Convert brake-pedal effort into the hydraulic pressure that operates the braking system with the Dorman First Stop Brake Master Cylinder M39721. It drops in as a direct-fit replacement for the 1987-1989 Mazda 323 and 1988-1989 Mercury Tracer (All engines), and Dorman precision-engineers it to match the design, function, and performance of the original unit on those applications.
- Cast Iron construction: the cylinder housing is built to match the casting material of the original part for similar performance.
- Durable design: all rubber components use a high-quality EPDM compound for resistance to glycol-based brake fluid.
- 100% new: made entirely of new materials, not remanufactured, and made to meet rigorous SAE International standards.
- Key specs: 0.875 in bore with two outlets sized M10 x 1.0; reservoir and sensor included; mounting hardware is not included.
The master cylinder pressurizes brake fluid to the wheel circuits when you press the pedal. If a worn or leaking original master cylinder is the cause of a sinking or spongy pedal or fluid loss, this replaces it — diagnose the cause before replacing. Because mounting hardware is not included, consult the vehicle service information for the correct fasteners and whether they may be reused. Country of origin: China.
Interchange: 18M401 · 783-14403 · 78314403 · 83-14403 · 8314403 · M900608 · 100-1772 · 1001772 · M-53403 · M53403 · 072-8709 · 0728709 · 12293 · 13-2213 · 132213 · 11-2213 · 112213 · 130.45403 · 131.45403 · MC119354 · E8GY2140A · E8GY2140C · M52213 · NM52213 · BJ8043400 · 2539721 · MC39721 · F119354 · Manufacturer part number M39721.
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
