Keg leak - can't find it

Ok, so I inherited some kegs from my brother, and one of the damn things won't stop leaking gas.

I did what I believe to be a full rebuild:
2 new gas posts with poppets
new o-rings all around, including on the gas pipes
keg lube on all o-rings.

When I got the O-ring kit from Midwest Brewing supply, the one thing I noticed was that the new o-ring for the main seal was completely round while the old o-ring was only half round and half flat on one side.

Did I get the wrong o-ring? I can't hear if it is leaking in that area, and putting water on it shows no bubbles.

I have used various different levels of pressure, and I've even rotated the top lid 180 degrees as I've read that that might be a cause. At this point, i'm about ready to throw the keg in front of a bus.

Thanks for pointers. This is driving me nuts.

I am not sure what size keg you have, but could it fit into a trash can or large rubbermaid tub? If so, fill the can or tub with water and submerge the keg.

Then look for the bubbles. This help to narrow down the location, ie top, bottom, or side.

Try using soapy water instead & if it's a slow leak make the soapy solution a little thicker

Then just brush the solution around the lid & posts if you don't see anything try the sides bottom

more than likely the Old o ring has flatten out over time I've seen
o-ring that were square (flat on 4 sides) but never seen one only flat on one side

Of course that don't mean they don't exist I'm just not aware of them if they do

The flattened Oring is out there. Two of my 12 pinlock kegs had them and replacing with standard rings had no ill effect. If you're not getting any bubbles at any of the connections, what exactly is your indication that you have a leak? Many a kegging noob have observed things and confused normal activity with leaks.

+! on the dishsoap and water. Just brush it all around, and see where the bubbles are coming from. If you can tell it's leaking now, then it's a big enough leak to show up right away.

You did not mention checking/replacing the pressure relief valve. That is often a source of leaks as well. Again, with the soap and water (or starsan solution) spray around the lid, the gas posts, AND the pressure relief valve.

If it is leaking there try turning the valve lever/ring. Next try tightening it. If that does not work, unscrew it and dab some keg lube on the tip of the spring and screw it back in. Test it again. If all else fails, replace the pressure release valve but PLEASE don't throw it in front of a bus! That would be a shame.

Yup +1 on dish soap for leaks. I actually just had this same problem, but you could actually see leaking as the beer foamed around the O-ring. I got my corny from Midwest too, so I gave them a call. The guy I talked to said he had a keg that did the same thing, and to solve the problem he just pulled up on the lid and turned the pressure to 30 psi for a few seconds to form a tight seal. Might one to try that one on for size. Bobby's right about people just starting to keg. When I first started I ran through two 5lb CO2 tanks before I finally had everything sealed.

Bobby_M said:

If you're not getting any bubbles at any of the connections, what exactly is your indication that you have a leak?

Click to expand...

I charge the keg with (up to) 60 PSI of pressure, and disconnect the hose.

Sometime within 24 hours, I pull the pressure relief valve, and there is no pressure in the keg. I literally could just pull the lid open without burping the keg. I don't do that becasue I'm hoping that at some point, I'd either not get it to open, or I'd lose a finger as the thing started to keep pressure.

The other 3 kegs I have do not do this. I store them with about 5 PSI once I sanitize them to keep them clean for my next batch. I can go weeks and still have the pressure in them when I need to open them for the new batch.

The one area I haven't explored is the pressure relief valve. I'll tackle that today.

Thanks all for your replies.