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

[MIAHALLEN]

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-cool...ak-qdcs-leaking-everywhere.html?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.



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



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.

 

[onefstsnake]

Ive personally never used these. Mostly because of price.

Here's my QDC's

 

[frank anderson]

I bought 5 VL4N male + female sets in July, 1 Male disconnect was weird, the model number branding was in bold compared to that of the others, I couldn't get it to connect with the female VL4N, tho I was able to return it to the store, awaiting replacement..

Been working on my system and using them for quick disconnect and draining, as for testing them goes, surely more then 10 times so far, no problems... (finger crossed)

 

[Devil_Dog]

2 inch spring clamp from home depot. .99 cents ea. Works great. Needed something on the fly and these where on my desk. Great discovery.

http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053

I just sold a few Koolane QDC's that I never used. Kinda glad I did. I was going to order some more but glad I didn't.

 

[muddocktor]

Miah, are those fittings able to be disassembled? Because to me it looks like the new one might be having an o-ring failure, since the center plunger is sticking out as compared to the older model.

 

[MIAHALLEN]

The center plunger is not sticking out, the ring around it is recessed when it shouldn't be. The spring which closes the ring isn't pushing it out into its proper place when the fittings are disconnected. I don't think the O-ring has failed based on the feel when I press the ring in manually (it feels like metal on metal rubbing).

 

[muddocktor]

Since I've never seen these before, let me pick your brain a bit. When you make the fitting up, what depresses in the fitting, the middle part or the part around the middle? From your last post, I am assuming it's the part around the middle inside the connector. And you say you feel metal to metal too, huh? Is there a way to take them apart to check for shavings or anything like that inside? Of course since yours are under warranty I wouldn't try to take them apart to clean them, but for someone who has 1 of these acting up and it's out of warranty that would be the first thing I would try before just buying a replacement.

 

[MIAHALLEN]

I'm sure you CAN take them apart, but I'm sure it takes special tools to do so. The only seem is very tight, without any obvious release/screw/rivets/etc...
If I can figure out how, I probably would, cause I'd really like to get these working, I spent a lot on them....and even more on the equipment I'm trusting them to.

 

[MIAHALLEN]

I've now observed this on my male connections as well.

If you all think Koolance should address the issue, please add your input to my thread in their forum
http://forums.koolance.com/viewtopic.php?f=11&t=2326

 

[frank anderson]

Update since my last post:

This issue did pop up once for me with a male connector while I was changing my loop order, my entire set was drained through another set of disconnects so no spill was involved, however it does bring to light the problem Miahallen is having..

I have removed the male in question and replaced it with a spare I had laying around, I proceeded to wash it out with tap water and poked at it with a plastic tweezer to see if the ring would pop back into place, it did not..

I poked at it with the plastic tweezers from the inside and pushed the ring back into place, left it for a few days and went back to it and see if the inner ring would stay put... and it did, I have used it once for draining since then and the male VL4N part that was previously in question is now working as normal again...

Should this problem even be occuring in the first place?

 

[MIAHALLEN]

Should this problem even be occuring in the first place?

No it should not!

My two year old QDC have been connected & disconnected well over one hundred times and still work perfectly EVERY time!!! But every single female fitting I purchased in April fails nearly every time, and now the males are starting to fail as well. This is very obviously a design flaw when they updated the design.

BTW - if I shack the connectors for 30-60 seconds vigorously, like a salt shaker, the seals will eventually close.

 

[Ilden]

I have two brand new (in box) sets of Koolkrap QDCs. Never used them. My reason was that they were too damn restrictive to flow. Ended up using brass ballvalves and BP D-plugs instead.

I see story after story about rusting or leaking Koolkrap fittings. I'm glad I never used mine, even if it was a waste of $80.

 

[CJ145]

I have 2 sets of 5/8" VL4N's that I will keep an eye on. 15-20 disconnects so far with no leaks yet. So far they are great!

 

[frank anderson]

I will be tearing my entire system apart soon to move my stuff from a HAF X to a Caselab M10, hopefully everything will go smoothly, but if the disconnects don't work the way it should, I will definitely take pictures and post on Koolance forum this time..

 

[CJ145]

Why did I have to read this thread, one of my female QDC's did this to me yesterday. I quickly put it back together and tapped it on a hard object. It closed fully the second time but did leak a few drops more than they should be. I think it's time to contact koolance.

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

I can vouch for this as well... 24v iwaki RD-30 hehe.

 

[MIAHALLEN]

Official reply from Koolance

We've found an issue after cutting open the bad fittings. The internal o-rings were a hair out of tolerance. This prevented the plunger from fully sealing when disconnected. Unfortunately, there's not a way to tell if a particular fitting is affected without disconnecting the male and female sides (a towel is recommended). Either the plunger surface won't sit flush with the inside, or if it's already installed, there could be continuous dripping.

We've screened our inventory and removed any other QDC's which exhibited the problem. Different styles of VL3N and VL4N fittings were affected, but the products aren't serialized so it's difficult to tell how recent the stock was.

If customers find they have VL3N or VL4N quick disconnects which leak when separated, please submit an RMA request (http://www.koolance.com/support/rma/). We'll need to know your part numbers, quantity, and invoice number/date. We'll take care of the shipping. If you've recently sent in QDC's for this problem, please contact our technical department (http://www.koolance.com/company/contact/) to obtain a refund on the original shipping and replacement fittings if needed.

We apologize for this issue and thank everyone for bringing it to our attention. O-rings are always a critical part and it's regrettable we didn't catch these when they arrived from our supplier.

 

[frank anderson]

Official reply from Koolance

Indeed I am having the same problem you are having (again) with these disconnects..

I have sent a email requesting a RMA and found out that the quick disconnects that I purchased was not from a authorized reseller, I have taken the issue with the company that I have purchased them from (Linke Computers HK Ltd.).. lets see where this goes..

 

[MIAHALLEN]

GL Frank

 

[WildArmsfx]

2019 - Just had this happen to me. Another delay.

My female arrived DOA. Same symptons and same problem. QC internal fitting will not go flush to provide a clean fit. After pushing the male into the female to see if it was just a one off thing, it was not.