This has often cropped up before. General consensus is, they're not very good to start with, and soon lose pressure. The amount of travel in the pedal can increase alarmingly!
FWIW, my two-penn'rth is, bleed it properly (I use a Mityvac, some, as posted above, favour the speed-bleeder thingeys). Anyway, make sure you get the bleed nipple above the reservoir. Personally I hook it round the near-side pillion footrest.
When it the travel is minimal and it's good and hard, you ca help keep it that way by wedging a old socket/piece of wood/whatever between the pedal and the frame boss above whilst the bike's not in use, to force the brake "on".
Hybrid Mode
