Is it okay to run a D5 dry and topless for a couple seconds?

VanGoghComplex

VanGoghComplex

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Since I moved my D5 into my new Heatkiller Tube, it's been making this annoying tic-tic-tic sound. I originally thought the top of the impeller was chattering against the pump volute, so I sanded a few thousandths of the plastic off the impeller and didn't tighten the screws down as tight next time - it still made the same noise.

In the interest of troubleshooting I'd like to run the pump outside the pumptop for a couple seconds to see if it makes the sound there. This shouldn't hurt anything as long as I don't exceed a couple seconds, right?
 
My understanding is that the ceramic bearing definitely needs water to lubricate it, and running it dry for even a short period of time will do damage.

No personal experience, just what I have read.

Maybe you can run it open in a container of water somehow?
 
Zarathustra[H] said:
My understanding is that the ceramic bearing definitely needs water to lubricate it, and running it dry for even a short period of time will do damage.

No personal experience, just what I have read.

Maybe you can run it open in a container of water somehow?
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Well, I went ahead and tried it... Just let it spin for a second or two and it was dead silent. I wet the bearing with a few drops of coolant first just to give it a little cushion.

I found the source of the noise in the Heatkiller pump top, unfortunately. After shining a light into to the volute I could see where the plastic top of the impeller had been striking and scarring the POM.

I snagged an exacto and some 1500grit sandpaper and did some very ginger sculpting. The noise is very very much reduced. I think I found the right spot but I didn't take quite enough material off.
 
Yeah, a common problem with some pump tops, unfortunately. Don't know if its caused by out of tolerance manufacturing of the tops, pumps, or a combination of the two.
 
Nobu said:
Yeah, a common problem with some pump tops, unfortunately. Don't know if its caused by out of tolerance manufacturing of the tops, pumps, or a combination of the two.
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That sucks. Is there much to do for it other than try to sand out the points of contact? Or buy another pump? Or gripe at Watercool?
 
VanGoghComplex said:
That sucks. Is there much to do for it other than try to sand out the points of contact? Or buy another pump? Or gripe at Watercool?
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Wouldn't hurt to let them know. I would just hit it with some 150 grit, polish it, then put some shallow marks in it to see if and where it's still touching. If the marks show no wear after use, then it's probably good and you can polish the marks out.
 
Arcygenical said:
Thicker O ring. :)
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I think you hit the nail on the head. You've got to be careful of aftermarket parts. I've seen 3 or 4 different thickness orings on various d5 pumptops and reservoirs. From bp, xspc, ek, swiftech, barrow and koolance. There's no ryhme nor reason either. I've got a bp res oring (bright yellow) that is far smaller than any of my orings including another pair of black bp orings for a dual pump top. The pair that came with the dualtop match the ek swiftech and koolance pump orings. While an xspc res oring is alot beefier than any of my pump orings. The oring from a ek xtop is also thinner than the pump orings. For some reason manufacturers aren't always sticking to the correct specs.
It may not seem significant but the wrong size orings can cause rubbing if it's too thick and leaks if it's too thin.
 
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Interesting. The o-ring I am using came with the Heatkiller reservoir. It's a different size and style than the one that I used with my old EK pump top, and fits into a channel in the bottom of the res. I'll ask Heatkiller about a thicker replacement.
 
Makes you wonder though if you'll lose pump efficiency with too large an o-ring and too much clearance between the impeller and top.

Actually I wonder if that is the reason behind the difference in performance between the various pump tops
 
Nimisys said:
Makes you wonder though if you'll lose pump efficiency with too large an o-ring and too much clearance between the impeller and top.

Actually I wonder if that is the reason behind the difference in performance between the various pump tops
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I'm sure it factors in, but I sure bet I'm losing efficiency from my pump getting hung up! This system typically flows 1.0gpm with the pump wide open. After my plastic surgery I checked the flow at 1.1gpm. I should have recorded the pump RPM before I worked on it.
 
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