Convertible Top Pump Fluid?? 1963 Valiant

Don't use brake fluid if you have plastic lines from the pump to the cylinders. Brake fluid will eat the plastic over time. Automatic transmission fluid, sans red dye, is the same stuff most cars from the '60's were filled with from the factory. I asked a service rep from Hy-Dro-Electric about this subject for my '67 Fury convertible, and was told to use Dex-Merc trans fluid.