I wasn't talking about the csystems pumps i meant PaulDriver's setup.

Well, I'm coming back with an update. My two MkII suddenly decided to change the tune (pun intended). I'm lacking equipment or technical expertise to measure any kind of change in the flow except visually monitoring my reservoirs. The change in sound was quite abrupt. Btw I'm operating the pumps the regular way now, meaning powering up with the system and shutting 'em down. They were really quiet for a while but now they sound like model airplane just about ready to to take off. I want to compare it to a Vantec Tornado. I wish I had a mic to record a little sound file for your listening pleasure. I don't know if any of you had this problem and how it further developed, in other words, how long it was 'til a total failure. If this is what normally happens with these pumps after a while than they render a silent set-up virtually non-existent. My loops are made with shrouded Papst 4412fgl/BIX 120 combo, csp mkII, DD RBX and dual 3.5" res, 1/2ID Tygon running a 20% Zerex mix, on the cpu and the similar set-up with DD NV-68 block on a video card.
I haven't noticed any changes in temperatures since that would be the only thing I can really monitor for changes but they sound really loud now.
I'm curious how is this going to develop but am not sure I want to put any of my beloved expensive hardware at risk.
Has any of you guys experienced anything similar before the failure occurred? Kindly share.
Thank you.

When my pump went it just stopped working, it didn't change noise level or anything. Sounds like the end is neigh for your pump.

That's what I'm afraid of. Time to plumb back my old l35 and go check out those new DDC's.