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Good tutorial for Shimano hydraulic brake flush and replace?

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Good tutorial for Shimano hydraulic brake flush and replace?

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Old 03-29-23, 07:22 PM
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Wattsup
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Good tutorial for Shimano hydraulic brake flush and replace?

My XT brakes haven't had the fluid replaced in like 5 years. I think it's time. 😵‍💫 Can someone link to a really good tutorial with video and/or pics? I can do most everything else on the bike, but I'm kind of intimated by this one.

Thanks...
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Old 03-29-23, 07:37 PM
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Polaris OBark
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Park Tool's website has what you need.

It is a pretty easy procedure, but you need to have some tubing and Shimano's bleed funnel or a syringe with the correct fitting. You don't need the expensive kits, just the $12 funnel and some tubing will work fine.

Last edited by Polaris OBark; 03-29-23 at 07:45 PM. Reason: added link
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Old 03-29-23, 09:24 PM
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Originally Posted by Polaris OBark
Park Tool's website has what you need.

It is a pretty easy procedure, but you need to have some tubing and Shimano's bleed funnel or a syringe with the correct fitting. You don't need the expensive kits, just the $12 funnel and some tubing will work fine.
Thanks. I also found a great video that illustrates the gravity bleed too. The gravity bleed seems so simple. Why do some use the syringe and push fluid in through the caliper?
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Old 03-29-23, 09:42 PM
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Sometimes air bubbles are hard to dislodge, and a syringe can work better. You can also create negative pressure easily with a syringe, which is a simple way to remove gas (air) from a fluid.
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Old 03-29-23, 10:00 PM
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Originally Posted by Polaris OBark
Sometimes air bubbles are hard to dislodge, and a syringe can work better. You can also create negative pressure easily with a syringe, which is a simple way to remove gas (air) from a fluid.
What is meant by "negative pressure?"
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Old 03-29-23, 10:10 PM
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The videos make it look simple, but it's very messy the first few times. Have plenty of rags and rubbing alcohol available
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Old 03-29-23, 10:11 PM
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What brakes do you have?

Shimano XT has been through multiple versions (3 major and several more minor) which require different processes.

A little more detail would be useful!
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Old 03-29-23, 10:20 PM
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Originally Posted by Wattsup
What is meant by "negative pressure?"
Less than one atmosphere.

If you have fluid with gas dissolved in it in a syringe, you close the tip, and then start to pull out the stopper, it will create a partial vacuum above the fluid, and pull out air bubbles. It is a useful trick if the brakes feel too mushy.

But don't worry about it unless you have to.
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Old 03-31-23, 08:06 PM
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Old 03-31-23, 08:08 PM
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Old 03-31-23, 10:01 PM
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hydraulic disc brake bleeding done right (Shimano)



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