Montana CDL — Air Brakes Practice Test 7

11.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

12.You are about to park in freezing weather and your brakes are very wet. What does the manual suggest doing before you stop?

Set the parking brakes hard so the shoes cannot freezePour water over the drums to wash off road saltDrive in a low gear with light brake pressure so the brakes warm up and dry outDrain the air tanks while the vehicle is still rolling

13.You pull hard on a slack adjuster during the walk-around and it travels roughly an inch and a half at the point where the push rod attaches. What does the manual say about that brake?

It probably needs adjustmentIt is within limits; up to two inches of travel is acceptableIt shows the automatic drain valve has failedIt means the spring brake is still applied

14.How do the brake lights come on in a vehicle with air brakes?

A cable linked to the brake pedal pulls a switchAn electric switch that is worked by air pressure turns them onThe governor sends a signal each time it cuts inThe driver turns them on with a dash control before braking

15.In stab braking, you release the brakes when the wheels lock. What does the manual say happens if you put the brakes back on before the wheels are rolling again?

The vehicle will not straighten outThe spring brakes will applyThe ABS lamp will come onThe stop will be shorter

16.On a long grade your application pressure gauge shows you are using more and more pressure just to keep your speed steady. What does the manual tell you to do?

Slow down and shift to a lower gearSpeed up so more air flows over the drumsSwitch the front brake control to "slippery"Pull the parking brake knob to rest the service brakes

17.You have parked with the spring brakes applied. Why does the manual warn against pressing the brake pedal down now?

It would release the spring brakes and let the vehicle rollIt would trip the low air pressure warningIt would drain the separate tank used to release the spring brakesThe springs and the air pressure acting together could damage the brakes

18.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

19.Every vehicle built since 1994 has automatic slack adjusters. According to the manual, when do they adjust themselves?

Each time the governor cuts inDuring full brake applicationsWhenever the parking brake is setOnly while the vehicle is backing up

20.On an icy road, the driver of a pre-1975 truck moves the front brake limiting valve control to "slippery." What does the manual say about that choice?

It is the required setting any time the pavement is slickIt doubles the air pressure sent to the front brakesIt shuts off the rear brakes so the front wheels can steerIt cuts stopping power; braking is unlikely to skid the front wheels even on ice, so the control belongs in "normal"