New Mexico CDL — Air Brakes Practice Test 1

1.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

2.Your brakes are out of adjustment. According to the manual's passage on spring brakes, which of your brakes are affected?

Only the regular service brakesOnly the emergency/parking brakesBoth the regular brakes and the emergency/parking brakesNeither of them, provided the tank pressure is still in the normal range

3.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

4.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

5.Which of these is NOT part of the manual's procedure for a normal stop in an air-braked vehicle?

Pushing the brake pedal down and controlling the pressure for a smooth stopPulling the parking brake knob as the vehicle slows, to help it stopWith a manual transmission, leaving the clutch alone until engine rpm is near idleChoosing a starting gear once you have stopped

6.Two controls in the manual's passage on parking brake controls are described as spring-loaded. Which pair is it?

The yellow push-pull parking brake knob, and the trailer hand valve on a combination vehicleThe front brake limiting valve control, and the brake pedal or treadle valveThe manual air tank drain valve, and the safety relief valve on the first tankThe modulating control valve, and the release valve in a set of dual parking control valves

7.Section 5 mentions chocking the wheels in several places. In which of these situations does it NOT mention wheel chocks?

Testing the low pressure warning signalChecking slack adjusters on s-cam brakesHolding the vehicle while very hot brakes coolRunning the brakes-applied air leakage test

8.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

9.A New Mexico applicant scores 92% on the general knowledge test and 76% on the air brakes knowledge test the same day. Under the MVD's passing score rule, where does that leave the air brakes test?

Passed, because the two scores average out to more than the 80% requiredPassed, because 70% is enough on an air brakes testNot passed, because the air brakes test alone requires 90%Not passed; each part is graded on its own and needs 80% or better

10.In the Step 7 check, a driver finds that air pressure is building too slowly and plans to let it catch up on the highway. What is the manual's instruction?

Drive, but hold the engine at a fast idle at every stopDrive, and drain the air tanks at the first rest areaDo not drive until the problem has been fixedSet the front brake limiting valve to "slippery" and continue