Hello,

I don't have enough on my plate with my Linux PID and my real paying jobs. So I bought a Rancilio s27 and am rebuilding it.





Now that everything is taken apart, I have a lot of questions.

Firstly, the pressure gauge appears to be stuck at 1.3 bar all the time. I opened it up and it does appear to be okay inside, with nothing to adjust. Should I basically just scrap this and buy a replacement? Or is there some method to calibrate it?


Also, I haven't been able to find any rebuild guides for any machines. So I'm not sure about a few things.

1. Should I take apart all the valves?

2. Should I take apart all the electro valves?

3. I know that I should use teflon on threads, but I wonder is there is also some sort of sealing grease I should use on valves or any other location?

4. Can I open the boiler without having to replace the gasket?

I have opened and cleaned mostly everything. Opening up the boiler does indeed crack the gasket into little pieces, but I get the impression it was already leaking. Taking apart all solenoids gives me the impression that one of its solenoids must have been leaking as well. Thankfully it appears as if it will be pretty cheap to replace all these o-rings.

Still not certain about if the steam valve requires some sort of grease, or if teflon tape is adequate. The valve is so incredibly tight that I can't get it open.

I was also shocked that the solenoid's third state outlet (release) was plugged up with black gunk! I didn't photograph it, but it was disgusting. I hope I never drink coffee from a machine like this.

The pressure valve now works, by just soaking it in some acid. I appears that the scale was blocking up the pipe quite significantly, but somehow when it became unstuck it broke off the tip of the needle. So I had to epoxy it and it's a little rough. Too bad I'm too cheap to buy a new gauge.

The pipe for the pressure-stat was also so scaled up that it appears to have been completely blocked. I never tested the machine prior to purchasing so I'll never know if that was an issue too. Through the length of the descaling I noticed that the HX would empty of water a LOT faster as it progressed. So I imagine that the actual small tube into and out of the HX to the group head was also severely blocked.

I can't remember where, but my friend told me of getting espresso somewhere that took 5 minutes to pull the shot. I imagine they never cleaned their machine! It's such a shame that a majority of the espresso machines out there just aren't used properly.

Looking good. I would move the needle back to zero and see what happens with the rest of the restore. If it goes well, get a new gauge, if not leave this one in place. After all, you either re-use the current gauge or buy a new one. If you re-use it, I've no idea how to calibrate it without another gauge so you see the problem...

Read some of the other restore threads as to the use of Teflon tape on threads. Most of the rebuilds don't use it, or are very judicious in it's use. Don't let the threads from the tape get inside the system or you'll be taking things apart again.

Mark

Good point, I'll make sure to be careful with it.

For the gauge -- I submerged it in the acid and it went past zero because the tip broke off somehow. So I imagine it works now but will never really know. I'm starting to think that I might have to measure the pressure, since the the pump and the pressurestat could both be mal-adjusted.

Great images, as you were descaling your s27 I was doing the exact same thing! We have owned (and used) this machine for about six years (bought on e-bay from a Chinese restaurant owner) and, with exception of a leaky steam valve, never had an issue with it until a few weeks ago when the pressurestat failed to do it's job. So instead of just replacing the part I felt the need to, at the very least look at the insides (since it did come used from ebay and all) Remarkably it was quite clean but I did descale the boiler interior. One of the things I noticed in one of your posted images, is that you submerged the entire boiler unit (including the heater coil contacts), I am wondering if this may damage the element ie. will water get into it?

The boiler is usually submerged in water!

I didn't want to try and take the element off because I don't want to damage it.

The tube to my pressurestat, and others were totally clogged with scale. So that might be your problem.

The boiler is usually submerged in water!

But NOT the exterior area where the heating element leads come through the boiler top - the area George is referring to. See this site for a fix in case the solution penetrated the heating element leads - http://www.orphanespresso.com/ .

I'd remove the element and replace those o-rings and stick the element in a 200 F oven for a couple of hours. Take some resistance readings before and after - I guesstimate around 10 ohms. I'd also apply the same comment to your submersion of the entire pump assembly. You may get lucky and everything is OK but it would be hellacious to reassemble and then need to disassemble.

You also dropped you entire pump in acid. You may not have any bearings left. You should have put some descale in the pump, not drop the entire pump in an acid bath. Once it dries out for a couple days, try turning the impeller shaft with your fingers. If it grinds or sticks, you will need to have the pump rebuilt or replaced.

Crap,

I submerged the pump because of this page even has a photo of a submerged pump.
http://www.espresso-restorations.com/pumpmotor.html

It's the closest I've come to a useful how-to in regards to restorations.

Does anyone know of any thread for rebuilding a pump? I haven't found one.

I suppose I might as well remove the element at this point. I have dismantled everything else. I was imagining that those gaskets would be rocked as well since they all have been so far.

EDIT: I found only instructions on finding a shorted boiler at that site, nothing on fixing the issue you suggested I might have. Do you have a specific link? I looked at all the rebuilds there.

Let the pump dry out (but give it a good rinsing with clean water first). Then see if it still turns freely. If it does, no harm done.