Can’t figure out a slow leak..

[woodsy]

Hey HBT,

These forums have helped me get through countless experiences of worrying if I was doing it right, and now I’m reaching out for a little more help.

My kegging system has a slow leak, and for the life of me, I cannot seem to pinpoint and/or fix it.

About 4 months ago I ordered a 2 faucet basic homebrew keg kit from kegconnection with a taprite dual body regulator and 2 ball lock kegs. I got the new 5lb tank filled locally and they said I got about 3.5lbs. I put it all together as per instructions, tightened all points, including the Gas In and Beer Out connections, performed the spray test with starsan on everything, listened for hissing and looked for bubbling, and all seemed well.

Finally I filled a keg up with a nice vanilla coffee porter, let it carb for a week (did an amazing job leaving it alone and not worrying) and went to pour a brew, and the tank read EMPTY.

I tightened the tubing connections to the regulator, some of which were looser that i thought when I set it all up. I thought this might fix it, so I filled up the gas again, hooked it up, and let it sit.

I was able to pull a few gallons of beer from each of the two kegs I had hooked up, but I noticed after about a week back on gas, the dial was dropping. Was this due to temp change? I don't know. I am new to this. One week later (2 weeks back on gas) i come back from a weekend away and I'm out of gas..

Before I fill up for the THIRD TIME having not even completed a keg's worth of drinking, I figured I must have missed something, or had a slow leak, and re-read everything I could on the subject.

-I bought teflon tape, put it everywhere where there was a thread. (MFL couplers to hose, hose to regulator, regulator to tank)
-I got a wrench large enough for the job of tightening the regulator to the tank properly (I had been borrowing one that wasn't as hardcore as I'd like)

I filled up again and tightened down as hard as I felt comfortable, and let it go back to work. I left it alone for a few days, checking the fridge every day to make sure it didn't drop down immediately, in case the timing of when the leak occurs had anything to do with it, and after about a week it was fine.

I left town for two weeks over the holiday, and came back to the needle on the dial just barely above empty, well into the red. Beyond frustrated I leak test my new wort chiller (thanks grandma) and go to sleep. Next morning, (about 3 weeks on gas) it's all out.

I have had various thoughts to which I am unsure of their respective worth or insanity:

1) I have a danby minifridge converted, and below is a photo of how crammed everything is. After the first leak completed, I thought maybe since things were so tight, there may have been some stress on a joint somewhere causing the leak. To combat this, I coiled all of the lines in a way that reduced this as best as I could.



2) My regulator claims that the connection to the cylinder does not require an o-ring, as there is a little built in part... this doesn't seem very effective, as it's nearly flush with the face of the pipe. Would a real o-ring help, or hurt, in this instance?



3) If you're looking to find a leak of the slowest kind, just dunk the damn thing in the bath. Now.. I'm not about to go swimming with my regulator, but.. how much of it do you think I can really submerge? Can the ball lock connectors get totally dunked? What about the joints of the regulator up to the dials? an entire co2 tank?

HBT.. please.. save me from this headache. this sober, sober headache...

-woodsy

 

[thrillhouse]

My method in diagnosing a leak is to open the tank with the regulator shut off to the keg to 12 psi, then shut off the co2 tank. If there is a leak between the tank and regulator, the pressure gauge will drop. Once you rule out the regulator, do the same thing but with the regulator open to the tank. If you have a manifold, do the same but with the manifold closed then move on to the kegs.

Also, as an FYI, I've heard you shouldn't use teflon with co2 connections.

Good luck!

 

[day_trippr]

Hard to tell for sure from the picture, but the o-ring on that tank coupler looks kinda chewed up. You might try to find a direct replacement - but I bet it you pick up a standard fiber washer intended for conventional CO2 couplers it would work just fine and at least give you one fewer place to look for your leak(s)....

Cheers!

 

[zachattack]

Slow leaks are frustrating. I feel your pain, many of us have gone through this. But once you find the leak and fix it, man it feels good!

I have a few thoughts:
1) Tapered threads (NPT) are the only fittings that need pipe tape. It can actually prevent a proper seal with MFL fittings and the CGA fitting where the regulator screws into the tank. So remove the tape except on the threaded connections going into the regulator, or any wyes, ball valves, etc. Those should be all taped up from the factory.

2) My taprite regulator had a build in o-ring that quickly looked squished like that, but it didn't leak. I was suspect though, even though my leak ended up being where the CGA nipple screwed into the regulator. I swapped it out with a traditional nipple that uses the washer instead of the integrated o-ring. I agree with day_trippr that it shouldn't hurt to have the regular washer on top of the o-ring.

3) I agree with thrillhouse to take the kegs out of the equation and first make sure the tank, regulator, etc. don't leak. A good way to do that is to shut off the gas flow to the kegs, then open and close the main valve to pressurize the regulator. Then close it and see if the pressure drops after a while (overnight). Unfortunately this method isn't foolproof, since some tanks can leak around the packing in the main valve if the valve isn't fully opened. So it's possible (though unlikely) that CO2 can leak from the regulator out the top of the valve if the tank valve is closed, giving you a "false positive" for a regulator leak. When you have the kegs hooked up, make sure the valve is opened all the way.

4) For very stubborn leaks, use dish soap diluted with some water, and brush it on with a q-tip. This is a bit more viscous than star san, so it'll stick around. Go to a quiet room and paint every connection with the solution, then listen carefully for any hissing/bubbling. Use a bright flashlight to watch for bubbles. Make sure you hit every threaded part on the regulator, really just cover the whole thing with a thin layer of soapy liquid. Like I said above, after a year of use the CGA nipple started randomly leaking, and it isn't unheard of for leaks to be present on brand new regulators.

