I have just acquired a Linea 2AV with the older style bolt on groups. I see that one of them has been weeping from the junction with the boiler in the past. It doesn't seem to be leaking at present. Having read about the need for a specific pressure test procedure after replacing the gaskets, I'm not relishing the thought of doing the job. Can I wait until it starts leaking again, or are there more problems I may cause by not addressing it now?

To the best of my knowledge the issue was cause by a dissimilarity in metals and resulted in tiny amounts of corrosion and gunk but no loss of pressure. The original gaskets were a sort of thin cardboard/paper material with some green goop that was used to apply them. I worked on a machine that had those and the weeping was bad - serious builldup of gunk on all three groups - but it never had pressure issues. They eventually released a reddish rubber type material as a gasket and also made available Viton green gaskets as an option. The Viton are said to be a true long term solution to the issue.

Several times over the years I have had that problem with my LM. I have been able to get a socket on the nuts and tighten them down a bit which helped for a while. I think one of the isssues has been the loosening of the nuts from the heat. Just be very careful not to snap off a stud.

By the way, the subject line for some reason causes me to think of some sort of Gahan Wilson cartoon.

Bernie

"By the way, the subject line for some reason causes me to think of some sort of Gahan Wilson cartoon."

An tour group from La Marzocco, Italy, were in tears after missing their connecting train frrom Boiler, Texas to Houston. Boiler junction, because of the many trains that pass through it, has seen many a traveller caught out.

Hi
I'm from the Netherlands so I would like to apologise in advance for my english

About a month ago I bought a used 2-groups la marzocco Linea. I've descaled all the parts and completely rebuild it.
a couple of days ago I fired it up, and it's working well. except for a minor leaking from under the group-to-boiler gasket on 1 of the 2 groups. I tried tightening and loosening of the bolts and repositioning the gasket, but that didn't help. The other group doesn't leak.
The machine is from the year 2000 and has the bolt on groups. I used new green viton gaskets (to my knowledge they don't need any sealant)

Can anyone please help me with this?

Thanks!

Lex

The problem with the leaking groups is many. In a clean water environment nothing usually happens. The problem usually occurs because of scale build up on the top surface of the gasket. Since the gasket has an opening just a bit smaller that the opening in the boiler and also the throat of the group, there is a lip or shelf that collects "stuff". After a while the "stuff" actually grows and makes its way to the edge of the group. This is why you only usually see the group leaking from the bottom (thats where the shelf collects the stuff). Once it starts leaking it will continue. But I always error on the cautious side "if it's not bothersome then don't touch it". There is another source that is from the contact surface between the group and the boiler. The group has a nice machined surface and the tube is actually a standard size (4" SCH30). The tube varies a bit in diameter and also concentricity (roundness). Therefore the sealing surface can vary quite a bit. Originally there was a paper gasket (Novus30) and it actually woked quite well. It did require a sealant however and it was not NSF approved. This is why the Orange Silicone gasket came into existence. Then it turned out that the silicone that was originally specified was discontinued and another was used as a "exact" substitution. It turned out that this material reacted to certain minerals in the water and in some cases actually disintegrated. Then they introduced the welded group to boiler design. The cool thing is that La Marzocco actually warrantied all of the affected boilers and then offered a 5 year boiler replacement program for those machines. They actually sent an entire boiler assembly...... Complete........ WOW. Then came the green Viton gasket (it does not need sealant). This was never used in production for the USA but is available as a replacement part. They have had good success with this one. One thing to watch out for when replacing the gaket is breaking the studs off. Both the studs and nut are stainless steel and they will gaul if you are not careful. Once gauled then it requires too much torque to remove and snaps the stud off. When installing be sure to use lubricant to make the threads as slippery as possible to reduce torque.


Bill C

Well, I solved the problem of my leaking boiler.
I got an e-mail from espressoparts, recommending Loctite #262 to use as sealant. That worked.
I applied it on both sides of the gasket, then bolted everything back on (using lubricant on the bolts to reduce torque, as suggested by Bill) let it cure for about 8 hours. And when I fired it up again, the leak was gone.

Lex