Turn every press of the brake pedal into hydraulic pressure with the Dorman brake master cylinder, First Stop part number M630406, a direct-fit replacement for the 2005-2008 Chevrolet Cobalt, 2007-2008 Pontiac G5 and 2006 Pontiac Pursuit. The master cylinder converts the force from your foot on the pedal into hydraulic pressure and sends it through the brake lines to the wheels.
This Dorman master cylinder is engineered 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 casting material of the original part, for performance similar to the factory unit.
- Durable design: every rubber component uses a high-quality EPDM compound that resists glycol-based brake fluid.
- 100% new: made entirely of new materials, for quality and safety.
- Strict specifications: produced to meet rigorous SAE International standards.
A master cylinder may need replacing if the brake pedal slowly sinks under steady pressure, if the pedal feels soft or low, or if brake fluid is seeping from the cylinder. These symptoms can have other causes, so diagnose the brake system before you replace parts. See the "Vehicles it fits" section for complete fitment details.
Interchange: 100-2348 · 13-3196 · 10-3196 · 130.62136 · 355-47094
1002348 · 133196 · 103196 · 13062136 · 35547094 · 22721986 · M4093 · NM4093 · MC390985 · F142625 · MC142625
This part cross-references / interchanges with the following part numbers:
100-2348, 13-3196, 10-3196, 130.62136, 355-47094, 22721986, M4093, NM4093, MC390985, F142625, MC142625
Frequently Asked Questions
Is this the right brake master cylinder for a 2005-2008 Chevrolet Cobalt?
Yes. It is listed as a direct-fit replacement for the 2005-2008 Chevrolet Cobalt. The "Vehicles it fits" section shows the full fitment chart, so you can confirm it for your vehicle.
What does a brake master cylinder do?
It converts the force applied at the brake pedal into hydraulic pressure. That pressure travels through the brake lines to the brake components at each wheel.
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 standards is the Dorman First Stop M630406 built to?
It is made to meet rigorous SAE International standards. Its cylinder housing is constructed to match the casting material of the original part.
Does it need to be bled after installation?
Yes. A master cylinder is typically bench bled before installation, and the brake system is bled afterward. Follow the vehicle service information and use the brake fluid it specifies.
