You are reading a single comment by @Saffronspokes and its replies.
Click here to read the full conversation.
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
Saffronspokes
The usual advice for this is to hold in the moving piston (with a tyre lever, spanner, or similar), then pump the lever, so all the hydraulic pressure should then go to the stuck piston.
Last time this happened on an ancient set of Shimano brakes I had to both apply a bit of gentle pressure from a syringe at the lever to get it to come out. This is a a bit of a last resort as you can damage seals applying too much pressure.
Then once they're out clean them up with some brake cleaner, and apply a few drops of mineral oil.