Shimano Dura-Ace 12v ST-R9270 bleed screw with lever seal - Y0MX98020

The bleed screw with seal ( Shimano, part number Y0MX98020 ) is a genuine spare part designed for the Shimano Dura-Ace ST-R9270 12-speed hydraulic road shifters. It ensures the bleed port on the lever is sealed, guaranteeing the proper functioning and reliability of the hydraulic braking system.

This small screw plays a vital role in maintaining the system’s pressure and seal: it prevents air and contaminants from entering the lever whilst securing the brake fluid inside the master cylinder. In the event of loss, damage or a faulty seal, replacement with a genuine Shimano part is strongly recommended to maintain optimum braking performance.

Role of the bleed screw

• Seals the bleed port on the lever
• Maintains the seal of the hydraulic circuit
• Protects the system against air and contamination
• Enables the brake to be bled

Compatibility

• Shimano ST-R9270 (Dura-Ace 12-speed Di2)
• Also used on certain recent 12-speed-compatible road levers Shimano (Ultegra / GRX depending on OEM variants)

Symptoms of a faulty screw or seal

• A small leak at the lever
• Gradual loss of braking pressure
• Seepage around the bleed port
• Difficulty in achieving a clean bleed

Workshop tip

On recent Dura-Ace levers, this screw is small but critical: a slightly crushed or misaligned seal is enough to cause a micro-leak. In this case, replacing the screw and seal assembly is often more reliable than simply reassembling the part.