Oil pump problem

[1976RD400C]

I'm sprucing up the 100 Twin Jet and have the cylinders off for hone and rings. I noticed over the course of several days, the oil lines to the cylinders, that use banjo bolts to hold them on, are leaking oil out. Maybe about 1/4-1/2 teaspoon out of each line. The oil tank is full. I'm worried that if this isn't addressed, it will leak down oil into the motor while parked. Any ideas why the pump is doing this? Thanks

[m in sc]

check valves need to be cleaned out. yes. it will absolutely drip into motor.