Montana CDL — Air Brakes Practice Test 4

1.On an older ABS system, the yellow malfunction lamp is still lit as you pull away from a stop. According to the manual, when might that still be normal?

For the first 55 miles of every tripWhenever the parking brake knob is pushed inUntil the governor reaches its cut-out pressureWhile your speed has not yet passed five mph

2.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

3.According to the manual, how well the spring brakes hold or stop a vehicle comes down to what?

How fast the compressor can rebuild pressureThe position of the front brake limiting valveWhether the brakes are properly adjustedHow much alcohol is in the evaporator

4.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

5.An air disc brake has a brake chamber and a slack adjuster, just as an s-cam brake does. Which part does the manual say takes the place of the s-cam?

A return springA wedgeA treadle valveA power screw

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 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

8.Your test vehicle has primary and secondary air brake systems. For the emergency brake test, what does the manual's inspection section say you must explain to the examiner?

That the secondary system is used only for the trailerThat the valves pop out as soon as either system falls below 100 psiThat there is a backup system, so the valves will not pop out when only one system loses pressureThat dual systems are exempt from the emergency brake test

9.You are building air pressure in a dual system before a trip. At what point does the manual say the low air warning light and buzzer should go off?

As soon as either system passes 20 psiWhen both systems reach a manufacturer-set value that is above 55 psiOnly when both systems reach governor cut-outWhen the primary system alone reaches 100 psi

10.The manual describes air brakes as three braking systems in one. What does it say the emergency brake system is built from?

A separate set of brake shoes used only when the pedal failsParts of the service brake system and the parking brake systemThe trailer hand valve and the tractor protection valveA hydraulic backup circuit that works without air