DIAGNOSIS A leak during brew points to a failed internal seal or a cracked water reservoir. The most common leak source is the rubber gasket where the reservoir meets the brewer, or the internal diverter valve.
FIX First, check the reservoir. Remove it and inspect for hairline cracks, especially around the bottom and handle. Dry the reservoir and brewer base completely. Reinstall and run a cycle while watching closely. If you see water seeping from the seam where the reservoir meets the brewer, the gasket (the black ring on the brewer's intake) needs cleaning or replacement.
IF THAT DIDN'T WORK If water is coming from inside the machine body, the internal diverter valve that directs water to the pod may have a failed O-ring. This requires disassembly—contact Keurig support for a warranty repair or replacement part.
HEADS UP Do not ignore this. Water inside the electronics will cause a catastrophic failure. Place a towel under it and stop using it until the leak is resolved to avoid a short circuit.