Turn pedal effort into hydraulic brake pressure with this Dorman brake master cylinder, part M630919 from the Dorman - First Stop line. It is a direct-fit replacement for the 2011-2018 BMW X3 and the 2015-2018 BMW X4 (engine: All; one per vehicle). Precision-engineered to replicate the original master cylinder's design, function and performance on those applications, it is built from new, high-quality materials.
- Precise replacement: the cylinder housing is designed to match the original part's casting material and is intended to 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 quality and safety.
- Strict specifications: built to meet rigorous SAE International standards.
Specifications: the master cylinder material is cast iron, the bore diameter is 1 in, and there are two outlets. The rearward outlet size and the secondary outlet thread diameter are both M12x1.0. The reservoir, sensor and mounting hardware are not included, so transfer or replace components as the service procedure directs. Consult the vehicle service information for the correct fasteners and whether they may be reused. Country of origin: Taiwan.
Signs this part may need replacing include a soft or sinking brake pedal and brake fluid leaking at the cylinder. Other brake faults can cause similar symptoms, so diagnose the hydraulic system before you replace parts.
Interchange: 100-4091 · 130.34028 · 355-31027
1004091 · 13034028 · 35531027 · 34336797471 · 34336857872 · NM55686 · MC391514
This part cross-references / interchanges with the following part numbers:
100-4091, 34336797471, 34336857872, 130.34028, 355-31027, NM55686, MC391514
