Question What helps prevent wheel lockup when braking? Answers An Anti-Lock Braking System (ABS) Air brakes An alternator Explanation The purpose of an Anti-Lock Braking System (ABS) is to prevent wheel lockup while brakes are being applied. This questions appears in the following tests: Alaska Air Brakes Arizona Double Arizona Air Brakes California Class A Knowledge Test Hawaii Class A Knowledge Test Idaho Air Brakes Maine Class A Knowledge Test Maine Air Brakes Maryland Air Brakes Minnesota Class B Knowledge Test Missouri Class B Knowledge Test Missouri Air Brakes New Hampshire Air Brakes Ohio Air Brakes Ohio Air Brakes South Dakota Class A Knowledge Test Tennessee Air Brakes Utah Air Brakes Vermont Air Brakes Vermont Air Brakes Washington Class B Knowledge Test Washington Air Brakes Wisconsin Class A Knowledge Test