6/12/96 Dear Michelle, When I first began using these with my clients, I had problems with suction also. Two things I learned from M_ is that adapter (yellow piece that fits onto while cylinder with yellow piston inside) must be screwed on tight and that it is helpful to grease rubber gasket on yellow piston with a small amount of vegetable oil so that it moves more freely. See if this helps. I have no personal experience. this info is offered only from the perspective of helping other mothers. Certainly if you consistently find the older kit to be more effective you should let M_ know. Anna Utter, IBCLC Gaithersburg, MD [log in to unmask]