Sherman,

Yes, those are all the tools I used as well. I didn't mention them earlier on because this sort of project, I feel, should only be taken on by a bit of a handyman, and my assumption would be that just such a person would have those tools. Great to actually provide a detailed list though.

I would add one more "tool": a digital camera to document your work, and to know where stuff goes if you can't remember!

RAS wrote:By "pressure valve", do you mean the pstat, the 3-way or what?

I misspoke. That, and I had to reread OE's description. Realizing now that my '90 has a "half rail", I only need to install the teflon seal between the steam faucet (AKA "safety valve") and the rail.

Also, I found that removal of the hx was a LOT easier if I removed the 3-way first (by removing the retaining nut under the solenoid). In OE's video, Doug says that they're flathead screws. I don't know if/when this changed, but in my model they're 3mm allen screws.

-s.

She lives! Reassembly completed, no leaks, pstat is cycling between 1.2-1.4. Pics to come...

Regarding the baked/petrified boiler gasket, I tried several different methods:

1. Prying with a pick/awl: ultimately failed, as the gasket was too hard
2. Chipping with a flathead screwdriver: failure - the head is too dull
3. Dremel with wire brush: failure - gasket material too hard
4.MAPP torch: failure - succeeded in charring the gasket material, then chipping away the. Flakes, but too many small bits
5. 1/2" wood chisel: SUCCESS! - as RAS mentioned, you have to use a steady and light touch to keep from damaging the brass, but the chisel is sharp enough and has enough mass to keep the cutting edge from deforming (unlike a utility knife).

I placed the heating element flange in a vise and lined the vise jaws with silicone pot holders, then closed the jaws just enough to keep the flange stable, not so much to keep it from moving altogether.

OK, here we go. For the purposes of these instructions, a "seal" is a rubber/silicon o-ring with a circular cross section, and a "gasket" is a rubber o-ring with a square cross section. Silicone tubes don't require any special instruction, and if you have to replace the pump or pstat, you'll have to refer to someone else's instructions, as I haven't had the pleasure of working on those parts (yet).

I've found that the Maxi can be separated into the following major groups:

1) Grouphead assembly
Tools needed: 5mm hex key, philips screwdriver, awl/probe tool
Serviceable parts: grouphead gasket, group seal

This can be serviced by removing the 4 hex bolts (5mm) that attach the grouphead to the boiler. The dispersion screen is attached by a philips screw. A probe tool comes in mighty handy in removing the grouphead gasket, as it is mounted independently of the dispersion screen.


2) Steam valve and wand assembly (very similar, if not exactly the same as a 67 Cremina)
Tools needed: adjustable wrench, 15mm wrench, large and small flathead screwdrivers
Serviceable parts: valve seal, bib seal, steam wand seal

Use a screwdriver, needlenose pliers, or other blunt instrument to press on one side of the steam knob cover near the rim. With enough force, the cover will pop off, exposing a flathead retaining screw that holds the steam knob on. Remove the screw, then you can use the knob to work the valve assembly loose. Once the assembly is out, there are 2 replaceable items - the valve seal/o-ring and the bib washer.

The steam wand can be removed by using a 15mm wrench on the nut that holds the wand to the steam valve body. Once the wand is removed, there is a small o-ring that can be replaced.


3) Heating element assembly
Tools needed: flathead screwdriver, 5mm hex key
Serviceable parts: boiler gasket, safety thermostat

Straightforward stuff here. Start under the grouphead and use a flathead screwdriver to remove a small screw that holds the bottom plate in place. The plate slides forward and out, exposing the heat element flange and wiring. Remove the spade connectors, then use a flathead screwdriver to remove the safety thermostat. Next, a 5mm hex key will remove the 6 bolts. Once removed, the boiler gasket is an easy replacement.


4) Water reservoir assembly
Tools needed: 5mm hex key
Serviceable parts: 2 valve seals

Pull the reservoir out, then use a 5mm hex key to remove the reservoir valve from the body.


FOR ALL OF THE FOLLOWING STEPS, THE OUTER CASE MUST BE REMOVED.

5) HX assembly
Tools needed: adjustable wrench, needlenose pliers, 3mm hex key
Serviceable parts: medium-sized seal connecting HX to boiler, 2 small seals inside HX assembly

I've found that it was easiest to remove the pipe connecting the boiler to the steam assembly, as this pipe somewhat blocks the connector leading from the HX to the grouphead. So, remove this first, then HX-grouphead connector is much more easily accessed. At this point, I found that removing the 3-way solenoid made things a LOT easier. So, remove the silicone pipe that connects the 3-way to the faceplate, then use an adjustable wrench to loosen/remove the nut (under the solenoid) that holds the solenoid onto the 3-way valve. Remove the solenoid and lay it down gently

Back to the top of the boiler, remove the 4 bolts holding the HX onto the boiler. There is a medium-sized seal that can be replaced. Now that the 3-way solenoid is out of the way, you can disassemble the HX and replace the 2 small seals inside of the HX.


