Turn pedal effort into hydraulic brake pressure with the Dorman brake master cylinder M21698 from the Dorman - First Stop line. It is a direct-fit replacement for the 1955-1959 GMC 300 (All engines) and the 1955-1959 GMC 370 (All engines), one per vehicle, and is precision-engineered to replicate the original master cylinder's design, function, and performance.
Made from new, high-quality materials, it is intended as a safe, durable replacement for the original unit.
- Precise replacement: the cast iron cylinder housing is made to match the casting material of the original part and is intended to deliver similar performance.
- Durable design: every rubber component uses a high-quality EPDM compound for resistance to glycol-based brake fluid.
- 100% new: made entirely of new materials for quality and safety.
- Strict specifications: built to meet rigorous SAE International standards.
Specifications: cast iron housing; 1.25 in bore diameter; one rearward outlet, sized 7/16-24; reservoir included; no sensor included. Mounting hardware is not included. Consult the vehicle service information for the correct fasteners and whether the originals may be reused. Country of origin: Taiwan.
Interchange: 83-52004 · 100-2764 · M-90004 · 13-21698 · 10-21698 · 130.80004 · 355-71008
M900037 · 11204 · MC509410 · 2621177 · 5454494 · 5459980 · MC21698 · F21698 · F36666 · MC36666 · 8352004 · 1002764 · M90004 · 1321698 · 1021698 · 13080004 · 35571008
This part cross-references / interchanges with the following part numbers:
83-52004, M900037, 100-2764, M-90004, 11204, 13-21698, 10-21698, 130.80004, MC509410, 355-71008, 2621177, 5454494, 5459980, MC21698, F21698, F36666, MC36666
