How much of a loss of fluid have you had after the hard braking started? When the bladder lets go in the bomb the nitogen escapes an the space is filled with p/s fluid.Maybe 250 or 300 cc. Did you have to add only once? or is the leak on going? Wet under the car? As suggested check the weep hole in the booster on the brake master cyl. Maybe just a defective bomb. By the way is your steering normal? Coop