If you're talking about the dash brake light, then it might be indicating low fluid in the reservoir. It may be sloshing away from the sensor as you accelerate.
Sounds like Glenn might need new brakes. Adding fluid is a temporary fix. As the brakes wear down, the fluid that is in the resivour get displaced into the calipers. As Mookie said, the fluid goes sloshes away from the sensor indicating a "problem" causing the light to come on.
Also adding fluid to it and then doing your brakes makes a mess if you don't open the bleeders to prevent stuff from going back into the line, Or perform a flush.
Pushing the calipers back will push fluid into the reservoir, and if you fill it now and do brakes you will have fluid spill all over place..
Don't mix synthetic and stardard fluid. Get the fluid from the dealer. Also, keep brake fluid from getting onto your paint. It will remove it and fast.....