When I push down my brake pedal, it almost hits the floor, I fill it up with brake fluid, and it will still go to the florr. What is wrong with it?

 

Possibly a bad master brake cyclinder, if it's not leaking and bled properly. Also, you can search the internet at google or yahoo for do it yourself automotive brake troubleshooting. I did that a few months ago, and my CRX had a bad master brake cylinder. It was only like 50 bucks at Advance Auto with trade in of the old one. It's simple to change. You just need somebody to pump your peddle while you bleed them after you've installed it.

 

Honda master cylinders are known faults. Bleed the whole system and see if there is any improvement. If not, replace the master cylinder since it is obviously leaking.

 

Well, When the car sits for a while, or when I drive it for awhile and don't check it the brake fluid seems to magically dissapear. Does that mean I should replace the master cylinder?

 

Yes, because it is leaking from somewhere and that is a well known place it can leak from. Have you checked all around the master cylinder for leaking fluid?

 

Here you go. http://autorepair.about.com/cs/troub...g/a/bl302a.htm
If the fluid seems to magically disappear, then it could be leaking anywhere in the lines, or most likely from the wheel cylinders. I'm also sure it could be leaking from the master cylinder. Mine had no leak at all when i had to change mine(the master cylinder). My brake pedal just went all the way to the floor, and you had to pump it to make it stop. My brake fluid looked like black water, which is probably what caused the master cyclinder to go bad.