If the brake switch is easily accessable you may want to bleed the switch itself. I had one that did that, and after several blead still wouldn't function correctly. I blead the switch, just loosened the switch like a blead screw, and that cured the problem. I guess a small pocket of air was traped there and normal bleading wouldn't get it out. The pedal was good not spungy, but brake like wouldn't stay on. Now I use mechanical switches............ Hope this helps...........