What are the causes of excessive brake pedal travel? The main one I know of would be worn pads, but my pads are brand new. The pedal easily goes near to the floor, but near the end of it's travel the brakes grab fairly well. I just can't push the pedal much farther and it's making the car brake poorly. I have bled the system until I went through two liters of brake fluid, there are no leaky calipers (all of them new, and I double-checked each piston anyways), there are no leaky lines that I can tell of, I splashed some brake fluid over the master cylinder by accident because I was pumpthing the pedals too hard (DOH) so I can't tell if that's leaking, but I don't think it is. When all the bleeders are closed and I pump the pedal, the level in the MC doesn't go down any. Open them up, it goes down noticably. I don't think I have a leak in my system anywhere, and the pads and calipers are brand new. It would seem that a stuck piston wouldn't cause a pedal to go down farther, easier, though that's not something I've checked for yet. I'm running out of ideas here -- the fluid in the MC is crystal clear now, as is all the fluid that comes out of the lines. If there ARE any bubbles in the system, god knows where they're at.

Anybody have any ideas here? Next thing to replace I guess would be the MC, but I'd like second opinions of far more knowledgable people than myself before I go out and buy ANOTHER brake part.

And all's I wanted to do was change pads. :cry

 

Did your MC go dry by chance? If so you might have air trapped in it and will need to 'bench bleed' it. Did your brakes work fine before you bleed them? If not you might need to adjust the rod that inserst into the MC through the firewall, it is thread and allows for adjustment.


[Modified by Fevre, 9:51 AM 11/26/2002]

 

I actually kept the MC near overflowing the entire time I was bleeding them, and when I was almost done I let the level of fluid get to where it should be.

The brakes worked great before I started working on them. It's just that the pads in the back were nearly gone so I figured I'd go ahead and get a full set of pads, and while I was at it, I went ahead and replaced one of the calipers because the bleeder screw snapped the last time I bled them. (Fortunately, it snapped when it was closed.) Since then, the brakes suck.

 

OK, I will ask. You say bleeder every time , but you do know there are two. Previous posts have talked about tapping calipers with rubber hammer, etc.

 

Actually, there's six -- two in front, four in back. But the front driver's side screw snapped off last time, so.. yeah. I've tried everything I can think of, except.. Bleed some more! *sigh* I always wondered why anybody would need such a huge bottle of brake fluid that you see in parts stores.

 

Ok I am out of ideas, but please post the final solution for futre reference.
Good luck.

 

No wait, one more thought. You could try removing the wheels and have someone apply breaks while you hand turn rotors, this might tell you if it's front or rear, or if you have excess travel before anything happens. On another thread, they were talking about the booster and the pedal connection not being right.

 

I might try that. I think, though, that it's simply, well... all of them. :( That's leading me to believe it's got more to do with the MC than anything else. Also, something I want to ask.. Will an air bubble that gets in the rear lines make it's way into the front lines? I'm under the impression that it wouldn't, but I've been wrong before. Just something I want to be sure about.

 

I was searchung the archives and found this, http://forums.corvetteforum.com/zerothread?id=301969

Two things new check the rubber lines, maybe they are swelling and see the post about gravity bleed.

I have to do my breaks this winter, so I am interested in the outcome.

 

I'm going to try to bench bleed the MC, just to rule that out.

 

No dice, no bubbles in the MC. I also tried replacing the MC but the rear brake line that bolts into the MC seems to be rounding off. :mad :cuss :mad :cuss :mad It's too dark to mess with it much more tonight. Man this is depressing me.

 

It still sounds like you have air in the lines. I've tried every way imaginable bleeding the brakes on both the 71 and 82. The only way that works consistantly is to gravity bleed them. It's a long time consuming process but it works every time.

 

Well, I think I found the problem. One of the rear bleeder screws was leaky. I didn't notice it before because the last time I bled the brakes because I got brake fluid all over the calipers. I got a massive air bubble out of the rear left side, and it's helped the brakes a lot. The light doesn't even come on anymore! hehe Tomorrow I'm going to get four speed bleeders for the rear and bleed them that way. I think I'll let them gravity bleed first for a couple of hours, though. I'll post again tomorrow with the results of the gravity bleed and new bleeders. Thanks again for the help, and one last thing... I haven't looked at it yet, so.. if it's easy, just tell me and I can probably figure it out.. How do you adjust for pedal height? Is it just a bolt or something near the firewall?