Picture of How to bleed hydraulic bicycle brakes.

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.

Picture of 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 2:

Picture of
Remove the wheel and brake pads.

These pads are held in with two split pins; remove the pins and the pads just slide out.

Make sure that you do not touch the pad surface with your fingers as this will contaminate them.

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

Picture of 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.

Step 4: Setting up for bleeding.

Picture of Setting up for bleeding.
Put the 8mm spanner over the bleed nipple.

Attach the tubing to the nipple and attach a container or rag to catch the fluid.

Put rag around this to catch drips.

magura use their own fluid called magura blood
chequamie2 years 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!
Jonno0133 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)  Jonno0133 years ago
Great walkthrough! :D
FriendOfHumanity (author)  jessyratfink3 years ago
Thank you kindly.