F 150 4WD Pickup V8-281 4.6L VIN W EFI (1997)
Brake Fluid Level Warning Switch: Description and Operation
Brake Master Cylinder
The brake master cylinder 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.
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) hydraulic circuit or secondary (rear) hydraulic circuit will cause
the warning indicator to activate.
NOTE: If the brake fluid level warning switch is inoperative, the brake master cylinder reservoir must be replaced.
Refer to Brake Fluid Reservoir service and repair for procedure.
