brakes
 

On my 1974 vette the brake pedal goes to the floor and barely stops the car, the brake light stays on. The master cylinder is full of fluid. There are no leaks on the floor. What could be wrong? Any help is greatly appreciated. Thanks

No symptoms are usually caused by a bad master cylinder. Do you have power brakes?

yes, I have power brakes

Can you pump the brakes up by repeatedly pressing on the pedal?

I can pump the brake pedal but it barely comes up and stops the car. It does not come up all of the way to where it should be.

When you pump them up, does the pedal still go to the floor? If so, then I'm pretty sure it's the master cylinder then.

Yes, the pedal goes all the way down to the floor. Do you think the master cylinder needs to be rebuilt or replaced? Is it possible that a seal or something is bad?

Well if the bore is not pitted w/ rust you might be able to rebuild if you can find a kit.

I'll check to see if there is any pitting and if not kits are available from MidAmerica Motorworks. Thank you for your help. I will let you know what the results are when I fix the problem. Thanks again!

How are your brake calipers?

Haven't checked them yet but will do.

As you may be aware, the calipers are known to rust internally and then leak. Replacements w/ st-st liners are available now.

Hey... I found this forum useful that has provided me great information on cars. I am glad that I am here.

Glad you found us.

73 Shark: I'm back from vacation! Would one bad caliper cause the brake pedal to go to the floor? I would think that I would still be able to stop the car by pumping the brake pedal. Right now the pedal barely comes off the floor.

Only if the caliper is allowing the brake fluid to squirt out but then you's notice the fluid on the wheel.

Most likely a master cylinder or power brake booster cuz the pedal should return even w/o fluid. Check the return spring. I think there is one but not sure and out of town now.