Answer to: Disassembled portafilter & now my shots are not calibrated properly.This is a great answer, and the picture goes a long way to show how actually simple and straightforward it is to keep the portafilter clean, instead of the widespread fearmongering and dire warnings that abound most everywhere else online! Two Thumbs Up, Henry H! Going further, lifting the spring shown in the picture will also lift the needle valve on its hinge (don't worry, it won't fall off, just lift the spring and put it aside, it'll slip right back on no problems). This exposes the valve seat for cleaning and it's then just a matter of using a toothbrush, some Q-tips and a household degreaser such as ammonia (caution, it's fairly corrosive, use dishwashing gloves) or glass cleaner to remove the gunk that may have made the mechanism stick in a partially closed position. When you do that, just be careful not to do it too forcefully, notice on the picture the little feather spring, how it should be set in, should it come off. I simply put my finger on it while I work with the toothbrush so it won't. In any ...