Replacement Parts

Rebuild kit for the rear brake master cylinder of Harley-Davidson Touring models from 1986–1991. Check piston Ø.

Rear brake master cylinders that are compatible with this rebuild kit were fitted to many Harley-Davidson models from autumn 1987 until the changeover to the Milwaukee Eight generation. A detailed model list can be found under “Facts”; the listing is based on the OEM number as reference. The piston diameter in the rebuild kit is 17.5 mm (11/16”). The material is compatible with DOT4 and DOT5 brake fluid. Unlike rebuild kits for earlier model years, the piston and seals are not replaced individually here; instead, the complete bore assembly with preassembled internal components is replaced. Installation is performed with slight pressure, secured by a 3/4”-16 locknut.

Harley-Davidson lists this part as a “reservoir adapter.” In reality, it is a small fluid reservoir into which the actual brake master cylinder sleeve is inserted. Supplied complete with the required two O-rings. The hose nipple fits hoses with an 5/16” inside diameter.