La Dorio Atlas Hydraulic 3 group Restoration

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

#1: Post by simondorio »

Hi everyone,

This thread is for the restoration of my 1964 La Dorio Atlas Hydraulic 3 group :)

I'll post quite a few photos of work right up until now then I've some questions I'll ask at the end.

I've owned the machine for over 10 years, and now having moved to a house with a nice shed I can dedicate some space and time to do this lovely machine justice.

From my searches it appears that La Dorio only made hydraulic machines for a short time in the 1960's.

My machine is one of the early ones and was sold new in Australia by a company in North Sydney.

It was discovered in an old shop in Melbourne in the early 1990's. The hydraulic circuits had been disconnected and blanked off so it looks like it had just been used for steaming duties the last part of its commercial life.

The owner I purchased it from had not disassembled the machine - he only had the larger trim pieces and some pipes re-chromed.

So my first task was to take a good look inside:

Boiler covered in lots of asbestos which had to be very carefully removed wet and with PPE.

Old float fill valve which no longer worked.

Needs a slight clean. :shock:

Even with some good heat/penetrene/impact application, 15 out of the 16 boiler studs snapped off.

Boiler is 3400w so will easily run from a normal Aussie 15A 240v outlet. Both elements no good but we have a good local element manufacturer in Melbourne who can make new ones to match.

The actual frame and bodywork is in pretty good condition. Just 2 repairs needed and some corrosion which will be fixed. I'll likely keep the chrome main panel original for the time being as the corrosion is hidden when the group is installed.

I'm doing the restoration from the inside out - that is I'm working on getting the machine up and running with one group first, before I do a full cosmetic restoration for a couple of important reasons I'll explain below.

After asbestos removal I cleaned and descaled the boiler slowly over about a week in a citric bath.
The machine then went into storage for 8 years up until now :-)

There are lots of different designs of hydraulic groups - many of which you can see here: ... st-1819383

Unlike the Cimbali group which has auto return valves the La Dorio system has a single hydraulic valve on top of the group which I believe performs the down and return motions (don't know yet as I havn't tested it!). Water is directed at mains pressure into the top of the large hydraulic cylinder, forcing it and the smaller group piston down. Moving the valve to another position directs water underneath the double acting hydraulic piston forcing it to the return position.

Pressure multiplication is 3.4 so 2.5Bar water pressure gives 8.6 Bar in the group.

After disassembling and cleaning the boiler and groups it was ready to send off to a local engineer for:
16 X new boiler studs
15 X group flange studs
12 x hydraulic top lid studs (very small with no margin for error !)
3 x new pins made for 'ristretto mode' (allows half shots to be pulled) - see above pic with small bakelite handled lever with rusted pin,
custom pin wrench tool made to remove hydraulic piston seals.

Next post with engineers work.......


#2: Post by kropoffee »

very cool!

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simondorio (original poster)

#3: Post by simondorio (original poster) »

Here's the boiler and hydraulic cylinders back from the engineers:


Above pic wrench tool for removal of hydraulic piston seal worked a treat.

Now the main challenge with this machine and the reason I suspect there are none that I can find currently in operation is the design of the hydraulic group.
The sealing width of the top of the hydraulic cylinder is only 9.5 mm.

And worse there's only 2.3mm sealing width from the water channel to the outside edge - not nearly enough for the old paper gaskets to hold 2 to 3 bar water pressure!

The later version of this group (not mine) had a beefed up hydraulic cylinder:

It was fitted with wider flange area, an Oring to seal around the return pic and 5 or 6 bolts instead of 4 like mine.

Which gets me finally, to two questions I have: !

1) What material should I use to make boiler end plate gaskets? Teflon or Loctite 515 ?

2) My engineer said Loctite 515 will seal up the hydraulic piston tops - but there is only 9.5mm flange and 2.3mm in parts. What do you think would work? I'm happy to test and can get more engineering work done if necessary.


simondorio (original poster)

#4: Post by simondorio (original poster) »

2 more pics, front and back. All original - the fine front artwork is a one off by La Dorio, the only other one this intricate is in the Maltoni collection. There are a coupe of very plain designs with drink glasses etc but most Altas machines have plain blue or pink fronts.