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Another CO2 leak

Yea seems like at least once a year I get one… I filled the 20lb cylinder abour a month ago and checked it a couple times in the first few weeks after reinstalling. I used a felt washer on the high pressure line to cylinder and cranked it down good. Seemed fine. Looked in this morning and the High pressure gauge was showing close to empty. I shut it off at the cylinder and tonight 12 hours or so later the low pressure guages look like the picture below. I have check valves on each of the four lines and I gave the prv on each keg a little quick tug. They all seem pretty well pressurized. So I’m thinking my leak is between the CO2 cylinder and the gauges. Or maybe between the low pressure gauge on the right and the Y? Make sense? Still why does the left guaage show pressure? where is that pressure being held?

Check valves in the line? That would prevent the kegs on the left gauge from losing pressure back into the system. Drawing beer from them would eventually lower the pressure. If that is the case the leak should be somewhere in the right side.

That’s what I was thinking at first but the pressure the gauge is registering must be before the check valve right? Since the check valve would keep the pressure in the lines to the keg?

So theoretically if the line from the cylinder to gauges is leak free then the gauges shouldn’t lose pressure when the tank it turned off?

Am I over complicating this? Bottom line is I guess I need to take the time to check every connection…I’m actually beginning to think it would be better to just get 2 more low pressure gauges and simplify the whole thing…less connections = less opportunity to leak right?

Hold it a minute, you used a FELT washer as the primary seal to the tank? I would suspect that alone would allow just a very minute amount of gas leak all the time… I’ve only used the hard plastic ones… I even get them from the hardware store… 1/2" Try that before you start buying and changing stuff out… Thats a large area to check with soap/water … Sneezles61
If you take them apart, you’ll see on both faces there is a small circle indent… When the plastic washer is compressed it creates another gasket at that point… I see my my discards washers definitely show that area not compressed …

yea i’ve used the plastic ones too. Robert’s Oxygen guys swear by the felt ones. They’re very hard compressed felt and you can tighten them more than the plastic ones. If you tighten the plastic too much they distort and get stuck in the end of the high pressure fitting. I’ve had pretty much identical results with plastic or felt.

I see… not sure you need to over torque stuff… I still am not sure felt is good… I’m not dissing your guys helping you… Like in my trade… peeps think styrofoam will stop moisture from moving from one side to the other… Its permeable… Gas can pass through it… Why do ICF’s work then? Oh oh… really getting off track… Sneezles61

you could be right. Only basis for argument I have is that a big gas distribution company recommends them…well tney do sell gas…

I’m about to go dunk the whole assembly in a bucket of water.

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So, submerged the entire rig as pictured above along with the gas QDs. After the initial escape of air around the parts it settled down and there was “nary a bubble” as my gramps would say. The kegs all seem well pressurized after the gas being off a few days and me pulling nothing.

So that points to the high pressure line to keg connection I guess it’s in for a dunking now. Kind of a pain because I have it in a cabinet…


Submerged the entire top of the CO2 cylinder and got a constant 1 small bubble per second from the inside of the nut where it encompasses the cylinder valve nipple. So definitely a loss of seal with the gasket. I feel like the nut was not as tight as I had it. I used teflon tape on this joint because I thought it might be leaking there before. It definitely was not leaking around the threads but they shouldn’t have loosened up either…

I’ll definitely get a plastic gasket with my next refill.

You guys that use the plastic gasket take the rubber o ring out right? I took mine out long ago because I was advised to do so by the same guys that recommend the felt gasket. You need to see the felt gasket @sneezles61 It’s not the kind of felt you’re thinking of. It’s more like compressed paper really.

Well, now you know where the leak is… I won’t say that they are wrong and I’m right… I will just go to a piece of info I gained many years ago… Plastic isn’t permeable, thats why its used for vapor barrier, and gas tanks, and etc, etc… I won’t say its the go to product for everything… In this case… I would always use the plastic washers, and every time you change/disconnect the tank, change that too… Over tightening isn’t as good as we think it is… Get it tight, then give er a half spin and test… I would rather hear about your brews rather than woes… Just trying my best from over here to help you trouble shoot … Sneezles61
No rubber O-ring… just the plastic one… And no Teflon tape…

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That is certainly an effective way to detect and locate a leak. I’ve been tempted to do it myself more than once but wondered if it is OK to get the gauges and regulators wet - after all, we use check valves to keep the liquid (beer) out of the regulators. (Yes it also prevents backflow and leaks from one keg to another.)

Have you seen any negative effects of the dunking ?
Anybody know if submerging this equipment is OK ?

I took offf the gauge covers and blew everything out with compressed air after. I think it will be fine.

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I refilled the cylinder today and hooked it up with a plastic washer. This is what I get.

I’ve tried just snugging it plus 1/4-1/2 turn…leaks…cranked it down hard…leaks…There’s some residue from an old plastic washer in the “o ring slot” in the face of my high pressure line nipple. Wondering if that’s breaking the seal somehow. Also the face of it is pretty scarred up…I seem to remember a plastic washer that wouldn’t come out once and digging it out with a screwdriver or knife…guess I buggered up the face of that nipple so badly it won’t seal…that sucks…$50 for a new one…

You can buy replacement stems and nuts. You just need to know if you’re stem is left hand or right hand thread. Typically they’re 1/4" NPT, and LH thread on the high pressure side, but you have that adapter or extension, right?

Looks like 1/4" npt RH thread going into the brass stem for the cylinder connection. It’s just a standard high pressure hose. I don’t have any kind of adapter or extension.

I already ordered the hose and I’d honestly like to just be done with this. If I got a stem and couldn’t get it to seal it would just extend the aggravation…

You may need to have an exorcism… That gadget is going to haunt you… Ifn the new one works… I’d go out to a swamp with that old twit and toss that son of a gun so hard… Holler some extremely choice explainative words… Take a deep breathe, then RDWHAHB !! Sneezles61

I was thinking more along the lines of throwing it on the burn pile for the annual october bonfire.


Revitalizing this old thread rather than start another regarding gas leaks. Remember kids simpler is better!

Besides my serving setup discussed above I also have a 5 lb cylinder for carbing in my conditioning fridge. Turns out the manifold pictured below has cost my untold $$$ in gas leaks. The center valve keeps coming loose and leaking. Even when tightened it can leak if you get it in just the wrong position partially closed or open…so 86’ed that bad boy today and went back to the old inline T setup. It’s not as fancy but as someone tole me years ao when working with gas lines the fewer splits or worse yet mechanical devices in the line the better. KISS!


That looks like my snake except I used clear tubing

I agree. The less mechanical the better. Cheap tees have served me well over the years. Better then the blocks. And neither will carb at different volumes so it doesn’t matter.

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