Has anyone had problems with the motor or suction going bad on this pump? I'm borrowing my sister's pump. She used it to pump twice a day for a year. When I started using it, I only had to turn the suction strength half way. But now, the suction doesn't seem as strong even when I have it on the strongest suction. I've tried changing the white valve and the bladder knowig that these parts do tend to wear out, but it doesn't seem to make a difference. I've also noticed that the milk gets sprayed onto the sides of the bottle (on the inside of the bottle) and some of it gets up into the area where the bladder is. That indicates to me that the suction isn't correct. Any advice/suggestions on how I can fix it?