Spongy breaks after new calipers and bleed

[Toughers87]

Hi guys, investigated my brakes the other day and found the piston seals to be broken and leaking. Ordered new calipers, I flushed the old brake fluid for new before fitting new calipers then bled once more once the calipers were fitted (with new pads) how ever they were still spongy. Looks like it has a new master cylinder too. Abs pump also looks new (can't guarantee) 

The order which I flushed was n/s rear o/s rear n/s front o/s front, abs pump. I didn't pump the break with abs tho and nothing came out. Felt unsure so repeated the process again without doing abs pump. Changed calipers and done it again, again without abs pump. 

What have I done wrong?

[BachelorDays]

Don't know if this is relevant but happened in my MB E Class. I would also get a BAS error indicating a BAS booster error. The pedal would sink and require a double press. I think some air was stuck in the booster. Went on for a while and then settled.

I can't help but feel that the initial bleed with a leaking system has probably contributed to it, although looks like the system has had its share and more of issues. You could give it a while and keep pumping the pedal to see if it settles.

Best of luck.