BMW 34317668631 Rear Brake Master Cylinder

( Manufacturer Part Number: 34317668631 ), ( Part Type: Brake Cylinder ), ( Placement On Vehicle: Front ), ( Country Of Origin: Germany )

Review BMW Rear Brake Master Cylinder fits K1200S 2005

The **BMW 34317668631 2005 K1200S Rear Brake Master Cylinder** is a precision-engineered hydraulic component designed exclusively for BMW s iconic K1200S motorcycle, a high-performance dual-sport adventure bike renowned for its balance of sportiness and off-road capability. This master cylinder is a critical part of the bike s braking system, responsible for transmitting the rider s foot pressure into hydraulic force that activates the rear brake caliper, ensuring reliable stopping power in both on-road and off-road conditions. Crafted from high-grade materials, including durable aluminum and corrosion-resistant steel, this master cylinder is built to withstand the demands of aggressive riding, from spirited cornering on paved roads to rugged trail conditions where dust, debris, and moisture can compromise less robust components. The design incorporates a sealed piston system with precision-machined seals and a robust return spring, guaranteeing consistent brake pedal feel and minimizing fluid leakage over time. Compatible with BMW s original brake fluid specifications, typically DOT 4 or BMW s proprietary M5 fluid, this master cylinder is engineered to maintain optimal hydraulic pressure and braking efficiency, even under prolonged heavy use. Whether you re a performance enthusiast seeking to upgrade your braking system for enhanced modulation or a restorer aiming to restore your K1200S to factory specifications, this OEM-quality master cylinder delivers the reliability and performance expected from BMW s engineering legacy. Its compact yet robust construction ensures seamless integration with the bike s existing brake lines and caliper assembly, making it an ideal replacement for worn or damaged units while preserving the original aesthetic and functionality of the braking system.

### **Pros and Cons of Buying a Used BMW 34317668631 (2005 K1200S Rear Brake Master Cylinder)**

The BMW 34317668631 rear brake master cylinder (part of the K1200S braking system) is a high-quality component designed for performance and reliability. Here are the key advantages of purchasing one:

1. **OEM Quality** BMW s master cylinders are built to strict standards, ensuring durable performance and compatibility with the K1200S s hydraulic braking system.

2. **Reliability** When in good condition, these components are known for longevity, especially if the bike has been well-maintained.

3. **Performance** The master cylinder works in tandem with the front brake system to provide strong, consistent braking power, which is crucial for a high-performance motorcycle like the K1200S.

4. **Ease of Installation** As an OEM part, it should fit seamlessly into the existing brake system with minimal modifications, assuming the bike s frame and brake lines are intact.

5. **Resale Value** BMW parts retain value, and an OEM master cylinder is more likely to be accepted as a replacement than an aftermarket alternative.

6. **Compatibility with Upgrades** If you plan to upgrade other braking components (e.g., larger discs, better calipers), this master cylinder will integrate well with those modifications.

7. **Warranty Potential** If purchased from a reputable dealer or with a warranty, it may come with some level of protection against defects.

1. **Age and Wear** A 2005 model is over two decades old, meaning the master cylinder may have internal wear, corrosion, or leaks. Older components are more prone to failure, especially if the bike has been ridden hard or neglected.

2. **Cost** OEM BMW parts are expensive, often costing significantly more than aftermarket alternatives. A used or refurbished master cylinder may still be pricey.

3. **Potential Hidden Issues** Even if the master cylinder appears functional, internal damage (e.g., cracked bore, seized piston, or contaminated fluid) may not be immediately visible. A thorough inspection or professional testing is recommended.

4. **Maintenance Requirements** Brake fluid must be changed regularly (every 2-3 years or as recommended by BMW), and neglecting this can lead to corrosion inside the master cylinder, reducing its lifespan.

5. **Limited Availability** Finding a genuine OEM part in good condition may be difficult, especially if the bike has been modified or the part has been in storage for years.

6. **Risk of Counterfeit Parts** If buying from an unverified source, there s a chance of receiving a fake or low-quality replica, which could fail prematurely.

7. **Compatibility with Modifications** If the bike has been heavily modified (e.g., custom brake lines, different calipers), the OEM master cylinder may not work optimally without adjustments.

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### **Conclusion**

The BMW 34317668631 rear brake master cylinder is a high-quality, reliable component that is well-suited for a K1200S, especially if the bike is otherwise in good condition. However, its age introduces risks of wear, hidden damage, and higher costs compared to newer or aftermarket alternatives. If you re confident in the part s condition (preferably with a recent inspection or rebuild) and can afford the price, it s a solid choice for maintaining or restoring the bike s braking performance. If budget or uncertainty is a concern, a reputable aftermarket master cylinder (e.g., from brands like Brembo, Magura, or a trusted BMW aftermarket supplier) may offer a more cost-effective solution with similar reliability.

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### **Recommendation**

- Purchase from a **BMW-approved dealer** or a trusted used parts supplier to ensure authenticity.

- Have the master cylinder **inspected or rebuilt** by a professional before installation to check for internal damage.

- Consider **flushing the entire brake system** and replacing the brake fluid to prevent contamination.

- Budget for **additional brake maintenance** (e.g., bleeding the system, checking brake lines) to ensure optimal performance.

- Explore **high-quality aftermarket alternatives** (e.g., Brembo or Magura master cylinders) that are designed for BMW motorcycles and may offer better value.

- If the bike is otherwise in good shape, prioritize **regular brake inspections** and fluid changes to extend the life of any master cylinder.

- If the master cylinder is failing due to age, consider **upgrading the entire braking system** (e.g., larger discs, better calipers) for improved safety and performance.

Ultimately, the best choice depends on your budget, the bike s current condition, and how critical the braking system is to your riding needs. For a 2005 K1200S, investing in a reliable master cylinder whether OEM or aftermarket is essential for safety, but always prioritize quality and professional installation.

Details:

Removed from 2005 Bmw K1200S Good working condition.

part #: 34317668631 prices

• $34.99-$51.97

specifications cyclevintagee:

• for models: K1200s
• for makes: Bmw
• for years: 2005
• mpn: 34317668631
• part type: Brake Cylinder
• placement on vehicle: Front
• country of origin: Germany

shipping cyclevintagee:

• class: Standard
• cost: $19.48
• transit: 5-9 Days
• carrier: FedEx
• service: FedEx Ground / FedEx Home Delivery
• type: Calculated

payments cyclevintagee:

• money order
• wallet: Apple-pay
• credit card: Mastercard
• other

offer cyclevintagee:

• availability: In Stock
• quantity: 1
• started: February 28, 2026
• best offers: True
• sold: 0
• options: Ship-to-home

returns cyclevintagee:

• policy: No Returns

seller cyclevintagee:

• # reviews: 2475
• rating: 100.0%
• city: Berkeley, California

general cyclevintagee:

• Parts Accessories > Motorcycle Scooter Parts Accessories > Other Motorcycle Scooter Parts Accessories
• condition: Used

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