Chosen Solution
When I start to pull a shot, everything sounds normal, works normally. Then the pump gets very quiet and stops pushing water through the coffee. To me it seems as if a valve gets shut, but the pump is still trying to pump. If I turn it off, then on again, it works briefly, then gets backed up (or loses pressure?) again. It works fine without the Portafilter in place. It works with an empty PF - but it leaks out the top so much that the pump isn’t really being challenged. All screens are clean, and I’ve tried single shot pods (my norm) and double shot with Starbucks ground espresso, loosely tamped. Thanks for your help!!
If water flows through the portafilter when there’s no coffee in it then it’s very likely your pump is failing and needs to be replaced. That’s assuming nothing is leaking while it’s running (ie. the steam wand).
Hi, I was having the same problem. My machine was purchased in 2004, and I must admit I took poor care of it, until the last couple of years. I found the solution, between this site and Youtube. A new pump solved the problem (https://www.amazon.com/gp/product/B00B8K...). Replacement is fairly easy, takes about 30 minutes, all you need are Phillips screwdriver and a couple of metric wrenches (10 and 12mm). One video I found was not very helpful, about half of it was useless (https://www.youtube.com/watch?v=sMVy6l7f…) but it at least familiarizes you with the internal workings.
I’ve had the same problem with my unit; sometimes a quick on/off of the steam wand fixes it for me. I took my unit apart and the pump seemed okay, but it’s hard to tell when it’s inconsistent. I think Henry’s probably right though. I think this may be the correct pump- I’d check with yours to make sure though. http://www.amazon.com/dp/B00B8KBVZE/ref=…
Just had this happen with used machine. Pump ran fine, pumped water out steamer, not brew head. Turned out to be calcium blocking the passage above the boiler spring loaded valve. Twirling a small drill bit by hand cleaned out the calcium.
