Abstract: A locking knob for an air brake valve may include a push rod and a locking ring. The push rod may include a knob head at a first end of the push rod, first thread along an exterior surface of the push rod, and a cavity within the push rod exposed at a second end of the push rod opposite of the first end, the cavity configured to house an actuating arm of the valve that is held fixed to the push rod. The locking ring may include a channel that is configured to house the push rod, and second thread within the channel that is configured to mate with the first thread. Rotation of the locking ring restricts movement of the push rod and actuating arm.