SLI Fittings for Asus P6TD-Deluxe

[Roch]

OK, so I spent yesterday afternoon putting the loop together. It all went in (although a bit of a squeeze to get it all in) and I've left it over night to leak test, 12 hours so far.

what's bugging me now is the noise. The pump is really loud (it's making a "droning" noise) and there's a large water "whooshing" noise every 10 or so seconds.

If I turn the case on it's front the water noise disappears. I've tried filling it up more but it's as full as it can be. I'm concerned i've done something wrong with the way i've set it up, has anyone got an suggestions, i'm kind of panicking .

EDIT: when I put the case on its side the water noise stops completely and the pump quietens somewhat, is this trapped air?