Check valve: An accusump injected into the oil line from any arbitrary point will add oil pressure and subsequent flow of oil away from the accusump. The goal with the check valve is to make sure that this pressurized oil feeds the 'IN' or 'RETURN' side of the engine, and doesn't fight the oil pump going the other way.
If I see this correctly, the brass check valve is under the frame out of sight. If it is indeed there, it's in the wrong place and needs to be moved as explained above.
The electric valve kit on the Accusump is essential, and I'm glad to see one on your installation. There's no intelligent way to plumb a ball valve into the cockpit operated by the driver which is reason #1.
Reason #2 (the really good one), comes from blown race motor stories of woe. I spin out in the grass cuz some knucklehead ran me off the track and I stalled the motor, (when in a spin, both feet in for f*&k sake!!!
).
Now I'm pissed and I want to vehemently get back into the race. I fire up the motor, & mash the gas pedal to chase this guy down.
Anyone wanna guess at the failure?
Motor stalls, I didn't close the manual Accusump valve.
Of course I didn't close the freaking valve, I was spinning, scared and pissed! Now, I've got an open Accusump valve, and I've lost whatever stored pressure was once there.
Fire up the motor and instead of feeding oil to the engine, the oil pump recharged the Accusump instead.
Spun bearing, lost race, damaged ego & pocket book. One manual ball valve removed from said race car never to be used again.
The electric valve takes care of all this automatically via a solenoid and a pressure transducer. Duh.