EXNAVI 4‑Piston Hydraulic Brake Kit Ceramic Pistons Shimano M640

Description

Product Overview

The EXNAVI 4‑Piston Hydraulic Brake Repair Kit provides a direct, high‑performance replacement for Shimano brake caliper pistons. Each piston is forged from automotive‑grade phenolic resin, offering superior heat resistance above 400°C and excellent impact and aging durability. The turbofan airflow design creates eight‑point contact for optimal heat dissipation, eliminating the common issues of ceramic cracking and oil leakage. Package dimensions are compact at 0.65 x 0.65 x 0.35 inches, weighing only 0.01 ounces, making storage and installation effortless.

Usage

Designed for Shimano models MT420, MT520, M640, M6120, M7120, M810, M820, M8020, M8120, and M9120, this kit excels in extreme riding conditions—downhill racing, mountain trail descents, and long‑distance road rides. The pistons maintain consistent braking force even after prolonged exposure to heat, ensuring rider confidence on steep grades and technical sections. Ideal for cyclists seeking reliable performance without frequent maintenance.

Why Choose Us

EXNAVI combines automotive‑level material standards with precision engineering to solve the fatal defects of traditional ceramic pistons. Our pistons never crack or break under stress, and the phenolic resin prevents oil seepage, extending the life of your brake system. Backed by a 4.1‑star rating from 60 verified customers, the kit ranks #4 in Automotive Replacement Brake Caliper Pistons, reflecting trust and satisfaction.

Key Features

• High‑temperature ceramic pistons resist heat over 400°C for consistent braking.
• Automotive‑grade phenolic resin eliminates oil leakage and cracking.
• Turbofan airflow design enhances heat dissipation, extending component life.
• Exact fit for major Shimano brake models, ensuring easy installation.
• Responsive customer support and hassle‑free warranty for peace of mind.

FAQ

Is this kit compatible with all Shimano brake calipers?

The kit fits Shimano MT420, MT520, M640, M6120, M7120, M810, M820, M8020, M8120, and M9120 models only.

Can the pistons handle extreme downhill riding?

Yes, the ceramic material tolerates temperatures above 400°C, making it ideal for high‑heat scenarios like downhill or long descents.

Will installation require special tools?

Standard brake service tools are sufficient; the pistons are designed for a straightforward swap with the original units.

What warranty does EXNAVI provide?

We offer a 12‑month warranty covering manufacturing defects and provide dedicated after‑sales support.

Does the kit include all necessary components?

The package contains four ceramic pistons ready for installation; additional seals or hardware must be sourced separately if needed.