Possible collapsed brake line?

[nlzn]

I'm not sure what's going on here, maybe you guys can help.

A few weeks ago my pedal went right to the floor. I bled all 4 and wasn't getting any pressure. Had the cylinder replaced. Bled it, problem solved.

Cept now the suckers are squihsy as hell. If i smash them at a decent speed all the way I can feel the ABS kicking in and the pedal fluttering against my foot. But there's no stopping power. It didn't use to be like that, ever. So I bled an entire quart of fluid through them starting with the backs first. Recently I've started to notice a slight grind above 30mph that's making me think maybe a caliper isn't retracting all the way. BUT Ive dealt with a seized caliper before and it basically caught on fire when that happened. (Red hot and smoking hard).

Where would you guys start?

 

[illeffekt vr-4]

I'm not too familiar with ABS setups but I know that on other cars (not dsm's) that have ABS the pump also has to be bled.
When you do bleed the wheels make sure you start with the farthest one and start working your way up:

1. Passenger Rear
2. Driver Rear
3. Passenger Front
4. Driver Front