On the German forum someone calls this type of jig a torture instrument
If he reads this I'll say to him I find that hilarious but it does work.

I quickly worked on cleaning the group. The bearings are pretty stuck but I have new ones if needed. I am very happy I have an ultra sonic cleaner that fits bigger parts. Check out the before and after on the inside of the aluminum group housing. Most of the sludge came off after the first cycle but I left it in a little longer to get all of it. The piston is plated and is brass underneath. I will likely not attempt to remove the rod since I have a method to reassemble the group when parts arrive.







The rubber stops for the fork were so dry and worn there is a permanent mark on the lever fork where the chrome was rubbed away by the hardened rubber. I needed to drill into the rubber and take a punch to leverage it out. I've never seen this hard of a rubber part.


I did a quick polish of the aluminum parts and at this point I have very little to do until parts arrive. It's just a waiting game at this point.

I ran into something unexpected. Out of curiosity I measured the diameter of the original spring to be 42mm. The height was 169mm and there are 14 ± 1 windings. I think the height is lower than the factory spec. This diameter may be an issue as all new springs are 45mm in diameter. The smaller spring diameter is so the spring does not rub against the preinfusion cylinder, which has to stick out into the group bore to be raised by the piston to open the preinfusion valve. I would need to assemble the group to truly see if there is an effect with the 3mm larger diameter spring, but I am asking if anyone would know if it is not an issue that I use the larger diameter spring (ie a replacement spring) or if I need to either use the original spring again or have a custom spring manufactured. The original spring is actually not in bad condition and I think I could just put it back in the goup if needed.




It may be a little difficult to see but the smaller diameter spring can more easily be centered without touching the cylinder. The larger 45mm diamater spring is pushed to the left of the picture in order to not touch the cylinder

I've been cleaning up the exterior bits to keep my hands occupied. Everything except for the backsplash turned out very satisfactory. The back panels are really in great condition. The only serious flaw I found were some scratches in one spot. The emblem is also in great condition. I just used a little soapy water to wipe down these parts. The group and drip tray have some scratches but they still turned out fine. I am trying not to rechrome anything since this is a 'survivor' machine to quote car enthusiasts.









The cup tray has really nice patina. It's super scuffed but it shows the age in a respectful manner.

kitt wrote:Also curious what the other lever in the top cover behind the group is

I think this is what you were referring to. It's a knob that can open and shut a little metal grate to allow heat to escape. I think it's for the warming of cups or regulating the interior? I am not certain why it's there.




The backsplash is definitely the most scratched piece. I am trying to get the best luster from it but the decades of wiping it with a cloth have left many little scratches over time. I'll keep working on this one


The little feet are adorable. I need to still get into the knurled parts for cleanup.

Hello:

IamOiman wrote: ... measured the diameter of the original spring ...

Some time ago, no idea how much as these days it is hard to gauge, I came across a post/article about lever machine springs.
Maybe it was here at HB?

The OP made a thorough study of the original OEM he had at hand as well as two or three replacements available and came to some interesting conclusions.

For the life of me I cannot remember where I saw it, maybe it was Bidowee in his Lever from scratch ... thread?
Can't find it but I found this:

Vintage Lever Spring Specifications

BTW: looking great! 8^*

Cheers,

CIV

This is not something I have seen before on other lever machines. I cleaned up the piston spring and it appears to be made of a bronze alloy, phosphor bronze? Really unique stuff and I thought initially the brown stuff was just grime buildup. I don't think it easily reacts or corrodes. I think it was designed specifically to accommodate the preinfusion mechanism while maintaining normal spring specs. I've said this before but the spring is also branded with FAEMA 5 57, which is something I have also not seen on a spring piston before. The spring measurements are 42mm OD, 6.5mm coil diameter, 29mm ID, and 169mm height with 14 ± 1 coils. I am actually going to use it rather than get a replacement as its tensile strength appears intact.



