Brake Fluid Level Switch

Check for continuity between the terminals (A) with the float in the down position and the up position: See Fig 1 .

1. Remove the brake fluid completely from the reservoir. With the float down, there should be continuity.
2. Fill the reservoir with brake fluid to MAX (upper) level (B). with the float up, there should be no continuity. See Fig 1 .

Fig 1: Testing Brake Fluid Continuity

Courtesy of AMERICAN HONDA MOTOR CO., INC.