Motorcycle Front Brake Master Cylinder Rebuild

Replace the master cylinder on your vintage British bike to get a more responsive front brake.

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by Keith Fellenstein
Our bike for this project is Keith's own 1974 Triumph T150 Trident, ready for an upgraded front brake master cylinder.

This motorcycle front brake master cylinder rebuild uses a conversion kit by LF Harris to easily get a more responsive front brake on your classic British bike.

If you feel like we’re overdoing the brake work here, you might be right. Brakes are boring, but efficient stopping is probably more important than fast acceleration, especially on a vintage motorcycle.

Early versions of disc brakes on British bikes suffer from bad hydraulic ratios, among other problems like chrome plating and solid rotors. Bad hydraulic ratios lead to the common complaint that the brake feel is bad, requiring too much effort to get good stopping power.

An easy and available fix is to drop the master cylinder size from 5/8-inch diameter to 1/2-inch diameter. Sleeving is also an option, but a built to purpose 1/2-inch cylinder is far better.

This How-To will cover rebuilding a common threaded British master cylinder to the smaller diameter version. As always, it’s good to have a factory shop manual on hand, just in case. Let’s jump in and get started.

  • Updated on Jun 13, 2022
  • Originally Published on Jun 8, 2022
Tagged with: British motorcycle, how-to, motorcycle brake repair, Triumph
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