Yamaha RD400 (all years including Daytona) Rear Master Cylinder Rebuild Kit. This reproduction kit is assembled with high quality seals and includes main piston seal, spring with cap, circlip, dust boot, and banjo bolt washers, all the wearable parts that need to be replaced when rebuilding the master cylinder. Yamaha stopped making the rebuild kits several years ago and the other aftermarket kits had fitment issues, and were also recently discontinued, so we decided to produce our own aftermarket kit. We have tested the parts in this kit for fitment and performance.
See here for alternative kit made with OEM seals RD400 Rear MC kit – OEM