I have just found this post on a uk forum(xdrivers) and this is a quote from it.
"well had a good conversation with a newly opened indy to me (hes just resently parted from main dealer after 9 years and is 40miles closer than where i was going and 3miles from my work

) he said hes 99% (seen 5 x5s sent to him the same as mine) sure that what weve done is forced the seals on the master cylinder inside out from bleeding the brakes by pressing the pedal to the floor 100s of times, so ive ordered a new master cylinder (Β£55 motor fators) and he said to fit this and then bleed from the beging with the pressure bleeder which will take a fair bit of time! anyway today they have got alot worse with use but the fluid level is exactly the same so no leaks, he said that when the seals have been poped just the front calipers work. However when i asked to book it in with him he said it was a simple job for my bro who did all the new brake pipes and in his explanation he never menchioned anything about laptop for abs unit, last time we bled it running so the abs etc was powered up! also there is no abs brake function on inpa and it has everything else. i could be wrong and my brother is going to phone him when he does it. oh well get the e46 out for some fun!"
Link to the full post.
brake bleeding