DOT 5.1 brake fluid

[Ed White]

The owner's manual with my new 450EXC specifies DOT 5.1 brake fluid. All I see at the auto parts places is 3,4 or 5. The counter guys don't know anything about 5.1. Do I have to get this from KTM and pay the big price, or will something else work?

 

[el presidente]

i get mine from the local KTM dealership at about 9 dollars a bottle.

 

[Layton]

You can use DOT 4. DON'T use DOT 5 because it's not compatable with 4 or 5.1

 

[wsmc831]

5.1 is basically 4 with a higher boiling point. any decent motorcycle shop should have some by Motul, Castrol..ect.

 

[fatty_k]

I use the Motul 5.1 fluid for my clutch. It was $8 a bottle.

 

[Layton]

Originally posted by fatty_k
I use the Motul 5.1 fluid for my clutch.

That may be ok for a GasGas but it shouldn't be used in a KTM clutch. The rubber seals are not compatible with brake fluid from what I hear.

 

[wsmc831]

I've been told many times to use atf in the clutch...though have not heard using brake fluid is damaging...hmmmmm.

 

[Jaybird]

Brake fluids should not be used in any juice clutch as they are all caustic.
In the brakes, use cheap DOT 4 and be happy. Change half way through season.

 

[TM-Frank]

Jaybird,
Brake fluids should not be used in the Magura M/Cs that are OEM on KTMs and Husabergs, but Brembo, AJP and Grimeca make clutch M/Cs for brake fluid and from Magura you can get these too (see http://download.magura.de/offroad.pdf )
You could even buy just the brake fluid restistant piston and retrofit it to your KTM clutch.

 

[Jaybird]

But, regular fluids that are less caustic will also work in those type of clutches. I see no good reason to use brake fluid. ANd you know how much I like ATF :)

 

[TM-Frank]

Me too! I buy it in 25 Liter drums. :)
But brake fluid is thinner (lower viscosity) and may result in lighter clutch pull.
And we all have it in the garage anyway.

 

[Enduro_Nut]

I likewise run Motul in bikes and my race car, but DO NOT mix various fliuds. Do a complete flush prior to changing. The synthetics having a much higher boiling point and wind up with less fade(if a fliud boils air gets into the system and thereby you get fading.).

 

[Bfaster]

Ed,
If you plan on riding the bike to the limit, Motul 5.1. The 4 stuff will boil and fade halfway through a race. I change brake fluid every other race and it is impressive to compare the old vs. new. If you think about $7 bottle of brake fluid the $20 for oil changes, and the $20 for the race gas, probably doesnt compare to what you spend to travel, eat, etc. for your riding time. Some people operate in a false economy. I prefer to buy sandwich meat and bread and save the "Happy Meal" money for the stuff that really matters. There is my $.02 worth.

See you on the trail.