Coffcarl wrote:I don't think you will get away with not removing the boiler, or at least the boiler cap.

That will be next step.

Coffcarl wrote:Remember i asked if running the pump to the heat exchanger eventually overflowed the boiler through the vacuum breaker? If so, then there is a leak in the heat exchanger.

Sorry, I forgot to respond to that one... I couldn't get it to overflow when I tried that test. But that was a while back, I think I maybe just didn't run things long enough. If the water is going past the flow meter, and into the boiler, but not out... I would think it would eventually fill!

jgrosjean wrote:I am sorry for being so cavalier about this machine in the first place. I guess I have had good luck with my machines and grinders.

Don't be sorry, thanks for all of your help! I'm having fun... as I kid I always got to take apart (with a hammer) machines, but never had the slightest clue what was happening inside. Now I'm actually getting "some" clue, it's been great!

jgrosjean wrote:I gather if a machine freezes with water in the boiler the heat exchange tube will crack.

Unfortunately that seems to be a high probability in this case. The machines were stored indoors, but the building didn't look particularly used or heated when I picked them up. And the boiler did have water when I got it. I do have the parts machine too... I'm going to try opening that boiler first (for practice) and it might still have a good heat exchanger.

Good news is that from what I can tell the heat exchanger is good in the parts machine. At least I don't see any obvious holes or splits, and if I blow in the intake I get air out the outtake. I guess now I'll open the "working" machine and see if the heat exchange really is the problem.

Great to hear!

Here's what the boilers look like from both machines before I've done any cleaning. I guess not clean, but a whole lot cleaner then most rebuild machine boilers that I've seen. Didn't find any "gunk" in the bottom of the boiler:





I guess since they are all apart I will do the soak stuff in citric acid and make it shiny process which I see many posts about. Looks fun! The problem with those posts is often I also see a commenter saying "oops, you shouldn't have soaked that part". Is there a recommended post describing what parts to soak, or general tips on the process of soaking everything? Also should I take the heating element and heat exchanger off before soaking?

So definitely a split in one of those tubes, right?

You will have to solicit descaling advice from someone else. The only machine I have rehabilitated was in general working order and the only descaling I did was to fill the tank with a dilute citric acid silution and heat up and run it through the boiler.

I would say, once everything is working, you ought to put a standard under the counter filter between your water source and the machine. To protect from scale. I use an omnifilter two stage filter, sedimenr, and carbon. People do all sorts of wacky things for their water source, but filtering is necessary.

Also, I have heard (and it makes sense) that you should put some sort of standard auto shut off valve on your water source if it loses back pressure, indicating a leak or burst hose. That will protect you from a flood.

You should probably replace any gaskets that you had to remove to get at components. Either cafeparts.com or espressoparts.com. i can predict that you will be ordering various orings and valve seats and other assorted rubber parts.

Progress!

Boiler still fills as needed, but now I can also dispense out from the head:
Please let me know exactly how far I've progressed

Does the dispensing look about right? I don't have the filter or distributer on because the filter is jammed with old coffee. But other than that does the flow look right? Also what about pump sound? I fear it sounds a bit like youtube videos that I've seen demoing pumps that are about to fail... Thoughts?

I still have heating element disconnected so haven't tested that whole other fun part of the machine.

Looks good to me! The proof is in the pudding though, so proceed. You must have reused the boiler gasket, so hopefully you won't have any leaks when it comes up to pressure.

Coffcarl wrote:Looks good to me! The proof is in the pudding though, so proceed. You must have reused the boiler gasket, so hopefully you won't have any leaks when it comes up to pressure.

I'm not sure if it makes sense, but my goal is to first fully test the "cold" system which I don't think I need a good boiler gasket for. Once I'm confident that is working then I'll wait for gasket parts, connect heating element, and see if the other half works. I plan to take it all apart again if I get that far, I'm getting faster at that!

With that said there at least appears to be some pressure in the HX system produced by the pump. There were leaks in various places when dispensing until I tightened things up.

I guess next thing I need to do is test dispense pressure, so I need to wait for gaskets now anyway

Not to get too far ahead of you, but it looks like the pressure gauge on that machine just measures boiler pressure, so you will want a way to measure pressure at the grouphead. I also am not sure how that is adjusted in a machine with a rotary pump. On ones with a vibe pump, there is a spring regulated valve called an opv, that you loosen or tighten to regulate the threshold at which water is diverted back to the input side of the pump.

You will want to rig up something to get an idea of the pressure, and set it somewhere between 9 and 11 bar. A standard pressure valve attached to the portafilter instead of the spout will suffice. The difficulty will be getting a tight fit without leaks, using teflon tape. As well as wrapping the spout threads, i removed the filter basket and wrapped the top of the portafilter with copius amounts of teflon tape.

Some people attach a needle valve to simulate the back pressure of a full basket, but in my view that is overkill.

In addition, you will want to adjust the boiler pressure for a good compromise between enough pressure (hot enough) to produce good steam, and cool enough to not scald your espresso and not require a long flush before pulling a shot. This is doen with smapp adjustments to the pressurestat. These are just things to consider once you have the machine basically operating