Expedition 2WD V8-281 4.6L VIN W EFI (1997)
Brake Fluid Level Sensor/Switch: Description and Operation
FLOAT AND MAGNET
The brake fluid level warning switch is an integral part of the brake master cylinder reservoir. It consists of a float containing a magnet and a reed
switch mounted in the bottom of the brake master cylinder reservoir.
PURPOSE
When the brake fluid in the brake master cylinder reservoir gets to a predetermined level, the floating magnet actuates the reed switch, causing the
red brake warning indicator to illuminate. Loss of brake fluid from either the primary (front) or secondary (rear) system will cause this system to
activate. If the brake fluid level warning switch is inoperative, the brake master cylinder reservoir must be replaced.