Montana CDL — Air Brakes Practice Test 6

1.You have just come down a steep grade and your brakes are very hot. The manual says not to use the parking brakes yet. How does it say to hold the vehicle in the meantime?

By leaving the transmission in neutral with the engine idlingWith wheel chocks, on a level surfaceBy holding the foot brake down until the drums coolWith the trailer hand valve

2.During the final air brake check, the compressor does not cut in and cut out the way the manual describes. What danger does the manual see in a governor that is not working properly?

The ABS lamp will stay litAir pressure could fall short of what safe driving needsThe spring brakes will never releaseThe brake drums will overheat while parked

3.Suppose the low pressure warning signal has failed and air is leaking away unnoticed. What does the manual say this could lead to in a single-circuit air system?

A gradual, gentle stopAutomatic shutdown of the engineSudden emergency brakingNothing until the tanks are refilled

4.During a trip you find that the safety relief valve on the first air tank has been releasing air. How does the manual treat that?

As normal behavior whenever the governor cuts outAs a reminder that the tanks are overdue for drainingAs proof that the spring brakes are about to applyAs a sign that something is wrong and a mechanic should fix it

5.A bus has lost its main air pressure and the spring brakes are on. The driver uses the spring-loaded control fed by a separate air tank to release them and move. Why does the manual say to plan that move carefully?

The separate tank refills only when the engine is switched offUsing the control disables the service brakes for the rest of the tripThe separate tank holds only enough air to release the brakes a few timesThe spring brakes will not reapply once they have been released this way

6.Some of the brakes on your vehicle are out of adjustment while the rest are adjusted correctly. What does the manual say happens as you keep braking?

The out-of-adjustment brakes lock up while the others releaseThe out-of-adjustment brakes quit doing their share first, and the others can then overheat and fadeAll of the brakes share the load evenly anywayThe spring brakes take over for the out-of-adjustment brakes

7.You are unsure whether your truck was built late enough to be required to have ABS. Where does the manual say to look for the date of manufacture?

On the registration card kept in the cabOn the vehicle's certification labelOn the air compressor governor housingOn the back of the yellow parking brake knob

8.One half of your dual air brake system has dropped very low on pressure while the other half is normal. What does the manual say this means for you?

Nothing changes, because the good half runs every brakeThe spring brakes release and cannot be reappliedThe brakes at one end of the vehicle, front or rear, will not work fully, so stopping takes longerThe trailer brakes lock at once

9.An applicant takes the CDL skills test in a truck with air over hydraulic brakes. Under the manual's restriction list, what must the state place on the license?

An L restriction: no CMV with any type of air brakesAn E restriction: no manual transmissionA Z restriction: no CMV whose braking system works fully on airNo restriction, because air over hydraulic counts as full air brakes

10.How does the manual say a manually operated air tank drain valve is worked?

By pressing a button on the dash while the engine runsBy pumping the brake pedal until the valve opensWith a quarter-turn of the valve, or with a pull on a cableBy unscrewing the safety valve on the first tank