DOT ( 3 ) brake fluid
It all depends on what part is leaking what fluid. Brake cylinder would leak brake fluid. Axle seal would leak gear oil.
where is it leaking from?
brake fluid leaking from a brake drum indicates the brake slave cylander on that wheel is leaking and needs to be replaced you will not see the actual leak with out removing the brake drum
What color fluid?
In a 2000 Ford Windstar : ( DOT 3 brake fluid meeting Ford specification ESA-M6C25-A ) according to the Owner Guide
Brake fluid in a Toyota Sequoia could be leaking from several places. Check the wheel cylinders first as they are a common place to leak.
Seal in brake caliper is leaking and needs replacement Flexible brake line to the caliper is leaking and needs replacement
Replace the leaking part
There would be break fluid OUTSIDE of the lines and reservoir
take it to the shop to get fixed!
Worn brake shoes or pads. A leaking brake pipe. Low brake fluid. Air in the brake fluid pipe.