Yes, you shouldn't be able to see the flow cascading out the top nipple. The flow should be under the fill level. You can check flow with your pinkie finger. Even after a good run at the track, my IC water temp. is never too hot to dip the pinkie in. It's nice to be able to monitor the fill with the reservoir. I anticipate that some day perhaps, I'll see it low and may have to buy one of Rudy's custom IC's.