Easy Fill Battery System - Anyone Have A Problem With?

[GeoGeo]

Anyone else have a problem with overfill when using an easy fill battery watering system?

[Biker Dog]

I have them on both carts and they worked great. Until I had new batteries installed. Still works in the one cart but in the second cart it over fills the batteries and does not shut off. I was told air is getting into the system from either a loose hose connection or a loose cap on one of the batteries. I can NOT find either of these loose connections. If anyone can tell me what else to look for I would appreciate it.