Howdy got a question for the (far smarter) masses. My brake pedal is going to the floor when I try to stop. It stops fine, just has excessive brake pedal movement. Pumping the pedal doesnt help, I have no leaks in the system, and all the compoants "look" fine (calipers, lines,MS, etc etc). Im not at home right now so have limited access to tools and such., are there any easy checks I can make to determine the prob? Thanx much
Glenn

Sounds like its time to bleed the brakes,they probably have either water or air or both in them.Vettes are notorious for this especially if they set for a while like over winter,just because they look fine on the out side,doesn't meen anything.take the master cylinder cover off,see if there are any water droplets in the bottom.I would totally bleed and flush out the system,and replace the brake fluid,do not drive the car like that,you are putting to many things on the line,your life ,your cars life,and every body elses out there on the road.brakes are nothing to fool with,if you cant do the work yourself take it to a shop and have it done,but don't keep driving it like that

I agree with Ron 78, don’t drive until you have the problem solved. One thing is to check the soft brake lines. They can lose there ability to resist pressure and start to bulge. This bulge would adsorb the brake pressure (pedal almost to the floor) and exhibit the same symptoms as you described. If left untreated they might eventually burst. Good luck.

Check the vacuum line hose going into the power brake booster. All tight and secure ?

Thanx for all the info. I brought it by a shop the other day and they did a drain and flush on it. They couldnt fix it but thought it may be the booster. I just wanted some opinions from yall cause to me it really feels like air in the system
Glenn

Does the pedal go to the floor as soon as you step on it? If the Master cylinder is going bad then it usualy will stop and slowly go to the floor as you are sitting with your foot on the brake. If after you had the brakes bleed and it still wasn't any better then I would say it is the master cylinder.

The pedal just goes damn near all the way down then right before it hits the "floor" it starts working as an actual brake. When you release the pedal it slowly raises for the floor

It is possible this is a power booster problem. What happens to the pedal if you push it when the engine is off. If the pedal will pump up, let it sit a few minutes. Now push it down. If the pedal is still low, it's not the power booster. If the pedal is high, start the car. If it goes almost too the floor again, the power booster is the problem. If the pedal is not high after pumping and the vacuum is gone, look for play in the wheel bearings or warped brake rotors. The rotor problem is more noticable when the car is moving, and can be overcome sitting still. Loose wheel bearings will allow the rotors to "flop" sideways, pushing the pistions back in the calipers. When the brakes are applied they have to straighten up the calipers before they will hold. Just two more things to check.

Ken Styer

I thought that the pedal would be hard to push if it was a Brake Booster problem. I have been chasing pedal fade for a while,it's very annoying, I notice that my brake fluid had a brownish look to it, does that mean air/water. I had blead the brakes completly last year along with ,replacing the calipers ,master cylinder,brake lines from rubber to steel braid. Thinking about changing rotors next I had them cut when I changed the calipers and pads, maybe I have too much runout. Any suggestions.

Tom

The booster can fail two ways. If the vacuum diaphram ruptures, the pedal will get harder to push. But if the valves fail, it can become harder, or more often cause the pedal to drop.

Ken Styer