The red warning light comes on when I apply foot break. It does not happen all the time.

The car manual says the red warning light has two functions, ie, if the hand break is still on, or applied, or if the brake fluid level is below line.

The red warning light usually comes on if say I am going down a slope, or hill and I have applied the foot break. Also could I have a leak as when I apply the foot break it feels slightly different in that I feel it takes slightly longer to break ?

Any ideas out there anyone ?