All not well in QDC land....[Koolance QDC manufacturing problem?!?]

After seeing a couple posts at OCN and Koolance own forums about Koolance Quick Disconnect leaking problems...I knew my experience was not isolated.
http://www.overclock.net/water-cooli...?highlight=qdc
http://forums.koolance.com/viewtopic.php?f=11&t=1724 (post #3)

I now have 10 males and 8 female QDC VL3N series quick disconnections used in various applications. The first set I bought about two years ago, the females are still working fine today. However, I recently bought a bunch of new sets, and the new female connectors have all failed. To be clear....the new connectors worked fine for the first few months over dozens of connect/disconnect operations. But now, the spring loaded mechanism meant close the valve in the female end no longer closes completely, allowing the connection to drip when disconnected (see the images below).

edit - I have verified the problem is not related to low loop pressure.

I suspect a minor change in manufacturing that is causing the long term failure of these parts. Tim [Koolance] eluded to a change in manufacturing tolerances last year (post #8).

If I am correct, Koolance should issue a recall on these parts. In the mean time, be sure to check your connections within the 1 year warranty period and get RMA replacements if yours connectors are showing similar problems. If you are already outside the warranty period, please be careful with your connectors when breaking your systems down to prevent leaking on your HW ;)

Here is a shot of my older QDC, both female fittings have been serving me well for about two years now.

http://i161.photobucket.com/albums/t...n/good_QDC.jpg

Here is a shot of the newer QDC failing to seal properly....all of my newer female QDC fitting do this consistently now.

http://i161.photobucket.com/albums/t...en/bad_QDC.jpg

Also, I need your comments please, let us know if you have older/newer QDC fittings, and whether or not you've seen similar issues.

That is most unfortunate... I am willing to bet a cheaper spring is responsible. Was there a cost difference to you between the old and new parts?

Nope...zero indication of any change (other than what I mentioned)....its simply speculation at this point. :-/

Since all of them have exhibited this failure, there isn't much that could cause it besides insufficient pressure applied by the worn spring. I suppose you could take them apart an examine, but then you'd have to ruin your two good sets.....

I suspect cheapened manufacturing which either 1) was to keep prices the same as they have been, or 2) increase profit per item sold.

I've seen both happen. I am hoping that it was just for #1 and it was done in good faith, not #2.

But, either way, the change was a mistake.

Well, all businesses should evaluate their costs and streamline them for maximum profit. However, many times they go too far and end up hurting the product in an attempt to keep profits up.

I have 3 of the female connectors and mine are all okay so far but then I've not disconnected/reconnected them a lot since I got them, only about 5-6 times total. I'll keep an eye on this for sure. Thankfully all my connectors are outside of my case so if there was a leak it wouldn't be a disaster but I can imagine how this would be terrible for people who are using these on their CPU, GPU and such. Of which I've seen a few users on this forum making use of them in that fashion for quicker part upgrades.

I hope Koolance sorts this as the connectors are a brilliant idea and look great.

I have already RMA's one female for not wanting to lock all the way and now have another one doing the same thing. I also have two female connectors doing what you described. All of these are the VL3N models, the "no drip" type. My older QD's with the black plungers do not exhibit this problem. I was going to post on here, but just not had time. From what I can tell just fiddling with them is that the outer ring that is suppose to seal is not cut quite right and get's stuck. I actually have to hit the outside of the fitting with a hard object to get it to close all the way and therefore it leaks. It would be nice to hear what Koolance has to say, but based on past RMA's and issues, they will just replace them and never investigate the issue. This happened with my controller board when it went out, the fitting's I just sent back and the bleed kit I posted with funk on it. It's great that they replace them, but at $5 per incident to send them back it starts to add up if you have several items go out over a few months. As much as I love my QD's it makes me want to stop using them and just go back to the old way of doing things. The other option is to try some of these:

http://www.aquatuning.us/index.php/cat/c689_Phobya.html

They work like the ones you find on air compressors, but I have no idea on how restrictive they are or how well they actually work.

