So, got a CoolIT Domino A.L.C water cooling system quite some time ago, and at one point, it developed a heckuva loud whine.

Now this thing wasn’t quiet to begin with, but when it got to the point where I’d hear the water pump whining over 6 other fans… I pulled the thing and replaced it with a Noctua. Or a Zalman. Or something else I can’t remember.

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It had been sitting in it’s box ever since. I had a bad experience with a ThermalTake water cooling system years ago (water seeped through the pump seal, got in the electronics, shorted stuff, melted the resorvoir, etc), and wasn’t eager to repeat that experience.

Anyway, since it was effectively junk, I figured I’d pull it apart and see if I could fix the whine.

And I did.

Here we go.

First, a 2mm hex key takes care of 2 screws on the panel. I included the key in the picture in case you don’t know what it is. Alternately, I’m sure a 6-point screwdriver (torx, etc) would work fine, as long as you have the right size.

Now with those screws out, don’t pull the panel off just yet – the pump is still attached.

Sorry, the blue is kinda hard to read (you can click for a larger version, but your eyes won’t bleed any less).

The 2 screws in the upper left are what’s holding the pump itself to the panel. You can remove 1 and just loosen the other to get enough room to rotate the clamp (next pic shows the clamp rotated).

The 2 main screws give you access to all the wires. Note that later on when you re-assemble, this can be a pain to get back on (the wires tend to get in the way and you end up having to route them carefully).

As promised, above you can see I’ve rotated the clamp away (blue arrows). You also see the wires – normally they’re coiled around something, but I’ve had this off a few times when swapping the fan and found it easiest just to jam them in as you see it.

You can kinda see where the wires plug in, but I’ll give you a pic with a better angle.

I’ve labelled these in the pic.

The 2-pin wire with a white base (bottom one) has to be oriented the correct way when you re-install. It’s not “keyed”, so it’s possible to put it in backwards. If you do happen to put it in backwards, the thing will beep like crazy when you re-install and put power to it. It’s for the temp sensor. It’s also quite short, so it’s a real pain to get re-connected later. You pretty much have to remove it though.

The 3-pin (red/white/black) is for the water pump itself. It’s keyed (the standard motherboard-header plug), so you don’t have to worry about remembering the orientation. You might be able to get by without disconnecting it, but I disconnect it anyway.

The 3-pin (black/black/black) is for the 120mm fan. I didn’t remove it this time around. If you plan to replace the fan at the same time (or ever)… well now you know where it is.

Anyway, once all that jazz is disconnected, you’ll get the panel off and have room to access the water pump.

First, the thin top plastic “plate” which covers the electronics.

Remove the 4 screws to get that out of the way.

Then, the plate has 2 clips which have to be pried, while you use something thin/sharp to pry the plate up and off.

If you have 3 arms, you’ll have an easier time than the rest of us. As you pry, work your way around – eventually you’ll get the thing off. The clips will probably be in bad shape by the end.

Oh, and the whole thing might rotate while you’re prying – make sure it doesn’t pop out of the rad. And make sure you don’t crack anything while you’re at it.

Now that the plate’s off, more prying!

This one’s almost worse – there’s a rubber O-ring which seals this together, it’s quite tight, and you’re fighting it while trying to pry the electronic assembly (which includes the pump) out.

If you find it frustrating, keep in mind that installing it again later is even worse. So if you can’t handle any worse, now’s the time to turn back.

Basically, a screwdriver and a thin knife tends to work best. Use the thin knife to open a space, jam the screwdriver in there, then try to get the knife in on the opposite side. You’ll have to pry quite a bit, and since the thing is plastic, something might break.

Do your best to keep the little circuit board from flexing too much while prying. Get a helper if need be.

Above, you see we got the pump out. It’s just coolant sitting in there.

Oh by the way, in the last step, I made sure this side was facing up so I didn’t lose any coolant.

Unless you’re replacing the coolant, you’ll have to somehow keep this thing in an upright position while you work on the pump. The whole thing’s gonna want to tip/flip over and spill everything out.

Above is the pump itself that we pulled. The part that spins (right side) is just held on magnetically.

Not 100% positive, but I believe the electronics are completely sectioned off from the water (so no gasket or anything that can fail). The shaft you see doesn’t spin or anything, so it’s not connected to a motor. Rather, it appears that the thing is not only held on magnetically, but also spins magnetically, probably through some form of switching (unless the magnets beneath the circuit board are actually connected to a motor and spin, but I didn’t want to try cutting out the circuit board to check.

