I had the exact same issue when I restored my '81 Livietta. It is documented HERE.

Upon reassembly, my fitting wasn't "all the way" tight at the point of alignment - and it leaked. I got some Loctite 567, applied it to the threads, and it solved the issue. Not a single drop of leaking water since, going on 8 months of daily use.

Hope that helps,
Pete

Thank you all. I'm idling in 'do nothing' mode right now. The case is off the machine and I'm just watching the leak carefully when I pull shots to make certain the electricals remain dry. The machine is pulling shots really well right now so I'm hesitant to start taking it apart. Also it does appear that the removal of the brew tube from the HX block is a kind of 'exploratory surgery'. No one seems quite certain what's in there or what will happen if it's removed. I'm going to finish this bag of Vivaci then decide what to do. Thanks for the input. This is my only machine at the moment and I really don't want to damage it with a botched repair attempt. Maybe a small leak is the lesser of two evils for the moment.

Ah Dumpshot,
I hadn't seen your post there......you're the third person to recommend Loctite. A fellow HBer just coincidentally dropped off an HX block with the brew tube attached for my Maximatic spare parts stash and this one had loctite on the brew tube in the same place where my leak is. Im beginning to think that this is a common leak point and a common fix (via loctite). Thanks.

Why not give these guys a call and find out EXACTLY how it should be ? http://www.cerinicoffee.com/

I stand by my original comments but, obviously, application of the correct Loctite will also solve the problem. However, it is NOT the way to do it.

Thank you Eric. That is an excellent idea. I'll give them a call tomorrow. If at all possible I'd certainly like to do this the right way and not be too afraid to take the tubing off. I'll report back shortly. It's also the case that I could disassemble the donor HX block with it's attached brew tubing and do a trial run , removing the tube to see what's in there. Thanks again.

Okay. It's been quite awhile but I thought I'd bring some resloution to this thread. I'd had a series of vexing issues with my Maximatic since I'd gotten it a couple of years ago, poor extractions, early blonding, channeling , bitterness. Pretty much every gross crema deficiency on the list. I was grinding with a new Vario and could see no problems there. Long story short, in a fit of 'let's try something and see what happens' I swapped out the Ulka for a new one of the same type from Espresso Parts. Still no real luck with correcting the problems but in the spirit of 'the pump is new so how can that hurt?' I simply moved on to some other facet of espresso extraction and more or less concentrated on technique. During this time the leak developed.

Reading a thread about Maximatic restoration here on HB ( I had just listed the machine for sale on Craigslist out of frustration) I ran across a reference to old Ulka pumps versus new Ulka pumps and that there can be great differences in pressure produced by the two. Of course pressure being a critical aspect of espresso making I immediately swapped out the pump for the older one and two things happened: The extraction problems went away almost entirely. It seems I'm now in the ballpark pretty much with every shot more or less. And secondly , the leak at the HX block went away.

So I'm surmising that the difference in pressure between the two pumps was tremendous. ( I'll be building a gauge this week to measure the old pump's pressure) and was causing catostrophic failures of the coffee puck which I had semi- mitigated through heroic grinder adjustments on the vario. Also the pressure must have been just high enough with the new Ulka pump that the darn machine simply sprung a leak at the HX block.
So I'm taking down the Craigslist ad, and am in love with the Livietta once again. I'll also be ordering a fluid o tech pump with opv and installing next weekend. One question many are sure to ask is:' If it was the pump then why weren't the extractions good to begin with?' And the answer is that I think there was more than one problem at the start ( bad brew gasket ) and the pump got switched out before i could isolate one cause or another. A classic tail chasing senario. But in the end it was the pump after all other fixes were applied.