63 wheel cylinders

[Joe M.]

When I went to order new front wheel cylinders for the 63 from NAPA I saw in their description that the components were compatible with silicone brake fluid.

This begs the question, are there rubber components that are not compatible with silicone brake fluid? Could they referencing the fit and finish of the pistons to the the wheel cylinder instead?

Is this just a marketing ploy as someone suggested?

Thanks,
Joe

[John D.]

Re: 63 wheel cylinders

My 63 has had silicone brake fluid in it since 1979-1980. It sat untouched though for about 15 years and the silicone fluid saved the brakes big time.
I agree with you assumption of the advertising. John D.

[Joe M.]

Re: 63 wheel cylinders

Just took the left front wheel cylinder apart and noticed the old rubber cups that ride against the piston were softer, more flexible than the cups in the rebuild kit. Additionally the old cups were noticably larger in diameter than the new cups by an amount you could easily see.

Could the old cups have been swollen?

I have been using the SSBC silicone brake fluid. The system was put together with all new parts when I switched to silicone.

[John D.]

Re: 63 wheel cylinders

Joe, Sorry can't help you on this one. Wait for others to chirp in. Now if this was a carb or FI post adn you saw old rubber stuff all swollen up you might suspect the owner is using corn fuel. John

[Joe L.]

Re: 63 wheel cylinders

Just took the left front wheel cylinder apart and noticed the old rubber cups that ride against the piston were softer, more flexible than the cups in the rebuild kit. Additionally the old cups were noticably larger in diameter than the new cups by an amount you could easily see.

Could the old cups have been swollen?

I have been using the SSBC silicone brake fluid. The system was put together with all new parts when I switched to silicone.

Joe-----


It's like this: most modern brake system rubber components are manufactured of a material that is SPECIFICALLY designed for use with any DOT-rated brake fluid (i.e. 3, 4, 5, 5.5). Older brake system rubber components were not SPECIFICALLY rated to withstand DOT 5 fluid. However, I've never heard of any problems with such components when used with silicone brake fluid. Most folks change all of the rubber components of their system when they convert to DOT 5 silicone fluid. So, they "automatically" get the benefit of materials specifically designed for use with silicone fluid.

There is absolutely no difference with respect to cast iron, brass or stainless steel used for brake system components as far as compatibility with different brake fluids. All of the metals used in the brake systems, new or old, are compatible with any of the fluids.

Stainless steel or brass are better when using DOT 3, 4, or 5.5, though, since those fluids absorb moisture and will corrode cast iron.