Make sure you service the calipers i.e. slowly pump the pistons out by a few mm, clean the whole caliper then push the pistons right back into the caliper body, they should move easily with one finger pressure anymore and there starting to seize!
Check the discs are within spec and dont have a lip on them if they are out of spec or lipped change them, refit the calipers and put the pads back in. Pump the level until pads come in contact with the discs now check there is free movement of the front by spinning it (front end off the ground) you should get up to a full turn, not less than half with one pull any more/less and something isn't right. In this case check the pads are square in the caliper bodies and/or the pads aren't binding.
The next bit is curial ride carefully avoid heavy braking for about 20 miles then begin to build up the braking force until you reach 100 miles job done.