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Corny keg leaking

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LPD1902

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Hi Everyone,
I have a used ball lock corny keg which is leaking from the out post.
So far I've replaced the O-rings, installed new poppets and even put new posts on, and it still pushes the sanitizer past the out post at the bottom.
I did find that the previous owner had used a Firestone Post on this keg.
Would that have somehow messed up the threads so it does not seal properly?
If so, is there a way to repair this?
Thanks in advance for your help!
LD
 

deuc224

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Same stuff i went thru with a new keg, nothing stopped it from leaking. So ill pass on the only advice that helped me, if its threaded, teflon tape the hell out of it.
 

Dland

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It is possible the threads were messed up. There is a difference between C kegs and many of the Firestones. They are close enough that someone could possibly have force threaded the on the wrong part (but they'd have to be a bonehead or completely un mechanical).

To repair perhaps a whole lot of teflon tape?
 

camonick

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Maybe a fatter o-ring on the liquid dip tube would help if you can find one. I don’t think the threads are what seals that connection. @day_trippr might have a trick.
 

camonick

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One other thing is to double check to make sure the dip tube isn’t too long/ and or in the incorrect position and preventing the post from screwing on completely.
 

day_trippr

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Ordinarily, the post riser threads don't seal anything at all - neither the dip tube flange nor the post itself.

All of the sealing is done by the small O-ring under the dip tube flange: as the post is tightened down on the top of the dip tube flange that O-ring bulges outward. As the post is screwed tight the compression downward on the O-ring seals the top of the threaded riser to the underside of the dip tube flange, and the outward "bulge" seals against the inside wall of the post. Et voila!

All that twisting during compression can damage a dry O-ring with tiny tears in the surface, so always at least wet the O-ring before installing, and better still use some "keg lube". And of course make sure one is using legit size O-rings. If there's still a leak give the top edge of the threaded riser a close inspection for dings, the dip tube flange for splits or bends (the flange should be smooth and flat), and the inside wall of the post for heavy scoring. As these kegs tend to work, there'd have to be something out of normal...

Cheers!
 
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LPD1902

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Wow!
I didn't expect so many responses so quickly, you guys are great!
I'll try using the Teflon tape and keg lube.
Not sure why I didn't think of those...

When I bought it, it had quite a bit of pressure, so I assumed it would be fine. Then as soon as I filled it with some beer ready for carbonating, all hell broke loose!

Thanks again for the suggestions.
I'll let you guys know later what worked...
Best,
LD
 

day_trippr

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I advise not using tape. Given what I've already related above, it's unlikely to help and may interfere with the way things should work...

Cheers!
 
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LPD1902

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Hi everyone,
It took a little longer than I expected to get back.
I tried another set of o-rings, swapped posts, tried the tape anyway, and even tried thread dope for potable water, nothing has worked.
I‘ve ordered a pair of bulkheads as that would be cheaper than scrapping the keg.
If anyone has any other ideas, I’m open to trying them.
Thanks!
LD
 

camonick

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Is the keg in question full right now? Can you provide pictures of your o-ring and dip tube? As stated above, when everything is assembled correctly, the o-ring is what seals that connection and nothing else. Where are you sourcing your o-rings? You stated that the keg was holding pressure when you received it, so it was functional then. I’m not sure what might have changed. The o-rings I use look like this F58A40B3-5D0D-48D7-9760-01A143100D44.jpegwhen installed on the dip tube. Do yours look the same?
 
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LPD1902

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Hello,
The keg in question has only sanitizer in it, as the last time I tried put beer in it, it started to have issues.
I thought it was old o-rings, etc. so I cleaned a different keg for that batch and purchased an o-ring set from the local homebrew shop.
However, nothing has worked.
I've been brewing and kegging for over 6 years now. This is the first time I've encountered an issue like this.
I'm going to try doubling up the o-ring on the dip tube. I think short of that, or installing new bulkheads, that's my only alternative before scraping the keg.
I've attached a couple of pics for you.
Please let me know what I'm missing.
 

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camonick

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I’m not sure what you’ve got going on. In the first picture with the dip tube sticking out, the profile of the o-ring doesn’t look round and the top flange of the dip tube isn’t flat and could possibly be cutting/gouging the o-ring when the post is tightened down on it.
the dip tube flange for splits or bends (the flange should be smooth and flat),
It might be the angle of the pictures, but the dip tubes (top flanges) don’t look the same in each photo.
You’ve got me stumped.
 

Yesfan

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Hi Everyone,
I have a used ball lock corny keg which is leaking from the out post.
So far I've replaced the O-rings, installed new poppets and even put new posts on, and it still pushes the sanitizer past the out post at the bottom.
I did find that the previous owner had used a Firestone Post on this keg.
Would that have somehow messed up the threads so it does not seal properly?
If so, is there a way to repair this?
Thanks in advance for your help!
LD

Are those poppets the universal ones? I had one keg that leaked through the gas post. I didn't catch it until I saw my 20lb co2 tank was emptied. Hooking up the spare and doing a little process of elimination, I found the leak came from a keg that had a universal poppet on the gas post. I also remembered connecting the gas disconnect on that keg was a little tighter than the others. Wished I had put 2 and 2 together before having to lose all that co2.
 

day_trippr

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The focus isn't great obviously but in the second picture the dip tube flange looks ok. As the edge of the flange is actually folded over around the perimeter during manufacturer there will be some overall curve but the key is that the rim is level all the way around.

The top of the threaded riser looks like there's some accumulation of debris. I'd get that bright, use a fresh O-ring with some keg lube, and see what happens...

Cheers!
 

IslandLizard

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it still pushes the sanitizer past the out post at the bottom.
It's leaking from the bottom of the post?
If so, that means the o-ring isn't sealing, or there is a crack in the very top end of the dip tube.
Are you sure you're using the correct post for the stub?

Most diptube o-rings from the manufacturer have a squarish profile, and are somewhat higher than regular circular profile o-rings. From your picture it looks you have one with a squarish profile.

Although there is some flex, make sure the diptube isn't too long, bottoming out before the post is tight.
Was the keg/post sealing fine before? Then suddenly it started leaking?
 
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LPD1902

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These same o-rings work fine on all of my other kegs.
However, on this keg, I add a 7.8 x 1.9 o-ring under the normal o-ring, and it seems to be holding pressure better.
I’m going to leave it like that for a day or two and see how it does.
When I take it apart, I’ll inspect the dip tube flange and post seat with a magnifying glass
Thanks for all the suggestions!
 

gnef

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Do you have a spare dip tube to try to use?
 
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LPD1902

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Yeah, I have one other spare keg. I can try the dip tube from that one.
Thanks!
 
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