C.Z.
Hi C.,
I have a friend who just had twins, after having had two other children previously. Her breast pump wasn't working at full speed so she called "Milk Works" in Lincoln and also Medela. Both places suggested she purchase a new one. They said that useage with two or more children really does put wear and tear on the unit and that her best bet was a new unit. They both also said that repairing the unit is costly and makes more sense to replace.
Hope this helps!
C.