Designed to turn every press of the brake pedal into hydraulic pressure for the brakes, the Dorman First Stop Brake Master Cylinder M39451 is a new aluminum replacement for a worn or leaking unit. It fits many vehicles, among them the 1983-1987 Dodge Charger, 1988-1989 Dodge Lancer and 1987-1994 Dodge Shadow (all engines); see the Buyer's Guide tab for the full list.
Dorman precision-engineered this master cylinder to mirror the original unit'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 cylinder housing is constructed to match the original part and is designed for similar performance.
- Durable design: every rubber component uses a high-quality EPDM compound for resistance to 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: aluminum master cylinder with a 21 mm bore diameter and two outlets; the rearward outlet size and the secondary outlet thread diameter are both 3/8-24 in. The reservoir is included; mounting hardware and a sensor are not. Country of origin: China.
Signs a master cylinder may need replacing include a soft or sinking brake pedal and brake fluid seeping from the unit. Other brake components can cause similar symptoms, so diagnose the cause first. Install according to the vehicle service information, which covers the correct fasteners, whether originals may be reused, and bleeding the brake system.
