Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Silicone vs. ordinary brake fluid

Helpful observations, Icepack

I am going to go with my experience, internet brake lore and your last supposition.

The presence of water in the caliper pistons has nothing to do with conscientious brake fluid changes. You've got that covered. But we often have calipers their squeezing wet discs at various, often high speeds. For example, water will get between the pads, forcing us to squeeze a layer of water rather than the discs directly when we are going though a flooded road area. That is no fun, especially with the added danger of hydro-planning, a feature of a light, limited clearance care, with a large closed, area at its center.

And high pressure water water will also seep through into the caliper pistons. There are those that say that water will enter the pistons even at rest, but I can't see that.

I also think you are right and that this water will boil/burn away with regular usage. However, few Morgans are regularly used. One arrives home after a drive on a wet day and then we leave the Morgan for a long period. Ergo, no water burn off. Until the next drive, the water sits there, when it can be burned off in the normal course of regular driving. I imagine it can be assimilated with glycol brake fluid theoretically, but it is at the very ends of the fluid routing. The complaint most often mentioned it that it rusts the pistons, one of the most common causes of brake seizure along with rusted discs. Yes, you can break them free, but the ongoing damage, eventually necessitating a caliper rebuild, happens faster than mundanemobiles require. Like anything, usage is the best preservative.

So my conclusion is that cars not only need brake fluid changes, the frequency of which is determined by ambient conditions, but they also need frequent usage. Few of us can manage the latter. So we must merely resign ourselves to more frequent brake rebuilds or stainless steel caliper pistons. I use them, but I never thought of this reason before. So thank you. I swapped them in because the regular choices are mild steel, aluminum, or plastic. Plastic never thrills me and both the aluminum and mild steel corrodes along with the bores. It doesn't take a lot of work or money to tweak a trad to be fully reliable, comfortable and long lasting. That perception has changed a lot in the last 20 years, which says about the Factory than it does of us.

gmg