Another option is to remove the pump so you can get a better grip. It's not difficult to do: just disconnect the input and output lines, then loosen the screw in the ring clamp at the motor.

Thanks all. I'm generally not afraid of home repair, but my technique seems to be insufficient for brass fittings. I guess it means a lot more disassembly before attacking something (I was irresponsible with the water mixer check valve), and proper seating of sockets before applying torque, but frankly, I'm scared.

What about a general descaling? I use lightly filtered tap water, but the water here is very low in minerals (I tested it when I got the machine - I forget the actual numbers, but they're low).

The city has a zillion LM equipped coffee shops. I wonder who does their on-site repair? Hmmm....

Best,

Matt

OK!

I did a fuller disassembly, got the water mixer check valve off, soaked it in vinegar (distilled white), rinsed it, and reassembled. So far, no obvious leakage back into the tank, but we'll see.

Thanks again for all the wonderful support !

--Matt

Spoke (wrote?) too soon. The flow back into the reservoir has returned. I can go back to Chris Coffee and order a new check valve, but the tech there wasn't sure what I needed to do, as I have the old internal plumbing. Should I contact LM directly?

Thanks,

Matt

Matt - you have seen this? - /downloads/ ... aulics.pdf

Not sure if it would help any but still . . .

Eric,

Thank you for that link. I only need to know what to order given that my current machine has the old setup. I'm not sure what partial changes are wise. Probably I can just add the check valve at the pump and replace the water mixer check valve. I'd do exactly what was done earlier in the thread by John, but I don't know what parts to order.

Best,

Matt

Well, After spending the day trying to upgrade the check valves in my GS/3, I am filled with admiration for you guys who do such good work on your machines. It's not all back together yet, as I also need a new braided hose - the old one won't seal with the new check valve on the pump.

BUT

I fear I've made a mess of the steam boiler side of things. I tried to upgrade the vacuum breaker valve and there is now persistent hissing from the new elbow (A2017). And in trying to loosen another copper tube on the steam boiler, the fitting in the boiler itself came loose and now won't seal - persistent hiss. I have no idea how to replace the copper tube in question, which is supposed to be replaced by the two piece pipe with check valve.

My question - is it dangerous to proceed? Should I just send the whole thing out to a professional?

Thanks again,

Matt