How to fix a leaky keg?

I just bought my first kegging setup from LHBS. Ball-lock with regulator and hoses and a set of new O-rings.

I broke the keg down, replaced all the O-rings like it said to.

Put a batch of beer in it, pressurized to 10psi. Tried to shake it a bit and noticed some liquid coming out of the IN valve. When I stopped shaking it didn't seem to leak anymore. I'm no expert but it seemed like the hose didn't have very tight connection with the valve?

I took a pair of vice grips and tightened both valves as tight as I could.

Then I pressurized and let it sit 24 hours in my kegerator. Next day I try some and it's totally flat and my tank is mostly empty!

What the hell! Did I buy a bad keg or what? Do I need to replace the poppets?

You could start with the poppets, but if you have the CO2 connected to the in valve the pressure shouldn't allow liquid to come out of it. If the CO2 isn't connected and you have liquid coming out then you definitely need to replace the poppets. You may want to check the relive valve to make sure it isn't leaking as well.

Some CO2 may have escaped from your in valve but most of it probably dissolved into solution. I use the connect and wait method to carbonate so my kegs sit for 2 weeks or so at serving pressure in the kegerator. The whole time CO2 is dissolving to form an equilibrium. After a day or two my beer would still be flat too. Many people force carbonate in a few days but they also leave the CO2 connected I think.

A leaky in valve is not a bad thing if the CO2 is always connected.

I think he means that his CO2 tank is almost empty which would indicate a leak. When I built my kegging setup, I put some dish soap and warm water in a sprayer and checked every single fitting for a leak. You will see a leak right away if there is one.

Yeah, that's what I meant. My 10# CO2 tank was almost empty.

I connected the CO2, pressurized to 10 psi, left it connected and started rocking the keg back and forth. That's when the liquid started leaking out of the IN valve. So I disconnected and tightened both valves.

Then I left the CO2 connected at 10 psi and put the whole setup in my kegerator (with the CO2 connected and on). The next day the tank was almost emtpy.

I would start wth the poppets and relief valve. For what it is worth, I first pressurized my kegs to about 25psi to set the lid o-ring. It has helped me eliminate some small leaks.

Also, if you are determining the tank as "almost empty" by looking at an indicator gauge, its going to show much lower after you have put the tank in the fridge and it cools off. Take the tank back out of the fridge, let it warm up, and see what the gauge says. +1 also on initially pressurizing at 25-30 psi. I have 1 pin lock that the lid is a little wonky on, and it won't set at anything under 30. Once its set, its fine at lower pressures.

bk0 said:

I connected the CO2, pressurized to 10 psi, left it connected and started rocking the keg back and forth. That's when the liquid started leaking out of the IN valve.

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This does not making any sense. If you have your CO2 disconnect correctly seated on the "in" post (I'm not sure what you are referring to by "valve," but assume you mean "post") with 10psi, I can't see how beer could escape through the gas post. Is it leaking at the base of the gas post where the post seats against the keg itself?

bk0 said:

I just bought my first kegging setup from LHBS. Ball-lock with regulator and hoses and a set of new O-rings.

I broke the keg down, replaced all the O-rings like it said to.

Put a batch of beer in it, pressurized to 10psi. Tried to shake it a bit and noticed some liquid coming out of the IN valve. When I stopped shaking it didn't seem to leak anymore. I'm no expert but it seemed like the hose didn't have very tight connection with the valve?

I took a pair of vice grips and tightened both valves as tight as I could.

Then I pressurized and let it sit 24 hours in my kegerator. Next day I try some and it's totally flat and my tank is mostly empty!

What the hell! Did I buy a bad keg or what? Do I need to replace the poppets?

Click to expand...

I think it would help if you were a little more specific. There aren't any parts called "valves" on a ball lock keg. There are dip tubes, posts, poppets, quick disconnects, barbs, swivel nuts/MFL fittings, etc. and there are numerous o-rings and washers. So it would help to know exactly what you're talking about, and feel free to post some pictures. Is your quick disconnect threaded or does it have a barb?

This should help to start things off. In the meantime, a couple questions:

1) Did you use keg lube on the o-rings?

2) When you said you tightened the "valves" with vice grips, what exactly are you talking about? You tightened the post? You tightened MFL fittings? You tightened worm-drive screw clamps?

3) Exactly where was the beer leaking around the "in" side? Under the post? Around the poppet? Around a tube on a barb? Through a swivel nut/MFL connection? Was this with the quick disconnect attached or not? A picture might help.

4) As posted above, how are you determining that your CO2 tank is almost empty?

