Pumping ???

I had a hard time staying in the pocket the last 2 years, so I did some research and asked around and finally decided to buy the Drew Danielo Pro Carbon Xl. What a differnce, compare to my Phase 5 Prop. The board is larger and lighting fast. Now I can finally stay in the pocket without using a rope.
I am trying to play around on the wave without a rope but sometimes I fall to far back . I tried to place more weight on my front leg but I can not catch up. Since I been always using a rope in the pass to bring myself back to the pocket ... can someone explain the basic move to pumping. I seen it being done on videos but I still do not understand the principle on how it's done.