HELP NEEDED: Very little braking effort on the front

[puglove]

Ok guys so my DT has suddenly decided the front brakes they want to do very little work, they are still working slightly as they are still cleaning up the discs. But when you slam on the anchors the back end tucks down and the rear end locks up, Im thinking it maybe the ABS pump but i dont want to go ripping it all down and buying parts to find out it isnt the ABS pump.

Oh and iv swapped the calipers for xsi one with no joy if anything its worse

Any help will be much appreciated