An Unexpected "Problem"

[Eldraad]

Dug out my old watercooling stuff from the K6-2 days. Found two blocks I had made, an Aluminum block and a copper "Cap" block. Put the aluminum one on my T-Bird and have no problems. But, looking at the copper "cap" going to waste (just too small to fit the t-bird reaching all four pads) I decided to modify it for the t-bird. Picture a Martians head...you know, kinda round with two antenna (one at each side of the top of the head). After some cutting and pouring a lot of epoxy it looks pretty much like one of the polyblocks (but for$6.50).

The problem is...there is a swirling whirlpool of an Air Bubble right in the center where the core will rest! No water there, just Air...center of the storm kind of thing. No matter how much/long I bleed the inline system (added a res tank) the air "always" collects here...even when it is the low spot in the system. Swish swish swish! Pinching one of the hoses lowers the flow enough to remove the air but a few mins later...the "Eye" is back. Gooping the pump seams today to see if air is creeping in somehow. Did anyone who had a Polyblock have this problem? Since they seem to work the same I wonder if you had some tips?

Thanks alot...time to play with that bubble!