Cusco Brake Master Cylinder Stopper Kit

2002–2007 Subaru Impreza WRX / 2004–2007 STi

Part #: 666 561 A

Overview

The Cusco Brake Master Cylinder Stopper Kit is a high-quality performance upgrade designed specifically for Subaru Impreza WRX models from 2002 to 2007 and the Subaru STi from 2004 to 2007. This kit is engineered to enhance the rigidity of your vehicle's brake system, providing more precise pedal feel and improved braking response during spirited driving or track use. Whether you're a street enthusiast or a competitive racer, this component helps support your vehicle's braking performance by reducing flex and movement in the master cylinder assembly.

Manufactured by Cusco, a renowned name in the automotive performance industry, this stopper kit reflects the company's commitment to quality, durability, and performance. With years of experience in developing suspension and chassis components, Cusco's products are trusted by enthusiasts worldwide to deliver consistent, reliable results. Installing this kit is a straightforward upgrade that can make a noticeable difference in your vehicle's braking feel and overall handling, especially during aggressive driving conditions.

Key Features

The Cusco Brake Master Cylinder Stopper Kit offers several key features that make it an essential addition for Subaru performance owners:

• Constructed from high-strength steel with a durable coating to resist corrosion and ensure longevity under demanding conditions.
• Designed to increase the rigidity of the master cylinder mounting points, reducing flex and movement during braking.
• Improves pedal feel by minimizing unwanted movement, resulting in more direct and confident braking response.
• Engineered with precise fitment for Subaru Impreza WRX (2002-2007) and STi (2004-2007), ensuring seamless installation without modifications.
• Backed by Cusco's extensive research and testing, guaranteeing top-tier quality and performance.
• Suitable for street use, track days, or competitive motorsport applications where braking precision is critical.
• Part of Cusco's comprehensive lineup of chassis and suspension upgrades aimed at enhancing vehicle handling and stability.

Construction & Design

The Cusco Brake Master Cylinder Stopper Kit is crafted from high-grade steel, ensuring strength and durability. The components are TIG-welded for precise assembly and feature a corrosion-resistant coating to withstand harsh environments. The design incorporates a compact, lightweight structure that does not add unnecessary weight to your vehicle, maintaining optimal handling characteristics. The kit mounts securely to the existing chassis points, reinforcing the master cylinder mounting area and reducing flex during heavy braking. This thoughtful engineering results in a more responsive brake pedal and improved overall braking performance.

Performance & Benefits

By installing the Cusco Brake Master Cylinder Stopper Kit, you can expect a more solid and consistent brake pedal feel, especially under aggressive driving conditions. The increased rigidity helps prevent master cylinder movement, which can lead to spongy pedal response or inconsistent braking. This upgrade supports better modulation and confidence when braking hard, making it ideal for spirited street driving or track use. Although it does not increase brake force directly, the improved stability and response contribute to safer, more predictable braking performance.

Installation & Fitment

The installation process is straightforward and designed for enthusiasts with basic mechanical skills. The kit mounts directly to the factory chassis points using the included hardware, with no cutting, drilling, or modifications required. It is recommended to follow the provided instructions carefully to ensure proper alignment and secure fitment. The process typically takes less than an hour, making it an accessible upgrade for those looking to enhance their vehicle's handling and braking response without extensive downtime.

• Direct bolt-on installation with factory mounting points
• No cutting, drilling, or tuning required
• Includes all necessary hardware and detailed instructions

What's Included

• High-strength steel master cylinder stopper components
• Mounting brackets and hardware
• Installation instructions

Ideal For

• Subaru Impreza WRX (2002–2007)
• Subaru STi (2004–2007)
• Enthusiasts seeking improved brake pedal feel and response
• Track day and racing applications
• Street drivers looking for enhanced vehicle stability during braking