If your Oster Blender is leaking, check the following: Is the sealing ring over the blade? Is the threaded bottom cap on tight enough? Is the jar cracked at the bottom? Is the threaded bottom cap cracked? Is the sealing ring missing? Is the sealing ring cracked, broken or rotting? Does the item being blended exceed jar capacity? Unfortunately, there are no parts available for Oster blenders. if your Oster blender is within warranty, please contact a local service centre.