I got VL4's but I've used them like.. twice so far..

so.. that probably means nothing

this post was rather useless.. sorry about that

For what it is worth, my old VL4 (note, not N) do not exhibit this issue after many many dozens of disconnects / reconnects.

Well, its looking more and more like the new versions have undergone some adverse changes.

Most likely switch of manufacturer for cost.. is this apply to the newer no -spill version as well ??

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Originally Posted by QuadSLI

Most likely switch of manufacturer for cost..

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That is the general consensus.

Damn, and I was just going to get some for my upcoming STC-101 build.

Well I suggest that everybody that is having this problem contact Koolance with grievance immediately if you have not already.... :)

Maybe they will (or already are) make the appropriate changes.

A little ironic that the "no drip" ones are the ones leaking.

Quote:

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Originally Posted by Sparky

A little ironic that the "no drip" ones are the ones leaking.

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Haha yea, and also the ones that aren't no drip aren't leaking.

So just to confirm VL3 and VL4 are fine, VL3N is not, and VL4N is unknown?

Another bit of problem is that VL3N are most commonly used ones @LC.

Yeah I also have the same prob on a few of my VL3N's too.. I ALWAYS put paper around the connector just incase to catch drops. They do come good again though if you clean them and cycle the connection a few times.. I think it might be just a tiny bit of build up. Since they are built to such tight tolerances it wouldnt take more than a fine film to compromise the smoothness of the operation and increase resistance. Maybe Koolance should look into upping the spring rate a tad!

Quote:

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Originally Posted by Vicey

I have 3 of the female connectors and mine are all okay so far but then I've not disconnected/reconnected them a lot since I got them, only about 5-6 times total. I'll keep an eye on this for sure. Thankfully all my connectors are outside of my case so if there was a leak it wouldn't be a disaster but I can imagine how this would be terrible for people who are using these on their CPU, GPU and such. Of which I've seen a few users on this forum making use of them in that fashion for quicker part upgrades.

I hope Koolance sorts this as the connectors are a brilliant idea and look great.

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How long ago were they purchased?

Quote:

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Originally Posted by CedricFP

For what it is worth, my old VL4 (note, not N) do not exhibit this issue after many many dozens of disconnects / reconnects.

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How long ago were they purchased?

Quote:

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Originally Posted by Phatboy69

Yeah I also have the same prob on a few of my VL3N's too.. I ALWAYS put paper around the connector just incase to catch drops. They do come good again though if you clean them and cycle the connection a few times.. I think it might be just a tiny bit of build up. Since they are built to such tight tolerances it wouldnt take more than a fine film to compromise the smoothness of the operation and increase resistance. Maybe Koolance should look into upping the spring rate a tad!

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How long ago were they purchased?
I think they should just go back to the prior design.

Yeh I had a set of old ones (vl3n) that worked fine, they had red o rings FWIW.
New set I got a few months ago. (from PPCs) black o rings, and they don't fit together a nicely when they are
connected. Feels like the o ring is too big, is the best way to describe it.

They work fine though so far, no issues with dripping, and they do go together.

FYI - My VL3N's were purchased early last year and came with the black o-ring.

The older style with the plunger never did this, however, they were more restrictive and obviously not "No drip" type. A stronger spring might fix it, but I think we will continue to see this type of issue with this series until the design is changed.

Has anyone used the QD's by Phobya that I linked too earlier? They are like air compressor QD's.

Just also wanted to say, make sure you have relieved the pressure in your loop from your res or a t-line before you undo them. It might not fix it but it cant hurt! ;)

Quote:

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Originally Posted by Phatboy69

Just also wanted to say, make sure you have relieved the pressure in your loop from your res or a t-line before you undo them. It might not fix it but it cant hurt! ;)

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This was the first thing I did....but trust me, low loop pressure is not the cause :(
And it CAN hurt....when you disconnect, the flow from the faulty connection will be much greater since there is no vacuum holding in the water ;)