Dorman Clutch Master Cylinder CM39903 — Direct-Replace OEM-Fit for Select Honda & Acura, Restores Pedal Feel

If your clutch pedal feels soft, sinks to the floor, or you see fluid where the master cylinder sits, replacing the master cylinder is often the fastest way to restore confident shifting. The Dorman CM39903 is reverse-engineered to mirror the factory unit’s dimensions and mounting points, providing a like-for-like swap for compatible vehicles. It uses durable components engineered for compatibility with standard brake fluid and comes with Dorman’s U.S.-based engineering and quality control oversight.

Which vehicles does this Dorman clutch master cylinder fit?

The CM39903 is designed specifically for a set of late-1990s and early-2000s Honda and Acura models. Fitment depends on model year and trim, so confirming your exact vehicle before ordering is important. Use the vehicle selection (garage) tool to verify compatibility with your VIN or trim level.

• Acura Integra: select years 1994–2001
• Honda Civic del Sol: select years 1993–1997
• Honda Civic (various trims): select years 1992–2000
• Always confirm trim/year using the product fitment tool

How does this replacement compare to the original equipment?

Dorman’s CM39903 is crafted from measurements and specifications derived from the original part to ensure correct geometry, port locations, and mounting. That means installation typically follows the same steps as the factory unit without modification. The internal seals and exterior fittings are built to provide compatible performance with your vehicle’s hydraulic clutch system.

• Reverse-engineered to match OEM dimensions and ports
• Direct-mount design for bolt-on replacement
• Sealing and materials formulated for standard brake fluid use
• Meant to restore pedal feel and hydraulic pressure similar to factory

What should I expect during installation and maintenance?

Installation generally requires basic hand tools and bleeding the clutch hydraulic system afterward to remove air. Follow vehicle-specific procedures for safe removal and installation: support the vehicle, disconnect lines carefully, and avoid introducing contaminants into the fluid. After installing the new master cylinder, properly bleeding ensures consistent pedal travel and engagement.

• Basic hand tools and a brake-fluid-safe container for flushing
• Bleed clutch after installation to eliminate trapped air
• Inspect lines and slave cylinder for wear while replacing the master
• Dispose of old fluid according to local regulations

What are the key features and durability expectations?

The CM39903 uses robust rubber sealing components and corrosion-resistant surfaces to withstand typical under-hood environments. While no aftermarket part can promise indefinite life, Dorman provides quality control oversight and engineering support to help the part meet or closely match the longevity of the original unit when installed and maintained correctly.

• High-grade rubber seals compatible with standard DOT brake fluid
• Precision-machined interfaces to reduce leakage risk
• Manufactured with U.S.-based engineering validation
• Intended as a direct substitute for the OEM master cylinder

Who is this for: The Dorman CM39903 is aimed at DIY mechanics, independent repair shops, and owners of compatible Acura Integra, Honda Civic del Sol, and Honda Civic models who need a reliable direct-replacement clutch master cylinder. If your vehicle’s clutch pedal is spongy, drops under pressure, or you observe hydraulic fluid loss at the master cylinder, this unit offers a factory-style replacement option — just confirm year and trim with the fitment tool before purchasing.