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  Chicagoland MG Club:Tech Tips

Silicone Brake Fluid: Snake Oil, It's Not

When was the last time you changed your brake fluid? Yes, that's right, your brake fluid. Not just topped it off, but changed it? If you answer "never" or "years ago", you may wish to consider that failure to do so every couple of years can be an expensive oversight!

The problem is twofold: conventional brake fluid is hygroscopic (it absorbs moisture from the atmosphere) and water causes corrosion. A third consideration is that constant heating and cooling (which happens when you use your brakes a lot) also causes eventual deterioration of hydraulic fluid. Most British sports cars these days, we surmise, are either restored (or at least very clean) and saved for occasional use only, or they are worked very hard as everyday drivers! The former spend most of their time parked, driven only occasionally; the latter are driven often and the brakes get lots of use.

If your car does a lot of sitting around, every time you take it out, there is a chance that one or more wheel cylinders will have stopped working due to corrosion. Eventually, you will have to rebuild your brakes again, even though you have put very few miles on your car. With today's costs for wheel and master cylinders, changing brake fluid regularly seems a much more attractive alternative.

Perhaps the most attractive alternative, however, is making your next change the last one you'll need to do! How is this possible in light of what we said earlier? By replacing your conventional brake fluid with silicone brake fluid.

There have been many views put forth about this product, but two are inescapable: it must work as brake fluid or it never would have received DOT 5 approval, and, it physically cannot absorb moisture. This latter point was confirmed in a test performed by two members of the Society of Automotive Engineers, with the results published in SAE Paper #780661. They reported "After two years of service and 56,295 miles, the physical properties of the (silicone brake) fluid were unchanged, and the water content was 0.00%. System wear and corrosion were non-existent."

In the interests of long-term safety and economical maintenance of your valued car's brake system, it would appear that substituting silicone brake fluid for traditional, polyglycol-based fluid is an excellent decision. The side-bar to this story is a reprint from the flyer which accompanies the silicone brake fluid we now sell, answering the most commonly asked questions about this excellent product.

No, it's not snake oil, and it won't make bad brakes work well, but if you've got good brakes and you want them to stay that way, consider one last brake fluid change - to silicone brake fluid!

  1. What's so good about this stuff?
    Answer: Nobody ever thinks about brake fluid- until the brakes go bad. Mainly, silicone brake fluid doesn't absorb moisture, which is the cause of most corrosion, pitting, wear, and deterioration in your brake system. It's also nice that it lubricates, (the old stuff doesn't) it preserves, (the old stuff doesn't) and it doesn't harm paint (the old stuff - ever see it spilled on a fender? Moan...).

  2. Is this stuff compatible with the old fluid -or do I have to disassemble ... and replace ... ad nauseam?
    Answer: It is compatible with all automotive brake fluids and all brake system parts in all autos - foreign, domestic and antique. Believe it!

  3. What'll it do to foreign (read British) systems?
    Answer: Make 'em last forever! No, seriously - the best preservative known for natural rubber is (you guessed it) silicone! Your British car never had it so good!

  4. Must I get all the old fluid out?
    Answer: As much as possible - get that old stuff out! The sooner the better. It's not as hard as you might think to get out 97% or so.

  5. Will this stuff cure my leaky brakes?
    Answer: Now, gee... This isn't snake oil. No, this won't reverse the aging process created by your old brake fluid. Be sure your system is in good condition. Now, put our silicone brake fluid in and it will stay that way indefinitely.

  6. Isn't this stuff a little more expensive?
    Answer: You're kidding. Checked out the cost of a brake rebuild lately - if you can find the parts for that orphan? We've got one test car with 8 years and 137,000 miles on it and the hydraulic system is brand new! There's no wear, there's no corrosion, the hoses still pass burst tests as new, everything's new! We don't know - it may last forever

Now if we were all engineer types we'd be talking "cost effectiveness", "safety considerations", "life cycle costs"... while tearing our pocket off to get our billfold out. Quick - this may be the best money you've ever spent.

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