I'm facing such problem in my CULTUS 2005 carby, he car brakes when the brake discs are cold, once or twice you hit the brake pedal with some force and BOOM, there you have more or less NO BRAKES, i mean it.
The brake fluid NEVER drops, the pedal is NOT soft and DOES NOT touch the floor. I am unable to figure out the reason and Not brave enough to let some desi ustaad experiment on 