Brake Fluid?

[kohnerbownerr]

just another simple and likely stupid question.. time to change brake fluid in my bike, it obv takes DOT4, but will any DOT4 due? manual says no petroleum or silicone based fluids, and the only kind I can find at a local auto store is DOT4 synthetic at autozone (http://www.autozone.com/autozone/acc...er=349153_0_0_), will it due? and I did indeed do a search with no luck. thanks!

[Wild-Bill]

That stuff or the Valvolene DOT4 Autozone carries works just fine. You could also use DOT5.1 (not to be confused with DOT5) if you like spending money.

[thetable]

DOT3, DOT4, and DOT5.1 are all compatible.

DOT5 is NOT compatible.

[Wild-Bill]

DOT 5.1 is not recommended for mixing with DOT 3 or 4. If you feel like you need the higher boiling point of 5.1 then do it when you rebuild the system.

[thetable]

DOT 5.1 is not recommended for mixing with DOT 3 or 4. If you feel like you need the higher boiling point of 5.1 then do it when you rebuild the system.

Don't confuse DOT5 and DOT5.1. DOT5.1 is just fine to mix, DOT5 is a big NONONONONONO to mix with anything.

[Wild-Bill]

I'm not confusing them, trust me. I've seen mixed opinions on whether or not to mix DOT4 and DOT5.1. The DOT5.1 has a higher viscosity than DOT4 as well as the slightly higher boiling point and since there seems to be some controversy over mixing them I'd say to take the most conservative route and keep them separate.

With DOT5.1 there's also some consideration given to the higher viscosity. Because it's thicker the brakes won't release as easily when you let go of the lever/pedal. Systems designed for it use larger orifices to allow for that but our systems were designed for DOT4 so there may be something there to consider.

If you want to go with the DOT5 (silicone based, higher boiling point than DOT4 and won't eat paint) then you definitely need to clean out the entire system before changing over. There's no controversy over that at all. Don't mix them.

Bottom line is that our bikes were designed to use DOT4 and the inexpensive stuff from the local auto parts store works well. DOT4 is good enough for much higher performance bikes than our Kats so I'd say we've got a pretty significant safety margin sticking with it.

[thetable]

With DOT5.1 there's also some consideration given to the higher viscosity.

Might want to redraw those spec sheets. DOT 5.1 max viscosity is lower than DOT4 or 3. That is why Motul's RBF600 and RBF660 are DOT4. They are too thick at -40*.

There is no debate about compatibilty. They are compatible.

Some numbers... http://www.motul-oil.co.uk/pdfs/brak...0_TDS_(GB).pdf

[kohnerbownerr]

ended up getting the valvaline DOT3/4 cause it was a dollar cheaper. thanks!

[kohnerbownerr]

Can I get the hose to bleed the breaks at any hardware store?

[thenastiestnate]

Can I get the hose to bleed the breaks at any hardware store?

Yes. Any tubing that will fit the nipple will be fine to catch the fluid.