Secondary regulator leak - how to fix?

[eulipion2]

I have a 4-body secondary similar to the one in this picture (lifted from Google):

The leak is coming from the little hole to the left of the adjustment screw. I've sprayed all four regulators with StarSan, and only one of them bubbles, so I'm pretty sure that's the leak. I have a rebuild kit on the way (always good to have), but I'm wondering if it's just a matter of tightening/lubing something inside, or if I'll actually need to rebuild it?

Thanks!

 

[day_trippr]

Is the regulator also unable to hold a low pressure setting?

I'd expect leakage through that vent hole would be caused by a cracked or mis-seated diaphragm. That part is typically included in a rebuild kit...

Cheers!

 

[eulipion2]

Is the regulator also unable to hold a low pressure setting?

YES! That's how I first noticed it the leak. Put a Scottish on at 6 PSI, had a fairly constant hiss. Bumped it up to 10 and the hiss stopped, but the empty CO2 tank the next day tells me it wasn't fixed.

Well, hopefully the kit gets here tomorrow and I can get back to drinking my kegged brews.

Thanks, day_trippr!

 

[eulipion2]

Rebuild kit showed up today. Five minutes later, the regulator is back in place and holding pressure nicely. I'll have to check the tank tomorrow, but I'm pretty sure that was the only leak.

As I don't know how old the regulators are, or when they were last overhauled, it probably wouldn't kill me to buy some more rebuild kits for if/when they start leaking. I hated having kegerator service disrupted!

 

[orangehero]

How did you determine it was leaking from the weep hole?

I'm trying to assemble a secondary regulator bank with the same model regulator but I'm tearing my hair out getting rid of the leaks. I've assembled and disassembled the units a million times, trying to isolate which component is leaking.

The leak is so slight, about a 2 psi drop from 15 psi after 24 hours, but after a few days the pressure is almost gone. Dunking the reg in a bucket of water reveals nothing, but I know there's a leak. Maybe such a slight leak doesn't matter?

 

[thumpersk_a]

Don't know about anyone else but when I'm leak testing my system I crank the pressure to 60psi and leaks show up easier while soaping fittings and parts

 

[day_trippr]

That'll help with some things, may hurt with others.
A keg that has trouble sealing at a carbing level may be tight at 60 psi...

Cheers!

 

[eulipion2]

How did you determine it was leaking from the weep hole?

I'm trying to assemble a secondary regulator bank with the same model regulator but I'm tearing my hair out getting rid of the leaks. I've assembled and disassembled the units a million times, trying to isolate which component is leaking.

The leak is so slight, about a 2 psi drop from 15 psi after 24 hours, but after a few days the pressure is almost gone. Dunking the reg in a bucket of water reveals nothing, but I know there's a leak. Maybe such a slight leak doesn't matter?

In this case, when the pressure was at about 6 psi, I could feel and hear the air coming out. I bumped the pressure a little, and I guess the higher pressure sealed the diaphragm a little better, but when I sprayed the hole with StarSan it still blew bubbles, so there was still a leak.

If you're using flare fittings, make sure you're using flare washers anywhere there's metal on metal (everywhere but on the keg disconnects). For the various threaded connections, I used teflon tape and some pipe dope on everything. After that, StarSan solution or soapy water is my first test for leaks. Even slow ones should bubble, though they might be really tiny. Spray anywhere that has a connection and inspect thoroughly for even tiny bubbles.

Here's my general technique:

First, start with the CO2-in turned on, but the CO2-out off, so that only the regulators are pressurized. Turn off the CO2-in and let the regulator hold pressure, overnight if need be. If the pressure drops, obviously there's a leak. Re-pressurize, leaving the CO2 on this time, and spray all connections - between fittings, between the dial, the ball valve, and the various relief valves on the front and back. It may even help to try both higher and lower pressure, say 4 and 20 psi. Probably best not to leave the CO2 on overnight this time.

If the regulators are leaking from a connection, reapply teflon tape/pipe dope, and try again. If the leak is coming from the regulator body itself, apparently you need to rebuild it.

If the regulators hold pressure, then the leak is further down the line. Again, assuming a multi-body secondary (and assuming you have on/off valves on each regulator), pressurize one line at a time while disconnected from the keg, with the disconnect connected to the line, NOT the keg. Spray each connection with StarSan solution. Inspect.

If all your lines hold pressure, then you have a leaky keg. Pressurize, spray all connections with StarSan, and inspect.

It's a tedious process, but my 5lb CO2 tank lasted a good long time until this leak occurred. But now all seems well again.

 

[yohoe]

In this case, when the pressure was at about 6 psi, I could feel and hear the air coming out. I bumped the pressure a little, and I guess the higher pressure sealed the diaphragm a little better, but when I sprayed the hole with StarSan it still blew bubbles, so there was still a leak.

If you're using flare fittings, make sure you're using flare washers anywhere there's metal on metal (everywhere but on the keg disconnects). For the various threaded connections, I used teflon tape and some pipe dope on everything. After that, StarSan solution or soapy water is my first test for leaks. Even slow ones should bubble, though they might be really tiny. Spray anywhere that has a connection and inspect thoroughly for even tiny bubbles.

Here's my general technique:

First, start with the CO2-in turned on, but the CO2-out off, so that only the regulators are pressurized. Turn off the CO2-in and let the regulator hold pressure, overnight if need be. If the pressure drops, obviously there's a leak. Re-pressurize, leaving the CO2 on this time, and spray all connections - between fittings, between the dial, the ball valve, and the various relief valves on the front and back. It may even help to try both higher and lower pressure, say 4 and 20 psi. Probably best not to leave the CO2 on overnight this time.

If the regulators are leaking from a connection, reapply teflon tape/pipe dope, and try again. If the leak is coming from the regulator body itself, apparently you need to rebuild it.

If the regulators hold pressure, then the leak is further down the line. Again, assuming a multi-body secondary (and assuming you have on/off valves on each regulator), pressurize one line at a time while disconnected from the keg, with the disconnect connected to the line, NOT the keg. Spray each connection with StarSan solution. Inspect.

If all your lines hold pressure, then you have a leaky keg. Pressurize, spray all connections with StarSan, and inspect.

It's a tedious process, but my 5lb CO2 tank lasted a good long time until this leak occurred. But now all seems well again.

Thanks for the process! Found out my 2nd and 4th regulator are leaking (interesting - I wonder if they're connected?). Now to figure out why...

 

[Jakeh53cc]

Do you keep the regulator in the kegerator where the temp is around 40 or below? Does it stop when warm if so? If that is the case the diaphragm could be going bad. I have this issue with a O2 regulator I use to service medical O2. If I warm up the regulator it stops. I'd say replace the diaphragm. I keep mine in the kegerator without issue, but it the cold is known to mess with them when going bad.

 

[eulipion2]

Thanks for the process! Found out my 2nd and 4th regulator are leaking (interesting - I wonder if they're connected?). Now to figure out why...

My guess is the diaphragm as well. Buy a couple rebuild kits (and a couple extra if you can swing it - always be prepared!) and swap 'em in.

I expanded my secondary setup to 8 regulators shortly after my last post (almost a year ago), had to rebuild two of the four, and haven't had any leaks since.