I had a problem using refillable K-cups. I have several refill cups so I can have more than one cup of coffee before I need to clean the refill cups. Sometimes the Keurig would spray water and coffee all over and only partially fill the cup. After reading about the washers on the needle inspected my Keurig and the refill cups. One of the refill cups lost the gasket on top that kept the coffee from spilling over. I threw away the broken refill cup and my problem is solved.