What I ended up doing was sanding the edges of the part on the right-side – basically anything that might touch/rub the left-part when assembled.

Then, I dried everything, put a couple drops of machine oil on the little spindle, and hooked the thing up to the motherboard header of a running machine for a dry-run. Note that by doing this, I’ll probably have some oil residue in with the coolant, so you may not want to use any oil – up to you.

It wasn’t whining during the dry-run, so I reassembled everything.

Re-assembly

It’s essentially the opposite of removal, but a few notes.

As I mentioned previously, that O-ring causes problems. I ended up popping it off with a thin knife, and putting it in the housing (the picture you see with the coolant), but the pump wasn’t sliding back in any easier.

It might be a good idea to lightly oil the ring first to encourage it all to slide together, though of course that’s a little more oil residue that’ll get in the system, and there’s no guarantee it’ll be any easier. It should be, but no guarantees.

It’s also quite possible that you’re basically pressurizing the system putting the thing back in – remember, the rest of it is sealed, so as soon as that O-ring makes a seal, it’s compressing the bit of air you pushed in with it. Would be interesting to pull out (or drill out) the fill-cap to see if it goes in any easier, though obviously you’d lose coolant & have to replace it. 

In the end, I ended up pushing the pump in as much as I could, and started threading screws in to draw (force) it together. Essentially I was “pressing” the thing in, tightening each screw gradually so it wouldn’t go cockeyed (if it doesn’t go in evenly, there’s a higher chance it’ll either cut the ring, snap something, or dislodge the ring.

Even by the end, with all 4 screws back in, the whole thing wasn’t flush. However, it didn’t leak, and perhaps over time it’ll work those gaps out. If it’s pressurized air in the system that was causing the problem (which I really suspect), well… we’ll see if it ever makes it’s way out.

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Another couple things I mentioned earlier but will go over again:

• the temp sensor – if you hook it up backwards, the thing will beep like crazy and the display won’t come on.
• the wires are a pain, so route them carefully. If the main cover doesn’t go on flush, you probably have to move wires around

Finally, do a dry run before hooking it up to your CPU. Find another system, and plug it into a motherboard header. Actually, a better idea is probably to use a 3-pin-to-4-pin-molex adapter, just in case you somehow created a short circuit (a short circuit on a motherboard header tends to blow the header &/or the motherboard – a PSU should deal with a short much better which makes a molex connector a better idea).

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Results

The crazy annoying whine is gone. I did hear some gurgling as it pushed the air out of the system (another good reason to do a dry run).

There’s still a whine to it, but it’s more like the initial soft-ish whine when I got it.

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Thoughts

1) This is obviously fairly risky, and not terribly easy. It was worth it for me, since the thing was essentially going to sit in a box until it got thrown out otherwise. Don’t attempt it unless you’re willing to accept that you might break it. Also be very cautious – water systems cause problems if they leak. Problems like all your components being shorted out.

2) The water pump is fixed at about 3000 rpm. Switching the speed on the Cool IT Domino only reduces/increases the fan speed. Update: Experimented. I hooked the thing up to a fan controller. As you lower the RPM, the whine decreases in pitch. Once it hits about 2100 rpm, the pitch was low enough to be beyond my hearing range. Below 2000rpm, the Domino starts freaking out (beeping). However, it was possible to get the pump itself down to ~61rpm (though I assume no cooling would take place at that speed).

3) The fan that comes with the Cool IT Domino isn’t the quietest around. I’d previously replaced it with a Noctua (back  before I realized it was the *pump* that was whining – not the fan). If you’ve pulled the thing apart, you’ve probably realized it’s just 4 more screws to replace the fan at the same time. Feel free to do it (watch your temps though obviously).

4) If I wanted to reduce the soft whine remaining, I suppose the next step would be to insulate the pump housing. I suspect the best way would be to use “Great Stuff” – the expanding polyurethane foam you use for insulating gaps & cracks in the home. Put in a tiny bit (it expands), and while it would make a permanent mess, it would probably do a decent job of insulating. Otherwise, I’d be looking at getting another pump.

5) If you do this, good luck! Feel free to leave a comment with your results.