...Adding brake fluid.

Dot 3...but unless you have "leaks", do not add brake fluid. When you get to the point you do need to add fluid...it's time to replace some wear items like shoes/pads/rotors. I would advise a clean/lube/flush at 3 years though.

 

What frodoz said.

Something interesting: when your car's been sitting, at least overnight, "sneak up" on it. Go in through the front passenger door, reach across and pop the hood. If it's like 3rd gen, this will prevent the brake system from waking up, doing some pressurizing thing. Check the brake fluid level; it'll likely be higher than usual. Then open the driver's door and watch the reservoir over the next few seconds, as the pumps work: the level will likely drop about 1/2".

@NutzAboutBolts hasn't done a 4th gen fluid change video, he's all 3rd gen, what he has. But worth watching anyway, I think they're very similar.

I've done our 3rd gen a couple of times now, pretty straightforward. With each change I went through two pint bottles of Toyota DOT3 fluid, that worked out about right.

I've attached some repair manual info.