brake fluid question

[ept250rider]

for both the front and rear brakes, it calls for dot 4 brake fluid ONLY, but i just bled both brakes with dot 3. is there a major difference/danger to running dot 3 vs dot 4??

[brucem]

The difference between the DOT (Department of Transportaion) ratings of brake fluid are the boiling point ranges that they achieve both dry (no water absorbed) and wet (about 3-4% water content). For DOT 3 the dry boiling point is at least 401 and the wet 284 degrees. DOT 4 raises the bar to 446 and 311 respectively. Those are the DOT ratings mind you , and there are high performance brake fluids that exceed those ratings

just looked it up on the internet and this is what it says..I don't think it matters too much

[MXtras]

If you ride hard, use the highest boiling point fluid you can get. If you simply pleasure ride, the DOT3 will be fine.

FWIW - bleed your brakes completely at least twice a year to keep the fluid fresh and the brake system clean. It's cheap preventative maintenance.

Scott

[ept250rider]

i better switch out to the dot 4 just to be on the safe side since i race motocross. i dont need to be putting other people in danger because i cant stop

[MXtras]

That's very considerate of you!

I wish I could recall what I use. I searched and searched for the highest boiling point fluid I could find as I have issues with boiling my front brake fluid. I do not recall exactly what I use but I believe it is synthetic and made by Valvoline. It has a very high wet boiling point - higher than any of the motorcycle fluids. I always run sintered pads, I added insulators between the pads and the caliper piston and I bleed the fluid before and during each event in between motos, so I am definately picky about the fluid as well as the overall condition of my brake system. I really need oversized front discs, I know...

Now that I think about it, I wonder what Amsoil offers for brake fluid?

Scott

[ept250rider]

how can u tell when your brake brake fluid boils?? i ride in 100 degree temps all the time and i dont exactly use the most high quality fluid thats out there

[crfjedi393]

Originally Posted by ept250rider

how can u tell when your brake brake fluid boils??

You'll know. Usually it's your front brake that boils first and the handle will get very spongey or squishy(for lack of a better word). Cross country racing is hard on brakes. Depending on what class you ride in MX, you could probably get by without worrying about it boiling. If you ride the A class, you'll need to worry about it.

---------- Post added at 07:22 PM ---------- Previous post was at 07:00 PM ----------

I just called my riding bud. He has pretty much tried everything out there over the years and his recommendation is Motul High Temp brake fluid. (I already knew it's what our crew runs but couldn't think of the name.) Brake fluid is one of those things you don't think much about but if you ever boil it in a race you will start spending the money on the higher quality stuff. And all DOT 4's are not the same quality.
Ok, there's my input for what it's worth.