How does brake fluid create moisture? I think someone's feeding you BS...

 

i think he means its more hydro-something. hydroscopic or something. which it is, but i'm curiuos about the 2 week change interval lol

 

Hygroscopy. Dot 4 is more hygroscopic than Dot 3, and both will absorb water from the air.

 

A little late for the answer, but in case anybody else is wondering -- no.

 

I've spent a fair amount of time in Glasgow, doing airplane testing. And yeah.

 

Now wait. I just bought a quart of Valvoline Dot3/Dot4 Synthetic. Don't tell me I have to change my brake fluid every two weeks! That can't be right. Hell, every 6 months would be too often for me. I've gone 3 years on the factory Dot3. Is there any truth to this?

 

I would suggest flushing the OEM fluid every couple of years. I would suggest flushing DOT4 fluid every year.

There is absolutely no benefit to DOT4 fluid unless you track the car.

 

You guys are looking into this wrong.

DOT3 and DOT4 fluids have almost identical composition. Different companies have different additives to raise dry or wet boiling points. However, since DOT4 has higher wet boiling points than DOT3, it requires less moisture absorbed to bring DOT4 fluid out of spec.

But if Honda recommends DOT3, putting in DOT4 doesn't mean you have to change it any more often than you would normally. It'll fall out of DOT4 spec earlier, yes, but that's why Honda spec'd DOT3 in the first place.

 

If I unbolt the caliper or disconnect the line would that make it easier or faster to do the gravity bleed?

 

Here's a description from www.inlinefour.com

http://twincamtech.stores.yahoo.net/motbrakfluid.html

For everyday driving, we recommend using Motul D.O.T. 5.1 brake fluid. This is an excellent brake fluid to use when upgrading your brake system with braided stainless steel brake lines, brake pads and sloted rotors. It can be mixed with SAE J 1703, D.O.T. 3, 4, and 5 synthetic brake fluid. Motul D.O.T. 5.1 brake fluid has a 509