MTB brake parts and accessories

Maintaining and repairing MTB brakes

A hydraulic disc brake requires little maintenance, but a few very specific parts. Shimano, SRAM, Magura, Hope, Jagwire and Elvedes cover bleeding, repairs and hardware.

Which brake fluid?

• Mineral oil from Shimano and Magura: stable over time and does not absorb moisture.
• DOT from SRAM: performs better at high temperatures, but is hygroscopic, so it must be replaced periodically.
• Both must never be mixed : one mistake will destroy the system seals.
• Each brand requires its exact specification, including between two DOT fluids.

When should you bleed the brakes?

• After any hose cut or replacement.
• When the lever becomes spongy or the bite point moves closer to the handlebar.
• As preventive maintenance, once a year for a DOT system, less frequently for mineral oil.
• The bleed kit is brand-specific : fittings and reservoirs are not universal.

Which wear parts should you plan for?

• Olives and inserts : required every time a hose is cut.
• Piston seals and pistons : to restore a leaking or sticking calliper.
• Calliper and disc bolts : often lost or damaged during removal.
• Brake pad springs and pins : small parts that are easily lost in the workshop.

Precautions

Protect discs and pads throughout any work: a trace of fluid or degreaser on the braking surface results in a loss of power and persistent noise, which can only be corrected by light sanding or replacing the pad material.

To find out more: How to choose an MTB bleed kit

See also: MTB brake pads · Hoses · Brake maintenance