When I step on the brake pedal I hear a hissing sound and the pedal goes all the way to the floor and the brakes barely stop the car. This doesn't happen every time but most of the time. Any ideas of what this could be? My husband just put new brakes on the car right before this started happening.

  • What all did your husband change when he "put new brakes on the car"? Nov 29, 2015 at 12:38
  • He said he only changed the front brake pads and routers (sp?) Dec 1, 2015 at 6:07

3 Answers 3


If pumping the pedal until it's hard doesn't permanently fix it:

Because you say the pedal went to the floor and you heard a hissing, my guess is the master cylinder is bad or you have a brake fluid leak. The hissing is likely because the brake booster is being pushed farther than it was ever expected to (pedal to the floor) so the rubber membrane inside is slipping temporarily and causing a vacuum leak.

Either way, this is nothing to mess around with. Don't drive on it; get it addressed as soon as possible.


Try just pumping the brakes several times with the engine running and see if that doesn't help. It could just be the calipers need to be filled back up with fluid which will adjust them to where they need to be. When I say pump them several times, continue pumping/releasing until the brake pedal gets hard.

  • Do you mean like bleeding the line to get air out? Dec 2, 2015 at 1:50
  • @JeanneO'MalleyWhitaker - No. I'm saying just pump the brakes. You are trying to ensure the caliper pistons are fully extended and actually pressing against the pads (which will now be pressing against the rotors). I'm thinking after they were installed, they were still collapsed. Just need to be pumped full of juice ... I don't know if that's what happened ... just thinking it could sure be a possibility, though. Dec 2, 2015 at 2:06

Please make sure.

During the replacement of brake pads ., was the brake oil resiorver cap removed or not? , when caliper piston was being pushed.. If not may be its seals of master cylinder got damaged. Due to this padle is spongy or got down.

  • I am not sure if it was removed will check on that but when he first replaced then they worked great for about 4 to 5 days. Dec 2, 2015 at 1:51

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .