Convertible Top Pump Fluid?? 1963 Valiant

OK. Personally, I wouldn't use brake fluid even if that's what the owners manual recommended. I dont like the stuff at all. It generates rust, removes paint, tastes bad, drys skin, etc, etc. I wouldn't even use it in my brakes if there was a substitute.

Transmission fluid is 20W hydrolic oil. It's color and odor comes from the high temp additives, friction modifiers, and detergents in it.
Your top system doesn't need that crap no more than your floor jack does.
There is some info on refilling the system, not exactly a working link. Google should find it.
Tips - Cylinders & Pumps - Hydro-E-Lectric.htm
Good luck