Isomac Itala repair/overhaul, some advice needed

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

#1: Post by RobAnybody »

Hi all,
This afternoon I picked up a Isomac itala (according to the sticker at the bottom), can't find a date anywhere on the machine but it appears to be newer than the one mentioned here: The unknown ITALA: A story of violence, romance, and disaster
According to the previous owner the machine has issues with attaining pressure, but hey I got it for free :D

The only thing missing from the accessories (2 portafilters, several baskets) was a blind filter so I wasn't to surprised when I removed the shower screen (which was already quite loose) to see the following:

The group itself was also quite dirty

I managed to clean it out a bit, can't get the dispersion screw out yet but I was able to pass water though using a syringe via the hole of the hex nut on the grouphead.
I managed to remove all the screws holding the housing (one had already been sawed off by the previous owner) which showed that the pump connection to the boiler most likely leaks

I've dismantled and cleaned out the pump, the mechanical bit appears to work.
I guess the next step is to check whether the pump actually pumps, since this is my first E61 machine I'm not quite sure how to safely test this without having the chance that I damage other parts of the machine (I can imagine the heating element dying because of a lack of water in the boiler and so on)
So tips and advice are highly welcome!

Thanks in advance!
Cheers,
Rob
LMWDP #647

RobAnybody

#2: Post by RobAnybody »

So in the meantime I found out that my Itala matches the design of the later Isomac Amica, for which there is somewhat more information available (a user manual for instance, though it is unfortunately not that extensive.)
I've been busy cleaning out the portafilter (looks like the first time that was done in a few years), cleaning of the few specs of superficial rust on the body parts.
Re-mounting the pump and fixing the leak from the pump to what should be the over-pressure valve and cleaning out the parts of the grouphead I could disassemble with my current tools.
The discharge valve and lever assembly contained quite some crud, the rubber seals and washers still looked fine as did the filter underneath the mushroom cap. Still need to pick up a larger spanner somewhere to disassemble the upper pipe and group collector and clean out both valves.

Now for.the question, what is the best procedure to test out the pump?

If I can get it to run I can proceed with a descale and get a blind filter to do a series of back flushes to get out all the bits I missed during the cleaning of the grouphead.
Thanks in advance for the feedback!

Cheers,
Rob
LMWDP #647

RobAnybody

#3: Post by RobAnybody »

Cleaned more of the body today and gave them a bit of a protective polish. The connection between the pump and the overpressure valve didn't leak the whole day so after a shot of liquid courage from my Pavoni I went to test the pump.
Hooked up the machine to a socket on the least important group (we still have fuses instead of breaker switches). Since the machine is still in bits I passed the water level sensor using sticky tape and put both tubes the water reservoir.
Hit the on switch, the hot water switch and the pump started doing its thing. Within a few minutes pressure was attained.

So yay for that!
Steaming also works without issues following the guidelines I found for the Amica. The grouphead will need some attention though since most of the water comes from one side of the dispersion screw
You can see the splatters on the left.

So for those with experience, what is the best way to do this?
Re assemble the machine, put it upside down and put diluted citric acid on the grouphead?
Backflushing using dilute citric acid instead of backflushing detergent?
All tips/suggestions are welcome!
Cheers!
Rob
LMWDP #647

RobAnybody

#4: Post by RobAnybody »

I pulled the upper tube from the grouphead this morning and was greeted with the following
The scale was even bumper than visible on the image, including greenish deposits which reminded me more of copper corrosion than scale, suggesting damage to the chrome plating.

I brushed off some of the ticker scale and then placed the lower part of the tube in 0.5% warm citric acid. After about 5 minutes I noticed that there was no chrome whatsoever appearing form beneath the scale so I removed the tube from the acid, rinsed it with cold water and with cleaning soda to neutralize the acid.

I brushed off the remaining scale and found there is hardly any chrome left. After polishing the tube to get it as smooth as possible it looks like this:

Should I remove the rest.of the chrome plating to get it even smoother or just leave it like this?

The inside of the the group looked much cleaner:


I guess with this much scale on the upper tube a boiler descale is in order. So what is the best way to do that on this machine?
Should I use citric acid or is it to to aggressive?

Again all help is much appreciated!
Cheers,
Rob
LMWDP #647

earlgrey_44

#5: Post by earlgrey_44 »

You seem to be doing just fine - the shortest path from useful coffee appliance to problematic door stop is making coffee with typically hard water, while doing nothing to clean the machine. You're the lucky person who gets to reverse the process, and the price was right.

You have enough functionality restored to do a descale, and that would be my next move. Citric acid is appropriate for the level of scaling you are seeing and is not too aggressive. A helpful link:
Water, Scaling and Descaling with HX espresso machines?

Be aware that it's easy to damage the brass dispersion screw trying to remove it - use a screwdriver big enough to fit snugly and try using use heat to loosen it, and try that only after the descaling procedure. With a little luck, the descaling will restore free flow around the screw. I wouldn't worry about the chrome. Internal chrome loss on these things is normal and inevitable.
Trust your taste. Don't trust your perception.

RobAnybody

#6: Post by RobAnybody »

Thanks for the encouragement and advice! I have a blind filter currently on order so as soon as it is in I'm going to run the descale procedure.
I started with cleaning out the exterior of the dispersion screw and surrounding area today. This is before;

And this is now:

At the current pace I hope to have her up and running somewhere next week.
Cheers!
Rob
LMWDP #647

RobAnybody

#7: Post by RobAnybody »

So after a succesfull descale (not so much scale in the boiler, luckily) I followed up several rounds of backflushing. The first 5 flushes coming out of the discharge valve looked like the cheap coffee you get from vending machines.
After borrowing a proper adustable wremch from the lab I was able to also disassemble the grouo collector which even after the backflushing, still contained quite some crud. All rubber seals wirhin the group were still quite flexible, the onky part that showed some wear was the upper valve guide of the infusion valve.
Since the whole assembly functions nice and fluently after the cleaning I decided not to change that part yet.
The max pump pressure dropped from 13 to 10.5 bar after the descale, but i also noticed the retun flow from the OVP had increased so most likely the OVP had some scale in it. The pump itself responds normally and builds pressure quite fast so that appears to be in order.
I haven't been able to remove the dispersion screw from the grouphead but by flushing brushing and backflushing I managed to get a more all-round flow instead of a directional spray.
Lastly I replaces the tubing for fresh (FDA approved) cured silicone tube (the benefits of working in a lab which has this type of stuff laying about) and calibrated the low water switch.
After re assembly and a final polish this is the end result:


The only thing missing are the hot water and steam decals above the knobs, but I haven't been able to find those online.
Now I'm going to hunt down a fitting tamper so I can give her a proper test run.
Cheers,
Rob
LMWDP #647

earlgrey_44

#8: Post by earlgrey_44 »

Congratulations, another old Isomac resurrected from the dead! Nice job.... :D
Trust your taste. Don't trust your perception.