When I was bleeding it, The 8mm bleed screw on the side of the pump kept turning around in the housing. I have been told that cone like shape thing that the bleed screw goes into(wish I had my manual with me so I could give you the correct names for everything) are only pressed in and my one broke up! I did have a old pump that was with the boat when got it so I took the housing off that one and it worked fine for a half an hour then stopped. Since then I have not been able to get it to run.I think when it broke up some fragments must have gone into main body of the pump, So time to change the pump I think.