Happy new year!
The pictures tels the story....this happens especially when the machine is cold/warming up.
I tried tightening the 4 bolts holding the piston, and it went away for a while after i greased the piston seals.

I am not sure about the part next to which i drew the arrow and while its bubbling around it.

Any thoughts?

Katzer wrote:I am not sure about the part next to which i drew the arrow...

This diagram is from the Profitec Pro 800 Review:



It's used to cut off flow from the boiler to the grouphead while replacing the piston seals, for example. Also see What's in here? #Londinium for related discussion.

Two questions:
1. Why does that cut off part leak?
2. Should there any water pass the seals?

I am starting to suspect that the cut off does not cut and the seals do not seal ...

Water coming out between the 2 group halves is a sure sign that your seal is worn, especially if you recently lube them. How long have the seals been installed? As for the water cut off valve there is an o'ring I believe on the threaded part that should stop water from weeping up. If the machine has several years of use it's not a bad idea to completely remove the valve & ball to check for scale in the small passages.

Thank you so much for the advice!
I have had the machine for 15 months, but it has pulled over 3000 shots and it has been on for 12 hours a day in the first 8 months then i stopped turning it off...
So i guess this translates to more then a few years of home use.
I have a set of cafelat silicone piston seals, but I dont have a spare o ring for the valve, but I will check it and maybe some Molykote grease can give it a new lease until i get a replacement.
I am in Maine so the water is very soft, but there is a little scale outsifethr group from the dripping so some build up probably took place.

When I opened tte piston for seal lube, everything was pretty clean. However, I only lubed it for tge first time a couple of months ago (my bad).
I used to be much more religious about that with the La Pavoni. At the time I lived in Israel where the water is hard and it was pretty messy every time I opened it up.

I keep my well water in the 40-45 PPM hardness range & my boilers stay pretty much scale free. Despite this when I removed the group sleeve & that shut off valve I found scale on the group wall & scale partially blocking the passage from the valve to the group feed opening. Worth checking every couple years.

I think the seals are bad and causing the leak on the grouphead. The water seeps into the cutoff part, gets hot enough from the temperature of the grouphead and looks like its bubbling back out. When you change the seals on the piston, both problems will go away. My Pro800 looked similar when the seals failed and replacing them fixed the issue.

Yup. The seals were shot. The cafelat silicone seals were a breeze to put in. I actually spent quite a bit of time with a single edge razor on cutting the old one out.
After the replacement and cleaning the cut off (there was a little scale on the threads), everything is like new plus the spring "groan" is gone now..
There is an adjustment screw on the cut off, which seems to control how much room the ball has to go.
What is the desired setting here?
Brand new the screw was all the way out, allowing maximum movement.

Actually, spring groan still there but not as bad as it used to be... any success stories eliminating it?
I saw one about the spring alignment but i could see anything misaligned when i had it out.

I'd leave the screw backed out for full flow. I played with various settings on my Bosco but ended up back where it was when it left the factory; full flow like yours. As far as spring groan you just have to try moving the spring over at the top. Look at the sleeve & see if you can see a wear spot where the spring is touching. If so try to move the spring over a bit away from that side.