Brake Pedals and Lights
Brake Pedal Leverage
Brake Pedal Measurements
Stoplight Switch Operates the rear brake lights Normally open switch, usually mounted on the brake pedal mechanism When the brake pedal is pressed, it closes the switch Also used for cruise control, transmission, ABS and traction control systems
Examples
Typical Brake Light Circuit
Testing a Brake Light Switch
Brake Warning Light Switch Also called the pressure differential valve Warns the driver of a pressure loss on one side of a dual brake system If a leak develops in either the primary or secondary brake system, unequal pressure pushes the switch piston to one side, grounding the indicator circuit
Brake Warning Light Circuit
BRAKE! Warning Light Circuit
Checking Brake Lights Press the brake pedal Note if any/all work including 3 rd brake light All inop – check fuse and/or switch One inop – check bulb and socket
Seriously?
Close Inspection