Hey everybody need your help. My brake light came on and won't go off and brake pedal is going to the floor. Any suggestions. Thanks Frank in WV

First thing I'd do is to check for brake fluid around any of the calipers and junctions in the brake lines. If there isn't any fluid showing anywhere next check the level of brake fluid in the master cylinder. If it's low, don't just refill it - bleed the entire brake system. Chapter 9 in either the Haynes or Chiltons manuals has the correct sequence to use.

If the pedal stays solid after that you most likely solved the problem for the short term. But something caused the pedal to go soft. A possiblity is brake rotor runout which causes air bubbles to form in the brakes lines. You might want to have them checked also.

Hope that helps. Any other tips out there?

Thanks Norsky, Will check this before driving this weekend. Frank in WV

Check all lines & connections for any leakage. If all looks ok,, then pump on the brake pedal a few times w/ the engine off, then hold down the pedal with firm pressure. If your foot sinks to the floor, then it's your master cylinder. Oh yeah, how does brake rotor runout cause bubbles in the brake lines? I've been in the automotive repair business for 19 years & have never heard that.
Bill

BacaBill said: ... how does brake rotor runout cause bubbles in the brake lines? ...

I've never experienced it, just read about it here on the site in other threads and in repair manuals. I don't know if I can describe it correctly, but as I understand it if your rotors are not true they will cause the caliper pistons to pulse in and out very quickly which causes the air bubbles to form in the brake lines. Then when you step on the brake pedal you get the spongy feel or nothing but floorboard.

Anyone please feel free to correct any or all of that explanation.


Jim O.
Save the Wave...!!!

BacaBill,
Look up Vette Brakes and Parts on the internet (they are located in Florida). Send them an e-mail asking about rotor runout. They will give you a true ear-full of information on it. It is for sure real !
My guess is that many mechanics don't know about it because it basically occurs during high speed driving like on a turnpike or freeway and unless the problem is bad, it won't show up till you drive at 65 for a number of miles. As the rotors get worse, it will show up in shorter and shorter high speed hops. Many mechanics deal with the same type of local commuters on a year in year out basis and this type of problem just in not previlent. It is kinda like you have to know about it to look for it. If someone comes in with a mushy pedal or no pedal at all, most places will do a quick check, find no leaks, bleed the brakes, top off the fluid and send the customer on their way. Problem fixed, and may never show up again...if the car stays off the expressway.
Before I get a lot of flack, I have experienced the problem and had mechanics continue to tell me the master cylinder was bad and kept replacing it. I finally e-mailed Vette Brakes and took their answer with me to a mechanic. He told me that Vete Brakes was full of crap. I went to a Corvette specialist. They said it is a 'common' problem and had the car fixed the next day. My problem had gotten bad enough that it would show up with about 5 miles of 70 mph driving.

|UPDATED|5/2/2003 5:50:17 AM|/UPDATED|

I had the same problem with my 69. The rear brakes would get air in them after a couple of weeks. I was too cheap at the time to fix it, just kept bleeding them. I should have fixed them, because one day someone pulled out from a parking lot and I couldn't stop in time.

It is a somewhat difficult fix, because the rotors are indexed to the hubs and riveted in place. You have to put the rotor back in the same orientation as it was removed. If a previous owner removed the rivets you don't know if they put the rotors back in the right orientation. Then they should be checked for runout on the car with a dial indicator.

Joe