Turn pedal effort into hydraulic brake pressure with the Dorman First Stop Brake Master Cylinder M39721, a direct-fit replacement for the 1987-1989 Mazda 323 and the 1988-1989 Mercury Tracer on all engines. Dorman designed this new unit to match the original master cylinder's design, function and performance on the listed applications. It is built from new, high-quality materials for a safe, durable replacement.
- Precise replacement: the cast iron cylinder housing matches the casting material of the original part, so it is intended to perform like the factory unit.
- Durable rubber components: every rubber component uses a high-quality EPDM compound for resistance to glycol-based brake fluid.
- 100% new: made entirely of new materials.
- Strict specifications: built to meet rigorous SAE International standards.
When you press the brake pedal, the master cylinder pushes brake fluid through its two outlets to the brake lines. These are signs a master cylinder may need replacing: a soft or sinking pedal, or fluid leaking at the cylinder. If the master cylinder is the cause, this unit replaces it. Bleed the brake system after installation as directed by the service procedure.
Specifications: 0.875-inch bore diameter. Two outlets, with M10 x 1.0 rearward and secondary outlet threads and a 1 mm primary outlet thread pitch. The reservoir and sensor are included. Mounting hardware is not included, so consult the vehicle service information for the correct fasteners and whether they may be reused. Country of origin: China.
Interchange: 783-14403 · 83-14403 · 100-1772 · M-53403 · 072-8709 · 13-2213 · 11-2213 · 130.45403 · 131.45403
78314403 · 8314403 · 1001772 · M53403 · 0728709 · 132213 · 112213 · 13045403 · 13145403 · 18M401 · M900608 · 12293 · MC119354 · E8GY2140A · E8GY2140C · M52213 · NM52213 · BJ8043400 · MC39721 · F119354
This part cross-references / interchanges with the following part numbers:
18M401, 783-14403, 83-14403, M900608, 100-1772, M-53403, 072-8709, 12293, 13-2213, 11-2213, 130.45403, 131.45403, MC119354, E8GY2140A, E8GY2140C, M52213, NM52213, BJ8043400, MC39721, F119354
Frequently Asked Questions
Is this the right master cylinder for a 1987-1989 Mazda 323?
It is listed as a direct-fit replacement for the 1987-1989 Mazda 323 with all engines. It is also listed for the 1988-1989 Mercury Tracer.
What does a brake master cylinder do?
It converts force from the brake pedal into hydraulic pressure. It then sends brake fluid through its two outlets to the brake lines.
What comes in the box?
The package contains the master cylinder, with the reservoir and sensor included. Mounting hardware is not included, so consult the vehicle service information for the correct fasteners.
What are the key specifications?
It has a 0.875-inch bore, a cast iron housing and two outlets, with M10 x 1.0 rearward and secondary outlet threads. The rubber components use an EPDM compound for resistance to glycol-based brake fluid.
What are signs a master cylinder may need replacing?
A soft or sinking brake pedal, or fluid leaking at the cylinder, are possible signs of a worn master cylinder. Other brake faults can cause similar symptoms, so diagnose the system before replacing parts.