5) Once you have the regulator out of the equation, pressurize the lines and check out the kegs. Make sure you don't over or undertighten the MFL fittings; get them finger tight, then just barely snug them with a 9/16" wrench. You don't want them to spin freely, but if they're too tight the plastic washer or QD will crack pretty easily. Get a pan of water and dunk the connection in there to make sure it's not leaking. Again, make sure you're in a quiet room, then hit the keg with 30-40 PSI, spray everything with star san, and then really really listen for hissing and bubbling. You should be able to hear most leaks.

6) Check every connection on the kegs again. The lid, gas post, and PRV are the 3 most likely places for a gas leak. If you haven't already, I'd put all 5 brand new o-rings on the keg and hit them all with a bit of keg lube, especially the lid o-ring. The oversized silicone lid o-rings can really help with sealing at lower pressures. If you're seeing leaking around the lid, try hitting it with 30 PSI, venting and setting it back at your normal PSI. That can help a good bit.

7) If the kegs are empty (sounds like they aren't) then you can dunk them in a tub with the gas QD attached and check for bubbles. You can also try using duct tape around the rubber handle on top to make a "bowl," then fill it with water. I haven't tried this, but I've seen it mentioned.

8) You can also pressurize each keg, then remove the QDs. Come back the next day and make sure they're both still pressurized. Of course you're taking the QDs and posts out of the equation, but it can still be helpful. Remember that any full kegs will absorb some CO2, but there should still be some pressure in the headspace.

9) Check all of your hose clamps. The gapless "oetiker" style clamps give a much better seal compared to regular worm-drive ones, it's worth upgrading.

Good luck... don't give up the fight! Also, a 5 lb tank can safely hold 5 lbs of CO2 as long as you don't store the tank where it's like 120 degrees. So make sure they're giving you a proper fill, or at the very least make sure they don't charge you for the full 5 lbs.

 

[woodsy]

day_trippr, the o-ring appears flat, and is pretty much flush with the rest of the surface. That was one thing that made me question it's efficiency.

Thank you all! I am much more optimistic now that I have a well laid plan of attack.

I wish I could get to try and fix it this weekend, but work calls. I'll give everything a try as soon as I can, and let you know where the issue was.

Cheers!

 

[BierMuncher]

Gas leaks will be much more noticeable at higher PSI's. Crank that gas up to around 30 and then check. But disconnect your gas-in connections to the kegs first.

• Dunk those gas-in connections in a glass of water.
• Like mentioned, I use soapy water with a spray bottle.
• I've seen people fabricate their own gaskets cut from a sour cream container.
• I had one nagging slow leak some years ago. The leak was a small worn pinhole underneath the rubber handle of my keg. It was slow enough that I couldn't hear it or get to it with soapy water.

 

[woodsy]

I was fortunate enough to find some time to fill up the CO2 yesterday, and was able to test everything that was suggested to me in this and other threads.

Long story (and long-night) short, I found a significant leak in the PRV on one of my keg lids.

I searched around quickly to see how to fix this, and came up with:

-apply some lube
-clean thoroughly (PBW/hot water soak, starsan and replace)
-buy replacement part

I was able to try the first two, which didn't fix it. I still got plenty of bubbling when I sprayed with StarSan:



I tried moving the good PRV into the problem lid, and this did not help. It still bubbled. I also used the original "problem" PRV in the previously fine lid, and that didn't provide a good connection, and now BOTH were leaking!

I took off both lids, o-rings, and PRV's and gave them a PWB/hot water soak. Put them back in the original pairings, pressurized and sealed. The original leak still leaks. The good set, seems good again. (for now..)

I am checking daily to make sure that my fiddling around hasn't loosened up the good lid/PRV.

So, I am ready to order replacement parts it seems..

My concerns are this:

1) There seem to be two options, flat seals and o-rings.
http://www.midwestsupplies.com/pressure-relief-valve-cornelius-ball-lock-kegs.html
http://www.kegconnection.com/lid-pressure-relief-valve-new/#

I only want to buy the o-ring style because I have the flat seal and it doesn't work. Any thoughts or insight would be much appreciated.

2) When I switch the PRV's and the good one suddenly doesn't work, it makes sense that the problem could be with the lid, no?

Again, HBT has been the best resource for advice, insight and all levels of knowledge that I have come across. For this, my beers and I are ever grateful!

Thanks again.

Woodsy

 

[woodsy]

After speaking with a rep from KegConnection.com regarding my issue, they have offered to send a replacement lid and PRV, free of charge.

I went with this company because of the positive reviews I saw on HBT. +1 for KegConnection.com

Hopefully this solves things for a while.. until the next snag hits!

A labor of love, indeed.

Woodsy

 

[LowNotes]

Bummer on all the CO2 fills, but it sounds like you got the problem isolated. Thanks for posting the pic of the bubbling PRV too, helps to show others what it should look like. I just hooked up my first CO2 tank 2 weeks ago and lost all my CO2 due to not tightening the threaded connection out from the regulator to the gas-in line of the keg. I finger tightened it the first time, but think I may have either loosed it when positioning the tank, or it just came loose when put in the cold fridge environment and exposed to high pressure. It didn't make any noise at all until it got above 25 PSI, but then it rapidly became audible, and I could even feel CO2 coming out. I tightened up all my threaded connections with a wrench, and everything has been holding steady pressure for 3 days now. Just wanted to share for other people who inevitably run into similar problems.