Air in lines... ugh...

Ok, well I have a water cooling set together, I've put together others before and haven't seen this problem. I have a bonnneville heatercore 2*120 size, a resevoir by noise isolation technology, tygon tubing an Eheim 1200 pump and a RBX block. The problem is that the air will not go away.. it makes no sense. The res will be the highest thing.. the system will be running. bubbles will start shooting into the resevoir, less appear to be shooting out... and yet none collect..

The order goes Pump->radiator->processor->reservoir->Pump...

The pump is lower than the reservoir which unfortunately can't be the highest thing in the case all the time. However it is "locally" the highest object as it is higher than the processor.

It just seems like the air won't go away.

Here's a secondary question, could this be happening because the system is under pressure? The cap on my resevoir seems to pressurize the air because when I take it off water tends to rise to the top.

I don't get air in my setup at all..

However bubbles form in the resevoir, and it seems to be under very high pressure I can hear air hissing out of the caps.. And when I unscrew the top cap it lets out a large pressurised hiss.

Is this normal?

My first question when I see something like this:
Do you have hose clamps on your tubing?

I have most often seen symptoms like that when there is a very small leak someplace in the system; so small that there may be NO visible water but air can get in.

The other things I have seen are :
1) system not completely bled of air- it forms bubbles at a slow point which get "re-absorbed" when the flow is moving faster.
2) An aditive that causes bubbles with very small amounts of air in a system. Water Wetter for example: with just a small amount of air in the system you can get foaming or bubbles.

I have no additives and it is foaming and bubbling.
I am not using any hose clamps, I shall pick some up at work Monday morning.

I had that issue with my system. I was sort of worried but figured I'd let it bleed for several days and it indeed did the trick. I had the exact issues, when I unscrew my res, it makes a pressurized hiss sound, etc. I do have worm drive clamps on all of my components but the foam eventually left the system and now it's great. With my Hydor L30, the foam wouldn't leave at all.