I was driving my 2005 Honda Civic EX a couple of weeks ago, and a car was turning so i had to slow down. i hit my brakes and nothing happened. the pedal went to the floor and i still had nothing. i pumped it a few times and a little bit came back, enough that i didn't hit the car in front of me. After the car turned and i got my speed up, i hit the brakes and they were fine. in the next few miles, if i pressed the pedal lightly it would catch and i would slow down for a mili-second before the pedal went to the floor again. coming up to a red light, i had to downshift and use my e-brake so i didn't hit anyone, even tho i had been going slow. I had absolutely no brakes at all. i was on my way to my dads garage, so when i go there i told him what happened, and he said it sounded like a blown brake line. We got in the car to take a drive and him to see what i was talking about, and nothing happened. The brakes were fine. we then figured that it must have been the brake master cylinder bypassing, but i have been driving it for almost a month and nothing else has happened, brakes are fine. has anyone else had a problem like this before?

 

master cylinder may be failing.

 

It does sound like a master ,usually the brakes will begin to fade or feel spongy,you will have to pump them a few times.