brake pedal goes all the way to floor

[Jwillert]

Just rebuilt a caliper and put in new pads. now the pedal goes almost to the floor before any braking. What is going on?

John

[FPB111]

This must sound like an obvious question but you did bleed the brakes?

[wideRSR]

Air compresses.. fluid doesn't...

[JohnJL]

Ha! I just posted the same thing on another thread. I've owned 3 of these cars, rebuilt calipers 3 times and am having this same problem...

[Jwillert]

Yup, blead the brakes twice. No luck.

[Quicksilver]

There is still air in there somewhere or the pedal linkage is massively messed up.

(Obligatory stupid question...)
Did the calipers go back in with the bleeders at the top?

Also are you pressure bleeding them? If there is a huge quantity of air in the lines it is almost impossible to bleed them with the old 'pumping the pedal' method. It can be done but it is surprising how much fluid you can pump through the system before it is really purged.

[ChrisBennet]

In my experience, SC's and Carreras cars (you don't mention the year of the car) can exhibit a similar behavior where the pedal goes down real easy and then gets suddenly firm. This is causes by pushing the pistons way back before inserting the pads.

To keep this from happening, you need to extend the pistons such that there is barely room to get the pad into the caliper i.e. you need to gently tap it into the caliper.

I take the pads out one at a time and put something thinner than a brake pad in it's place (like a screwdriver), press on the brake pedal to extend the piston then pry the piston back a little at a time until I just get tap the pad in.

-Chris

[Groesbeck Hurricane]

John,

Take the calipers back down and follow Chris' advice. I would believe he is dead on. I had same issues, did his method, took care of the issue.

[Jwillert]

Thanks guys. I'll have to try the pad solution. Why can't, however, i get more fluid in the lines now that the pads are against the rotors?

john

[3.2 CAB]

Jwillert, depending on where the bleed screws are on the calipers or wheel cylinders, there could be trapped air, which could be causing the problem you are asking about.
I had a similar problem on a different make of automobile. I was not happy with the feel of the pedal after doing some work on the brake system. I actually did things sort of backwards. I connected a pressure feed source of brake fluid to the bleeder screws and actually, reverse bled the system. I had already changed out the components that were bad, and had fresh fluid through-out the system, but the pedal just didn't feel as firm as I wanted it to be. One by one, I would connect the fluid container line, then open the bleeder. I would then pressure feed new fluid into each wheel cylinder till there were no more bubbles appearing in the reservoir. This was done at all 4 corners, following the pattern of the longest to the shortest run in the brake lines. It worked great! I have also flushed and replaced the brake fluid in a similar fashion, except there was suction applied to the bleeder screws and a large source of fresh fluid was available for the master cylinder, so the reservoir would not be drained of fluid. I have not ever really seen calipers and pads that did not "self adjust" most of the time that new pads are installed into calipers and the rotors are still within "spec" there is not a lot of extra space, between the new pads and the rotors. What little space is there has never been a problem in getting the brake pedal to feel right after completely servicing the system ie: flush, bleed, etc. Good luck!! Tony.

[JohnJL]

I took all the pads out in succession and with the wife working the brake, "exercised" each pad. There was no difference until the very last pad, the front left "S" calipel. When I bled the inside (no bubbles though!) everything firmed up.

[Jwillert]

Can't wait for the weekend to give these a try.