Turn pedal effort into the hydraulic pressure your brakes rely on with the Dorman First Stop Brake Master Cylinder, part number M39634. It is listed for several Ford models, among them the 1987-2003 Ford F-150, 1987-1993 Ford F-250 and 1987-1996 Ford Bronco; see the "Vehicles it fits" section for the full list. Dorman precision-engineered this unit to replicate the original master cylinder's design, function and performance on the listed applications, and built it from new, high-quality materials for a safe, durable replacement.
- Precise replacement: The aluminum cylinder housing is constructed to match the original part's casting material, helping it deliver similar performance.
- Durable design: Every rubber component uses a high-quality EPDM compound that resists glycol-based brake fluid.
- 100% new: Made entirely from new materials for high quality and safety.
- Strict specifications: Built to meet rigorous SAE International standards.
Specifications: 1.063 in bore diameter, two outlets and an M18 x 1.5 rearward outlet size. The reservoir and sensor are included. Mounting hardware is not included, so consult the vehicle service information for the correct fasteners and whether the originals may be reused. Country of origin: China.
A soft or sinking brake pedal, or brake fluid leaking around the unit, are signs a master cylinder may need replacing. Other brake components can cause similar symptoms, so diagnose the cause before replacing it. If the original master cylinder is the problem, M39634 replaces it.
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Frequently Asked Questions
Will this 1987-2003 Ford F-150 master cylinder fit my truck?
M39634 is listed for the 1987-2003 Ford F-150 and the 1987-1996 Ford Bronco. Check the "Vehicles it fits" section to confirm your exact vehicle.
Is this also a 1987-1993 Ford F-250 master cylinder?
Yes. It is listed for the 1987-1993 Ford F-250. The "Vehicles it fits" section shows every listed application.
What comes in the box?
The package contains the master cylinder, which includes the reservoir and a sensor. Mounting hardware is not included, so check the vehicle service information for the correct fasteners.
What are the key specifications?
It has an aluminum housing, a 1.063 in bore diameter, two outlets and an M18 x 1.5 rearward outlet size. Its EPDM rubber components resist glycol-based brake fluid.
What are signs a brake master cylinder may need replacing?
A soft or sinking brake pedal, or fluid leaking around the unit, may indicate a worn master cylinder. Other brake parts can cause similar symptoms, so diagnose the cause before replacing it.
