Question A modulating control valve can control the: Answers Spring brakes. Landing gear. Air brakes. Anti-lock braking system (ABS). Explanation A modulating control valve allows a driver to gradually apply spring brakes. In equipped vehicles, the valve is controlled by a lever located on the dashboard. Take a FREE Practice Test Now This questions appears in the following tests: Massachusetts Knowledge Test Class B , Delaware Air Brakes , District Of Columbia Air Brakes , Florida Air Brakes ,