I completely misunderstood, I went off on a tangent when I saw flat beer.

Star San in a spray bottle is a good way to find leaks. I would look for leaks at the regulator to bottle interface. Even a small leak on the high pressure side can deplete your bottle pretty quickly.

Sorry, I'm new to kegging so I don't know all the terminology yet.

When I say valve I guess I mean "post". The thing you connect the gas and beer lines to.

When I tightened the "valves", I mean I used vice grips to screw the posts tighter into the keg body.

When it leaked, it appeared to be leaking around/underneath the line connector. So maybe the poppets?

More answers:

1) Did you use keg lube on the o-rings?

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No. Didn't know such a thing existed.

2) When you said you tightened the "valves" with vice grips, what exactly are you talking about? You tightened the post? You tightened MFL fittings? You tightened worm-drive screw clamps?

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See above. I tightened the posts I guess.

3) Exactly where was the beer leaking around the "in" side? Under the post? Around the poppet? Around a tube on a barb? Through a swivel nut/MFL connection? Was this with the quick disconnect attached or not? A picture might help.

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This is a ball-lock quick connect (I assume) for the gas line. You pull up on the collar, press it on the post and release the collar to seal. It was leaking between the post and the quick connector.

4) As posted above, how are you determining that your CO2 tank is almost empty?

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The "high" side gauge on the regulator dipped into the red zone (below 800). I read somewhere that the high side gauge usually won't move at all until the tank is almost empty. Is that true?

Thanks for everybody's help!

If the tank is in the fridge, then no, it's probably not almost empty.

Thanks for clarifying! The high side gauge does a great job of telling you the temperature, but not much else. You need to weigh the tank to know how much CO2 is left.

So it sounds to me like your corny is leaking beer (when you shake it and get beer up that high) from under the gas (gray) QD when it's attached to the post. Is that correct? Does it also leak from the same spot if the disconnect is off?

It sounds to me like it could be 2 things:

1) A bad gas dip tube o-ring. If it still leaks with the QD off I'd suspect this. You actually shouldn't be really cranking down on the posts as you'll just mangle the o-ring. So I'd check and replace that first. I think most use a 7/8" 12-point wrench, much easier than vice grips. Take off the post, make sure you put the dip tube o-ring in the right spot, lube it up, and tighten snugly but don't really torque it.

2) A bad post o-ring is likely if it only leaks with the QD attached. This one definitely likes to have lube on it and needs to be in good shape. I think these guys are where many leaks start.

It could also be the QD itself, though that's unlikely unless you took it apart and put it back together incorrectly. There is a rubber washer in the QD that can be replaced.

I don't *believe* it leaks with the disconnect off, but I'm not sure I tried to shake it at that point.

Thank you for your help! I'm going to check the gas dip o-ring.

If it doesn't leak with the QD off, it can't be the dip tube o-ring. I'd check that post o-ring. As others mentioned, spraying with soapy water or a star san solution is a good way to find leaks. A bit easier than shaking and waiting for beer to come out. You can also submerge it in a tub.

Good luck!

So I've determined it's probably the gas inlet poppet/post.

Because:

a) now my tank is truly empty (determined by gauge and by weight)
b) there's a strong CO2 smell in my top-loading chest kegerator even when I haven't used it for days
c) I took off the gas tube and the poppet was stuck partly open and gas was venting from the keg. I put the tube back on and I could still hear a faint hiss of gas leaking.

So now should I replace just the poppet or the whole post/tube assembly?

bk0 said:

So I've determined it's probably the gas inlet poppet/post.

Because:

a) now my tank is truly empty (determined by gauge and by weight)
b) there's a strong CO2 smell in my top-loading chest kegerator even when I haven't used it for days
c) I took off the gas tube and the poppet was stuck partly open and gas was venting from the keg. I put the tube back on and I could still hear a faint hiss of gas leaking.

So now should I replace just the poppet or the whole post/tube assembly?

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Poppet valves were my first guess for what went wrong. I just had the same problem on the out side of one of my kegs. Leaked a good growler's worth of a good IPA on to the bottom of the fridge. Sigh.

Somebody correct me if I'm wrong here, but the metal posts rarely need to be replaced if you can replace the o-rings and the poppet valves.

PistolsAtDawn said:

[...]Somebody correct me if I'm wrong here, but the metal posts rarely need to be replaced if you can replace the o-rings and the poppet valves.

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The only reasons to replace a post (aside from conversions) are it's stripped or deformed (eg: the top lip that captures the o-ring is chipped or bent beyond repair)...

Cheers!