Use this free Air Brakes commercial drivers license practice test to prepare yourself to get your CLP (commercial learner's permit). To learn more about Roehl's paid CDL training, view our Get Your CDL page or apply now.
 
Question 1 of 30

What is the best way to test if your vehicle's spring brakes come on automatically?

Continue to step on and off the brake pedal until the parking brake valve pops out, on tractor trailer vehicles
Continue to step on and off the brake pedal until the manufacturer's low PSI specification has been met for the spring brakes to deploy
Continue to step on and off the brake pedal until the parking brake valve pops out on single vehicles
All of the above