Instructables

How to bleed hydraulic bicycle brakes.

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Picture of How to bleed hydraulic bicycle brakes.
Hello,

There are different hydraulic brake systems and they vary slightly in their bleeding procedure but the principle is broadly the same.

I am bleeding some Hope C2s on a friend's  gnarly bike.

They are old but beautifully engineered and are closed system hydraulic brakes.

There are kits to make things easier but this is the old school way using a simple hose.


 
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Step 1: Tools and consumables and naming parts.

You will need an 8mm spanner ( preferably ring ended).

A 26 mm spanner or an adjustable.

Some clean rags.

A small length of tubing or a bleed kit.

The correct brake fluid. ( Some use DOT some use mineral )

Step 3: Taking the first step.undo this . . . .

The bike needs to be held upright ; in a stand or held by someone or leant ; but make sure that it is stable.

The nipple on the brake caliper should be pointing upwards ( the rear one is already  but the front one will need temporarily undoing by one bolt to allow it to be swiveled upwards.)

Adjust the brake lever clamp so that it is horizontal to the ground.

Put paper on the ground underneath the lever and brake to catch excess fluid.

Undo the large polygon nut ( master cylinder cap ) on the brake lever with a 26mm spanner.
magura use their own fluid called magura blood
chequamie1 year ago
shimano uses mineral; oil,NOT DOT BRAKE FLUID! and hope, hayes,magura, avid all use a variation of DOT Fluid Do you homework you can do major damage if you use the wrong fluid!
Jonno0132 years ago
Generally, Shimano brakes use hydraulic oil, and hayes/avid use DOT brake fluid. If you are not sure a quick google solves most problems. Great instructable friendofhumanity!
FriendOfHumanity (author)  Jonno0132 years ago
Thanks.
Great walkthrough! :D
FriendOfHumanity (author)  jessyratfink2 years ago
Thank you kindly.