La Marzocco GS3 conical retrofit - small leak out of group?

Equipment doesn't work? Troubleshooting? If you're handy, members can help.

#1: Post by newmanium »

After an exhausting retrofit of a ton of things on this GS3, it's back up and running along with the new conical valve setup.

I have a tiny drip out of the grouphead through the screen, about maybe a drop every 30-60s. I tore it apart and double-checked all the o-rings, replaced a few (if you pull out the conical valve, it appears to ruin the small o-ring on the bottom, so get a few of those if you need to tear it apart and plan on replacing each time it's taken out).

I made sure everything is nice and snug, all looks pretty solid. No clue where it could be getting a tiny leak from, as there's probably 6 points of entry. My machine is on line pressure which is around 5 bars right now, so another thought is get a pressure reducer and get that down to 2-3, see if that fixes it by itself. I never had leaks before with the previous setup, so I'm assuming this isn't normal, but for such a tiny leak not sure.

If somebody can sanity confirm that theirs *doesn't* have any leaks, even very small ones like this, I guess I'll maybe try one more round of pulling it apart, argh.


#2: Post by cebseb »

Does the leak happen actively when the machine is fully heated or does it only happen when the machine is not on or is currently getting warmed up? Those leaks used to happen in my old residence when my machine sat, cold and unpowered, but still plumbed in. My understanding was that the gaskets and o-rings fully seal against high pressures once they have fully expanded during heat. Take away the heat, then they relax and contract along with other components, resulting in a slight leak. My previous line pressure was about 3 bar and now that my line pressure is about 2 bar, I no longer experience the same leaking.

newmanium (original poster)

#3: Post by newmanium (original poster) »

Happens both unfortunately, I was wondering the same thing if warming up would expand the seals - it's more of a drip when turning on (when at 12 bar), but still keeps happening when fully warmed up with line pressure. Perhaps dropping to 2 bar will help, now with the new conical setup, there's zero need for any line pressure since the pump runs for all preinfusion.