Put some risers and new bars on and while in the process lost pressure in my front brakes so I replaced all the washers, which were bad, and put new fluid in. No matter what I tried I couldn't get pressure tried gravity bleeding, syringe method, hanging the caliper to get the air bubbles out with no success. So I took the lines off and plugged the master cylinder to see if it was bad and after some bubbles it started to push back and disrupt the surface of the fluid this is the only time it seemed to do this unless I push on the caliper. Any ideas?

 

bleed it properly. fill the master with fluid, put a piece of rubber hose on the bleed screw at the caliper. put some fluid in a bottle enough to completely immerse the hose. Pump the brake handle 3x and hold it down. Loosen the bleed screw, you should see air bubbles come out the hose. tighten the bleed screw down before letting go of the handle. do this several times. until there are no more bubbles then 3 or 4 more times. Make sure during this time to keep fluid in the master cylinder

 

There are tips on bleeding brakes in the DIY section. This is a common 'problem' and I have just answered a similar question!