Genuine OEM 21526773670 - Clutch Master Cylinder

Product Overview

This Genuine OEM 21526773670 clutch master cylinder is engineered to factory specifications for BMW vehicles spanning nearly two decades of production. The master cylinder is the critical hydraulic component that converts pedal pressure into the fluid force needed to actuate your clutch system, serving models from the E46 3 Series and Z3 through the E90, E92, and early F-generation platforms including the M3, M5, 1 Series, 2 Series, 3 Series, 4 Series, X3, X5, and Z4. Genuine OEM parts ensure perfect fitment, reliable operation, and compatibility with your vehicle's original hydraulic architecture.

This clutch master cylinder is sold individually. If your clutch system requires a complete overhaul, consider pairing this master cylinder with a matching slave cylinder and clutch fluid flush.

Symptoms of a Failing Clutch Master Cylinder

• Soft or spongy clutch pedal that lacks resistance or gradually sinks to the floor
• Clutch pedal travels to the floor without engaging the clutch, or requires excessive pressure to shift
• Fluid leaking from beneath the brake master cylinder area or around the pedal assembly
• Difficulty shifting gears, grinding noises, or inability to fully disengage the clutch
• Clutch pedal feels higher than normal or remains stuck in the up position
• Loss of clutch pressure over time, requiring repeated bleeding of the system

Cross Reference Numbers

This Genuine OEM 21526773670 is equivalent to or replaces the following part numbers: 2152-6-773-670, 21526773670.

Vehicle Compatibility

This part fits the popular models below. For Fitment Confidence, please use the vehicle selector tool above to verify exact compatibility for your vehicle.

• BMW 1 Series M Coupe 3.0 L6 Gas (E82): 2011
• BMW 128i 3.0 L6 Gas (E82): 2008–2013
• BMW 135i 3.0 L6 Gas (E82): 2010–2011
• BMW 228i 2.0 L4 Gas (F22): 2015–2016
• BMW 228i xDrive 2.0 L4 Gas (F22): 2015–2016
• BMW 320i 2.0 L4 Gas (F30): 2015–2018
• BMW 323i 2.5 L6 Gas (E46): 2000
• BMW 323Ci 2.5 L6 Gas (E46): 2000
• BMW 325i 2.5 L6 Gas (E46): 2003
• BMW 325xi 2.5 L6 Gas (E46): 2003
• BMW 328i 2.0 L4 Gas (F30): 2012–2013
• BMW 328i 3.0 L6 Gas (E46, E90): 1999–2010
• BMW 328i xDrive 3.0 L6 Gas (E90): 2009, 2013
• BMW 328Ci 2.8 L6 Gas (E46): 2000
• BMW 328xi 3.0 L6 Gas (E90): 2007
• BMW 330Ci 3.0 L6 Gas (E46): 2003, 2005–2006
• BMW 330i 3.0 L6 Gas (E46, E90): 2003–2004
• BMW 330xi 3.0 L6 Gas (E46, E90): 2001, 2003–2005
• BMW 335i 3.0 L6 Gas (E90): 2007, 2011, 2015
• BMW 335i xDrive 3.0 L6 Gas (E90): 2009–2010, 2012, 2014
• BMW 340i 3.0 L6 Gas (F30): 2016–2018
• BMW 340i xDrive 3.0 L6 Gas (F30): 2018
• BMW 428i 2.0 L4 Gas (F32): 2016
• BMW 435i 3.0 L6 Gas (F32): 2014
• BMW 435i xDrive 3.0 L6 Gas (F32): 2016
• BMW M2 Coupe 3.0 L6 Gas (F87): 2017–2018
• BMW M235i 3.0 L6 Gas (F22): 2014–2016
• BMW M3 Sedan 3.2 L6 Gas (E46): 2001–2006
• BMW M3 Sedan 3.0 L6 Gas (F80): 2015–2016
• BMW M3 Sedan 4.0 V8 Gas (E90): 2009–2010
• BMW M3 Coupe 3.2 L6 Gas (E46): 2002–2005
• BMW M3 Convertible 3.2 L6 Gas (E46): 2003–2006
• BMW M4 Coupe 3.0 L6 Gas (F82): 2015–2016
• BMW M4 Coupe 3.0 L6 Gas (G82): 2019
• BMW M5 Sedan 5.0 V8 Gas (E39): 2000–2003
• BMW M5 Sedan 5.0 V8 Gas (E60): 2006–2010
• BMW 525i 2.5 L6 Gas (E39): 2001, 2003
• BMW 530i 3.0 L6 Gas (E39): 2001
• BMW 540i 4.4 V8 Gas (E39): 2001, 2003
• BMW X3 2.5 L6 Gas (E83): 2005
• BMW X3 xDrive30i 3.0 L6 Gas (E83): 2010
• BMW X5 3.0i 3.0 L6 Gas (E53): 2001, 2003–2004
• BMW Z4 2.5i 2.5 L6 Gas (E85): 2003–2004
• BMW Z4 3.0i 3.0 L6 Gas (E85): 2005
• BMW Z4 M Coupe 3.2 L6 Gas (E86): 2006–2008
• BMW Z4 M Roadster 3.2 L6 Gas (E85): 2007–2008
• BMW Z4 Roadster 3.0i 3.0 L6 Gas (E85): 2006–2007
• BMW Z4 sDrive28i 2.0 L4 Gas (F22): 2012, 2015
• BMW Z4 sDrive30i 3.0 L6 Gas (E89): 2009–2011
• BMW Z4 sDrive35i 3.0 L6 Gas (E89): 2015–2016
• BMW Z8 5.0 V8 Gas (E52): 2003

