La San Marco 75 Export restore diary.

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

#1: Post by RuiReis » Sep 05, 2019, 7:32 pm

Greetings

I will restore this machine i just bought. She's is in a very good apparent condition and its seems have been taken care although not been used in the last years.
The boiler is working, i pluged it and i had hot water and steam. I didn't managed to get a coffee because it misses the portafilters. Didn't had any leak while on.

I will used this diary as thoughts repository too, this is a brand new world to me. Comments and suggestions are very welcomed.
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Lets start.
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Cover out and screws soaked in WD40
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The pressostat
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The frame and boiler have the same paint.
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Lever group, it's massive!!!
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A surprise... at least to me... i think it have a gas heating options. The boiler paint is pristine though, probably never been used.
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That's all for today. I will try to take photos with better light next time, thank you for reading.

nirdvorai
Supporter ♡

#2: Post by nirdvorai » Sep 06, 2019, 3:39 pm

Good luck.
Looks like an amazing gem to find. I really love the back of this machine.
Keep posted your diary.

Niro

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AssafL

#3: Post by AssafL » Sep 07, 2019, 5:17 am

Wow. Apart from a bit of discoloration looks new.

Does it power up?
Scraping away (slowly) at the tyranny of biases and dogma.

LObin

#4: Post by LObin » Sep 07, 2019, 4:44 pm

It looks like the hot water valve is drawing water from the upper back of the group and not from the bottom of the boiler like usual... :?:
LMWDP #592

Sander1981

#5: Post by Sander1981 » Sep 07, 2019, 4:47 pm

Nice find! Good luck with the restoration.

RuiReis

#6: Post by RuiReis » Sep 09, 2019, 3:37 pm

Thank you.

I have been reading how to dismantle the lever group and i think i'm capable now and today i managed to find a little time to play with...
AssafL wrote:Wow. Apart from a bit of discoloration looks new.

Does it power up?
Yes it does.... Too much :roll: i think the pressostat, sirai, isn't working... The overpression valve started to sing around 1.75 bar. I tried to tune it but unsuccesfully.
LObin wrote:It looks like the hot water valve is drawing water from the upper back of the group and not from the bottom of the boiler like usual... :?:
Just like you said. I never would thought this wasn't the usual configuration, my first one :wink:

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truemagellen

#7: Post by truemagellen » Sep 10, 2019, 12:25 pm

The diaphragm on the Pstat is likely shot. Just replace it and it will work again. Or for all the hassle PID it, you won't regret it.

RuiReis

#8: Post by RuiReis » Sep 10, 2019, 4:51 pm

truemagellen wrote:The diaphragm on the Pstat is likely shot. Just replace it and it will work again. Or for all the hassle PID it, you won't regret it.

I was thinking about it, cost wise it's even cheaper than buying a new Sirai Psat. I would install also a Ceme Psat as a redudant safety aproach if the PID fails. But... I don't know where to install the probe and mainly i don't know how the machine behaves in her original config... So i might follow the kiss route and just change the diaphgram, in the future the PID will be installed for sure.

Thank you a lot your input.

RuiReis

#9: Post by RuiReis » Sep 10, 2019, 5:07 pm

Taken out and innitially desassembled the lever group. The machine is prettier outside than inside :oops: A lot of residues on it, she was dirty... I have to do a lot of cleaning.

I have yet to do a tool to turn the piston.

I have found a great video of a factory worker mounting and desassembling the group.
https://www.dropbox.com/s/v1xwm0wi5ji9a ... e.avi?dl=0

Portuguese engineering
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Dirtyyyyyyyy
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truemagellen

#10: Post by truemagellen » Sep 10, 2019, 5:39 pm

Seems like a lot to do now but honestly it's in great shape just dirty.

My encouragement to you is that La San Marco group is brilliant. You will be achieving paint like, heavenly shots over and over with little effort. It will become your favorite machine I bet.

If you want a bottomless portafilters for it Izzo sells a really nice one for their Leva with tight tolerances, I believe it should fit but check with them first to be safe.