So, back a little ways in this book, I headcanoned Toy Freddy has the Animatronic equivalent of Type 1 Diabetes.

Here's how I imagine that works.

You see, his coolant systems are a bit...wack. Instead of regular coolant, it runs on water.

Hence the need to drink tea so often, he's topping off his coolant systems.

But there's a balance to this, too.

Too little water, and he overheats.

Too much water, and it seeps out of his
Coolant systems and damages his inner workings.

The water does seep out of the system slowly, but Rosie has made a water obsorbing substance he can consume to lower his water levels if need be, and flush ports where he can just dump the entire tank and it's contents out into a drain if need be.

So yeah, thats how this works!