Probably brake fluid, your caliper seal may have gone bad
That sounds like a wheel cylinder leaking brake fluid.
Could be the caliper or the metal line. You will have to have it checked.
You'll see either fluid or grease leaking out of it.
In the steering wheel fluid reservoir, passenger side of engine. Add dextron transmission fluid to it not "steering wheel fluid"
Rebuild the cylinders on that caliper.
Hub seal is leaking
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.
IF you have rear wheel drive it may be a grease seal for the rear differential. Otherwise it is probably a wheel cylinder. Check your brake fluid level. GEt this fixed ASAP- Safety concern. Wheel cylinder, brake fluid.. If it's a rear wheel drive vehicle, it may be the axle seal leaking as well. Hello... hello...
Failed caliper, wheel cylinder, hose, line, Vehicle is unsafe to drive.
There are 2 rubber seals on each end of the wheel cylinders and there leaking. REPLACE THE WHEEL CYLINDERS.
Most likely brake fluid. Check the master cylinder level.
You might be out of brake fluid. Our rear wheel cylinder was leaking and ran ours out of fluid and the light came on.