Well your question is kinda vague, so I'll assume you are using an 801 punched carto in a tank.
Hopefully you manually filled the carto with liquid first. The other variable would be the size of the carto hole/punch. It may need to be bigger. If you are using an extremely thick
juice maybe a few drops of water will help thin it and get the ball rolling.
Getting carto tanks working properly is a major point of discussion, look around these forums, there should be hundreds of posts to peruse.