Hi, I need some help again. Finally after 18 months (and replacing everything except the motor, I think) I have my milking machine set up. The maximum pressure I am getting isn't but 18 lbs and it drops down to about 12 when I open the valve as if I were milking. Problem is...I can't figure out how to get the claw/shells/inflators to stay on the cow. When I put two on at a time and then reach for the other two the forst two fall off. What am I doing wrong. I am getting so frustrated with this. I spent the winter hand milking because I couldn't get this thing going, but now I've got three jerseys to milk and I've got five more on the way. HELP please.