What Is the Shimano SM-BH90-JKS Hose Kit and When Do You Need It?

The SM-BH90-JKS is Shimano's high-pressure hydraulic disc brake hose kit, designed for top-tier Shimano hydraulic systems including XTR, Dura-Ace, and Ultegra hydraulic disc brakes that require the BH90 pressure rating. The BH90 hose is constructed to withstand higher operating pressures than the mid-range BH59 specification, and using the correct hose for the brake system is critical to maintaining sealing integrity and consistent lever feel over time. The kit includes the hose cut to a standard length along with the JKS banjo olive and insert fittings, which connect to the brake lever via the banjo bolt port found on Shimano's road hydraulic STI levers and select MTB levers using the banjo-style connection rather than the JK straight connection.

Installation involves routing the hose through the frame or handlebar, cutting to length, inserting the olive and barb at the cut end, and performing a mineral oil bleed to purge any air from the system. The SM-BH90 hose is compatible only with Shimano's mineral oil hydraulic systems and must not be used with DOT fluid brakes. For road cyclists and mountain bikers on Shimano BH90-spec high-pressure hydraulic disc brake systems such as Dura-Ace, Ultegra Di2, or XTR who need a replacement or build hose with the correct pressure rating and banjo-style lever fitting, the SM-BH90-JKS kit is the correct specification.