long "throw" normal on S calipers/brakes??

[Kaleid]

My 71S resto is nearly complete with a few bits left to tidy up...I took the car for a quick test drive and noticed that the the brakes require that I depress the pedal ALL the way down to engage- the car stops well but the "throw" is quite long...a world of difference from my 73.5T...my question is whether this is normal or not...I was told that that's the nature of the S caliper/brake setup and that maybe a large master cylinder would solve the issue (though that is not an option for me since I want the car to remain completely stock)...any thoughts on this? Apologies if a solution seems rather obvious to many of you as this is not my expertise...at all!

[orange911]

I would check that they are well bled, because I think you have air in it. It can't be the nature of the caliper, that is while it is up in the air. I could understand if you were driving it and the braking "felt" differently.

[edmayo]

It sounds like you have just put this car back together so there are several adjustments that can cause this. First, did you adjust the push rod to the master cylinder, might have too much free play. Did you rebuild the calipers, if so did you correctly orient the pistons to the 20 degree angle. If you have fresh rebuilt calipers, machined or new rotors, and new pads, it will take some brake usage to get the pads worn to the rotors and the pistons to move out on the spindle so that the pads are lightly dragging the rotors. All this is dependent on the first two items being correct. There is NO inherent problem with those calipers. You do have the calipers mounted with the bleeders up don't you.

[davep]

I agree with Ed's comments. The O-rings could be contributing to a lot of knockback at the present. That should go away. However, I'd doublecheck the bleeding.
Of interest is that the cars with the S calipers got the 20mm master cylinder instead of the 19. That 1/16" increase in bore is pretty significant. It would have required less travel and a bit more effort originally. Sadly the 20 is very hard to find now.

[Flieger]

When I got my rebuilt calipers from Eric Shea, they did seem to have a softer, longer pedal. The lower and longer throw was better for heel-toeing rev matching on downshifts. The softer pedal I attribute to the pistons not being seized. The longer pedal was most likely the knock-back from new seals. The brakes seem to have "worn-in" now and the pedal seems normal. I do not know if it is still longer than before, but it sure feels great to me.

[JohnT]

Here's what causes it and how to avoid it -

http://www.hillmanimages.com/912/030629-2937.html
good luck

johnt

[TEC69E]

I also recently installed some rebuilt S calipers on my 69E which came with the same from the factory, and all other brake components were left unchanged. When I first bled the system the pedal travel was long and new pads (Porterfield RS4) seemed to be almost non-existent . . . after a few miles I bled the system again and this time used some thread seal on the bleeder valves (speedbleeders) just to be sure I wasn't sucking any air back into the system . . . pedal was still a little long but the brakes felt better . . . after a few more miles and one more time bleeding the system the pedal throw is much shorter and the rock hard when it hits bottom.

Seems to just take time, patience, and lots of brake fluid.