Literally one thing is still not apart, and that is that inlet/hot water cam and fitting. I am pretty certain there is hard scale build up inside the fitting that is keeping the rod stuck, and there is a groove in this fitting where it built up as shown in the other fitting. It's soaking in the sonic cleaner. I hope to get it apart after the effort thrown into it. Are there any additional tips anyone could provide?

Hello:

IamOiman wrote: Are there any additional tips anyone could provide?

A "tool" I have used more than once is a small stainless pressure cooker.

Fill it with a dilute citric acid or white vinegar solution and give the piece a good cooking at full blast.
You will get it to a high temperature that more often than not will cause the metal the metal to expand enough to break the bond with whatever is in there and let the acid seep in to do its work.

As soon as you can open the cooker (very careful with that ...) take the part out and drop it in a bucket of salt and ice slush.
The part would be at ~80° C and the salt and ice slush at ~ 0° C or below.

Rinse and repeat if necessary.
Thermal shock can do wonders.

Cheers,

CIV

The heat trick worked very well, thanks CIV. I took my propane torch and heated up the fitting then dunked it in a little bucket of iced water. After three cycles I could start moving the cam around and eventually pulled it out. The whole cam seemed to be eaten by hard water and suffered damage. The cracks on the tip are pretty big and I am not super excited to keep it as is and may need to do a repair. I presume something like silver soldering is my best bet?

Hello:

IamOiman wrote: ... worked very well, thanks CIV.

You're welcome.

I was hesitant to recommend using direct uncontrolled heat, it is easy to go overboard without noticing it till it is too late.
Water in a pressure cooker has a limited range and heats in an even manner, unlike a propane torch.

IamOiman wrote: ... whole cam seemed to be eaten by hard water ...
... cracks on the tip ...
... need to do a repair.

From the photos, it seems to be in very bad shape.
I'd have to agree.

IamOiman wrote: ... something like silver soldering is my best bet?

Hmm ...
I really don't know if silver soldering will do, my guess is that it would not be (?) strong enough.
It would have to be brazed by someone with the proper skills.

Q: Is this a part that may be available from a donor machine?
Have you checked with P. Pratt, Pascal or Brooks?

That said, it seems to be a simple part, maybe you can have another one made in naval brass?
The trickiest part would be to get the cam shape right.
I pressume it is brazed on in the original part, a reasonably skilled lathe operator could easily do the job.

Cheers,

CIV

civ wrote: I was hesitant to recommend using direct uncontrolled heat, it is easy to go overboard without noticing it till it is too late.
Water in a pressure cooker has a limited range and heats in an even manner, unlike a propane torch.

Hmm ...
I really don't know if silver soldering will do, my guess is that it would not be (?) strong enough.
It would have to be brazed by someone with the proper skills.

Q: Is this a part that may be available from a donor machine?
Have you checked with P. Pratt, Pascal or Brooks?

That said, it seems to be a simple part, maybe you can have another one made in naval brass?
The trickiest part would be to get the cam shape right.
I pressume it is brazed on in the original part, a reasonably skilled lathe operator could easily do the job.

I was hesitant too with the heat but what I did was put a little water on it, and when I heard it sizzling/boiling away I stopped the flame shortly after so it did not get too hot.

My metal guy told me it's a rod with the cam part brazed on as a separate piece. I am reaching out to some people just to see if I have other routes I can take if they have an unlikely spare or can fab one. Otherwise I'll bring it to him for repair.

Hello:

IamOiman wrote: .. a rod with the cam part brazed on ...

Thought so.

IamOiman wrote: ... some people just to see if I have other routes ...

It looks to me like an essential piece/part of your Mercurio and from the state it is in, it may well be that a proper repair could cost you the same as making a new one.

The rod itself should be a no brainer for anyone with 9th. grade metal shop knowledge and although the cam is a job for someone with milling machine experience, it is not rocket science. Just have to get the cam dimensions right.

Hardest part may be to define and source the materials, but the piece is small so it should not be a difficult thing to do.

Unless you can get a spare original, I'd opt for a newly manufactured one.
Like I've said before, you'll only do this once. ;^D

Cheers,

CIV