Nightmare I had the same problems, Ive got cossie rears and ST170 fronts. I still have a spongy pedal, all be it a good braking system however. I used the eezibleed as to start with the pedal was terrible and would almost go to the floor with the engine running. I didn't bleed mine with the engine running, as far as im aware you dont need to.

I'd do as Tony suggests, bleed it up and use it a couple of days then try again, believe it or not my pedal has improved since bleeding the system.

See if any of these help:

https://passionford.com/forum/viewto...204&highlight=

https://passionford.com/forum/viewto...758&highlight=