I took my 1998 Honda Civic ies for it MOT about a month ago and it failed on the rear brakes. It had new pads, disks and calipers fitted, but there was still a problem that when the car was idle the foot pedal would push down all the way to the floor. The actual brakeing system was fine apart from the pedal problem. They then decided that it might be the master cylinder but the same problem kept occurring, where when the car was moving the pedal would be ok but when stopped would push all the way down. Next they thought it could be the servo, and again the same thing kept happening. So then the car was sent off to Honda to have the diagnostics run on it. The tests showed the braking sysytem to spot on but still there was that pedal problem. The next plan of action is to replaceparts one at a time until they can pinpointwhat is causing this to happen, but thats gonna cost me a fotune.So between the guys at the garage, some brake specialists and the Honda technicians no oneappears to have a clue as to why the brake pedal pushes all the way to the floor when the car is idle. I find it hard to beleive that no one on the planet knows why this is happening so if anyone outthere can shed some light on the subject then please help!

 

Does the car have ABS? That's going to make it complicated. Could simply be failure to bleed the ABS unit properly after replacing the calipers or master cylinder, but the Honda dealer should've picked up on that.

If it is a conventional non-ABS system with a vacuum booster, it would almost have to be the master cylinder or a fluid leak somewhere. I think you're saying it will stop normally but the pedal will sink down while holding it stopped.

 

Does the engines idle go down and jump around a little bit while you push the pedel down? Could be your brake booster failing, they also tend to make a whoooosh sound. If the pedel goes all the way to the floor you oviesly have fluid leaking out and not being "forced" down the line which isnt giving you any pressure back when you push the pedel down. It very well could be a rear wheel cylinder or a caliper that is leaking around the piston seal that you cant see.

Thats the biggest load of crap, lets replace parts until it fixes the problem! I had a guy at my work, the shop forman to be exsact that would do that. He was the biggest douche and was always thinking he was right. Just grinds my gears. Try searching around some forums on similar problems.