Turn every press of the pedal into hydraulic brake pressure with the Dorman brake master cylinder M39980 from Dorman - First Stop. It is a direct-fit replacement for the 1990-1995 Jeep Wrangler, precision-engineered to match the design, function and performance of the original master cylinder on that application.
A master cylinder is the heart of the hydraulic brake system. When the pedal is applied, it pushes brake fluid through the lines to each wheel. If worn internal seals or a leaking housing are behind a spongy or sinking pedal, this master cylinder for the 1990-1995 Jeep Wrangler replaces the failed unit with one built entirely from new, high-quality materials.
- Precise replacement: 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 from new materials, with quality and safety in mind.
- Strict specifications: made to meet rigorous SAE International standards.
Bleed the brake system after installation, following the vehicle service information. See the "Vehicles it fits" section for complete application details.
Interchange: 783-40012 · 83-40012 · 100-2668 · M-87012 · 13-2438 · 10-2438 · 130.67012 · 131.67012 · 355-42026
78340012 · 8340012 · 1002668 · M87012 · 132438 · 102438 · 13067012 · 13167012 · 35542026 · 18M531 · M900738 · 12309 · 5252626 · MC123547 · M2438 · M2738 · NM2438 · NM2738 · MC39980 · F123547
This part cross-references / interchanges with the following part numbers:
18M531, 783-40012, 83-40012, M900738, 100-2668, M-87012, 12309, 13-2438, 10-2438, 130.67012, 131.67012, 5252626, MC123547, 355-42026, M2438, M2738, NM2438, NM2738, MC39980, F123547
Frequently Asked Questions
Will this brake master cylinder fit my 1990-1995 Jeep Wrangler?
Yes. Dorman - First Stop M39980 is listed as a direct-fit replacement for the 1990-1995 Jeep Wrangler. See the "Vehicles it fits" section for full application details.
What does a brake master cylinder do?
It converts force from the brake pedal into hydraulic pressure. That pressure sends brake fluid through the lines to the calipers or wheel cylinders, which apply the brakes.
What are the rubber components made of?
All rubber components are made of a high-quality EPDM compound, which resists glycol-based brake fluid.
What are signs a master cylinder may need replacing?
Signs include a spongy or slowly sinking brake pedal, fluid leaking at the cylinder, or a dropping reservoir level. Diagnose the brake system to find the cause before replacing parts.
Does this Dorman master cylinder need bleeding after installation?
Yes. The brake system must be bled after installation to remove air. Follow the vehicle service information, including any bench-bleeding procedure it calls for.
