How Often Should Brake Fluid Be Flushed?

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pknowles

semi-retired...---... GURU C7Z06...---...
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This should get interesting :)

Really changing the brake fluid should be driven by your riding style. If you were performance driving and doing a lot of hard braking you should change it more often. the quick answer should be driven by the moisture content in your brake fluid and not a mileage/ date trigger.
 
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Coolbreezin

Active Member
DOT 3, 4 and 5.1 are all Glycol based. The Gycol traps moisture and should be changed out ever 2-3 years at most. Or if it changing to an off color rather than clear, it should be changed.
DOT 5 (used in Big dogs) is a silicone based fluid and will not draw in moisture like the other fluids. So, as long as you know the system has not been contaminated with outside water or dirt, there is no need to change it. Studies have shown that after many years of use, it still gives the same hydraulic and boiling limits as it would new. Because it doesn't trap moisture like the others, there is no concern about corrosion in the braking system.
I believe DOT 5 is also used a lot in military and in Northern parts of the world such as Alaska, Russia, Canada....
Soooo, change it if you feel you need to, otherwise if it's clean, don't worry about.
Thank you for info. I was starting to feel like King Slacker. I have 78,500ish miles and never changed my fluid.
 

Brent Herridge

Active Member
Wow. I have never heard of a chopper with near that many miles. It makes sense that the used ones I was looking at were for sale by people that didn't ride them, AND the speedo only works half the time, but still.........78K is amazing.

Who else has over 50k on their Big Dog ?
 

KnotSo

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Jersey Big Mike

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Wow. I have never heard of a chopper with near that many miles. It makes sense that the used ones I was looking at were for sale by people that didn't ride them, AND the speedo only works half the time, but still.........78K is amazing.

Who else has over 50k on their Big Dog ?
I had 57K on my first 08 K-9 when it got totalled in 2013.
 
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