# How often do you have to bleed your hydraulic disc brakes?



## mtx (May 15, 2007)

Just wondering, how often do you have to bleed your hydraulic disc brakes? I bought a new bike last June and it came with hydraulics...


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## bstyle74 (May 8, 2005)

Besides changing whenever you feel like the brakes are getting soft or squishy, you should probably bleed it at minimum every 2 years. Even if it is just sitting around, dot fluid will absorb water.


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## gumbymark (May 25, 2007)

I do it once a year.


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## chinaman (Jun 8, 2007)

as long as your levers do not feel spongy, it is fine.

shimano recommends that you replace the oil if it is "severely discoloured".
with DOT fluid ... i guess contamination will have the same effects.

check with your brake manufacturer/manual.


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## damaltor (Dec 14, 2005)

chinaman said:


> shimano recommends that you replace the oil if it is "severely discoloured".
> with DOT fluid ... i guess contamination will have the same effects.
> 
> check with your brake manufacturer/manual.


Shimano brakes use Mineral Oil, not DOT fluid. I think you'd run into big problems if you replaced the oil with DOT fluid.


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## reactiontime89 (Jan 4, 2008)

How often do you bleed the brakes on your car?


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## mtnbiker72 (Jan 22, 2007)

DOT 3 (Hayes, Avid) fluid should be flushed once a year as it absorbs moisture over time. I guess if you live in a dry climate you may not need to do it as often, but here in the PNW...I flush and bleed my Hayes once a year.

BTW-using DOT fluid in Shimano or Magura brakes will destroy the seals...use only the approved mineral oil in these brakes.


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## chinaman (Jun 8, 2007)

damaltor said:


> ... Shimano brakes use Mineral Oil, not DOT fluid. I think you'd run into big problems if you replaced the oil with DOT fluid ...


maybe i should have left a space between the lines, sorry dudes ...

but i did underlined OIL and did mentioned DOT fluid ...


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## damaltor (Dec 14, 2005)

chinaman...
Sorry, I see what your meaning was now. Not to lecture you or anyone else, but this is a perfect example of misinterpreted meaning due to improper sentence structure.

ie. If you simply capitalize the beginning of your sentences, your meaning is a lot clearer...

As long as your levers do not feel spongy, it is fine.
Shimano recommends that you replace the oil, if it is "severely discoloured".
With DOT fluid ... I guess contamination will have the same effects.
Check with your brake manufacturer/manual.


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## fatboywhitney (Feb 4, 2009)

*Sentence Structure*

Right On Brother damaltor!

A lot of attitude can be eliminated by your advice as well. Forums, texting and email will reap great rewards in areas of "drama" lessened.

Thanks, chinaman, for the tech info on the brake fluid.



damaltor said:


> chinaman...
> As long as your levers do not feel spongy, it is fine.
> Shimano recommends that you replace the oil, if it is "severely discoloured".
> With DOT fluid ... I guess contamination will have the same effects.
> Check with your brake manufacturer/manual.


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## mack_turtle (Jan 6, 2009)

as a mechanic, I have found that my customers seem to need to bleed DOT brakes (Avid mostly) more frequently than "mineral oil" brakes like Shimano.

i never bleed my disc brakes because they have cables. BB7s FTW!


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## MSU Alum (Aug 8, 2009)

Once in over 10 years, when they felt spongy.


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## eatdrinkride (Jun 15, 2005)

Haven't bled my xt's in since installing 4 years ago. Haven't bled the dot in my truck since I bought it in 07.


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## AndrwSwitch (Nov 8, 2007)

I think it took about three years for my Avids to need a bleed. I live and ride in the Pacific Northwest too.


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## zebrahum (Jun 29, 2005)

Zombie thread answer:

Once a year I try and bleed my Shimano brakes. Though I do have a set of 8 year old Hayes So1e brakes which I have neither ever changed the brake pads nor bled. I'm afraid that, at this point, if I ever need to bleed them they'll fall apart.


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