The Shimano Deore BR-MT520 / BL-MT501 Hydraulic Disc Brake J-Kit delivers powerful, consistent 4-piston braking in an affordable, trail-ready package. Pre-bled and ready to install, this rear kit pairs the BR-MT520 4-piston caliper with the BL-MT501 left lever — an ideal upgrade for all-mountain, enduro, and trail riders who want confident stopping power without the premium price tag.

Highlights

• 4-piston braking power: The BR-MT520 caliper uses dual-diameter opposed pistons for rapid initial pad contact and progressive, controllable modulation across the full lever stroke.
• Servo Wave lever action: The BL-MT501 lever's Servo Wave technology increases mechanical advantage through the lever stroke, so less hand effort is needed to generate strong braking force — reducing fatigue on long descents.
• J-Kit easy installation: The integrated olive in the brake lever simplifies hose fitting — route the hose, connect the barb, and you're ready. No re-bleeding required.
• I-Spec II compatible: The BL-MT501 clamp band supports I-Spec II integration, allowing a compatible Shimano shifter to mount directly to the lever body for a clean, uncluttered cockpit.
• Tooled reach adjust: Dial in lever reach with an allen key to suit any hand size, improving comfort and braking control.
• Pre-bled and ready: The kit ships pre-bled with Shimano mineral oil — simply connect, trim to length, and ride.

BR-MT520 Caliper

The BR-MT520 is a post mount, 4-piston hydraulic caliper designed for mountain biking. Its dual-diameter opposed-piston layout creates a wide pad contact area, generating strong braking force with excellent heat management. The caliper uses Shimano mineral oil and is compatible with D03S resin pads (included) as well as D02S metal pads. One-Way Bleeding capability simplifies ongoing maintenance.

BL-MT501 Lever

The BL-MT501 is a 2-finger hydraulic disc brake lever built for all-mountain and trail use. Its slim, stable profile keeps weight low while the aluminium lever blade provides a confident feel. I-Spec II compatibility enables tool-free integration with Shimano's RapidFire shifter range. The lever includes a clamp band for 22.2mm handlebar installation.

What's Included

This rear J-Kit includes: BL-MT501 left brake lever with master cylinder, BR-MT520 4-piston caliper, SM-BH90-SS brake hose (1700mm, black), resin brake pads (D03S-RX, without fin), connector insert and olive. Rotor and mount adapter are not included and must be purchased separately.

Compatibility & Fit

Caliper mount: Post mount. Hydraulic fluid: Shimano mineral oil only — not compatible with DOT fluid. Rotor compatibility: 140–220mm (rotor not included). Recommended rotors: SM-RT64 (Centre Lock) or SM-RT54 (Centre Lock). Lever clamp: I-Spec II clamp band (22.2mm handlebar). Shifter compatibility: I-Spec II-compatible Shimano shifters. Hose: SM-BH90-SS, 1700mm, straight joint. This is a rear brake kit with a left-hand lever — designed for Australian/standard setups where the left lever controls the rear brake.