The brake dust is from the brake pads, which wear over time from use, and release small particles which results in "Dust" it will usually just wash off with a garden hose.
on the back side of the backing plates ( dust shields by rotors )
you probly need new pads rotors jeck for dust on the brakes if so blow them clean with a compresor
In a 2000 Ford Windstar : ( DOT 3 brake fluid meeting Ford specification ESA-M6C25-A ) according to the Owner Guide
If the red " BRAKE " light in your dash is on that indicates that either your parking brake / emergency brake is on , or the BRAKE FLUID LEVEL in your brake master cylinder ( located in the engine compartment ) IS LOW
See sources and related links below to lookup Ford Windstar brake light lamp part numbers by vehicle year.
The brake warning light in a 2002 Ford Windstar can be triggered by several issues. Common causes include low brake fluid levels, a malfunctioning brake light switch, or a problem with the anti-lock braking system (ABS). Additionally, worn brake pads or issues with the brake system's hydraulic components may also activate the light. It's important to address this warning promptly, as it indicates a potential safety concern.
DOT ( 3 ) brake fluid
above brake pedel behind fuse block
3/16 for a metal line. And rubber brake lines don't have sizes.
brake light bulb out
You start by adjusting the rear brakes after you have inspected them.
Below and to the left of the steering wheel , by the brake pedal