Gentlemen,
I concur whole heartedly ..... FOT 5 silicon fluid is the only way to go in everything except cars with antilock brakes....theyuse only the DOT 3 or 4 fluid.
DOT 5 fluid is non hydroscopic....it does not absorb moisture and moisture is the ruination of braking systems....it causes the wheel cylinder pistons and caliper pistons to corrode and leak. In addition it causes the rubber flex connections to become hard and brittle over time. I replaced all of the brake system components (calipers, hoses, rear wheel cylinders, master cylinder, proportioning valve) on my 70 GTX, RS23VOA***** many years ago (10) following individual failures. I have NOT had any problems of any kind since the total system change over. The only regret is not having done it sooner. Yes, DOT 5 fluid is more expensive (3x more than DOT 3) but to me, cost is not the determining factor....better performance and reliability is. This is just my opinion