One of my regular routine maintenance items, change the brake fluid. I change it every single spring for the last 25 years of ownership.
I will use my last can of ATE Blue.
And one "while I am in there" additional part is the change the 10 year old rubber brake lines. They are looking fine, and I have no problems with the brakes at all, but 10 years is long enough.
So new rubber hoses, and new brake fluid. Whoo Hooo.