Air in primer pump bowl

[BCODERRE]

2012 prostar with maxxforce 13 is getting a lot of air bubbles in the primer pump bowl.
I ran a clear line from the davco filter to the primer pump and I see a lot of air bubbles in the line.
Does anyone have a fuel line schematic? I'm going to pick up some new fittings tommorow to make up a test line but I need to know what lines go where.
The davco filter has inlet on right outlet on left and what appears to be 2 return lines lower left.