Pedal going to floor suggests a leak. If the fluid level doesn't drop in the reservoir, that leakage is likely internal inside the master cylinder. That can also be caused by improper bleeding procedures. In normal operation, the pedal only goes about half way to the floor. Crud and corrosion build up in the bottom halves of the bores where the pistons don't normally travel. If you press the brake pedal all the way to the floor during bleeding, you are likely to tear the lip seals on that corrosion.
There may be rebuilding kits available for the master cylinder but very often they cost more than a professionally-rebuilt master cylinder with a warranty. You also have to clean that crud out, and if the master cylinder is made of aluminum, it will have an anodized coating that absolutely must not be scratched during cleaning. That means rags and cleaning chemicals only; no wire brushes.
Has the fluid level been dropping or have you seen puddles on the ground?
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Saturday, March 3rd, 2012 AT 11:45 PM