Leak in battery auto-fill system
 

I have a 2010 Star cart. After more than 11 years, a couple of the seals on the auto-fill battery water system seem to be failing. Rather than stopping automatically as soon as the cells are filled, water (acid) comes out adjacent to the cell cap. This is most noticible by one particular cell, but there is some small amount of seepage around a couple of other cells as well. Is this a common problem as this equipment ages beyond 10 years? Are replacement seals available? Or do I need to replace the whole battery watering system?