Leak Testing

Man of Honour
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I don't like these air leak testers because when it shows a leak is present it won't tell you where it is and on a loop the size of mine that is a major problem. I much prefer the old way of filling the system, providing power to the pumps only and letting the loop run overnight with kitchen roll under every joint. Using this method I have only had a leak once and that was on my very first build where I overtightened a fitting and cracked a plexi reservoir resulting in a slight drip every few minutes. Every othertime over my 16+ years of watercooling I have had no leaks apart from a O-ring failure on a brand new EK cpu block and a six month old EK gpu block. Both failed at the same time with a drip every 30 minutes or so. EK's customer support was the worst I have ever recieved and I ended up finding out the O-ring sizes for myself and replacing every last one. Since then I have avoided EK and have had no problems.

We used to use these air leak testers in the RAF for testing coolant systems and if you had a leak it was pretty obvious once you looked for it as there will be staining built up over time. We also used them on high pressure gas systems. If they showed a leak you then went around the system with a squeezy bottle filled with what was basically water and washing up liquid. You squeezed a small amount of liquid on each joint and if it leaked it will bubble. Pinch the connector up and test again and in 99% of cases there was no longer a leak. None of this applies to a water cooling loop so aside from retightening all connections and risking over tightening them there is little else you can do until you fill the loop and get coolant flowing which will show where the leak actually is. To me it seems that these leak testers are just another way to fleece people in a already very expensive hobby.
 
Associate
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i had a similar issue with mine, where it was leaking air over time. Reached out to EK direct and they said that was normal. Took minimal risks and did the paper towel way and can say looking good so far.. no leaks since my system was filled a month or 2 ago.

Regardless, if you are still unsatisfied, mix a drop of washing up liquid with water and using a q-tip or a finger, spread the solution around every port of the system. Leak test using the tester and monitor every port to see which one starts bubbling. That will be the culprit.
 
Soldato
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A quick simple test I normally do to see if there any school boy error type leaks is to set the loop up fully and add a flexible tube to a spare port, which for me is the fill port on the res, and simply blow into the tube to pressurise the system. If there are any major loose connections you will either hear it or be able to feel the pressure drop while you are blowing. A slightly more sophisticated way to use this method to spot minor slow leaks would be to the the same but add a valve to the blow tube, so you can blow to pressurise then shut the valve keeping the pressurised air in to loop. Then leave it overnight and open the valve. When you open the valve you will hear the rush of air as it escapes indicating that there aren't at least any slow leaks. The longer you leave it before cracking the valve the more confidence you would have. This is basically the same as a leak tester without the actual gauge. Personally I wouldn't trust these leak testing devices as I imagine you very much get what you pay for with that sort of kit.

Edit: Again, remember not to suck. Not that it won't equally act as a valid leak test, but that you'll be pulling seals in where they wouldn't go in normal circumstances, rather then them blowing out as normal.
 
Soldato
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To be fair he's been sensible
And tested individual parts of the loop
And components
Rather than assemble the whole thing then test
So he can tell which part is the problem
So kind of rules out the leak tester doesn't tell him
Where in the loop
And now he's tested the tester
As I pointed out that may be the actual cause

Good to see I am not the only old school
Dig out the washing up liquid guy :cry:

Old plumbers trick that one
It's entirely possible it's water tight anyway
And the leak tester is actually causing him undue paranoia
Which he wouldn't have had if did it without one

@Bubo am going to resist the urge
To comment about sucking Vs blowing :cry::cry:
 
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When I did my build, and it`s the only one I`ve done so far, I just used toilet paper around the joints and then jumped the pump from the 24 pin cable and ran it for a couple of hours with some deionised water. I didn`t see the point in spending more money on something that will tell me there is a leak but not where from, water will do that. I`m a big believer in making sure the pipes are properly de bured and don`t have any sharp edges and a bit of spit on the outside of the pipe to aid lubrication :D
 
Associate
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The point of a pressure tester is that you can dry test the build in stages and build up confidence before proceeding to wet test the whole system. If the wet test is at a fitting then simply tightening it might be enough. But if it is at a waterblock which has a crack or bad gasket then the system needs to be drained.
 
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Ok this is killing me. I keep thinking I’ve found the ‘problem’ point but then I can rule it out. Currently I think the issue is in my reservoir block with the D5 pumps mounted to it. Stupid question but just to rule this out: in an air test scenario, can air leak out of pumps for any reason?
 
Soldato
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Assuming it's still same setup @V F
It's an unusual front distro
With not one but 2 d5 pumps on it
Yes if the pumps weren't perfectly fitted
It has to be possible that the O ring
Could have moved, been damaged etc
Though by now I would have to be
Setting up an in out tube on the distro
And testing it with liquid
Much easier to find a liquid leak
Assuming that it even does leak with liquid
 
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Am using a cnc-ed flat reservoir type, it’s a very slightly modified Dynamic Duo made by Radikult.

Solved the issue, finally; was a loose fitting after all, a release valve mounted to the reservoir.

I can’t tell you how many hours and evenings I’ve spent getting this part of the loop sorted. I never want to hear another air pressure tester in my life….! I am imagining leak sounds, air escaping, and I can’t trust anything any more! Bottom line is, I think I was thrown by multiple different components and fittings up til now.

A week’s break from building for a family covid infection didn’t help, but still.

Now onto the next part of the loop build… :)
 
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Ok I officially am on the edge, or over it.

Now I’ve discovered that one of the ports on my bottom rad leaks. The rad is a Black ice sr2 360 multi port. I took all the fittings off and replaced them with plugs, and, having gone mildy insane with the leak tester chasing a leak, decided to stick some actual water in it to see what happens.

So one of the ports leaks water, but, it only leaks when I tip the rad up almost vertical, so that the port is at the bottom at the lowest point, ie, it’s under more water pressure. If I leave it horizontal, no water comes out. Yes it is full, so I am fairly sure water is against the port when it is horizontal.

I had previously air tested this rad a week or so ago and had thought it had ‘passed’, no issues. I diligently tried it again today prior to fixing it in for good and, well, the above saga played out… I had previously suspected this port as it didn’t appear to allow metal plugs to work, only those hard plastic ones that came with the rad.

On the plus side, think I now know my coolant colour. It’ll be a hint of ‘blood red of my soul’ mixed with ‘tears of desperation’….
 
Soldato
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If it is leaking from just one port then swap one of the plugs from a leak free port to the leaking port and test again, this will at least tell you if it is the plug or the port that is the issue. If after the test it is the same port leaking then I would say it must be something to do with the land on the rad fitting where the o ring has to seal, is it flat and square etc? If the leak follows the plug then there is your problem.

Also check if you haven't cross threaded the fitting, and the plug threads look good. I once had a barb fitting for a thermochil rad where the threads had been mal formed on the fitting. Luckily I didn't try to brute force the fitting into the rad as it would have destroyed the threads on the rad also.
 
Soldato
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Hmm interesting. What are you thinking, just a fine application of clear silicone within the the joint between the plug and the radiator port?
Yep or PTFE tape on the thread
I am assuming you tried a different fitting
Since you seem to be very thorough
Also double check it's not one of those fitting
With the longer thread
Those caught me out once as I assumed they all had
The same length
So basically it couldn't screw down far enough
Because the extra length meant bottom of the thread
Was touching something inside the radiator
Leaving the O ring not sealing properly
 
Associate
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otherwise if you can (have time), RMA the radiator. I've had the same issue before with an Alphacool Rad, where one of the ports was leaky, and managed to get a replacement from the supplier.

If it's an old rad, then new plug or PTFE is your best friend
 
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