Well yeah its just like the topic says, my pedal goes to the floor and its barely stops the car. Also when i press down on the brake pedal, i hear alot of air coming from were the brake pedal is. Okay so i thought it could be air in the lines, bled them, didnt work. now i replaced the master cylinder but im thinkin there was supposed to be a seal between that and the booster. is there a seal that goes there? My guess is yes... Also if anyone can shed some light on what it could be drop an opinion...thanx

 

did you redo the brake system before problems showed up ? did brakes just start going all the way to floor all of a sudden before you did any work on the brake system?

 

What year is your car? And no, there isn't a seal between the master and booster. The master cylinder is a sealed unit within itself. You could also have a bad wheel cylinder (drum brakes) or a bad caliper (disc brakes).
Did you bench-bleed the new master cylinder? Also, does your car have cruise control? I know that sounds like a weird question, but it could be the source of your "air" noise.

 

sorry i didnt get back at you guys right away.....
well the pedal just started going out of now where... we hadnt messed with the brake system for nothing....

umm the car is a '70 maro, we bench bled it before we put on the new cylinder... but the problem was still there,,,

we found the problem... it was booster.... it had a crack in it... the result for all that air.... i dont know how but it did... so we put a new one in... thanx for the suggestions though... =)

 

hope that the booster is the problem but could be the proportioning valve.