The trick on copper sealing washers if they're in OK condition, is you anneal them before re-use.

To anneal, put them on a thin piece of wire and heat with a torch or gas burner on a stove and quench them in water. They come out soft and will make a good seal. Over time, they will harden up on their own. (copper and aluminum you quench to anneal, steel and other stuff needs slow cooling).

http://www.eaavideo.org/video.aspx?v=57437956001

Nice tip! I'll give it a go. Thanks.

I asked the LM tech about the washers, and he said it should be OK to reuse the lower washer that goes under the pump fitting.

He is wrong . . . absolutely, positively, no doubt about it.

As regards annealing copper washers, quenching in water is wrong also . . . let them air cool. Just do a simple "google search".

You and/or they (whoever they may be) are being penny wise and pound foolish as regards the reuse of these washers. While you may end up A-OK (and I certainly hope you do), the advice you are being given is simply wrong.

Google is wrong.

Try it yourself. Aircraft mechanics and owners have been annealing copper gaskets since the Wright Bros.

Best bet is brand new though, even on aircraft.

Try it yourself.

I have physically done it, not hundreds, but perhaps a dozen of times and I stand by what I said. There is no hardware store when you are in the middle of an ocean and then you must rely on those with a tad more experience.

If "Google" is incorrect, as you so state, then perhaps, you should respond to "them" accordingly.

Sadly, my espresso machine is still down. Since LM didn't send me both washers I needed, I had to reuse the lower washer, which was all crusty and funky from the water leak. I cleaned it up with a bit of light sanding, then annealed it using a propane torch. Reassembled everything with a light wrap of Teflon tape on the threads, then turned the water back on. Immediately got a very small leak at the same place it leaked before. Disassembled the fitting and put some more tape on the threads. Reassembled, but it still leaks.

I emailed the tech at LM who's been helping me, and he apologized about not sending a full set of washers. He's going to overnight me some more washers. They should be here tomorrow. I can only hope that will do the trick. I'm starting to think the machine's never going to be back in action. I had to make regular drip coffee this morning.

If all else fails, I might have to have them send out a tech to work on the machine. Nice to have that option, though I don't know how long it will take for one to come out, or whether I'll have to take time off work, etc. Hopefully it won't be necessary to have someone work on it. This seems like it shouldn't require a professional to fix, but we'll see.

Oh, and the LM guy is also sending me a bunch of other spare parts (group gaskets, shower screens, gicleurs, etc.) in case I need to fix anything else in the future. Despite the hassle with fixing this leak, I have to say LM's customer service has been outstanding.

OK, looks like I'm back in business. The washers, and a bunch of other parts that the LM tech sent to me just in case, arrived today by overnight UPS delivery. I reinstalled the fittings with the new washer and some Teflon tape on the threads, turned on the water, and no leaks. I left it for an hour or so with turning on the power, and still no leaks. Yessss! Then I reinstalled the case and turned the power on, and it powered up fine. I tried a couple of blank shots, and some shots against the blind filter, and no problems. Then I tried pulling some real shots, and still no issues, other than the coffee being stale and thin from sitting in the hopper for the last two weeks. I swapped for some fresher beans, and pulled a nice shot.

So it looks like the Mini is back, though I'll have to keep an eye on it and make sure there aren't any small leaks happening. I also need to change out the water softener, since there's way too much scale in the area where the leak happened.