Brake issues....couldn't find in search

[Prime Lord]

Here's what I've got.

'93 Cobra Booster - New
'93 Cobra MC - new, from auto parts store
all new hard and soft lines
'04 Cobra calipers & 13" Discs - New
'04 Cobra Calipers & Rear discs - New
Stainless soft-lines
Ford/Wildwood Porportioning valve

Now, when the car is off, the pedal is worthless for about 3" and then becomes hard as a rock. When I start the car, pedal goes all the way to the floor and starts to grab about the last inch of pedal travel. I had somebody else do the work on my car since I didn't have time and he said that all 4 calipers bled out fine w/ no air.

Is this MC problems?? I'm gonna go back and bench bleed the MC today and re-bleed all the lines and see if that makes a difference. The guy who put my car together....I don't know if he bench bled the MC, so I'm gonna do it. I mounted the brake booster and MC to the car, I just never put any fluid through it. So I'm sure the pushrod is set right. Anyway. I'm gonna bleed this stuff and see if it changes, but I just wanted to know if there were other ideas. Thx.

Any other ideas?

 

[Mustang5L5]

It's also possible the calipers aren't bled all the way.

Sn95 rear calipers are notorious for trapping air when bled after a fresh install. They don't flow enough fluid. The best way to bled newly installed rear calipers is to remove the caliper, put a block of wood in the center and bleed them while holding the valve straight up and tapping it with a rubber hammer. You'll notice the fluid flow out of the rears is nowhere near as strong as the fronts.

I think you are on the right track. I'd do a complete re-bleed of everything.

ALso, the dead space you have can be taken up by adjusting the brake booster rod. However i'd wait til after you completely bleed everything for sure before adjusting it out.