DIAGNOSIS The silicone gasket (the black rubber ring) seated under the blade assembly is either missing, incorrectly installed, worn out, or has food debris preventing a seal.
FIX
- Unscrew the blade assembly from the bottom of the glass jar.
- Remove the black silicone gasket. Clean it and the groove it sits in thoroughly.
- Re-seat the gasket perfectly flat in its groove—no twists or folds.
- Screw the blade assembly back on tightly by hand. Do not use tools.
- Test with water before blending.
IF THAT DIDN'T WORK The glass jar itself may have a hairline crack, often near the bottom threads. Inspect it closely. A cracked jar cannot be repaired and must be replaced.
HEADS UP Always hand-wash the gasket and blade assembly. Dishwasher heat warps and degrades the silicone over time, causing leaks.