6) Sight glass/safety faucet assembly
Tools needed: small flathead screwdriver, needlenose pliers, 17mm wrench, 5mm hex key, probe tool
Serviceable parts: upper & lower sight glass seals (and copper crush washers), safety faucet washer (copper or teflon)

This goes a lot faster if you attack from the front, so remove the grouphead (step 1), then start unplugging spade connectors. You only need to remove 4 of them, a pair of blue/red that connect to the coffee switch, and a pair of blue/white that connect to the power switch. All 4 of these wires are grouped together and run down the steam-wand side of the machine.

Next, use a flathead screwdriver and needlenose pliers to remove the 2 small flathead screws that hold the faceplate to the chassis. You'll need the needlenose to hold the hex nuts on the other side of the chassis.

Now the faceplate should just slide up and off the chassis; it can't go too far because we haven't removed _all_ of the spade connectors, but you should be able to move it up and out of the way enough to hang it on the boiler through the grouphead hole. Once it's out of the way, use the 17mm wrench to loosen the upper and lower sight glass nuts. Tread softly here, glass and metal don't play so nice together. After the sight glass nuts are completely loosened, bring the faceplate back down, then use the 17mm wrench again to loosen the safety faucet. I'd recommend opening up the safety faucet as well, then using a 5mm hex key to completely disassemble it, followed by a nice bath in a warm citric acid solution (17-18g/L of water works well for me). With the safety faucet removed, the sight glass will slide out. Remove the sight glass, replace and lube the seals (and crush washers).


Whew.

Quick pressurestat calibration table:

1 PSI = ~0.068 BAR
1 BAR = ~14.5 PSI

PSI --- BAR
10 --- 0.68
11 --- 0.75
12 --- 0.82
13 --- 0.89
14 --- 0.96
15 --- 1.03
16 --- 1.10
17 --- 1.17

BAR --- PSI
0.5 --- 7.25
0.6 --- 8.70
0.7 --- 10.15
0.8 --- 11.60
0.9 --- 13.05
1.0 --- 14.5
1.1 --- 15.95
1.2 --- 17.4
1.3 --- 18.85

Humming along at 13 PSI.

-s.

Sherman,

Thank you so much for your detailed description and photos. With your online tutorial, I'll feel much more confident when I take on this same project!

Sherman,

Great addition to the discussion!

One recommendation I'd make is to insulate the boiler, as I have shown earlier in this discussion. Main benefit is that the water reservoir stays cooler. I'm sure there's some energy savings as well.

Sherman wrote:pstat is cycling between 1.2-1.4.

Sherman, please let us know how this setting works out for you. Seems a tad high to me, but that being said, I experimented with mine set around 0.85 - 1.0, and didn't like the results. Even with a short flush, espresso would taste sour. I don't recall exactly what I cranked it back up to, but 1.0 - 1.2 seems to ring a bell. Nice compromise with flush volume, brew temp (after a quick recovery), and steaming capability. And I may have already mentioned that this is the best steaming machine I've used. Gorgeous microfoam in a very short time. I'm getting to like this machine more and more.

It is a tad high. After some more tweaking, I'm finding more comfort near 13-15 PSI. The one thing that I don't like about this machine is the 3-way "sneeze". More often than not, I get up close and personal to watch the stream, only to be splashed in the face when I stop. I've gone as low as 8 PSI, and found that the steaming performance was compromised beyond my acceptable limits. Regarding shot performance, I've only had the chance to pull shots on some 10-day-old Red Line, and a recently homeroasted Kenya Karagoto (City+), and found that the shots were acceptable, but not spectacular. Still tweaking variables, but I'm finding that a 5-second flush (after flash boiling) brings me to "medium" temps, as the 8 second flush brings out some really pucker-y sour notes.

-s.

I recently received some insulation from RAS that, to my knowledge, was cut to fit the boiler for a Livietta/Maxi. Upon arrival, I attempted to install it, only to realize that the cutouts are just a bit different. RAS has a 54mm, and mine is 49mm. Is there a difference in the boiler designs between the 49mm and 54mm machines?

Also, my hack insulation job may be for naught; the outer casing and top are still warm to the touch. Upon further consideration, I come to figure that it's because I've only insulated the boiler body. The HX and other pipes that carry boiler-temp water are still un-insulated, which may explain the still-warm insides. If this is truly the case, I can imagine that the only benefit of boiler insulation is to reduce pstat cycling and wear on the heating element.

Thoughts?

Hi Bob - I am in LA and think I almost bought the same machine. Glad you have it working! Wondering two things:

• Could I buy some of the insulation from you?
  What shop did you use to do the powder coating?

I am rebuilding a Livietta, too.

Thx!

Peter