kiwi911

I've just rebuilt the brake system on my '81 SC - new seals in the standard calipers, rotors resurfaced, new ATE master cylinder installed & new pads fitted. The system has been bled extensively, using a pressure bleeder, followed by the 'traditional' two-person bleeding method to finish. I am confident there is no air in the system. The pistons all slide freely in the calipers.
My problem is - the brake pedal feels much softer on initial application than it did prior to this work, and, if I press the pedal down far enough it feels like it's hitting a mechanical stop, i.e. the pedal goes from being relatively soft to rock solid in an instant, after a few inches of travel. NB. when driving the car the brake pedal is effective (i.e. the brakes work) before the point of reaching this 'solid' position. The booster appears to be functioning correctly. There does not appear to be any excessive play in the pedal bushes or pedal to booster linkage.
Any thoughts / advice would be much appreciated thank you! <img src="confused.gif" border="0">

Bill Gregory

One common problem with brake overhauls is that the pistons are pushed all the way in when putting everything back together. So you step on the brakes and there's alot of pedal travel. If you do nothing, the situation will correct itself after around 100-125 miles of normal usage, as the pistons wiggle past the seals to get to their normal working relationship with the pads. Or you can try pumping the brakes hard and standing on them to get the pistons to move. The best fix, if you want to fix this immediately, is to pull the pads out of each caliper, and pump lightly on the brake pedal to push the pistons out just a bit. Too much, and the pads won't go back in. You want it to be a tight fit when you put the pads back in.

Hladun1

Is your pedal linkage properly adjusted? SC's have complicated mechanical linkages. The Haynes manual describes how to set the linkage. Basically you should have 10 mm of free pedal travel.

But make sure the brakes aren't dragging. The wheels should spin freely with only a slight drag. Otherwise you'll soon be doing another brake job

Matt Chamblin

What Bill said. I would be willing to bet money that is what you need to do. If it's not that, than you have air in your lines.