air warning light and buzzer shut off when both gauges reach 58 psi. How does that compare with Section 5 of New Mexico's manual?

It is too low; the manufacturer's shut-off value has to be greater than 60 psiIt is fine; the warning may shut off anywhere above 45 psiIt is fine; the warning should shut off once either system passes 55 psiIt is too low; the warning has to stay on until both systems reach governor cut-out

20.New Mexico's list of CDL restrictions has two entries about air brakes, L and Z. Which of them is printed with a note on how the restriction is removed?

Only LOnly ZBoth L and ZNeither one