I was told that you can use synthetic brake fluid that won't absorb water. If you do, you won't have to flush it out periodically because it doesn't deteriorate. Is this true?

 

You are mistaken or got very bad information!!!!!!!!!!!!!!!!!!

Synthetic brake fluid will absorb water and should be treated as any other brake fluid. Honda spec calls for DOT3 as I recall, and it is advisable to stick with that - DOT4 has diffedrent additives, which may or may not be compatible with Honda's brake components.

You may have mistaken synthetic with "silicone" brake fluid. That is DOT5, and it does not absorb water, but it is absolutely not recommended for the S2000, or any regularly driven street car. It is used mainly for museum cars.

You want brake fluid to be HYDRO (not hygro) scopic, because it will ensure that any water that gets into the system will be dispersed uniformly, and that degradation will be gradual. With non-hydroscopic brake fluids lke silicone DOT5, any water will tend to accumulate at high spots, and it is possibel to have corrosion and/or severe loss of braking performance if the water boils.

Please do not make any decisions on the service of your brakes based on your post.

I bleed mine every two years, or every time I run one of my cars at a track event. I do not fug around with brakes.

I also generally support the statements that stock parts are often the best alla round - people have more problems with brakes when they start monkeying around with pads, rotors, etc.

The wear indicators will screech long before any damage might occur from the pads, and it would not be warping anyway, but abrasion damage from the pad rivets.

 

DOT3 fluid has a boiling point that is too low for sport driving that includes much heavy braking. Most of us use a DOT4 or DOT5.1(synthetic) fluid with a higher boiling point. They are compatible and there have been no reported problems.

The stock pads are excellent for the street but cannot take high temps that come form repeated hard stops. Their friction levels drop requiring more pedal pressure for stopping and therefore generating a great deal of heat. Once glazed they recover as the problem surface is worn off but never seem to regain full effectiveness. Different pads are needed for heavy use.

 

Thanks for the information. Don't worry about me doing it wrong. That's why I asked. I only have 2,300 miles on my car and figure that by the time I get around to any sort of maintenance, there will have been plenty of people here that have done it right many times over (probably some that have done it wrong too). I'll ask before I do anything just to make sure that I'm not missing any details.

 

DOT4 has a higher wet/dry boil point of about 50degF/30degF higher than DOT3. Unless you have measured brake fluid temperatures with instrumentation, I cannot comment onwhether it is/is not acceptable for track use. I agre with the pad comments, but did not see where the questioner at the top of the thread was track-oriented.

RE: fluid compatibility - I have to assume Honda went with DOT3 for a reason - whether problems have or have not been associated with DOT4 is impossible for me, or any layman I would submit, to evaluate, as we do not have access to the engineering studies. For street use, which was my response, I plan to stick with DOT3 until Honda advises differently. Cheers.

 

Here is an interesting read about brake fluid specifications:

http://www.stoptech.com/whitepapers/brakefluid1a.htm

"As a trailing note on the DOT ratings, if your car was designed for a particular type of fluid, you should make every attempt to stick with that fluid! For example, if your car was delivered with DOT 3 fluid, the internal components of the system (seals, brake hoses, and fittings for example) were specifically designed and tested for compatibility with DOT 3. Because DOT 4 fluids contain a different chemical composition, the system may not necessarily react in a positive fashion to the borate esters floating around in the mix.

In certain cases, just the difference in viscosity of the two different fluids may cause the seals to wear at different rates. What starts as an annoying squeak might eventually become a torn seal or worse. The examples could go on and on, but the message here is this: it

 

I would guess that a majority of S2000 owners who track their car more than once or twice have switched to DOT 4 fluid. I haven't heard of any problems that could be attributed to the fluid.

The advantage of DOT 4 fluids are their higher boiling points, which is why it's necessary on the track. One downside is that DOT 4 fluids generally absorb water more quickly than DOT 3 fluids, although track use generally requires frequent bleeding and flushing, so this doesn't usually cause problems.