I'm helping a friend fix his tractor thats been sitting. I can prime the thing all day and i still hear air inside the pump. I tried bleeding it from the end of the small line that goes to the injectors and the primer started to feel a little tighter after a while but then i tried cranking it and the primer got soft again, and i started getting air all over again. Later i tried taking the line off the primer and putting my finger over it while i pump it, then i noticed theres hardly any pressure coming from there? is that normal? The filter bowl fills up but i think theres just not enough pressure to bleed the system correctly. Does anyone have any tips on getting this thing going? Thanks