Strange that it " seems to work for about a hour and then slowly declines in power" , this might suggest the bleed was sucesfull , but the problem may lie with pads or the lever itself . Unfortunate also that Magura offers a 5 year leakproof warranty , which is invalidated by not using the suggested blood type . I've spent sooo damned long fettling with hydraulic discs , screw that , I'll stick with a V-brake up front . Hope you get it fixed