This may also fit other applications. Please use the vehicle selector tool to verify fitment.

Often Replaced Together

For a complete clutch system repair, many owners replace the following at the same time:

• Clutch slave cylinder (hydraulic actuator at the transmission)
• Clutch fluid (DOT 4 or DOT 5.1 specification; system should be bled and flushed)
• Clutch disc and pressure plate assembly
• Clutch release bearing

Why Shop at eEuroparts.com?

• Proven Expertise: Over 25 years of experience with European vehicles means we know your car inside and out.
• Fitment Confidence: Our accurate cataloging ensures you get the right part the first time, backed by our fitment guarantee.
• Fast, Reliable Shipping: Most in-stock orders ship the same or next business day from our U.S.-based warehouse.
• Transparent Pricing: Competitive prices with no hidden fees or surprise charges.
• Exclusive Kits That Fit™: Complete repair solutions with no guesswork.
• Established Trust: Serving the European car community since 2000.

Frequently Asked Questions

How do I know if my BMW clutch master cylinder is failing?

A failing master cylinder typically produces a soft or spongy pedal that may sink gradually toward the floor, even when not depressed. You may notice the clutch requires excessive pressure to engage, or the pedal travels all the way to the floor without disengaging the clutch. Fluid leaks around the pedal assembly or beneath the steering column are also common warning signs. If your clutch system has lost pressure and bleeding the slave cylinder does not restore firm pedal feel, the master cylinder is likely at fault.

Is a clutch master cylinder the same as a brake master cylinder?

No. Although both are hydraulic master cylinders, they serve different systems. The clutch master cylinder operates the clutch disengagement system, while the brake master cylinder pressurizes the brake system. They are not interchangeable, and this part is designed specifically for clutch actuation on your BMW.

How long does a clutch master cylinder typically last?

Clutch master cylinders generally last between 80,000 and 150,000 miles, depending on driving habits and maintenance. Heavy city driving with frequent gear changes may accelerate wear. Once internal seals begin to deteriorate, failure can progress quickly. If you experience symptoms, replacement is recommended rather than repair, as the internal components cannot be serviced separately.

What tools and skills do I need to replace the clutch master cylinder?

Clutch master cylinder replacement typically requires a floor jack, jack stands, basic socket set, and brake line wrenches to disconnect the hydraulic lines. The job involves removing the pedal assembly cover, disconnecting the hydraulic line at the master cylinder, unbolting the cylinder from the firewall, and installing the new unit in reverse order. System bleeding is required afterward. This is considered an intermediate-level repair; professional installation is recommended if you lack experience with hydraulic systems.

Do I need to bleed the clutch system after installing a new master cylinder?

Yes. After installation, the clutch system must be bled to remove air from the hydraulic lines. Air in the system prevents proper pressure buildup and results in a soft pedal. Bleeding is performed at the slave cylinder using a one-way bleeder valve and clean clutch fluid. Follow the procedure outlined in your BMW service manual, and always use the correct fluid specification (typically DOT 4 or DOT 5.1).

Why is my clutch pedal still soft after replacing the master cylinder?

A soft pedal after master cylinder replacement usually indicates air trapped in the hydraulic lines. Bleed the system thoroughly at the slave cylinder, starting with multiple strokes of the pedal to build pressure. If the pedal remains soft after proper bleeding, the new master cylinder may be defective, or the slave cylinder itself may be failing. Inspect the slave cylinder for leaks and consider having it replaced as part of a complete clutch system overhaul.

Why Choose Genuine OEM?

Genuine OEM parts are manufactured to BMW factory specifications and have been validated for perfect fitment and long-term reliability. This master cylinder carries the same engineering standards as the part that left the factory, ensuring your clutch system performs exactly as designed. OEM parts are backed by manufacturer quality assurance and are the choice of BMW dealerships worldwide.

Order Genuine OEM 21526773670 today. In-stock orders ship same or next business day from our U.S. warehouse, and our fitment team is one call away if you need help confirming the right part for your BMW.

Note: All information on this page and in the FAQ is for general reference only. Verify fitment and consult a professional as needed. eEuroparts.com is not responsible for incorrect part selection or installation.